Hobson v Northern Sydney Local Health District

1. [1]

   HIS HONOUR: Brendan Hobson was born with Noonan Syndrome, a genetic disorder that prevents normal development in various parts of the body. A person can be affected by Noonan Syndrome in various ways. These include unusual facial characteristics, short stature, heart defects, other physical problems and possible developmental delays. One of the occasional, although not necessarily universal, manifestations of that condition is an unusual or idiosyncratic shape of the chest. Mr Hobson’s chest was affected in this way as the result of a severe lordoscoliosis.

2. [2]

   Because of Mr Hobson’s problems, he gradually developed difficulties in breathing. In short, in lay terms, the limited volume of his chest cavity began progressively to restrict Mr Hobson’s ability to fill his lungs with air. By at least November 2009, Mr Hobson’s condition had deteriorated to the point where, without surgical intervention, his prognosis was grave. Accordingly, in November 2009, when he was 24 years of age, Mr Hobson was admitted to Royal North Shore Hospital for a brace of operations designed to remedy this defect. The first operation was planned for, and carried out uneventfully on, 13 November 2009. The second operation was originally planned to take place two weeks later. However, in the events that occurred, to which detailed reference appears below, a decision was made to advance that surgery to the evening of 17 November 2009. It was in the course of that second procedure that Mr Hobson sustained a hypotensive insult to his spinal cord that rendered him a paraplegic. That condition is permanent.

3. [3]

   Mr Hobson initially maintained that his paraplegia resulted from the negligence of the four separate defendants. The first and third defendants were, however, released by consent from the proceedings on 21 November 2016. The remaining second and fourth defendants are respectively Dr Gray, the orthopaedic surgeon who performed the operation on 17 November 2009, and Dr Sparks, the attending anaesthetist. A decision was made to discontinue the surgery after approximately three hours when it became apparent that Mr Hobson’s vital signs had deteriorated alarmingly. He was returned to the intensive care unit. The operation was rescheduled and successfully completed some weeks later.

4. [4]

   However, Mr Hobson alleges in general terms that the operation on 17 November 2009 ought to have been aborted earlier when it became apparent that his intraoperative condition was critical and quickly deteriorating. He alleges that he would not have sustained any injury at all if that course had been taken in a timely way. On the contrary, even though the surgery was ultimately cut short, Mr Hobson complains that the remaining defendants negligently persisted with it to the point where the irreparable damage to his spine occurred and significantly well beyond some earlier stage in the operation when it could have been abandoned uneventfully.

5. [5]

   These complaints have been the subject of a large series of differently pleaded allegations that culminated in what became the third further amended statement of claim. It is important at an early stage to record the way in which Mr Hobson ultimately particularised his allegations of negligence. As against Dr Gray they are as follows:

   1. (1)

      Failing to ensure the provision of proper and effective spinal cord monitoring at the surgery on 17 November 2009.

   2. (2)

      Failing to delay or postpone (or advise the delay or postponement) of the surgery until the spinal cord monitoring was in place and a baseline reading obtained.

   3. (3)

      Continuing with the surgery when a baseline reading had not been obtained and/or when the readings of the monitoring were abnormal, and/or when the spinal cord monitoring was compromised by the administration of muscle relaxants.

   4. (4)

      Proceeding with such surgery when blind to whether the spinal cord was functioning normally.

   5. (5)

      Failing to halt or advise the halting of the surgery of 17 November 2009 following the earlier episodes of hypoxia and hypotension (occurring at or about 18.50, 19.10, 20.35 and 21.20) and related complications reported in the anaesthetic record between approximately 19.10 and 21.20 that evening.

   6. (6)

      Continuing the operation:

   7. (7)

      Failing to carry out or cause to be carried out spinal cord monitoring effectively or at all.

   8. (8)

      Failing to pause or cease the surgery when either a baseline had not been achieved and/or the results were reported to be abnormal.

   9. (9)

      Failing to have due regard to:

   10. (10)

       Failing to delay or postpone (or advise the delay or postponement of) the surgery until such time as Mr Hobson was haemodynamically stable, could be adequately ventilated and spinal cord monitoring was in place.

   11. (11)

       Continuing the surgery with Mr Hobson in the prone position.

   12. (12)

       Commencing the surgery before baseline spinal cord monitoring was established.

6. [6]

   The claim against Dr Sparks repeats the first ten particulars of negligence pleaded against the surgeon together with the following five additional particulars:

   1. (1)

      Commencing the surgery before baseline spinal cord monitoring was established, and before Mr Hobson was adequately ventilated.

   2. (2)

      Failing to ensure complete and effective spinal cord monitoring in the 17 November 2009 operation.

   3. (3)

      Continuing with the operation in the face of the abnormalities shown on the anaesthetic record referred to above.

   4. (4)

      Failing to inform the treating surgeon that a probable cause of the failure of the spinal cord monitoring was the use of the chosen anaesthetics and muscle relaxants and that an alternative which did not affect the monitoring should be used.

   5. (5)

      Failing to inform the surgeon that the likely cause of Mr Hobson’s ventilation problems was him being in a prone position and this could not be solved by any approach other than turning him supine.

7. [7]

   It can be seen that most of these allegations are common to the case against both Dr Gray and Dr Sparks. By reason of their separate roles, however, they necessarily raise slightly different considerations. This is discussed more fully later in these reasons. It will be obvious that spinal cord monitoring is alleged to be a significant element in Mr Hobson’s case against both of these defendants. This procedure therefore requires at least a rudimentary explanation.

Spinal cord monitoring

1. [8]

   Based upon the articles and associated literature to which my attention has been drawn, I take at least the following general matters concerning spinal cord monitoring, in its application to the facts of the present case, to be uncontroversial.

2. [9]

   Spinal cord monitoring, as the name suggests, is a procedure or technique designed to monitor the intraoperative integrity of a patient’s spinal cord during surgery. This is done by the stimulation and measurement of motor evoked responses via electrodes connected to the patient’s extremities. These signals are generated at various appropriate and convenient stages of the operation so as to provide information to the surgeon about whether the spinal cord has or may have been surgically damaged. Single or repetitive pulse stimulation of the brain in this way causes the spinal cord and peripheral muscles to produce neuroelectrical signals known as motor evoked potentials. This technique obviates the need to arouse the patient from an anaesthetised state in order to check whether the patient’s spinal cord may have been damaged in any way.

3. [10]

   The role of intraoperative monitoring in spinal surgery is to evaluate the integrity of the nervous system continuously while patients undergo procedures that have the potential to cause injury to the nervous system, particularly the spinal cord and spinal nerves. Since patients are under general anaesthetic, techniques for examining the nervous system are limited to those that can be applied to an unconscious subject. The task of monitoring personnel is to identify neural irritation or injury at a time when the surgeon can take steps to reduce or reverse it and to define the nature of the injury in a way that will allow the surgeon to complete the procedure without risking further injury. Ideally, this is done in an efficient manner without interfering with the flow of the operation or producing unnecessary interruptions.

4. [11]

   The risk of neural injury has long been recognized, and several other manoeuvers have been devised to try to detect and correct problems before they become irreversible. Electrophysiological intraoperative monitoring techniques have evolved, and now offer timely evaluation and feedback to the surgeon at a point where interventions can be taken to prevent irreversible neural damage. The aetiology of neural injury is varied, and mechanisms can range from structural compromise related to abnormal spinal anatomy to instrumentation-related injury and vascular insufficiency. The structures at risk include peripheral nerves, spinal roots, and spinal cord.

5. [12]

   The decision to perform intraoperative monitoring involves many factors, and the approach to monitoring is a team effort that includes the surgeon, monitoring personnel, and the anaesthetist. These factors presumably include an assessment of the risk of injury from a given operative procedure. That risk can vary from highly likely to none at all, and the decision to monitor in any given case will generally be that of the surgeon and the monitoring team. Since there are a variety of monitoring techniques and strategies, the surgeon and the monitoring team must also determine which neural structures are at risk so the appropriate monitoring protocol can be used.

6. [13]

   It will be apparent that spinal cord monitoring is far more complicated than this brief description is able to communicate. I have included the description in order to aid in the understanding of what follows. No part of the foregoing description concerning spinal cord monitoring in general, or references to its use in this case in particular, is intended in any way standing alone to inform or determine the remaining liability issues in Mr Hobson’s cases against either Dr Gray or Dr Sparks.

Background

1. [14]

   In 2008 or 2009, Mr Hobson was told that he should have an operation to straighten his thoracic spine. He had by that time developed some difficulty breathing and had also developed an intermittent problem with wheezing. He was told that the operation might assist with this breathing problem and also straighten his back. He was referred to Dr Gray at Royal North Shore Hospital. They met several times.

2. [15]

   Dr Gray told Mr Hobson that the operation would be carried out in two stages. One or more rods would be inserted to straighten his spine, held in place by screws. He was also told that spinal cord monitoring could be performed if Mr Hobson was a private patient. Mr Hobson recalls being told by Dr Gray, “The spinal cord monitoring will monitor the function of your spinal cord during the operation and tell us if the signal is too low or too high”.

3. [16]

   Mr Hobson was placed under general anaesthetic on 17 November 2009 but has no other relevant recollection of events until sometime in mid-December when he “realised something wasn’t right”. Somewhat extraordinarily, he was not told formally what had happened to him until early in January the following year.

Dr Gray’s evidence

1. [17]

   Dr Gray first saw Mr Hobson on 21 August 2009 at the Spine Clinic at RNSH. He noted that he had been diagnosed with Noonan Syndrome in his childhood and that he had had a series of associated syndromal features and medical problems that included severe thoracic lordoscoliosis with restrictive lung disease. The latter condition was the basis for referral to Dr Gray. The main concern was a worsening of Mr Hobson’s lordoscoliosis affecting his thoracic and upper lumbar spine with progressive deformity of his middle thoracic region and associated restrictive lung disease. Results of respiratory function at that time indicated a persistent restrictive pattern of lung disease with mild decrease and diffusing capacity with some responsiveness to bronchodilators. Mr Hobson had been on inhaled corticosteroids.

2. [18]

   It is uncontroversial that Mr Hobson would benefit from deformity correction surgery of his lordoscoliosis in order to increase his lung capacity and prevent further deterioration of his lung disease and eventual cor pulmonale secondary to pulmonary hypertension. Mr Hobson reported that he was finding himself increasingly short of breath, particularly with exertion. These symptoms had become progressively worse over the preceding 12 months. Mr Hobson had no lower limb neurological symptoms and had good bowel and bladder control. In summary, Dr Gray noted that Mr Hobson had a significantly reduced vertebra-sternal distance due to his thoracic lordoscoliosis causing the pattern of restrictive airway disease.

3. [19]

   Dr Gray discussed the option of surgical correction with Mr Hobson, including the combined anterior and posterior approaches in two stages, wedge osteotomies through the apex of his thoracic lordoscoliosis and subsequent posterior instrument fusion of his thoracic and upper lumbar spine. The first stage involved a thoracotomy with multiple anterior thoracic discectomies and wedge resections of the adjacent end plates in the form of a closing wedge osteotomy. That stage was planned in association with cardiothoracic surgeons and was to be performed by the RNSH cardiothoracic team. The second stage was the posterior instrumented fusion from T2 to L1, following the anterior release to correct the lordoscoliosis to a more normal kyphosis of the thoracic spine.

4. [20]

   The anterior procedure was performed on 13 November 2009 by Dr Gray, Dr Cree and Dr Marshman. The surgery was uneventful and successful. Relevantly, Mr Hobson was found post-operatively to be neurologically intact.

5. [21]

   The original plan was to perform the second operation after approximately ten days. However, on 15 November 2009 Mr Hobson was found to have extrinsic compression of his left main bronchus. His right upper lobe was normal and his right main bronchus was patent. Later that day Mr Hobson’s left lobe was found to be collapsed further. The ICU was having trouble maintaining his oxygen saturation. Dr Gray said that the original plan of performing the second stage of the operation two weeks later was not practical due to the compression of the left main bronchus and the collapse of the left lung. Dr Gray formed the opinion that persisting with the original plan would place Mr Hobson’s life at risk. The ICU staff asked for the second stage surgery to be brought forward.

6. [22]

   Mr Hobson was reviewed on 17 November 2009. The obstruction of the left main bronchus and worsening respiratory function were matters of escalating concern. The anaesthetic and spinal teams decided to bring the surgery forward in order to create more space in the mediastinum and to relieve the extrinsic compression. This included arranging for spinal cord monitoring. The surgery commenced at 7.00pm. Dr Gray described what happened thereafter in the following terms:

7. [23]

   Dr Gray was cross-examined about these recollections. This is referred to later in these reasons.

8. [24]

   An MRI scan of Mr Hobson’s thoracolumbar spine was performed the following day. That scan suggested anterior cord type syndrome of the thoracic spinal cord with signal change on the T2 weighted images in the anterior and middle part of the spinal cord. Post-operatively Mr Hobson had a complete neurological deficit of his lower limbs. The signal change was between T10 and T12 in the possible watershed area. Dr Gray thought that the changes were most likely secondary to an ischaemic event and other vascular ethology. No cord or thecal deformity was seen at or in the vicinity of the screws. All screws were in a good position. Dr Gray thought that Mr Hobson had suffered a hypotensive vascular injury to the lower part of his spinal cord.

9. [25]

   The second stage of the originally planned surgery was successfully completed on 11 December 2009.

Dr Sparks’ evidence

1. [26]

   Dr Sparks’ understanding of the need for Mr Hobson’s surgery, and the two stage plan to effect it, was the same as that of Dr Gray.

2. [27]

   On 17 November 2009, Dr Sparks was the Duty Director in charge of theatres for that day. He was contacted by either Dr Gray or his Registrar and told that the second stage of the surgery needed to be performed as soon as possible, “as the compression on the bronchus needs to be released”. Dr Sparks formed the clear impression from that conversation that the operation needed to be performed within the next 24 hours. Dr Sparks was aware that the operation would be a very challenging procedure requiring an experienced anaesthetist.

3. [28]

   Following the discussion with Dr Gray or his Registrar on 17 November 2009, Dr Sparks went to the ICU at about 12.30pm and spoke with the specialist on duty there. He did so in order to satisfy himself that the surgery was urgent and to assess Mr Hobson’s clinical status from an anaesthetic perspective. Dr Sparks gained the impression that the ICU was having difficulty adequately ventilating Mr Hobson because of the compression of his left main bronchus. In practical terms, that meant that the left lung could not be ventilated or suctioned and that Mr Hobson had to remain intubated. Dr Sparks was concerned that Mr Hobson was developing pneumonia, which would be fatal if ventilation and suction of the left lung were not improved.

