Court of Appeal (WA)|2005-08-29|Before: Malcolm CJ

Strempel v Wood & Anor [2005] WASCA 163 (29 August 2005)

STREMPEL -v- WOOD & ANOR [2005] WASCA 163 (29 August 2005)

JURISDICTION : SUPREME COURT OF WESTERN AUSTRALIA

Jurisdiction : DISTRICT COURT OF WESTERN AUSTRALIA

Citation : [2003] WADC 145

Appeal - Negligence - Medical practitioner - Post operative treatment - Breaching duty of care - Causation - Subsequent negligent administration of antibiotics - Damages

First Respondent : Mr J Gilmour QC & Mr E A Panetta

Second Respondent : Mr J Gilmour QC & Mr E A Panetta

Bennett v Minister of Community Welfare [1992] HCA 27; (1992) 176 CLR 408

Bolam v Friern Hospital Management Committee [1957] 1 WLR 582

Halley v Chudleigh [1963] ALR 616

Naxakis v Western General Hospital [1999] HCA 22; (1999) 197 CLR 269

Planet Fisheries Pty Ltd v La Rosa (1968) 119 CLR 11

Rosenberg v Percival [2001] HCA 18; (2001) 205 CLR 434

Tran v Claydon [2003] WASCA 318

Water Board v Moustakas [1988] HCA 12; (1988) 180 CLR 491

Maloney v Commissioner for Railways (NSW) (1978) 52 ALJR 292

March v E & MH Stramare Pty Ltd [1991] HCA 12; (1991) 171 CLR 506

Modbury Triangle Shopping Centre Pty Ltd v Anzil (2000) 205 CLR 254

1 MALCOLM CJ: I have had the benefit of reading in draft the reasons to be published by McLure JA and Le Miere AJA. The relevant facts and circumstances have been fully set out in those reasons. In particular, I respectfully agree with the summary by McLure JA of the facts and the issues raised in the appeal and the cross-appeal by the second respondent against the assessment of damages for the negligent administration of the antibiotic gentamicin.

2 McLure JA has convincingly demonstrated that the learned trial Judge was in error in failing to find that the second respondent was negligent to conclude that the conclusion was chronic rather than acute. The error was the result of the application of the wrong approach to the resolution of the issue. As McLure JA has demonstrated, the evidence did not justify a finding that the appellant suffered from pre-operative ischaemia or had any cause for ischaemia in his right leg. As McLure JA has pointed out, neither of the respondents had received any information to that effect or understood that to be the case. In any event, I agree with McLure JA that the evidence of Professor Tracy was that even if the occlusion was chronic, the ischaemia was an acute event requiring active intervention. What form that intervention should take could be determined by performing an angiogram to determine the nature of the injury to the popliteal artery.

3 I agree with McLure JA that the weight of the evidence at the trial was that an angiogram can assist in the identification in identifying the nature of an injury to an artery, and that the failure to conduct or arrange for an angiogram to be conducted, using the catheter for the purpose of probing the occlusion was a breach of the standard of care required of an ordinary skilled vascular surgeon. Although the point regarding the angiogram was not specifically pleaded, the issue was one which was raised and fully litigated at the trial without a specific amendment and required to be determined as McLure JA has demonstrated.

4 McLure JA has demonstrated that the respondents knew, or ought to have known, that had they carried out an angiogram on 25 September, they could have ascertained the nature of the occlusion and, in any event, the nature of the injury could be identified by the use of a wire in accordance with the expert evidence of Mr Milne.

5 I agree with the analysis by McLure JA of the reasons of the learned trial Judge and her Honour's conclusion that the weight of evidence at the trial supported a finding that, on the balance of probabilities, the nature of the arterial injury and the cause of the occlusion or thrombosis was such

that it could have been successfully aspirated in the course of the angiogram.

6 I agree with McLure JA that the evidence did not support the conclusion of the trial Judge that progressive ischaemia would have resulted in damage to the appellant's leg by the time the second respondent was in a position to revascularise it.

7 I am in complete agreement with the balance of the reasons to be published by McLure JA.

8 It follows that I agree with McLure JA that the appellant's appeal on liability should be allowed, but the appellant's appeal in respect of the quantum of damages should be dismissed and the second respondent's cross-appeal should be dismissed. I too would wish to hear from the parties whether the case should be remitted to the trial Judge for assessment of damages.

9 MCLURE JA: The appellant suffered personal injuries as a result of complications following a knee replacement operation performed by the first respondent, an orthopaedic surgeon, on 24 September 1998 at Hollywood Hospital. The second respondent, a vascular surgeon, examined and treated the appellant on 25 September when concerns arose about the adequacy of the blood supply to the appellant's right leg the subject of the surgery. Save for a finding of negligence against the second respondent in relation to the administration of an antibiotic (gentamicin) to the appellant in August to October 2000, the trial Judge otherwise dismissed the appellant's claims of negligence against the first and second respondents.

10 The facts and findings made by the trial Judge are detailed in the reasons of Le Miere AJA and not repeated here. It is sufficient to provide a short summary.