4. [29]

   Dr Sparks returned to the ICU with Dr Barratt at around 2.40pm. Dr Barratt was a senior anaesthetist with experience in spine and thoracic anaesthesia. Dr Sparks wanted Dr Barratt to assist him to perform a bronchoscopy in order to assess Mr Hobson’s left main bronchus. This was found to be compressed and stretched but permitted the insertion of the bronchoscope through the obstruction allowing measurement of the bronchus at about 5cm.

5. [30]

   The surgery was re-scheduled to the evening of 17 November 2009 to facilitate the availability of the physician in charge of the spinal monitoring equipment. Dr Sparks volunteered to be the anaesthetist. He was in favour of the use of a double lumen tube so that Mr Hobson’s left main bronchus could be splinted open, promoting ventilation of the left lung and improving oxygenation. Dr Sparks also expected that this would prevent air being trapped in the left lung, which might worsen during surgery in the prone position, and which in turn would increase pressure on Mr Hobson’s heart and lungs.

6. [31]

   Dr Sparks described what happened in the operation as follows:

7. [32]

   Dr Sparks was cross-examined about these recollections. This is also referred to later in these reasons.

8. [33]

   Dr Sparks said that he visited Mr Hobson the day following the operation. He expected to be told that Mr Hobson had signs of permanent brain damage. However, he appeared not to have sustained any such damage. It became apparent later that day that Mr Hobson had an anterior spinal cord artery infarct that led to his paraplegia.

Expert evidence – Mr Hobson

1. [34]

   Dr Westbrook is a consultant anaesthetist and an Honorary Senior Clinical Lecturer at Oxford University. He provided a series of reports to Mr Hobson’s solicitor.

2. [35]

   In his first report dated 10 January 2012, Dr Westbrook commented upon the cause of Mr Hobson’s paraplegia in the following terms:

3. [36]

   Dr Westbrook continued:

4. [37]

   Dr Westbrook expressed his opinion in the first report as follows:

5. [38]

   Dr Westbrook provided a supplemental report dated 21 October 2012. He expressed his conclusions in that report in these terms:

6. [39]

   Dr Johnson is an orthopaedic surgeon. He provided a series of expert medical reports. His most recent report is dated 9 August 2016. The following material is extracted from that report:

7. [40]

   Dr Heath is a consultant in clinical neurophysiology. He provided a report dated 5 November 2012. He indicated that:

8. [41]

   Dr Heath expressed the opinion that the “attempted instrumented fusion on 17 November 2009 would have carried a significant risk of spinal cord injury and hence required monitoring”. He indicated uncontroversially that the form of monitoring used in Mr Hobson’s operation is “a well-established and sensitive technique” but that “its usage is compromised by the anaesthetic drugs used in this case – Sevoflurane and vecuronium”. Dr Heath said that “these agents may preclude effective monitoring of spinal cord function using transcranial motor evoked potentials as a motor monitoring technique”.

9. [42]

   Dr Heath went on to express the following opinion:

10. [43]

    Dr Heath also furnished a supplementary report dated 7 August 2016. Part of that report is as follows:

11. [44]

    Dr Richards is a consultant paediatric neurosurgeon. He provided a report dated 1 December 2012. Referring to Mr Hobson’s second operation he commented in these terms:

12. [45]

    Dr Wilson-MacDonald is a consultant orthopaedic surgeon at the John Radcliffe Hospital, Oxford & Nuffield Orthopaedic Centre, Oxford, England. Dr Wilson-MacDonald provided a series of reports for Mr Hobson’s solicitors. His first report is dated 6 February 2013. Dr Wilson-MacDonald was provided with significant documentary and other material with the benefit of which he produced the following short description of the 17 November 2009 operation:

13. [46]

    Dr Wilson-MacDonald went on to express the following opinion:

14. [47]

    Mr Hobson’s solicitors subsequently provided Dr Wilson-MacDonald with some further information upon which they asked him to comment. He then provided a second report dated 3 October 2016. Some of what he considered included paragraph 41 of Dr Sparks’ affidavit, reproduced earlier in these reasons at [31]. Dr Wilson-MacDonald commented upon this in the following terms:

15. [48]

    Dr Wilson-MacDonald was asked a further series of questions. In answer to a question from Mr Hobson’s solicitors whether there was any indication from the available material that the 17 November 2009 surgery “needed to be done to urgently at the time to [sic] save his life”, he responded as follows:

16. [49]

    Dr Wilson-MacDonald was then asked whether there was any indication that the “operation performed on 17 November 2012 [sic, 2009] was urgent in terms of hours rather than days die [sic, due] to increasing difficulty of ventilating Mr Hobson in the ICU”. He said this in response:

17. [50]

    The next question directed to Dr Wilson-MacDonald was whether, “in the absence of traces from the spinal cord monitoring [there] was a risk to Mr Hobson’s life at the time such that continuing the surgery ‘absent the monitoring’ was reasonable”. Dr Wilson-MacDonald said this:

18. [51]

    Dr Wilson-MacDonald was then asked what should have been done if the spinal cord monitoring traces were abnormal or absent during the surgery. He said this:

19. [52]

    Finally for present purposes, Dr Wilson-MacDonald was asked what available alternatives there were to surgery at the time. He responded as follows:

20. [53]

    Dr Sawle is a consultant neurologist. He provided a report dated 4 November 2012. By reference, among other things, to the intra-operative anaesthetic recordings, Dr Sawle expressed the view that three episodes of hypotension at approximately 19.40, 20.38 and 21.12 could be identified. With respect to these recordings, Dr Sawle said this:

21. [54]

    Dr Sawle gave the following opinion about the significance of spinal cord monitoring in this case:

22. [55]

    Dr Sawle’s report then dealt with the topic of Mr Hobson’s stroke in these terms:

Expert evidence - Northern Sydney Local Health District

1. [56]

   Before it settled the proceedings with Mr Hobson, the first defendant relied upon the evidence of one expert witness. He gave evidence on the second day of the hearing. This is referred to below.

2. [57]

   Dr Barratt swore an affidavit on 12 November 2015. It was relevantly in the following terms:

3. [58]

   In a footnote to his affidavit Dr Barratt explained that “dead space” refers to lung units that are being ventilated (from the ventilator and breathing tube) but not being perfused (not receiving blood from the heart). This manifests as an increased gap between the end tidal (breathing tube) carbon dioxide and arterial (blood) carbon dioxide. This is normally in the range of 5-10mmHg.

Expert evidence – Dr Gray

1. [59]

   Dr Askin is a spinal orthopaedic surgeon specialising in the management and surgical treatment of spinal deformity in both adults and children. He furnished a report on behalf of Dr Gray dated 13 March 2014. His opinion set forth in that report is as follows:

2. [60]

   Dr Askin said that in his opinion Mr Hobson’s general medical condition posed a significant risk in the correction of his complex spine deformity, which “definitely required surgery”. He considered that Dr Gray acted in a manner that was competent in the current setting of spine deformity surgery in Australia.

3. [61]

   Dr Lambros is a consultant anaesthetist. He prepared a report for Dr Gray’s solicitors dated 22 October 2016. He was asked a series of specific questions and offered the following presently relevant responses:

   1. (1)

      Mr Hobson’s surgery and anaesthetic care were not compromised by the hour of the day.

   2. (2)

      Mr Hobson was preoperatively haemodynamically stable.

   3. (3)

      There was a definite downward trend in respiratory function but Mr Hobson’s “respiratory condition was not severe enough to preclude surgery” (joint anaesthetic experts’ opinion). Indeed, given the downward trend in the preceding hours, it may have been imprudent to wait further.

   4. (4)

      The decision to proceed was entirely reasonable, based upon the premise of a deteriorating (but still stable) patient, with the likely primary cause being that of extrinsic left main bronchial compression secondary to “marked AP narrowing of the thoracic cavity”, which could not have been addressed with only supportive ICU management.

   5. (5)

      It was reasonable to use vecuronium during the surgery. The last dose was required because of Mr Hobson’s parlous ventilation state and appears to have been necessary at the expense of losing spinal cord monitoring.

   6. (6)

      The anaesthetic technique used represented an appropriate standard of care where spinal cord monitoring was required with the exception of the administration of vecuronium which would have made monitoring meaningless for the duration of the action of the drug. There may have been sufficient recovery between the 18.30 dose and the 20.30 dose of neuromuscular function to provide a window of meaningful monitoring but not thereafter.

   7. (7)

      It is not 100 percent clear that Mr Hobson’s condition from a respiratory functional point of view would have improved without surgery and anaesthesia on 17 November 2009. It would have been difficult to justify a wait and see approach.

4. [62]

   Dr Manasiev is a specialist anaesthetist. He provided a report dated 26 October 2016. He gave his opinion in response to a series of questions set out in that report.

5. [63]

   Dr Manasiev was asked whether Dr Gray should have advised that the surgery be halted. He responded at length by reference to various specified times during the course of the surgery. These have been discussed by other experts as well. At the risk of too much detail, it is instructive to record a selection of Dr Manasiev’s views:

6. [64]

   Dr Manasiev went on to offer the following conclusions:

7. [65]

   Dr Silbert is a neurologist. He is an expert in spinal cord monitoring. He provided a report dated 26 October 2016. He completed a fellowship at the Mayo Clinic where he gained experience in all areas of general neurology and neurophysiology including intraoperative monitoring of the brain and spinal cord.

8. [66]

   Dr Silbert was asked whether, on the balance of probabilities, any, and if so which, of the types of spinal monitoring proposed by Mr Hobson, would have detected abnormalities in his spinal cord during the surgery. His answer was long but needs to be noted in full:

9. [67]

   Dr Silbert was also asked whether, on the balance of probabilities it is likely that spinal cord monitoring would have detected abnormality in Mr Hobson’s spine prior to the collapse at about 21.30. He responded in the following terms:

Expert evidence – Dr Sparks

1. [68]

   Dr Sheridan is a neurosurgeon. He provided a very short report dated 7 November 2016. He said that it was not Dr Sparks’ responsibility to decide the patient’s positioning before or during surgery. That was the responsibility of the surgeon. He said that the use of a Jackson’s table is standard care in managing patients having spinal surgery in the prone position. It decreases the cardiovascular effects of the procedure by allowing the abdomen to be decompressed and it minimizes the compressive effects on the chest.

2. [69]

   Dr Sheridan also said that the decision to reposition a patient during surgery is a combined decision of the surgeon and the anaesthetist. In prone spine surgery, as in the case of Mr Hobson, a decision to reposition the patient from prone would have meant abandoning the operation. That is not a decision to be taken lightly or in the absence of quite extensive consultation and discussion. It would not be solely the decision of the anaesthetist.

3. [70]

   Dr Sheridan also considered that the suggestion that Mr Hobson could have been repositioned during the course of surgery so as somehow to allow the surgery to continue is not practical. It is a decision that requires the surgery to be abandoned and the wound closed. It is never a simple matter and is limited to cases of emergency. Dr Sheridan said that, in an operation such as Mr Hobson’s, where the original decision to operate was taken in order to save the patient’s life, the concern would have been that he was going to die if the operation were abandoned.

4. [71]

   Dr Forrest is a specialist anaesthetist. He provided a report and two supplementary reports. The first is dated 26 October 2013. He considered that the cause of Mr Hobson’s intraoperative collapse was acute right ventricular failure. He said that that would account for the high central venous pressure, low oxygen saturation and low blood pressure that occurred at about 21.30. It would also account for the large difference in the carbon dioxide level measured in Mr Hobson’s blood and expired breath before then, and the congested “purple” appearance of his head when he was turned from prone to supine. Dr Forrest thought that Mr Hobson probably developed acute right ventricular failure because of predisposing factors and the use of the prone position for his surgery. The predisposing factors were his spinal deformity, which caused restrictive lung function, and his left lung collapse/infection due to bronchial compression. These factors would have caused the pulmonary arteries to constrict and thereby increase pulmonary vascular resistance. An increase in pulmonary vascular resistance can cause the right ventricle to dilate and may eventually decrease its capacity to pump blood. He said that the combination of increased pulmonary vascular resistance and decreased cardiac output causes the blood supply to the right ventricle to fall. When it falls below a critical level, acute, severe right ventricular failure can occur. Dr Forrest said, however, that it was not possible accurately to predict in an individual patient if or when this will occur.

5. [72]

   Dr Forrest considered that it was appropriate and reasonable for Dr Sparks to direct Dr Gray to cease performing surgery when the systolic blood pressure dropped to 95. That was because at about that time (21.30) Mr Hobson had rapidly falling oxygen saturations to less than 80 percent, a high cardiovascular pressure and severe respiratory and metabolic derangement. This systolic level signalled the onset of critical haemodynamic deterioration, which would likely have progressed rapidly to refractory cardiac arrest if the surgery had not been abandoned at that time and Mr Hobson turned to the supine position. Dr Forrest said, therefore, that it was appropriate and reasonable for Dr Sparks to request that the surgery be abandoned at that time.

6. [73]

   Dr Forrest considered that Dr Sparks provided a reasonable standard of anaesthetic management to Mr Hobson during the surgery. He reasoned as follows:

7. [74]

   Dr Forrest considered that Dr Sparks’ anaesthetic management of Mr Hobson was in accordance with widely accepted peer professional opinion in Australia as competent professional practice at the time the service was provided.

8. [75]

   In his first supplementary report dated 11 September 2015, Dr Forrest expressed the opinion that Dr Sparks was not responsible for the performance or supervision of spinal cord monitoring for Mr Hobson’s operation. He also considered that it was reasonable for Dr Sparks to have administered vecuronium at about 20.35 in an attempt to improve ventilation. He explained his opinion in the following terms:

9. [76]

   Finally, in his second supplementary report dated 31 October 2016, Dr Forrest was asked whether, by reference to the blood gas parameters at 20.21 and 20.37, the administration of vecuronium was a reasonable response to Mr Hobson’s then current metabolic state. Dr Forrest considered that it was, for the following reasons:

The conclaves of experts

1. [77]

   The orthopaedic conclave was attended by Drs Johnson, Askin and Wilson-MacDonald. Their joint report is dated 7 October 2016.

2. [78]

   All doctors agreed that there was no orthopaedic imperative for the surgery to be performed urgently. Dr Wilson-MacDonald went further and suggested that there was in fact no medical reason at all for the surgery to be carried out when it was. All doctors agreed that the decision was based upon the advice from the intensive care team at the time. That decision was not to be criticised as the intensivists and anaesthetists agreed that Mr Hobson was fit to undergo the procedure.

3. [79]

   All doctors agreed that the surgery should have ceased when the anaesthetists were unable to maintain the metabolic state in the form of satisfactory blood pressure and oxygenation. Dr Wilson-MacDonald noted that at 20.37, blood gas analysis demonstrated a deteriorating metabolic state following an episode of hypotension at 20.30 and considered that the surgery should have been discontinued very shortly thereafter. It was agreed among all doctors that at the time of the surgery the treating surgeons or physicians would not have been able to predict the respiratory outcome. They now have the benefit of hindsight. Dr Wilson-MacDonald and Dr Johnson were of the opinion that Mr Hobson would not have become a paraplegic if the surgery had not been carried out that evening.

4. [80]

   Spinal cord monitoring was considered by all to be a necessary part of Mr Hobson’s surgery. The doctors all agreed that in the absence of spinal cord monitoring, the surgery should not have commenced and should not have commenced until there were satisfactory motor and sensory evoked potentials. Spinal cord monitoring is not effective unless adequate baselines are obtained. Spinal cord monitoring should have been in place before the surgery commenced.

5. [81]

   None of the doctors was able definitively to say whether surgery should be continued in circumstances where spinal cord monitoring, once commenced, fails to produce adequate traces. This would depend on the nature of the spinal cord trace abnormalities. The doctors considered that in this case, where the indications were primarily to preserve or improve Mr Hobson’s respiratory function, serious consideration would have to be given to continuing the surgery. The doctors considered that if no baselines traces were obtained either before or during the surgery then in Mr Hobson’s case the surgery should have continued. On the other hand, if baselines had been obtained but subsequently disappeared, the surgery should have been ceased.

6. [82]

   There was agreement among all doctors that Mr Hobson became a paraplegic sometime after 20.30 when he became hypotensive for the first time. The surgery should have been abandoned when the anaesthetists were no longer able to maintain satisfactory cardio respiratory parameters.

7. [83]

   The anaesthetic conclave was attended by Drs Westbrook and Forrest. Their joint report is dated 12 September 2016.

8. [84]

   Both doctors considered that it was reasonable to proceed with the surgery on 17 November 2009 and to bring it forward in light of the bronchoscopy findings. Mr Hobson’s respiratory condition was not severe enough to preclude surgery. However, Dr Westbrook did not think that it was necessary to do so, and considered that it could have waited a further 24 to 48 hours.

9. [85]

   Both doctors agreed that Mr Hobson’s respiratory function would have improved had his surgery not been performed on 17 November 2009. That is because his lung function improved even though the surgery was not completed and his bronchial obstruction was not corrected. Both doctors agreed that Mr Hobson would probably not have become a paraplegic if the surgery had not been performed that evening, given his unexpected improvement in lung function and the subsequent uncomplicated completion of his spinal surgery.

10. [86]

    Both doctors also agreed that a single lumen tube could have been used as an alternative to a double lumen tube, but would have carried the risk of ineffective ventilation of the left lung due to exacerbation of the left bronchial compression in the prone position.

11. [87]

    Neither doctor was clear as to the cause of the oxygen desaturation at 20.35, but thought that it could have been related to checking Mr Hobson’s double lumen tube position or simply increasing difficulty with ventilation. That is what necessitated the administration of muscle relaxants at around that time.

12. [88]

    The significant point of disagreement between these doctors concerned the time at which surgery should have been abandoned. Dr Westbrook was of the view that in light of Mr Hobson’s significantly worsening haemodynamic state at 20.35, surgery should have been abandoned within two more minutes. That was because of the concurrent evidence of Mr Hobson’s worsening metabolic state evidenced by blood gas analysis indicating a severe acidosis. In contrast, Dr Forrest considered, given that Mr Hobson’s surgery was thought to be potentially lifesaving at that time and was well advanced, and also given that the period of haemodynamic instability and desaturation was transient at 20.35, that it was reasonable to attempt to continue to improve Mr Hobson’s ventilation and haemodynamic state. Dr Forrest was clearly of the opinion, however, that it was necessary to abandon the surgery at 21.30 given the severe respiratory and haemodynamic instability that suddenly occurred at that time.

13. [89]

    Both doctors agreed that the administration of vecuronium was unexceptionable in the circumstances of this case.

14. [90]

    Finally there was agreement between both doctors that the cause of Mr Hobson’s spinal injury was most likely the result of an inadequate supply of oxygenated blood to his spinal cord at around 21.30. Mr Hobson’s spinal cord was especially vulnerable to ischaemia because he had previously undergone ligation of the segmental spinal arteries during the first stage of the procedure, which may have reduced blood supply to his spinal cord. It was agreed that this most likely occurred during the cardiac and respiratory collapse that occurred around 21.30.

Submissions

1. [91]

   Mr Hobson accepted that the decision to bring the surgery forward was reasonable. He contended, however, that that did not inform the progress of the rest of the surgery and particularly whether it should have continued.

2. [92]

   There was no evidence that the surgery was so urgent that Mr Hobson would die on the table if the surgery had been terminated sooner. As the defendants accept, Mr Hobson’s blood oxygen and blood pressure were adequate and he was not in peril. There was therefore no reason to hurry to finish the job whilst blood pressure and oxygenation were within normal limits.

3. [93]

   Mr Hobson contended that Dr Gray and Dr Sparks both understood that reliance on those two parameters was inappropriate. He referred to the following cross-examination of Dr Sparks:

4. [94]

   However, the next answer should not be overlooked:

5. [95]

   Dr Gray’s evidence was to the following effect:

6. [96]

   Mr Hobson submitted, in circumstances where he began to have ventilation problems from the moment he was turned prone and began progressively to deteriorate due to his acidotic state, that by 20.37 at the latest, and probably much earlier, he was heading for an inevitable outcome, namely the spinal stroke that occurred at about 21.30.

7. [97]

   According to Mr Hobson, continuation of the surgery in those circumstances, without spinal cord monitoring, could not be justified by the existence of an emergency because there is no evidence to support the proposition that cessation of the surgery before its completion was likely to result either in immediate death or death shortly thereafter. Continuing the surgery exposed Mr Hobson to that precise risk instead of alleviating it.

8. [98]

   Mr Hobson reasoned by reference to the following facts that Dr Gray and Dr Sparks were in breach of the duty owed by them to him as professional medical practitioners.

9. [99]

   Mr Hobson contended that the second stage of the surgery was not so urgent that it needed to proceed regardless of any risks to Mr Hobson’s health that may have emerged or developed during the surgery. In this respect he relied upon Dr Westbrook’s opinion in his 24 August 2016 report in these terms:

10. [100]

    Dr Westbrook had previously offered the following opinion in his 14 November 2012 report:

11. [101]

    This needs to be compared with evidence given by Dr Gray as follows:

12. [102]

    The pre-anaesthetic assessment indicated that Mr Hobson had been suffering ventilation problems in ICU but was haemodynamically stable, with relatively normal blood pressure and blood oxygen. He was not then acidotic. That assessment indicated, however, that Mr Hobson had an extrinsic compression of his left main bronchus with left lung atelectasis, reduced ventricular compression and was difficult to ventilate. The plan was to release the extrinsic compression with spinal cord monitoring.

13. [103]

    Vecuronium was administered at 18.00 in ICU and at 18.30 and 20.30 in theatre.

14. [104]

    Having commenced the preliminary stages of the surgery, difficulties were encountered in satisfactorily ventilating Mr Hobson, commencing about 18.30 with particular difficulty achieving ventilation and metabolic parameters. These were described by Dr Westbrook in his 21 October 2012 report as follows:

15. [105]

    It was Dr Westbrook’s opinion that the surgery should have ceased at that point until satisfactory ventilation was achieved. However, satisfactory ventilation was never achieved during the surgery until Mr Hobson was turned supine at about 21.30. He had high CO2 levels from the moment he was turned prone.

16. [106]

    Dr Lagopoulos arrived late and commenced monitoring when Mr Hobson was prone and surgery had commenced. He gave the following evidence in cross-examination:

17. [107]

    Professor Lagopoulos indicated in his affidavit that the initial spinal cord traces were abnormal in that the “signal was slightly delayed and the amplitude was a little flat”.

18. [108]

    In the period of about 30 to 40 minutes before the administration of vecuronium at 20.30, the traces became “significantly abnormal” as reported by Dr Lagopoulos to Dr Gray on 5 or 6 occasions. These were clinically significant events.

19. [109]

    At or about 20.30, Dr Lagopoulos informed Dr Gray that the traces had been lost. According to Dr Sparks, the traces were lost before the final administration of vecuronium as suggested by his evidence as follows:

20. [110]

    At or about 20.30, Dr Gray, via Dr Cree, instructed Dr Lagopoulos to discontinue his spinal cord monitoring. Dr Lagopoulos discontinued monitoring but remained in theatre until the procedure was abandoned at about 21.30.

21. [111]

    The vecuronium given at 20.30 would have affected spinal cord monitoring for a period of about 30 minutes, and no more than 45 minutes. No further vecuronium or other muscle relaxant was administered after that. By 20.30 the surgery still had approximately three and a half to four hours to completion. Mr Hobson contended that had spinal cord monitoring been continued, there would probably have been monitorable traces by 21.15 at the latest.

22. [112]

    Mr Hobson submitted that a motor evoked spinal cord monitor would probably have detected and given warning of any potential injury to the spinal cord caused by poor perfusion. He maintained that spinal cord monitoring of the kind applied in these circumstances was mandatory for surgery of this type. Mr Hobson referred to the report of the orthopaedic conclave that established agreement on the following matters. First, in the absence of spinal cord monitoring the surgery should not have commenced. Secondly, the surgery should not have commenced until there were satisfactory motor and sensory evoked potentials. Thirdly, spinal cord monitoring is not an effective tool unless adequate baselines are obtained.

23. [113]

    The following questions and answers from the orthopaedic conclave report need to be recorded in full:

24. [114]

    It was, however, Dr Gray’s evidence that spinal cord monitoring was in place. This appears from the following evidence:

25. [115]

    Mr Hobson maintained that in proceeding with the surgery beyond 20.30 in the absence of spinal cord monitoring, each of Dr Sparks and Dr Gray was practising at a standard below that of a reasonably competent anaesthetist and surgeon, in Australia in November 2009.

26. [116]

    Mr Hobson almost immediately developed acidosis when turned prone on the operating table. This state continued and progressively increased until he was turned supine. Acidosis results in an increasing risk of end organ ischaemia including spinal cord damage. This risk progressively increased as Mr Hobson’s acidotic condition gradually deteriorated during the surgery.

27. [117]

    The spinal cord stroke was an inevitable consequence of the continuing and progressively worsening acidotic condition resulting in poor perfusion caused by excessive carbon dioxide levels. Dr Gray and Dr Sparks both knew of this risk. However, Mr Hobson maintained that both doctors erroneously relied only or predominantly on the parameters of blood pressure and oxygenation to satisfy themselves that ventilation was at all times adequate. Such reliance, without taking into account the signs of acidosis, particularly the elevated CO2 levels, was inadequate to support a conclusion that ventilation was satisfactory. Such a failure was below the standard of care required of a reasonably competent anaesthetist and orthopaedic surgeon, performing spinal surgery in Australia in 2009. This submission needs to be understood, having regard to the following evidence. First, that given by Dr Forrest:

28. [118]

    Secondly, evidence given by Dr Askin:

29. [119]

    Thirdly, the evidence of Dr Westbrook:

30. [120]

    Fourthly, Dr Forrest:

31. [121]

    Finally, Mr Hobson referred to the terms of question and answer 4 in the orthopaedic conclave report:

32. [122]

    Mr Hobson was always going to be vulnerable to ischaemia during the second stage of the surgery due to the first stage surgery ligation of the segmental spinal arteries that necessarily reduced blood supply to the spinal cord. Mr Hobson submitted that neither Dr Sparks nor Dr Gray considered that vulnerability in deciding whether to continue or abandon the surgery. Dr Sparks said this:

33. [123]

    Dr Gray’s evidence was as follows:

34. [124]

    Mr Hobson submitted that a failure to consider factors beyond oxygen saturation and blood pressure was indicative of a standard of medical practice below the standard required in Australia in November 2009 of a reasonably competent anaesthetist or orthopaedic surgeon, performing spinal surgery in the particular method adopted to treat Mr Hobson. He referred in particular to the evidence of Dr Barratt who Dr Sparks had called from the operating theatre for advice at a critical stage. This is referred to in detail later in these reasons.

35. [125]

    Mr Hobson was in respiratory difficulty from the commencement of the surgery and the surgical team had trouble ventilating him throughout. His metabolic state, especially as reflected in his blood gasses, was also poor from the start and continually deteriorated during the surgery.

36. [126]

    Blood gasses demonstrated a clear deterioration in Mr Hobson’s metabolic state as the surgery progressed. Samples taken at 20.08 and 20.21 had by then already demonstrated a very high carbon dioxide level despite various attempts at pulmonary ventilation with a double lumen tube. This was causing significant respiratory acidosis. From the early stages of the surgery, blood gasses disclosed evidence of an increasing lactate level suggesting inadequate organ perfusion. Blood gas samples at 20.37 and 20.51 demonstrated significant further deterioration of all parameters.

37. [127]

    A reasonably competent anaesthetist would have concluded that Mr Hobson was suffering a profound respiratory and metabolic acidosis. Both Dr Sparks and Dr Gray were aware of this dangerous downward spiral in Mr Hobson’s metabolic state.

38. [128]

    By 20.50 Dr Sparks had tried various means of reversing this deteriorating trend without success. In particular, maintenance of blood pressure and ventilation at reasonable levels after transient drops had failed to address Mr Hobson’s dire and deteriorating metabolic state.

39. [129]

    As noted above, Dr Sparks spoke to Dr Barratt over the telephone at 20.50 or thereabouts. Dr Barratt correctly suggested to Dr Sparks that the breastplate of the Jackson table may have been pressing on Mr Hobson, creating cardiac and pulmonary artery compression. This meant that a section of lung was being ventilated but not perfused. Dr Sparks agreed with this analysis. Mr Hobson submitted that a reasonably competent anaesthetist would have called a stop to the surgery by this time at the latest. Had the surgery been paused or halted at that, or any earlier time, and Mr Hobson turned supine, he would not have suffered spinal cord damage.