11 The first respondent performed the knee replacement surgery (arthroplasty) on the morning of 24 September 1998. Nothing untoward was known to have occurred during the surgery. The appellant returned to the ward with an epidural catheter in situ for the administration of pain relief.

12 At 7 am on 25 September, the first respondent reviewed the appellant in the course of a ward round. There were no indications of any problems

at this stage. To the contrary, the indications were positive: the appellant told the first respondent that the leg was very comfortable and the first respondent palpated (perceived by touch) the appellant's pedal pulses and his right foot was warm. There are two pedal pulses, the distalis pedis which is in the front of the ankle bone and the posterior tibial which is immediately behind the ankle bone.

13 From around 10 am on 25 September the appellant's pain began to increase and the hospital notes record that his pedal pulses were absent. At around 1 pm on 25 September the nursing staff telephoned the first respondent and informed him that the appellant was in excruciating pain. The hospital notes for that time record that the appellant's leg was pale, his toes were cool and that sensation and the pedal pulses were absent. The first respondent was in the operating theatre at this time and he asked a registrar, Dr Brankov, to see the appellant. Dr Brankov did so and informed the first respondent that he thought the appellant's leg may be ischaemic (affected by insufficient blood flow). The first respondent instructed Dr Brankov to obtain a specialist vascular opinion, preferably from the second respondent.

14 The second respondent saw the appellant at around 2.30 pm on 25 September. On examination, the appellant had a popliteal pulse but no pedal pulse. The popliteal pulse is in the popliteal artery. The popliteal artery runs down the back of the leg, continues behind the knee joint and, below the knee, bifurcates into the anterior tibial artery and the posterior tibial artery. The posterior tibial artery gives off to another branch called the peroneal artery.

15 The second respondent recorded in writing that he suspected that there was a major arterial discontinuity in the appellant's calf from his old war injury. As a result of stepping on a landmine in the course of active duty in the Australian Army during the Vietnam war, the appellant's left leg was amputated above the knee and he suffered injuries to his right leg. The second respondent suggested a duplex scan be performed, an ankle brachial index (ABI) be obtained, the foot be kept down, and Clexane 40 mgm administered. Clexane is an anticoagulant. The first respondent countermanded the suggestion for Clexane because the epidural was still in place. Clexane may produce bleeding at the epidural site.

16 The appellant had a duplex scan at around 3.30 pm on 25 September. A duplex scan is a diagnostic ultrasound examination. The duplex scan showed that the end of the popliteal artery was completely blocked, that there was no blood flow within all three of the main arteries to the leg below the knee and the ABI was zero. Collateral vessels were present. There was blood flow reconstitution in the right tibial artery at the ankle joint coming in from collateral arteries which joined up with the right tibial artery. The radiologist advised the second respondent by telephone of the results "because of the gravity of the findings". It was clear from the results of the investigations that the appellant had an acutely ischaemic leg. If blood flow was not restored to the ischaemic tissue, the tissue could die and the appellant could lose his lower right leg.

17 After receipt of the test results, the second respondent examined the appellant at 4.30 pm on 25 September in the presence of the first respondent. Neither the first or second respondent did anything further to investigate, identify or address the cause of the acute ischaemia or take any other measures to restore blood flow. This was described as a conservative approach. In substance, the decision was to do nothing.

18 In the course of the evening of 25 September the appellant's condition deteriorated. By 1 am on 26 September the hospital notes record that the appellant had severe pain in his right calf and his leg was very swollen. The first respondent was notified. He came to the hospital, examined the appellant, diagnosed compartment syndrome in the anterior tibial compartment and conducted an emergency fasciotomy.

19 A compartment is a series of muscles separated by fascia (a band of fibrous tissue). Compartment syndrome involves a build-up of pressure within the compartment which can be caused by a number of factors such as ischaemia, restoration of blood flow or haemorrhage. Compartment syndrome can also cause ischaemia. A fasciotomy is an operation to release the build up of pressure within the compartment to facilitate blood flow.

20 The trial Judge found that the occlusion of the popliteal artery was acute, not chronic; that the occlusion resulted from an injury to the popliteal artery occurring at the time of the arthroplasty; that the results of the duplex scan and ABI revealed that there was a 50 per cent chance the appellant would lose his lower right leg; and that the second respondent acted (or, more accurately, failed to actively intervene) because he concluded the popliteal occlusion was chronic.

21 Notwithstanding the risk to the appellant's right leg, it survived. The personal injuries the subject of the appellant's claim include necrosis (death) and debridement (surgical excision) of muscle tissue in the anterior tibial compartment, recurrent infections of the right leg, nerve and muscle damage to the right leg resulting in foot drop and secondary lymphedema. The injuries primarily relate to the compartment syndrome and fasciotomy.