40. [130]

    Dr Gray was aware, or should have been aware of Mr Hobson’s metabolic deterioration. A reasonably competent spinal orthopaedic surgeon in November 2009 in Dr Gray’s position should have ceased the surgery by 20.50 at the latest.

41. [131]

    The blood gasses at 21.01 showed a further deterioration in Mr Hobson’s metabolic state, such that eventual cardiovascular collapse was inevitable in the absence of corrective measures.

42. [132]

    Dr Sparks called upon the surgeon to “hurry up” at around 21.25, which was about five minutes before the spinal cord stroke. Had the surgery been abandoned even as late as 21.25, and Mr Hobson’s wound closed and turned supine, he would not have suffered spinal cord damage.

43. [133]

    Between 21.26 and 21.30 Mr Hobson’s cardiac, respiratory and metabolic status became critical due to a combination of mechanical, respiratory and cardiovascular factors. At or about that time Dr Sparks told or suggested to Dr Gray that the surgery should stop, and a team decision was made to cease the surgery.

44. [134]

    In the minutes that followed, Mr Hobson was rapidly sewn up and returned to the supine position where his metabolic and respiratory state almost immediately recovered. Due to inadequate supply of oxygenated blood to his spinal cord at 21.30, he suffered an ischemic spinal cord stroke, which resulted in paraplegia.

45. [135]

    Dr Gray’s contentions can be reduced to a series of propositions as follows:

    1. (1)

       Mr Hobson required the surgery that was performed.

    2. (2)

       Performance of the necessary surgery in a two stage process was uncontroversial.

    3. (3)

       Mr Hobson was adequately warned of all aspects of the proposed surgery and possible risks, including respiratory complications with prolonged ventilation, spinal cord injury causing paralysis and the possibility of abnormal vascular supply to the spinal cord, and the associated need for a pre-operative spinal cord angiogram.

    4. (4)

       The first stage of the surgical procedure was performed uneventfully.

    5. (5)

       The decision to bring the second stage of the surgery forward to 17 November 2009 was appropriate having regard to the opinion of the intensive care specialists that Mr Hobson’s condition was critical, deteriorating and potentially life threatening.

    6. (6)

       The decision to continue with the surgery at 20.30 was proper and informed by the same factors that underpinned the original decision to bring the surgery forward.

    7. (7)

       Spinal cord monitoring was rendered ineffective by the administration of a muscle relaxant which became necessary having regard to Mr Hobson’s critically deteriorating ventilation.

    8. (8)

       It was not a failure to conform to appropriate medical standards by not halting the surgery at some time before 21.25 because there were no indications for doing so before then.

    9. (9)

       There were no intraoperative indications that Mr Hobson had sustained a paralysing insult and his paraplegia was not detected until the day following the surgery.

    10. (10)

        Dr Gray acted at all times in a manner that was widely accepted by peer professional opinion as competent professional practice.

    11. (11)

        Mr Hobson’s paraplegia was not caused by any breach of duty by Dr Gray.

    12. (12)

        Dr Gray is not liable for Mr Hobson’s paraplegia because it was the result of the materialisation of an inherent risk of the surgery that could not be avoided by the exercise of reasonable care and skill.

46. [136]

    In the context of Dr Sparks’ understanding of the urgency of Mr Hobson’s need for the surgery, and specifically the blood gas being taken more frequently than usual, he submitted that an inference is readily available that he had not excluded the metabolic blood gas results (Ph, base excess and lactate), but rather that he permissibly placed a different and greater weight upon the blood pressure and oxygen parameters.

47. [137]

    Dr Sparks submitted that, in light of Dr Westbrook’s evidence, Mr Hobson had not established that Dr Sparks was in error, or acted outside the relevant standard of care, by failing to ensure that the surgery was abandoned at 18.50, 19:10 or 20:30. As to the decision to proceed with the anaesthetic beyond 20.30, he submitted that the opinions of Dr Forrest in the joint report, and in his other reports, were supported by Dr Manasiev.

48. [138]

    The orthopaedic surgeons in their joint report in answer to question 18, concerning when the surgery should have ceased, indicated that it was when the anaesthetists reached the stage that they were unable to maintain satisfactory cardio respiratory parameters. Dr Sparks maintained that that point was not reached until immediately before the surgery was terminated in fact. The orthopaedic conclave report made no reference to the time the surgery should have ceased.

49. [139]

    In all of his reports, Dr Westbrook provides no explanation as to what he says is the appropriate standard of care amongst anaesthetists with respect to when an anaesthetist should call a halt to surgery or why.

50. [140]

    Dr Sparks contended that the evidence of Dr Forrest and Dr Manasiev, coupled with the orthopaedic surgeons’ answer to question 18 in the joint conclave report, is preferable to that of Dr Westbrook.

Consideration

1. [141]

   A convenient starting point is the decision to bring forward the second stage of the surgery to 17 November 2009.

2. [142]

   Mr Hobson was reviewed by various medical practitioners on 17 November 2009. There was at this time an escalating concern about the obstruction and compression of his left main bronchus, his worsening respiratory function and difficulty ventilating him. The need to assist Mr Hobson to maintain adequate blood oxygen levels kept increasing. The surgery was brought forward as it was considered by the ICU team that it was urgent in terms of hours rather than days. There was a perceived need to create more space in the mediastinum in order to relieve the extrinsic compression of the left main bronchus. Dr Wilson-MacDonald confirmed the validity of the reasoning behind this plan.

3. [143]

   On 17 November 2009 at about 10.20, Mr Hobson was seen by a dietician who noted, “Extrinsic compression L main bronchus. Note: planned for OT Wed/Thurs”. At 11.00 he was seen by Drs Bennett and Penfold for the Acute Pain Program who noted, “? Further OT this week”. Dr Matthews also saw Mr Hobson that day and noted “R/V Dr Gray (spinal surgeon)/Dr Sparks (anaesthetist). Will plan for second stage tomorrow at [about] 10.00”.

4. [144]

   Dr Sparks was contacted by Dr Gray and was informed that “the second stage of the operation needs to be performed as soon as possible, as the compression on the bronchus needs to be released”. Dr Sparks formed the clear impression that the operation had to be done in the next 24 hours as ICU staff had been unable to extubate Mr Hobson. He then had moderately severe respiratory failure and was on a high level of increasing ventilator support. There was CT evidence of pulmonary consolidation in both lungs (developing pneumonia) and compression of the left main bronchus, which would be fatal if ventilation and suction of the left lung were not improved.

5. [145]

   At 14.40 Dr Sparks returned to ICU with Dr Stephen Barratt, staff specialist anaesthetist, to perform a bronchoscopy for the purpose of satisfying himself of the need for the surgery to be brought forward and to assess Mr Hobson’s clinical status from an anaesthetic perspective. The left main bronchus was compressed and stretched and the length of the bronchus was measured at about 5cm. Dr Barratt noted Mr Hobson’s trachea was deviated to the right and the left main bronchus was severely narrowed and effectively not functioning. It was difficult to ventilate Mr Hobson and a lot of pressure was being used to achieve this.

6. [146]

   Dr Sparks was satisfied that urgent surgery was required. He said that:

7. [147]

   Dr Sparks discussed the anaesthetic with Dr Barratt. They agreed that a double lumen tube would be required so that the left main bronchus could be splinted open during surgery. Dr Sparks approached Dr Barratt because of his extensive experience and knowledge. Dr Gray took on the role of attempting to co-ordinate and contact the surgical and anaesthetic teams.

8. [148]

   The decision to perform the surgery on 17 November 2009 was made that afternoon. It was initially intended that the operation would take place at about 10.00 on 18 November 2009, but only if a team with sufficient experience to perform the surgery was available. During the process of coordinating the surgical and anaesthetic teams, it became apparent that at least two members of the intended team (Dr Cree and Dr Lagopoulos) were unavailable for the morning of 18 November 2009.

9. [149]

   Mr Hobson has suggested that the urgency relating to the performance of the surgery on the evening of 17 November 2009 is mere confection. He alleges that planning to perform the operation throughout the evening of 17 November 2009 was in effect for the convenience of staff rather than for his benefit. Dr Gray does not assert that the operation could not have waited until 10.00 the next morning. What was problematic was that it was not possible to organize a team with sufficient skill to be able to perform what would undoubtedly be complex surgery. In particular, it was necessary to have Dr Cree, an experienced spinal surgeon who was involved in the first stage and who had seen Mr Hobson pre-operatively, as well as Dr Lagopoulos, the spinal cord monitor. Whilst an element of pragmatism was involved, it was an entirely appropriate arrangement designed to secure the best possible outcome for Mr Hobson. The expert evidence supports this proposition.

10. [150]

    For example, Dr Johnson agreed that “putting together a team of two highly experienced spinal surgeons, a highly experienced anaesthetist, who was a senior member of the college of anaesthetists and a spinal cord monitor person was something that would have some logistical difficulties”. He agreed that one would “perform the operation at that point in time when you could get that team together” and “plan the operation so that that team could be there”. Dr Askin agreed.

11. [151]

    The decision to bring the surgery forward to commence sometime after 18.00 on 17 November 2009 was the result of a consensus of the ICU Team, Dr Marshman (a cardiothoracic surgeon), and two senior members of the anaesthetic team in consultation with the surgical team. There were no dissenting views.

12. [152]

    Dr Gray gave the following evidence about his views at the time:

13. [153]

    Dr Gray said that he “was very concerned by the opinions voiced by Dr Marshman and ICU team and the worsening clinical condition of Mr Hobson that it could only end up in a fatality”.

14. [154]

    Dr Sparks was of the belief that Mr Hobson needed life-saving surgery within 24 hours of when he and others met to discuss the patient at 14.00 on 17 November 2009.

15. [155]

    Dr Sparks said in evidence that he would have refused to take Mr Hobson to theatre if it was merely elective surgery. Dr Sparks did more than simply accept that there was a need for urgency “because somebody else told [him] there was” and “[he] actually went up and examined the patient [himself] to satisfy [himself] that was true because it was such an important decision”. Dr Sparks also said that “a risk of not doing the procedure exceeded the risk of going ahead with the procedure”.

16. [156]

    Dr Sparks considered that it was an emergency procedure and the consequence of the surgery not proceeding was Mr Hobson’s likely death. He did not resist the suggestion that the surgery take place that evening.

17. [157]

    Dr Sparks considered that Mr Hobson needed life-saving surgery within 24 hours of when they were together discussing his condition at 14.00 that afternoon. His explanation of the rationale for bringing the surgery forward was as follows. The ICU specialists wanted Mr Hobson operated on urgently because they were unhappy with his ventilation. He was developing pneumonia. The CT angiogram report from the Sunday clearly showed that Mr Hobson had a compressed bronchus and was developing pneumonia. Dr Sparks was aware that Dr Marshman said that he needed urgent surgery.

18. [158]

    Dr Sparks had been told that Mr Hobson’s left main bronchus was compressed and it was not possible to pass a fibre optic bronchoscope to identify what was going on. As already noted, Dr Sparks in fact satisfied himself that Mr Hobson truly had pneumonia, and that his bronchus was occluded. There was bloody sputum coming out from his left lung. In addition, the blood gas deterioration was severe. The case notes revealed clear evidence of problems with ventilation on the left side of the lung, and bloody pus being sucked out. Mr Hobson also had a fever.

19. [159]

    In response to the proposition that Mr Hobson’s lung function would have improved if he had been treated conventionally in ICU, Dr Sparks in cross-examination said that his respiratory function would improve without the operation but his cardiac function would not because the uncorrected cardiac compression would remain. It was Dr Sparks’ opinion that “we always had to make this patient worse to make him better in the long term”.

20. [160]

    The decision to advance the second stage of the surgery in this case was in my opinion perfectly reasonable. As with several other aspects of what occurred on 17 November 2009, it is easy inadvertently to undertake an examination of the decisions that were made with the benefit of hindsight. Principal among those is the fact that, notwithstanding the catastrophic intraoperative events, and the fact that Mr Hobson’s respiratory and cardiac restrictions were not surgically alleviated, he later recovered sufficiently to undergo the procedure shortly thereafter.

21. [161]

    However, those attending Mr Hobson did not have the luxury of knowing what would later occur. The opinion that Mr Hobson was confronted with a potentially life threatening condition was not an isolated view at the time. Dr Sparks even went as far as to examine Mr Hobson physically in order to satisfy himself of the extent of the bronchial obstruction and the significance of his pneumonia. I am satisfied that both Dr Gray and Dr Sparks considered that there was a considerable risk that Mr Hobson might die if the surgery were not immediately performed. The fact that that decision appears now not to have been correct does not affect its reasonableness at the time it was made. The decision is not in my view one that can reasonably now be called into question.

22. [162]

    I pause to observe that Mr Hobson challenges the correctness of the decision to operate because of what he contends is the irreconcilable tension between what was at the time considered to be lifesaving surgery on the one hand and the intraoperative decision to abandon it when Mr Hobson’s condition deteriorated so significantly on the other hand. Mr Hobson in effect asks rhetorically how could it be sensible that the surgery was halted at a time when his condition was arguably considerably worse at 20.30 or 21.25 than it was in ICU when his very survival was the rationale for its commencement in the first place. In my view the answer lies in the fact that Mr Hobson’s condition before the operation was at worst associated with the strong possibility of his death if the operation was not brought forward. In contrast, the situation as it developed during the operation suggested that by sometime between 20.30 and 21.25 the chance of Mr Hobson dying had been elevated to one approaching a probability, not to say a certainty, if the operation were not abandoned. In that sense the intraoperative decision to halt the surgery is not weakened by comparison with the original rationale for attempting it. The significant issue is whether the decision to abandon the procedure was made too late.

23. [163]

    There is no evidence to suggest that the decision to proceed to surgery on the evening of 17 November 2009 was inappropriate. More significantly, there is no evidence to support the suggestion that anyone expected or even could have expected that Mr Hobson’s condition would improve. Mr Hobson’s concern that there is a tension between the two decisions necessarily requires evidence that Mr Hobson’s remarkable post-operative recovery could have been expected. On the contrary, Dr Lambros described it as “a surprising improvement”. He gave this evidence:

24. [164]

    As I have indicated, the decision to proceed with surgery on 17 November 2009 cannot be faulted.

25. [165]

    The uncontested evidence reveals that Mr Hobson’s spine was exposed in a routine fashion through a midline posterior approach and pedicles were displayed between T2 and L2. The pedicle screws were inserted into the left side between T7 and L2.

26. [166]

    Mr Hobson experienced decreased oxygen saturations as follows. At 18.50 he suffered an acute reduction in oxygen saturation and end-tidal CO2 with pulse and blood pressure remaining stable. This was due to changing the single lumen tube. At 19.10 he sustained an acute reduction in oxygen saturation and end-tidal CO2 with reduction in blood pressure and sustained reduction in oxygen saturation due to turning him to the prone position. PO2 saturation readings were between 85 percent and 90 percent when he was turned prone. It is normal for the oximeter to be dislodged when rotating a patient to the prone position. However, an arterial blood gas taken at the time gave a PO2 of 243, which is not defined as hypoxia. At 19.10 there was a mild drop in blood pressure. Dr Sparks was aware of this from the CT aortic angiogram that showed bronchial compression and pulmonary artery compression, so that increased compression while in the prone position was possible. Dr Sparks spoke to the surgeons about minimizing downward pressure when inserting the screws as it could cause cardiovascular compression and they agreed to this. The evidence supports the contention that these events would not have caused any significantly abnormal monitoring results.

27. [167]

    According to Dr Gray, Dr Lagopoulos was requested to do a run at various times and he reported that the monitoring was good. Dr Lagopoulos stated that Mr Hobson had normal MEPs in both lower limbs. At paragraph 21 of his affidavit dated 6 November 2016, Dr Lagopoulos stated:

28. [168]

    Dr Lagopoulos confirmed this version under cross-examination. He had previously written letters to Mr Hobson’s solicitor. Those letters do not suggest that the monitoring changed over a period of time prior to its cessation.

29. [169]

    Mr Hobson places particular reliance upon the evidence that Dr Lagopoulos informed Dr Gray of five or six occasions of clinically significant abnormalities in the traces at some time prior to 20.30. However, the evidence does not support the contention that those occasions occurred over an extended period of time. Moreover, Dr Lagopoulos explained the difference between the circumstances where the traces were abnormal and where they became significantly abnormal. He clarified that abnormal traces were in effect a reference to Mr Hobson’s baseline signal and that the traces became significantly abnormal when they actually deviated from that. His construct of “significantly abnormal” was taken from the literature. He operated upon the basis that it was “a decrease in compound muscle action potential amplitude of more than 50 percent over a period of one minute”.

30. [170]

    Professor Silbert confirmed that the concept of “significant” was not limited to the loss of the response, but to a sustained loss of the response. He said that it was common to have a transiently abnormal motor evoked response during surgery, particularly using Dr Lagopoulos’ definition of 50 percent. He considered that to be a “very sensitive measure of the change in MEP”.

31. [171]

    Dr Lagopoulos confirmed that until the time traces disappeared at 20.30, no “significantly abnormal” decrease in the relevant signal was detected. That was consistent with paragraph 13 of his first affidavit, in which he recounts events happening in a crisis and with great rapidity.

32. [172]

    Dr Lagopoulos confirmed that, from the perspective of a neurophysiologist, there was no “clinically significant event” and he continued to inform the surgeons that the monitoring was satisfactory until “the point when the anaesthetic machines alarmed”. Dr Lagopoulos denied that “there was something seriously going on” at that time.

33. [173]

    Throughout the course of the operation up until the time when the anaesthetic machines alarmed, Dr Lagopoulos continued to inform the surgeons that the monitoring was “okay”. Following the administration of vecuronium, Dr Lagopoulos was unable to detect any traces.

34. [174]

    The decision to bring the second stage of the surgery forward was due to the inevitable deterioration in Mr Hobson’s condition. Dr Gray contended that the rationale for pressing on with the surgery at 20.30 was informed by the same clinical imperative.

35. [175]

    In his evidence, Dr Gray summarised balancing the risks:

36. [176]

    Dr Gray accepted the proposition that there were considerations pulling in two directions. The administration of the vecuronium was necessary to assist to resolve the respiratory compromise on the one hand but the spinal cord monitoring was unavailable during the time that it was operating on the other hand. This created a tension between two important aspects of the surgery. It was Dr Gray’s clear understanding that the vecuronium would not dissipate as it did not operate in the short term but was essential to enable ventilation.

37. [177]

    From Dr Gray’s surgical point of view, Mr Hobson’s blood pressure and oxygenation were normal. He considered that these were the two single most important factors relating to cord perfusion. As will be apparent, Mr Hobson is critical of what he would characterise as a negligent over-reliance on the importance of these factors as a basis for continuing the surgery.

38. [178]

    Dr Forrest gave evidence regarding the impact of the pre-operative assessment of the critical need for the surgery, in the context of Mr Hobson’s contention that he would not die on the operating table if the surgery had not been done at that time. He said:

39. [179]

    Dr Forrest later confirmed his view:

40. [180]

    Dr Sparks considered that “in an elective operation, we would stop [the] surgery and we have done so in other cases. In an emergency operation, the cardiovascular and respiratory factors outweigh the spinal cord monitoring”.

41. [181]

    In response to the proposition that a simple alternative was to stop the surgery and turn the patient into the supine position, Dr Sparks indicated that it would not solve the problem, merely defer it, because the cardiac compression would still not have been corrected.

42. [182]

    Dr Gray was asked why they could not have waited until the effect of the vecuronium dissipated:

43. [183]

    Dr Gray indicated that reversing the effects of the vecuronium would defeat the whole purpose of giving it, supporting his belief that vecuronium was necessary until the conclusion of the surgery.

44. [184]

    The loss of traces at 20.30 may have been due to administration of vecuronium at that time. However, in evidence Dr Sparks recollected that the sequence of events was in the reverse order:

45. [185]

    It was Dr Gray’s recollection that the traces were lost after the administration of vecuronium:

46. [186]

    I am unable from the available evidence to resolve this difference of recollection.

47. [187]

    Dr Gray’s evidence was that Dr Sparks informed the surgical team that he may need to administer vecuronium and that a collective decision was made at that point that it was necessary in order to improve Mr Hobson’s ventilation. It was inevitable that as a result the monitoring would be lost. In any event, both Dr Sparks and Dr Gray were of the opinion that the priority to maintain Mr Hobson’s respiratory health was more important than any competing considerations at that time. It will be apparent once again that Mr Hobson is severely critical of this approach and characterises it as a breach of the duty he was owed.

48. [188]

    After Mr Hobson was paralysed with vecuronium, Dr Cree advised Dr Lagopoulos he could conclude his involvement in the surgery.

49. [189]

    At 20.30, Dr Sparks administered vecuronium in an attempt to improve Mr Hobson’s worsening ventilation. He formed the opinion that Mr Hobson’s PaCO2 was very serious and believed that if 4mg of intravenous vecuronium was administered, it may bring his PaCO2 down. As it was an emergency procedure and a likely consequence of not proceeding with the surgery was death, Dr Sparks felt obliged to take this course.

50. [190]

    By 20.30 the arterial blood CO2 level had risen from 64.7mmHg to 70.5mmHg. Dr Sparks was unable to detect any mechanical obstruction to ventilation but nevertheless gave vecuronium and informed the surgeons. Mr Hobson had to be paralysed through the use of a muscle paralysing agent in order to be ventilated.

51. [191]

    Dr Gray confirmed that the loss of traces at about 20.30 did not mandate that the surgery be paused. This was because there was no need to look for a reason why the monitoring had ceased. It was clear, according to him, that there was a reason for the monitoring to have stopped that did not have a surgical cause.

52. [192]

    Dr Gray confirmed the obvious proposition that whether surgery is stopped “depends on the circumstances of the surgery we are performing and the indications for performing that surgery”. Dr Gray confirmed that the surgery was not an elective procedure.

53. [193]

    Dr Gray indicated that he would not make a decision to cease surgery based upon medical parameters other than through taking the advice of his anaesthetic colleagues who were responsible for monitoring them.

54. [194]

    At 20.35 Mr Hobson’s blood pressure dropped transiently. Dr Sparks believed it was due to the surgeons using downward force to insert a pedicle screw. The blood pressure recovered before any intervention was required. At 20.45 there was one reading from the oximeter of 92 percent. Blood gas readings before and after were PO2 of 127 and 205, both of which did not indicate hypoxia.

55. [195]

    On this topic, Dr Askin gave the following evidence:

56. [196]

    In my view, the administration of vecuronium at 20.30 was reasonable in order to improve Mr Hobson’s ventilation. It was a singularly uncontroversial procedure in the course of attempts to do so. The evidence does not in any event suggest that there was an available or viable alternative. If at 20.30 Mr Hobson’s operation were to continue, it could not do so unless his ventilation was improved. Those performing the operation at that time were therefore confronted with a choice between stopping the surgery altogether in the face of Mr Hobson’s ventilation and respiratory difficulties or continuing with the operation if those difficulties could be corrected. The administration of vecuronium would correct those difficulties. However, the significant compromise in those circumstances was that the spinal cord monitoring was immediately neutralised by its administration and any form of spinal insult that spinal cord monitoring might otherwise have been expected to highlight would remain dangerously undetected. In other words, Dr Gray and Dr Sparks were effectively trading off any concern they might have had that Mr Hobson may be neurologically compromised if the surgery proceeded in the absence of spinal cord monitoring against the possibility that he might die if the corrective surgery were discontinued.

57. [197]

    It is not in issue that Mr Hobson had not sustained the neurological injury of which he now complains by 20.30. Cessation of the operation then would have meant that he would not have suffered from paraplegia and the operation to correct his spinal deformity could have proceeded at a later time. Mr Hobson’s paraplegia was sustained after 20.30 and before 21.25, or what amounts to the same thing, before the operation was finally abandoned. The significant question is whether the decision to proceed at that time was wrong. The answer to that question is partially informed by an understanding of what properly functioning spinal cord monitoring after 20.30 might have been expected to show.

58. [198]

    When cross-examined on this topic, Dr Westbrook gave the following evidence:

59. [199]

    This evidence has to be compared with the opinion of Dr Silbert that is extracted at some length earlier in these reasons to much the same effect.

60. [200]

    Drs Heath and Sawle spoke of this in their concurrent evidence as follows:

61. [201]

    Dr Gray argued in these circumstances that there would have been no time, from the point of view of motor evoked response monitoring, to respond to the cardiovascular collapse as there would have been no warning of Mr Hobson’s impending collapse. Nothing could have been detected until the vecuronium ceased to compromise the spinal cord monitoring. In the present case, the cardiovascular collapse would have supervened before that had occurred. This is in my opinion an inevitable conclusion having regard to the opinions of Drs Lambros, Silbert and Askin.

62. [202]

    Dr Sparks gave the following evidence in cross-examination:

63. [203]

    Dr Sparks had earlier given this evidence:

64. [204]

    Dr Westbrook and Dr Forrest agreed at the anaesthetic conclave that at about 21.20 there was a sudden reduction in oxygen saturation. The cause of relative bradycardia following the episode of hypotension was unclear but may have been due to a combination of patient and surgical factors. However, at the time, Mr Hobson’s oxygenation was adequate.

65. [205]

    At 21.24 the PO2 levels fell, Mr Hobson was bradycardic at 5bpm, hypotensive at 70/40 and had very low-end tidal CO2 level. Dr Sparks considered the drop in exhaled CO2 and blood pressure to be serious. About 2-3 minutes later (at about 21.28) Dr Sparks asked the surgeons to stop operating immediately and close.

66. [206]

    At 21.25 Mr Hobson’s blood pressure and his PaCO2 dropped. Dr Sparks considered the drops in exhaled CO2 and blood pressure to be significant. He administered adrenaline. At 21.30 Mr Hobson’s PaCO2 dropped co-incidentally at the time the surgeons were told to cease operating.

67. [207]

    Dr Sparks informed those present of a collection of anaesthetic difficulties he was encountering, including the ongoing reduction in oxygenation, hypotension, a decrease in end-tidal CO2 and an increase in PaCO2. He said words to the effect “I’m having problems with ventilating”.

68. [208]

    By about 21.25, the exhaled carbon dioxide expired waveform had diminished, the cardiovascular pressure was 37 and Dr Sparks was concerned that the right ventricle was failing. According to Dr Gray, Dr Sparks raised his concerns with the others saying words to the effect of “hurry up as the patient’s condition is deteriorating”. Dr Sparks gave this evidence:

69. [209]

    Dr Sparks was cross-examined to the following effect:

70. [210]

    At 21.30 it was clearly necessary to abandon the surgery given the severe respiratory and haemodynamic instability that suddenly occurred. As indicated, Dr Sparks had administered adrenaline and directed Dr Gray to stop the procedure immediately. The surgery was abandoned and the wound was rapidly closed. Mr Hobson was turned to the supine position. His cardiovascular status improved. There were concerns at the time that he may have suffered hypoxic brain injury due to the downtime of the cardiac arrest. He was taken to the ICU, intubated, ventilated and monitored.

71. [211]

    Dr Westbrook and Dr Forrest agreed at the anaesthetic conclave that during the process of instrumentation of the right side, between 21.26 and 21.30, Mr Hobson’s cardiac, respiratory and metabolic status became critical due to a combination of mechanical, respiratory and cardiovascular factors. These included obstruction of his major blood vessels in the chest, worsening ventilation due to his prone position, underlying lung disease, spinal manipulation, bronchial obstruction and low cardiac output due to acute right heart failure.

72. [212]

    According to the orthopaedic conclave in answer to question 18, the surgery should have been halted when the anaesthetists reached the stage that they were unable to maintain the metabolic state, meaning satisfactory blood pressure and oxygenation and satisfactory cardio respiratory parameters. This occurred at 21.30 when Mr Hobson suddenly became hypoxic and hypotensive. That is when the surgery was halted in fact. Question 18 anticipates both the anaesthetic events and the spinal cord monitoring events. It was only when Dr Sparks made the call that the surgery was halted.

73. [213]

    The decision about whether to stop the surgery at any particular time was a decision that had to be made by both the surgical and anaesthetic teams. The decision-making procedure involved the surgeons being aware of surgical issues, and the anaesthetists being aware of anaesthetic issues. Both teams were acutely aware of the pre-existing reasons for the operation being performed when it was. Dr Sparks stated that the decision to stop the surgery at 21.30 was his. This meant that he was the person who was aware of the anaesthetic issues that would have informed a decision by the surgeons and the anaesthetists operating together about what to do. Up until shortly before the cessation of the surgery, Dr Sparks had not informed the surgeons that he was having any difficulty with hypotension. It was only when significant issues arose after 21.20 that Dr Sparks informed the surgeons of the difficulties. Minutes after that Dr Sparks indicated that the surgery should stop:

74. [214]

    In response to the suggestion that Dr Gray should have stopped the surgery, turned Mr Hobson over and waited to see what happened, assuming he knew there were “problems” or difficulties with the spinal cord monitoring, Dr Johnson did not agree with immediately stopping the surgery:

75. [215]

    Dr Johnson continued as follows:

76. [216]

    Dr Johnson later gave this evidence:

77. [217]

    The conclave of orthopaedic experts agreed the surgery should have ceased when the anaesthetists were unable to maintain the metabolic state. Dr Wilson-MacDonald considered that the surgery should have ceased shortly after 20.37 when blood gas analysis demonstrated a deteriorating metabolic state.

78. [218]

    Regardless of what Dr Wilson-MacDonald opined in relation to anaesthetic considerations, the joint report, at answer 18, makes it clear that the surgeon is in the hands of the anaesthetist in relation to anaesthetic issues. Dr Forrest considered, in the context of Mr Hobson’s deteriorating condition and the prevailing circumstances, that it was reasonable to continue the surgery. In his 26 October 2013 report he said:

79. [219]

    It will be recalled that Dr Manasiev gave a summary of the overwhelming factors in favour of continuing the surgery at 20.30 in the context of Mr Hobson’s deteriorating condition. There was a potentially identifiable and reversible cause of the hypotension and desaturation. There was a quick resolution to normal values of blood pressure and saturation. The decision was balanced against the apparent necessity of the operation as a potential lifesaving technique. In those circumstances, Dr Manasiev considered that Dr Sparks and Dr Gray were warranted in not halting the surgery at that time and would be considered by widely accepted Australian peer professional opinion to have conformed to competent medical practice by continuing with the surgery.

80. [220]

    In my opinion, the decision to continue the surgery at and from 20.30 was reasonable.

Findings

1. [221]

   I consider that it is possible to find the following matters upon the balance of probabilities.

2. [222]

   First, the original decision to bring the surgery forward to 17 November 2017 cannot be criticised. Mr Hobson was considered by all accounts to be in extremis. He had or was quickly developing a serious lung infection. His left main bronchus was narrowed and was almost completely occluded. The double lumen tube was operating to splint it open, without which Mr Hobson’s left lung could not have been ventilated. The consensus at the time was that Mr Hobson might die if the situation were not urgently corrected. The decision to operate was made in that context. That decision was reasonable. I consider that it is prudent to make this finding even though it was indicated on the last day of the hearing that Mr Hobson no longer pressed the proposition that the surgery should not have commenced. I note Dr Westbrook’s opinion is to the contrary.

3. [223]

   Secondly, the decision to continue with the operation at and beyond 20.30 was perfectly reasonable. There were no anaesthetic or surgical indications at that time that the surgery should have then been abandoned. Mr Hobson’s ventilation improved with the administration of vecuronium to the point that continuation of the surgery was warranted.

4. [224]

   Thirdly, (and subject to point sixthly below), the absence of effective (or indeed any) spinal cord monitoring after 20.30 is ultimately of no direct significance, as Mr Hobson’s ventilation was critical and took precedence over the need to maintain it. Once it is accepted that the decision to proceed after 20.30 was reasonable, there was in the particular circumstances as they presented at the time no useful place for spinal cord monitoring. The attending doctors were faced with the choice of stopping or continuing at 20.30. There was no possibility of continuing after 20.30 without the administration of vecuronium, which neutralised the effectiveness of spinal cord monitoring. The administration of vecuronium in Mr Hobson’s particular respiratory circumstances was unexceptionable.

5. [225]

   Fourthly, Mr Hobson had not suffered any catastrophic intraoperative event leading to his spinal damage and paraplegia at any time before 20.30. The most likely time frame within which that event occurred is between 21.20 and 21.30.

6. [226]

   Fifthly, even if there was arguably no single unambiguous indication for stopping the surgery before the decision to do so was made, there were several factors which together certainly gave that indication. As Mr Hobson emphasises, the evidence of Dr Barratt, who was after all the expert to whom Dr Sparks turned when his options appeared to be evaporating, emphasises the importance of heeding several factors in combination. It is reasonably clear that Dr Barratt’s telephone input inspired the events that followed it. The attending doctors undoubtedly had access to several significant indicators of Mr Hobson’s condition, even if none taken alone pointed only in one direction. The combination of these factors provided a different perspective. The earlier indications available from Mr Hobson’s vital signs appeared to be that any deteriorations that were observed, in particular, episodes of hypoxia and hypotension occurring at or about 18.50, 19.10 and up until about 20.35, some of which were severe, were transient and recoverable but not such as to indicate that continuing with the surgery could not be justified. Up until about 20.35, Dr Gray and Dr Sparks were, in effect, permissibly taking an expectant approach, in the absence of material that indicated only one possible course of action. That position changed very shortly thereafter.

7. [227]

   This finding requires some elaboration.

8. [228]

   The contention that the surgery should have been stopped sooner appears to have initially arisen from Dr Westbrook’s first report in which he refers to the elevated PCO2 of 64mmHg. He continued in these terms:

9. [229]

   In his 24 August 2016 report, Dr Westbrook said this:

10. [230]

    Earlier in the same report, Dr Westbrook offered the following analysis:

11. [231]

    In cross-examination, Dr Westbrook conceded that the episodes of oxygen desaturation and low blood pressure at 18.50, 19.10 and 20.35 were of a transient nature, although the latter episode was against a background of deteriorating acid base. He conceded that there was no basis to stop the surgery at 18.50 or 19.10. Dr Westbrook agreed that when there was a drop in the blood pressure and oxygen desaturation at 20.35, both parameters were recoverable and quickly resolved. He also agreed that Mr Hobson was haemodynamically stable until 21.20, apart from the transient episodes referred to above.

12. [232]

    However, Dr Westbrook did not agree that it was reasonable for Dr Sparks to use the blood pressure and oxygen parameters as his dynamic guide for continuing with the surgery until 21.20. In essence, he maintained his position as identified in the anaesthetic conclave report, that the surgery should have been abandoned no later than 20.37.

13. [233]

    By contrast, Dr Forrest in oral evidence expressed the opinion that the parameters of blood pressure and oxygen were routine parameters for the management of these types of cases, and that it was reasonable to continue to make further efforts to alleviate Mr Hobson’s respiratory and metabolic acidosis. In the anaesthetic conclave report, Dr Forrest expressed the opinion that because Mr Hobson’s surgery was considered potentially lifesaving, and given that the periods of haemodynamic instability were of a transient nature, it was reasonable to continue to attempt to improve Mr Hobson’s ventilation and haemodynamic state, until the sudden, severe respiratory and haemodynamic instability that occurred at around 21.30.

14. [234]

    Dr Manasiev in both his report and in cross-examination expressed the opinion that these drops in blood pressure and oxygen were transient in nature, and that there were explanations for each event. He considered that it was appropriate to continue the surgery after each event at 18.50, 19.10 and 20.35.

15. [235]

    Dr Sparks’ evidence was that he was having difficulties with the anaesthetic and that he made a decision that, whilst the systolic blood pressure and the oxygen were normal to high, he would continue. If that changed he was obliged to stop. He said that in the presence of abnormal oxygen levels or low blood pressure the patient will definitely suffer permanent damage. He chose these factors as his criteria for stopping the operation.

16. [236]

    As set out earlier in these reasons, Dr Sparks reasoned with respect to those two dynamic parameters that “the risk of not going ahead exceeded the risk of going ahead and at that moment when the blood pressure and the oxygen dropped, that changed. The risk of proceeding exceeded the risk of not proceeding”.

17. [237]

    Dr Forrest’s evidence was to the effect that looking prospectively at the management of Mr Hobson’s anaesthetic, the doctors treating him had a belief that if the surgery was not completed there was a risk that he might die post-operatively from “refractory respiratory failure”. It was for this reason that he expressed the opinion that it was reasonable to continue the surgery using the haemodynamic and saturation monitoring and make further attempts to improve Mr Hobson’s ventilation.

18. [238]

    In cross-examination, Dr Manasiev said that the factors that would inform competent professional practice, with respect to anaesthetists and the continuance or otherwise of a surgery, were “the whole gamut of all the haemodynamic parameters” affecting a patient. He said that predominant among these were blood pressure and saturation, which indicate how the organs are being perfused. He conceded that other factors could not be excluded, but that different parameters would be differently weighted in terms of indicators of a patient’s stability.

19. [239]

    Dr Sparks understood that Mr Hobson’s need for surgery was urgent. He examined him and formed that view for himself. Dr Westbrook’s opinion that that view was “erroneous” is necessarily second hand and retrospective. Both Dr Westbrook and Dr Forrest in their joint report expressed the opinion that it was reasonable for the surgery to commence. I am however not satisfied that either Dr Gray or Dr Sparks conformed to the relevant standard of care in failing to halt surgery before 21.25.

20. [240]

    As I have earlier noted, the orthopaedic surgeons in their joint report indicated that the surgery should have ceased “when the anaesthetists reached the stage that they were unable to maintain satisfactory cardio respiratory parameters”. The orthopaedic surgeons made no precise reference to a time when the surgery should have ceased. Satisfactory cardio respiratory parameters were not being maintained by 20.30.

21. [241]

    In my opinion, the evidence of Dr Barratt is critical in this respect. At the risk once again of including too much material, I consider that Dr Barratt’s evidence in cross-examination is extremely instructive and is as follows:

22. [242]

    It is important not to lose sight of the fact that Dr Sparks and Dr Gray were confronted with what was patently a distressing and fraught intraoperative emergency. It is difficult to over-emphasise just how awful it must have been at that time for all concerned. It is clear that Dr Sparks had attempted all of the anaesthetic manoeuvres in his armoury to correct the problem without apparent success. Criticism of these doctors in those circumstances may seem harsh. However, it is not in question that stopping the surgery when no obvious answer to the problems confronting the doctors was presenting itself would have avoided the damage. We know with hindsight that postural adjustment from prone to supine produced immediate resolution of these problems. That was something which in my opinion Dr Sparks and Dr Gray should have foreseen and acted upon. Failure to do so amounted to a want of reasonable care. It was in my view not appropriate to take the risk that something that could not be explained would or might somehow spontaneously resolve or improve. It is no answer to insist that the surgery was lifesaving in circumstances where Mr Hobson’s respiratory difficulties at or after 20.30 had deteriorated below his pre-operative condition in ICU.

23. [243]

    Sixthly, there was a need to be particularly mindful of the consequences for Mr Hobson of his rapidly deteriorating ventilation by reason of the fact that spinal cord monitoring was absent or effectively neutralised. For present purposes it does not matter which it is. Indeed, I accept the opinion of Dr Silbert that he did not believe that SSEPs and MEPs would have detected significant spinal cord electrophysiological abnormalities prior to 21.25. In that sense I am not satisfied that the absence of spinal cord monitoring for whatever reason properly informs or supports a finding of negligence by either defendant. Its absence or ineffectiveness was a fact of life in the operating theatre at 20.30 and at the very point at which Dr Sparks telephoned Dr Barratt. It was however to my mind a critically significant factor that not only enlivened, but in fact heightened, the need to act conservatively and to proceed expeditiously. It told against the appropriateness of taking an expectant approach when the solution to Mr Hobson’s difficulties had not emerged or was not understood.

24. [244]

    Seventhly, and with respect to the previous finding, opinions such as that expressed by Dr Sawle, that if the decision to halt the operation had been taken early enough for the surgeons to close the wound, so that Mr Hobson could be turned supine prior to 21.30, the episode of cardiac collapse and spinal cord stroke at that time would have been avoided, do not appear to be controversial. At one level such opinions are afflicted with hindsight, and are no more than self-evident statements about timing: they say nothing about the propriety or otherwise of continuing with the operation after 20.30 or 20.37. They do not amount to a statement of opinion that the earlier hypoxic or hypotensive events mandated an earlier cessation of the surgery. Dr Sawle’s opinion was only that the damage sustained by Mr Hobson was much more likely to have happened as a result of the more serious cardiac event at 21.30 than the earlier episodes of hypotension. To similar effect, it was Dr Wilson-MacDonald’s opinion that if the surgery had been stopped after the first severe episode of hypoxia [at 20.30], then the paraplegia would probably have been avoided. As I have noted, however, so much appears entirely uncontroversial.

25. [245]

    Finally, I do not consider that it was inappropriate for the surgery to have proceeded when it did, having regard to Mr Hobson’s existing gliosis on his spinal cord and the reduction of the number of arteries supplying blood to his spinal cord following the first stage of the surgery on 13 November 2009. For a start, the effects of the first stage of the surgery were always going to be part of the surgical equation in the second stage. The two stage approach has never been criticised. Moreover, the factors that warranted the advancement of the second stage of the surgery necessarily included a consideration of immutable historical factors such as Mr Hobson’s pre-morbid condition over which Dr Gray and Dr Sparks had no control and which could not be changed. I have previously rejected Dr Westbrook’s opinion that the view held by Dr Gray and Dr Sparks, that the proposed surgery was considered to be lifesaving, was erroneous.

26. [246]

    Section 5I of the Act is in the following terms:

27. [247]

    In Paul v Cooke [2013] NSWCA 311, Leeming JA at [52]-[56] offered the following considerations:

28. [248]

    In my opinion, this case cannot be conveniently decided under this section. In my view, having regard to the considerable evidence marshalled by all parties, the second stage of Mr Hobson’s surgery was not attended by an inherent risk that he might suffer a cardiovascular collapse and vascular disturbance causing lower motor neurone injury, such as his anterior spinal artery syndrome, arising out of the circumstances as they occurred. Mr Hobson had a pre-surgical anatomical vulnerability to spinal cord stroke and the effects of hypotension. However, the damage sustained by Mr Hobson was not the materialisation of a risk that was inherent in undergoing posterior instrumented thoracolumbar surgery having regard to his medical condition at the time.

29. [249]

    Mr Hobson’s medical condition included the following:

    1. (1)

       He suffered from Noonan Syndrome which in his case included a significant lordoscoliosis and associated compromised respiratory function.

    2. (2)

       He had a pre-existing gliosis within his spinal cord at T11/12.

    3. (3)

       He came to the surgery on 17 November 2009 following the necessary division of his intercostal arteries on 13 November 2009.

    4. (4)

       He had sustained a post-operative compression of the left main bronchus as well as significant cardiovascular compression following that first stage of the surgery.

    5. (5)

       He suffered from a deterioration of respiratory function following the first surgery and had developed pneumonia and a collapsed left lung.

30. [250]

    Added to these matters was the fact that the second stage of the surgery necessitated a posterior approach requiring that it be performed with Mr Hobson in the prone position. That posture exposed him to the prospect, but not the inevitability, of further cardiopulmonary compression.

31. [251]

    However, Mr Hobson’s paraplegia could in the circumstances have been avoided by the exercise of reasonable care and skill. Neurological injury, including paralysis, was an inherent risk of the surgery. A negligent failure to abandon the surgery, meaning a failure to exercise reasonable care and skill, before his paraplegia developed was not.

32. [252]

    Section 5O of the Act is in the following terms:

33. [253]

    None of the experts in conclave was referred to or asked to comment upon the question of whether or not Dr Gray or Dr Sparks, in providing their relevant professional service, acted in a manner that (at the time the service was provided) was widely accepted in Australia by peer professional opinion as competent professional practice.

34. [254]

    On the third day of the hearing I asked Mr Woods of counsel for Dr Gray the following question to which he gave the recorded response:

35. [255]

    On the sixth day of the hearing, Dr Manasiev was asked in cross-examination whether Dr Gray was negligent in continuing the operation in the circumstances pleaded. Dr Manasiev confirmed what he said in his report, that it would be considered competent medical practice by Dr Gray to heed Dr Sparks’ direction and proceed with the surgery at 18.50, 19.10 and 20.35 and to halt the surgery at 21.20.

36. [256]

    Dr Forrest considered that Dr Sparks’ anaesthetic management of Mr Hobson was in accordance with widely accepted peer professional opinion in Australia as competent professional practice at the time the service was provided.

37. [257]

    As far as I have been able to determine, the evidence about these matters is otherwise completely silent. I have not been able to locate any evidence upon which Mr Hobson proposed to rely from a suitably qualified medical expert that suggested that Dr Manasiev or Dr Forrest should not be accepted. Nowhere in the submissions made on Mr Hobson’s behalf is the issue of s 5O even referred to or discussed. Written submissions provided by Dr Gray and Dr Sparks both elaborated upon s 5O, reliance upon which each doctor specifically pleaded. Mr Woods of counsel for Dr Gray also made a brief oral reference to the provision.

38. [258]

    Dr Gray and Dr Sparks bear the onus of establishing a defence under s 5O of the Act: Dobler v Halverson (2007) 70 NSWLR 151; [2007] NSWCA 335 at [54]-[61]; Sydney South West Area Health Service v MD (2009) 260 ALR 702; [2009] NSWCA 343 at [21].

39. [259]

    As I have previously observed, Dr Manasiev considered that Dr Sparks and Dr Gray were warranted in not halting the surgery before they did and would be considered by widely accepted Australian peer professional opinion to have conformed to competent medical practice by doing so. For the reasons I have given concerning the defendants’ negligence, I reject that view.

40. [260]

    I have concluded that Dr Gray and Dr Sparks were both negligent. I take it to be uncontroversial that Mr Hobson’s paraplegia occurred after 21.15 and before 21.30. It follows that if either doctor caused or permitted the operation to continue when the exercise of reasonable care and skill would have indicated and led to the conclusion that it be abandoned by 21.15 at the latest, the damage suffered by Mr Hobson would clearly not have been sustained. That damage was caused by the breach of duty consisting in persisting with the operation when it should have been abandoned. But for the operation continuing past 21.15, Mr Hobson would not have become a paraplegic.

Conclusions on liability

1. [261]

   Mr Hobson’s blood gasses demonstrated a clear deterioration in his metabolic state as the surgery progressed. Samples taken at 20.08 and 20.21 demonstrated a very high carbon dioxide level despite various attempts at pulmonary ventilation with a double lumen tube. This was causing significant respiratory acidosis. There were also several episodes of hypotension and reduction in blood oxygenation during the surgery.

2. [262]

   From the early stages of the surgery, blood gasses disclosed evidence of an increasing lactate level suggesting inadequate organ perfusion. Blood gas samples at 20.37 and 20.51 indicated significant further deterioration of all parameters demonstrating to Dr Sparks a profound respiratory and metabolic distress. Dr Sparks was aware of this dangerous downward spiral in Mr Hobson’s metabolic state. By 20.50 he had tried various means of reversing this deteriorating trend without success. In particular, maintenance of blood pressure and ventilation at reasonable levels after transient drops had failed to address Mr Hobson’s dire and deteriorating condition.

3. [263]

   Dr Barrett correctly opined that the breast plate of the Jackson table was pressing on Mr Hobson creating cardiac compression and pulmonary artery compression, so that a section of lung was being ventilated but not perfused.

4. [264]

   Dr Sparks was negligent in not advising that surgery should have been abandoned no later than approximately 21.00. He was alive to Mr Hobson’s metabolic deterioration which would have caused a reasonably competent anaesthetist to call a stop to the surgery. Had the surgery been paused or halted at that time, and Mr Hobson turned supine, he would not have suffered spinal cord damage.

5. [265]

   Dr Gray was also negligent for not ceasing surgery at that time. He was being alerted to the problems encountered by Dr Sparks and had the ultimate say in whether to continue or not. He was aware of Mr Hobson’s metabolic deterioration which would have caused a reasonably competent orthopaedic surgeon to call a stop to the surgery. I reject the proposition, if Dr Gray advances it, that he was in all respects dependent and reliant upon Dr Sparks concerning Mr Hobson’s condition or that the decision about whether to proceed with the surgery or abandon it was, or should have been, that of Dr Sparks alone.

6. [266]

   As the conclaves concluded, due to inadequate supply of oxygenated blood to Mr Hobson’s spinal cord at 21.30, he suffered an ischaemic spinal cord stroke that resulted in paraplegia.

7. [267]

   In my opinion, Dr Gray and Dr Sparks each breached their duty to Mr Hobson by failing to terminate, or to recommend or advise the termination of the surgery on 17 November 2009 following earlier episodes of hypoxia and hypotension (occurring at or about 18.50, 19.10, and 20.35) in the face of related complications reported in the anaesthetic record after approximately 20.37 that evening. They failed at the very least to provide a proper standard of care by not immediately terminating the operation after the completion of Dr Sparks’ telephone call with Dr Barratt in the face of the abnormalities shown on the anaesthetic record and with Mr Hobson evidently in uncorrectable respiratory and cardiovascular difficulties for as long as he remained in the prone position.

8. [268]

   I also consider that, whether it was or was not below an appropriate standard of care for the operation to proceed without the advantage of spinal cord monitoring, it is presently irrelevant. In this respect I limit my comments to a finding that, because Mr Hobson’s respiratory difficulties required the administration of vecuronium, the surgery should have been terminated when it became apparent that no reliable indications of the integrity of Mr Hobson’s spinal cord health would be available due to the masking effect of that drug upon informative traces. I have earlier expressed the view, which I maintain, that the absence of spinal cord monitoring, for whatever reason, should have heightened the doctors’ need for caution when proceeding without it. I am not satisfied, however, as a matter of causation that Mr Hobson has established that spinal cord monitoring, if operating effectively following Dr Sparks’ conversation with Dr Barratt, would have provided a sufficiently timely warning to avoid the damage that occurred. As Dr Lambros opined, there may have been sufficient recovery between the 18.30 dose of vecuronium and the 20.30 dose of neuromuscular function to provide a window of meaningful monitoring, but not thereafter. To like effect, Dr Silbert considered that SSEPs and MEPs would not have detected significant spinal cord electrophysiological abnormalities prior to 21.25.

9. [269]

   In this same respect I repeat and specifically accept what Dr Askin had to say on this topic as follows:

10. [270]

    It follows, having regard to the foregoing, that there should be judgment for Mr Hobson against Dr Gray and Dr Sparks.

Life expectancy

1. [271]

   Mr Hobson was born in February 1985. He was injured on 17 November 2009. For ease of calculation I propose to treat Mr Hobson as being 32 years old precisely. The difference between that age and his actual age in years and months is arithmetically inconsequential for the purposes of calculating damages.

2. [272]

   At the conclave of experts on damages, Dr Helprin and Associate Professor Adams agreed that Mr Hobson had a pre-surgical life expectancy of only five years because of his restrictive lung disease and pulmonary hypertension. That somewhat grave prognosis was significantly altered by the corrective surgery performed by the defendants. Each of these experts also agreed that Mr Hobson’s life expectancy would have been 85 percent of the normal expected years for his age if the corrective surgery had been successful: his life expectancy would have been reduced by 15 percent due to his pre-existing Noonan Syndrome and related complications. Both doctors agreed that Mr Hobson’s present (post-surgical) life expectancy is reduced by 25 percent of the years that would have now normally remained, had he not suffered from Noonan Syndrome and had he not become paraplegic.

3. [273]

   Limited to the issue of Noonan Syndrome on life expectancy, Associate Professor Adams offered the following view:

4. [274]

   On the issue of restrictive lung disease, he said this:

5. [275]

   Combining these considerations, Associate Professor Adams concluded:

6. [276]

   Associate Professor Yeo additionally considers that Mr Hobson’s paraplegia will reduce his life expectancy:

7. [277]

   Dr Dalton also considered that Mr Hobson’s life expectancy has been reduced by his comorbidities:

8. [278]

   Dr Flecknoe-Brown additionally considered the impact of Mr Hobson’s platelet dysfunction on his life expectancy:

9. [279]

   Mr Hobson relies primarily on Dr Helprin. Dr Collins offers an opinion that to some extent aligns with the defendants’ experts:

10. [280]

    As Dr Yeo observed, one can search the literature and not find a Noonan Syndrome survivor over the age of 61. Dr Adams’ original calculations produced a life expectancy to age 55 years. Mr Hobson contends for a life expectancy to age 71. The defendants conceded that a compromise was justified on the evidence.

11. [281]

    As I have noted, Mr Hobson is now 32 years of age. Despite his critical condition in the ICU prior to his operation, and notwithstanding the considerable intraoperative cardiovascular and respiratory assaults upon him, he quite remarkably survived. Although my ability to make findings of a technical medical nature based upon observations of Mr Hobson in the courtroom setting is necessarily constrained, he rather impressed me as a particularly resilient individual. His experiences in the operating theatre and since have tended to confirm that impression. Moreover, in the particular events that have occurred, Mr Hobson is likely from now on and for the rest of his life to receive close and constant expert medical attention of the highest order. These factors combine in my view to support a finding, admittedly somewhat impressionistic, of a future life expectancy of 30 years or to the age of 62.

Non-economic loss

1. [282]

   Mr Hobson’s original assessment of his own non-economic loss was 85 percent of a most extreme case pursuant to s 16 of the Civil Liability Act. His current contention is that he is now entitled to damages for non-economic loss calculated as 100 percent of a most extreme case.

2. [283]

   Mr Hobson is significantly disabled. His life expectancy has been relevantly reduced by the effects upon him of his paraplegia. He was formerly active within the confining limits of his respiratory restrictions and associated consequences of his Noonan Syndrome. Even so, he might reasonably have expected to enjoy a considerably enhanced and improved lifestyle and physical existence following corrective surgery if his paraplegia had not intervened. His non-economic loss is therefore permanent and severe.

3. [284]

   I do not consider that Mr Hobson’s loss equates to a most extreme case. It is however my opinion that his original assessment of 85 percent was entirely accurate. It is regrettably possible to imagine cases more extreme than that of Mr Hobson. He should be awarded damages of $514,500 under this head at that rate.

Economic loss – generally

1. [285]

   The defendants argued as follows.

2. [286]

   Dr Dalton considered the position if Mr Hobson’s injuries had not been sustained:

3. [287]

   Dr Dalton additionally considered that had the injury not occurred, this would have “increased his prospects of finding work as a veterinary nurse, albeit on suitable duties, or alternative employment of a semi-sedentary nature”. As a consequence of Mr Hobson’s paraplegia, Dr Dalton was of the following opinion:

4. [288]

   Associate Professor Yeo offered a similar analysis:

5. [289]

   Ms Hardy offered a similar opinion:

6. [290]

   With respect to alternative employment, Ms Hardy considered that:

7. [291]

   The defendants submitted that there is a significant prospect that Mr Hobson’s earning capacity would have been considerably diminished even if the surgery had proceeded without incident. Dr Cree considered that, even with successful surgery, veterinary nursing may have been beyond his capabilities. In the damages conclave report all experts deferred to the opinion of Dr Dalton in respect of Mr Hobson’s employment prospects and loss of earning capacity.

Past economic loss

1. [292]

   Mr Hobson was not employed at the time leading up to his operation, but was in receipt of a disability support pension. He had previously worked for a short period between 9 August 2008 and 1 October 2008 as a veterinary nurse at the Greater Western Veterinary Hospital and received net wages during that period of $160 net. He otherwise worked in a voluntary capacity doing that kind of work. Mr Hobson claims past economic loss upon the assumption that he would have commenced full time work as a veterinary nurse on about 1 January 2011. It is agreed that an arithmetical calculation of award wages in that role for the period from 1 January 2011 until 17 November 2016 is $210,000.

2. [293]

   The defendant’s contend that Mr Hobson’s capacity for work would have been reduced by reason of his Noonan Syndrome. Specifically, although not exclusively, they submitted that his ability to deal with animals would have been limited to small animals, thus restricting either his employability in general or his utility as a full time employee in particular. So far as the evidence reveals it, neither Mr Hobson’s work record on the one hand nor his true capacities in the workplace on the other hand has been well illuminated. Any fair determination of Mr Hobson’s pre-injury earning capacity is therefore a matter that eludes any obviously supportable calculation.

3. [294]

   Mr Hobson’s claim after a deduction of ten percent for vicissitudes is $190,000. The arithmetic supporting this claim is accepted by the defendants. The defendants have indicated a preparedness to allow the sum of $150,000 without reference to an arithmetical framework. Doing the best I can I consider that Mr Hobson had a work capacity that could have been exploited in some form of appropriate work. I do not consider that his capacity should be measured only by the prospect that he could have obtained or retained work in his preferred field. I think that a net sum of $175,000 fairly represents Mr Hobson’s past economic loss.

Past loss of superannuation

1. [295]

   Mr Hobson’s loss under this head amounts to $175,000 x 11.5 percent or $20,125.

Future economic loss

1. [296]

   Mr Hobson’s future working life does not automatically correspond to his life expectancy, even though in my opinion his life expectancy is less than what might be considered as an ordinary or usual retirement age. Indeed, Mr Hobson specifically concedes that he would be unlikely to work beyond the age of 60 years. In my opinion, that concession is overly generous to Mr Hobson. Although the difference may seem small, I would not expect Mr Hobson to be able to work productively much, if at all, beyond the age of 50 years. That is because the collocation of factors that are likely to combine to reduce his life expectancy could not realistically be expected to fall in simultaneously at the age of 62 years. Factors identified by the evidence, such as the potential for malignancy, cardiac interventions, bleeding problems, urinary tract infections and related problems, as well as organ dysfunction, are likely to affect Mr Hobson at different times and in differing degrees of seriousness. Added to these factors are Mr Hobson’s underlying restrictive lung disease and spinal deformity. The defendants have contended that these things would have operated progressively so as to reduce Mr Hobson’s employability, rendering him on their assessment unemployable beyond the age of 45 or 50 years.

2. [297]

   I consider that range to be too pessimistic. I agree that these factors are likely to become patent progressively rather than simultaneously. I do not consider that they will operate in combination finally to render Mr Hobson unemployable until approximately 10 years before his statistically anticipated death. In my view Mr Hobson is likely to remain employed in one form or another until the age of 52 years, or another 20 years in round terms.

3. [298]

   Mr Hobson and the defendants have all proceeded upon the assumption that a net weekly sum of $725 is an appropriate base figure for calculation purposes, representing net weekly earnings of a level 4 veterinary nurse under the Animal Care and Veterinary Services Award 2010. Applying a five percent discount rate multiplier of 666.4 over 20 years at $725 per week produces an amount of $483,140.

4. [299]

   Mr Hobson contends that a discount for vicissitudes of 15 percent should apply to that sum. The defendants on the other hand suggest that a discount in the order of 30 percent should apply. That is said to be because Mr Hobson may not be able to perform all of the duties of a level 4 veterinary nurse and may suffer from an inability to compete on the open labour market by reason of his underlying Noonan Syndrome. In my opinion the negative effects of any additional factors applying in Mr Hobson’s case have already been factored into my conclusion that he will not work until his expected date of death but will in all likelihood be forced to leave the work force at the age of 52 years. Any extra discount for the vicissitudes to which the defendants draw attention would in my view be a species of unfair double counting.

5. [300]

   I consider that Mr Hobson is entitled to damages for future economic loss in the amount of $410,670.

Future loss of superannuation

1. [301]

   Mr Hobson’s loss under this head amounts to $410,670 x 11.5 percent or $47,225.

Domestic care generally

1. [302]

   The defendants proffered the following matters for consideration.

2. [303]

   Dr Dalton said this:

3. [304]

   Ms Hardy calculated domestic assistance for Mr Hobson at 3 hours per week, garden maintenance at 1 hour per week and handyman services at 12 hours per year. This does not include allowance for daily assistance with meal preparation since Mr Hobson would have some capacity to undertake this for himself provided he had a fully wheelchair accessible kitchen. Allowance for assistance with transport is not included, on the assumption that provisions are made for Mr Hobson to gain his driver’s licence and have access to a hand controlled vehicle and wheelchair hoist when required.

4. [305]

   Ms Hardy additionally considered that:

5. [306]

   In the joint conclave report on damages, Dr Dalton’s view was that Mr Hobson required 10 hours of care per week. Despite his more generous assessment (21 hours per week and 28 hours after 50 years of age) Professor Yeo ultimately conceded in evidence that Mr Hobson only requires two to three hours per week for domestic cleaning, could order groceries online and up until the age of 50 would be able to attend, in large measure, to many of the tasks in respect of which domestic assistance and personal care is claimed.

6. [307]

   Given the opinions of Dr Dalton in accordance with the Lifetime Care and Support Scheme Guideline, and the pragmatic concessions by Professor Yeo, the defendants submitted that Mr Hobson’s claims were unreasonable. In the context of the assessments by the rehabilitation physicians and occupational therapists of the actual need for domestic assistance in his circumstances, a reasonable compromise would be to award 14 hours per week for domestic assistance up to and beyond age 50. That analysis is said to be designed to take into account Mr Hobson’s variable needs as he ages. An alternative approach would be to allow ten hours up to age 50, and, say 18 hours thereafter. These allowances accommodate at least partly Mr Hobson’s additional needs for holidays and the like.

Past domestic care

1. [308]

   Mr Hobson claims 40 hours of gratuitous domestic assistance and personal care per week from the date of his admission to Ryde Rehabilitation Hospital in February 2010 until the present time. That claim amounts in total to some $325,000 as at the end of 2016. The defendants concede the arithmetical foundation for that calculation. However, the claim has necessarily to be modified in the light of the evidence of Siobhan Hobson, Mr Hobson’s sister, which was in these terms:

2. [309]

   The defendants concede that Mr Hobson required domestic assistance following his discharge from Ryde Rehabilitation Hospital on 31 May 2010 until the date of my assessment. The defendants do not concede that Mr Hobson required 40 hours of assistance over that time. The defendants submit that an average of 20 hours per week through the relevant period would be appropriate. They contend that a sum of $185,250 would be a proper sum under this head of damages, once again up until the end of 2016.

3. [310]

   Calculation of hours required or provided for domestic assistance in cases such as this is notoriously unscientific and draws upon usually undocumented recollections of people whose principal concern is understandably the provision of appropriate care and assistance rather than the recording of how long it took to provide it. Ms Hobson’s assessment of “20 or more, maybe” is a perfect example of an honest recollection, the accuracy of which cannot ever confidently be tested.

4. [311]

   It is in my opinion a mistake to underestimate the challenges for someone such as Mr Hobson, who is rendered a paraplegic, and who is required to come to terms with the mental and physical consequences of that dreadful discovery. Accommodating to life with such a significant disability is too easily discounted as an everyday vicissitude in the life of the injured person. In my opinion, it is not a mistake to err on the side of overstating, rather than understating, the hours of assistance that Mr Hobson required following his discharge from rehabilitation. His sister was very conservative in her evidence in my assessment and played down what the true difficulties probably were.

5. [312]

   In my opinion Mr Hobson is properly compensated by a sum calculated upon the basis of 30 hours per week of domestic assistance during the period to May 2017. That produces a sum of approximately $285,000 in round figures, which I propose to allow.

Future domestic and nursing assistance

1. [313]

   Mr Hobson claims nursing consultation and treatment at the rate of two hours per week after the age of 40 years at $81.88 per hour. It is not apparently contested that this is supported by the findings of the experts in conclave. The sum of $163.76 per week deferred for 8 years until the age of 40 years on a life multiplier of 822 to age 62 years (M476.5) is $78,030.

2. [314]

   The members of the expert damages conclave agreed that after the age of 50 years Mr Hobson would likely require attendant care of two hours per day. That could be provided by a trained nursing aid or a personal care worker. Dr Dalton was of the view that ten hours of domestic assistance per week would be required, based on the upper level of recommended domestic assistance in the guidelines referred to in his report. Dr Yeo considered that Mr Hobson would require 21 hours of domestic assistance per week and four hours per day after the age of 50 years. Dr Dalton considered that provision of one to two hours per week of handyman assistance was reasonable. That level of assistance would necessarily be a function of Mr Hobson’s particular living arrangements from time to time. Dr Yeo was of the opinion that Mr Hobson would require three hours per week of handyman assistance until the age of 50 years and four hours thereafter.

3. [315]

   Mr Hobson claimed 21 hours of domestic assistance per week at $45 per hour and three hours per week of handyman and gardening maintenance at $50 per hour or a total of $1,095 per week. At that weekly cost to age 62 years, at a 30 year multiplier of 822, a total amount of $900,090 is produced.

4. [316]

   The defendants emphasised that Mr Hobson would benefit from the proposed housing modifications. On that basis they were prepared to concede 14 hours per week of assistance as a compromise. At a weekly cost of $376 to age 50 years, at an 18 year multiplier of 625, a total amount of $235,000 is produced. The defendants also accepted that Mr Hobson will require, in addition to agreed building maintenance costs, one to two hours per week of handyman assistance. At $75 per week, a sum of $46,875 is produced. These two amounts total $281,875.

5. [317]

   After the age of 50 years, the defendants contend that Mr Hobson will require 18 hours of domestic assistance per week together with 2 hours per day of attendant care as well as 1.5 hours per week of handyman assistance. The defendants contended that Mr Hobson was entitled to 12 years at these rates until age 62 years appropriately deferred.

6. [318]

   I feel compelled to resort to what I consider to be a common sense understanding and appreciation of the nature and extent of the difficulties confronting an individual who has lost the use of his or her legs at the age of 30 years or so. The apparently dispassionate and empirical analyses of these difficulties does not often or always in my opinion pay sufficient regard to the monumental adjustments in life that such unfortunately afflicted individuals are forced to make, not to say endure. The suggestion that three hours per day of assistance for Mr Hobson is on the generous side, even taking into account modifications to his home environment, seems to me to ignore the realities of life. By analogy with the time it takes to care for an infant, a disabled and paraplegic adult would in my view conservatively attract the need for at least 21 hours per week of domestic assistance. Having regard to the view I have taken, there does not appear to me to be any practical reason to distinguish or differentiate between the periods up to Mr Hobson’s 50th birthday and beyond it.

7. [319]

   I consider that Mr Hobson’s calculations are realistic and reasonable. I propose to allow the sum of $900,090 that he claims.

Past treatment expenses

1. [320]

   Damages under this head have been agreed at $200,000.

Future treatment expenses

1. [321]

   Damages under this head have been agreed at $200,000.

Holiday care

1. [322]

   Mr Hobson claims annual holiday care of 24-hourly assistance per day for three weeks at a total annual cost of $23,930, together with the sum per annum of $10,000 additional travel and accommodation costs for the carer. That is said to produce a total discounted sum over Mr Hobson’s 30 year expected life at the rate of $652.50 per week of $536,355.

2. [323]

   The defendants contest this claim in significant respects. They accept that Mr Hobson may require some assistance with holiday travel. However, as he aged he would have required similar assistance in any event as a result of the ongoing and progressive effects of Noonan Syndrome. It is submitted that it would be likely in such circumstances that Mr Hobson would have had reduced travel opportunities as a result of his condition and what would have been his limited financial resources having regard to his pre-morbid occupational prospects. The defendants proposed a cushion in the amount of $10,000 per annum covering the costs of the carer on either a gratuitous or commercial basis and including the carer’s additional travel and accommodation expenses, as well as any additional costs incurred by Mr Hobson such as business class airfares. That approach produces a sum of $158,000.

3. [324]

   In my opinion, a reasonable approach lies somewhere in between these two approaches. Allowance has already been made for Mr Hobson’s future domestic and nursing assistance. Mr Hobson’s approach makes no allowance for the double counting of that head of damages for the annual periods when he is on vacation. The real prospects are that Mr Hobson would not have been able to afford annual vacations away from home that required even modest financial expenditure. That prospect is also likely to have been affected by his progressing Noonan Syndrome symptoms on the one hand with a corresponding disinclination to travel far from home, as he became significantly more severely affected as he approached the age of 62, on the other hand.

4. [325]

   As with any calculation of this type, significant assumptions resting on what are very often frail foundations have necessarily to be made. I prefer the defendants’ approach but I consider that their annual allowance is too niggardly. I would allow a buffer of $20,000 per annum, producing over 30 years a discounted total of $316,150.

Motor vehicle expenses

1. [326]

   Mr Hobson claims capital motor vehicle costs of $32,600 together with replacement costs of $68,220 and running costs of $190,900 totalling $291,730.

2. [327]

   The defendants contend that there is a conceptual error in Mr Hobson’s base calculations. He claims both capital and running costs. The amounts claimed for running costs are based upon the NRMA Car Operating Cost Calculators for Toyota Corolla and Chrysler Grand Voyager. The NRMA document provides an average whole of life weekly cost based on new to five year private operating cost in cents per kilometres and dollars per week travelling 15,000 kilometres per annum. The whole of life cost includes the purchase price and takes into account depreciation and the value of the vehicle upon resale. In those circumstances Mr Hobson’s calculations contain significant double counting. Moreover, Mr Hobson has no need for an electric wheelchair at the present and would therefore not need the Chrysler Voyager until much later in life. In those circumstances any allowance for such a vehicle in the future would need to be appropriately discounted.

3. [328]

   The defendants contend that Mr Hobson is likely to require a suitably modified vehicle with hand controls. The discounted capital and maintenance costs associated with those modifications are approximately $4,500.

4. [329]

   The defendants accept that Mr Hobson does require a larger than average vehicle and accept that such vehicles cost more to purchase and to run. They estimate these extra costs at $50 per week. Over the plaintiff’s lifetime to 62 years, that cost would amount to $41,100.

5. [330]

   The defendants also accept that at some point Mr Hobson may require a mechanical lifter to facilitate the placement of his wheelchair components into the vehicle. They estimate that the need for that equipment would not arise until about the age of 40 years, or eight years from now. The cost of the lifter is $17,000 approximately, deferred for eight years, which produces a capital cost of $11,510.

6. [331]

   The defendants submit that by no earlier than around the age of 50, Mr Hobson will require a motorised wheelchair or the equivalent. Accepting that the cost of vehicle modification to accommodate such a wheelchair is $31,500, then the deferred cost to age 50 is $13,105.

7. [332]

   These sums total $70,115. Taking into account annualised replacement costs or the prospect that Mr Hobson may choose to continue his current arrangements relying on family and friends or take a combination of gratuitous assistance and taxis, at the estimated sum of $123 per week, amounting to $101,105 over his lifetime, the defendants propose a buffer under this head of loss in the amount of $125,000.

8. [333]

   I accept that there are errors in Mr Hobson’s calculations of the type pointed out by the defendants. Having had the opportunity to observe Mr Hobson in the witness box, however, I consider that he remains a relatively young man of quite some modest resolve and independence. If driving a modified vehicle that would provide him with the greatest degree of independence were an available option, I consider that he would adopt that course.

9. [334]

   Doing the best I can, I consider that Mr Hobson is entitled to damages as a buffer under this head of loss in the sum of $240,000.

Equipment requirements

1. [335]

   The parties are effectively agreed upon damages under this head, being only $30,000 apart on their competing assessments. I propose to allow the sum of $145,000 as the mid-point between the parties’ respective contentions.

Building expenses and maintenance

1. [336]

   Damages under this head have been agreed at $249,105. Running and maintenance costs have been agreed at $57.40 per week. Calculation of that weekly sum over Mr Hobson’s 30 year life expectancy produces a figure of $47,182. I allow the total sum of $296,285 under this head.

Conclusions and orders

1. [337]

   Upon the basis of my findings and calculations, there should be judgment for Mr Hobson against the second and fourth defendants for $3,828,075 plus costs. Allowing for the prospect of arithmetical error, I will invite the parties within seven days to draw any such error or other like concern to my attention before my orders are made final.