22 The issues raised in the grounds of appeal are whether the trial Judge erred in:

(1) finding that the respondents were not negligent in failing to diagnose an acutely occluded popliteal artery;

(2) failing to find the respondents were negligent in not performing or arranging for an angiogram and then surgically intervening;

(3) failing to conclude that the respondents' negligence caused the appellant's injuries;

(4) alternatively, in failing to give adequate reasons for the finding that there was insufficient evidence to reach the conclusion that the respondents' negligence caused the injury;

(5) not finding that the first respondent was negligent in offering total knee replacement surgery to the appellant; and

(6) awarding damages for the negligent administration of gentamicin below the range of a sound discretionary judgment.

23 The second respondent cross-appealed against the assessment of damages for the negligent administration of the antibiotic. It is convenient to begin with the challenge to the findings that directly relate to the second respondent.

Alleged Breaches of Duty by Second Respondent

24 One of the central issues in the trial was whether the occlusion in the popliteal artery was long-standing and pre-dated the knee replacement surgery (chronic) or sudden and related to the surgery (acute). The trial Judge found that the occlusion was acute, not chronic. There is no challenge to that finding.

25 The trial Judge rejected the second respondent's explanation given at trial for his conservative approach. His evidence was, in substance, that he recognised that the ischaemia (not the occlusion) had been caused by an acute event but did not surgically intervene to restore blood flow as the benefit of surgical intervention was zero; it was zero because irreversible tissue damage had already occurred in the approximately 30 hours that had elapsed since the surgery which was the cause of the acute ischaemia. His evidence was that nerve and muscle tissue only survive for around six hours once blood flow ceases.

26 The trial Judge found that at the relevant time (25 September) the second respondent concluded that the occlusion was chronic and, based on that conclusion, believed he could not remove it by surgery. Further, he believed he could not bypass the occlusion because the risk of failure of the bypass was significant and the risk of cutting the collateral circulation when performing the bypass was too high.

27 However, the trial Judge did not find that the second respondent was negligent to conclude and act on the basis that the occlusion was chronic. She explained why at [290]:

"This is because Professor Tracy, a witness called by the [appellant], who is a well respected, experienced and qualified vascular surgeon with the benefit of more time and more background material has also concluded that the popliteal artery was chronically occluded. My rejection of that conclusion does not mean that the second [respondent] was negligent in arriving at it given the material that he had to work with on 25 September."

28 In my view, this approach discloses error. A medical practitioner owes his or her patient a duty to exercise reasonable care and skill in the provision of professional advice and treatment: Rogers v Whitaker [1992] HCA 58; (1992) 175 CLR 479 at 483 and 489. However, the test for medical negligence is not what other doctors conclude, or say they would or would not have done in the same or similar circumstances; to treat that as decisive is to adopt a variant of the principle in Bolam v Friern Hospital Management Committee [1957] 1 WLR 582. The principle in Bolam, namely that the standard of care owed by a doctor to his or her patient is a matter of medical judgment, was rejected in Rogers v Whitaker at 487, 493. In some circumstances, questions as to the reasonableness of a conclusion or conduct are a matter of commonsense: Naxakis v Western General Hospital [1999] HCA 22; (1999) 197 CLR 269 at 275 - 276.

29 Thus, the fact that a medical expert, even if highly skilled and experienced, reaches the same conclusion as that under challenge, cannot itself justify a finding that the conclusion is within the scope of reasonable medical judgment. The question is whether there is a reasonable basis for concluding that the occlusion was chronic. That requires an examination of the basis on which Professor Tracy reached his conclusion. In concluding that the occlusion was chronic, Professor Tracy relied on information from which he understood that the appellant suffered from pre-operative arterial insufficiency and ischaemia in the muscles of the leg. The trial Judge concluded that the appellant's evidence fell short of establishing that he suffered from pre-operative ischaemia or had any cause for ischaemia in his right leg. Moreover, there is no basis for a finding that either the first respondent or second respondent had received information to that effect or understood that to be the case. As noted by the trial Judge, Professor Tracy acknowledged that, but for the pre-operative history on which he relied, there was nothing to point one way or the other to the cause of the post-operative ischaemia. The other relevant medical experts agreed that, based on the pre-operative and immediate post-operative history, the popliteal occlusion was acute.

30 The weight of the evidence supports a finding that there were no reasonable grounds to believe that the occlusion was chronic. However, whether or not the second respondent's error is material depends upon whether the cause of the occlusion is relevant to an assessment of what, if any, further action to take in light of the appellant's acute ischaemia confirmed by the duplex scan.

31 Professor Tracy's evidence was that even if the occlusion was chronic, the ischaemia was an acute event requiring active intervention. His evidence was that the ischaemia was a symptom, or indicated the development, of compartment syndrome and that a fasciotomy should have been performed after receipt of the report of the duplex scan. However, that opinion is inconsistent with the unchallenged finding by the trial Judge that there were no clear symptoms of compartment syndrome before the late evening of 25 September. Further, there is no challenge to her finding that a prophylactic fasciotomy is controversial.

32 The trial Judge then considered whether the second respondent should have arranged for an angiogram. She said:

"However if I am wrong in my conclusion that it was not negligent to come to the view that the popliteal artery was chronically occluded and to base his treatment on that view, then I accept Mr Milne's evidence that at the very least it was appropriate to perform an angiogram to determine the nature of the injury to the popliteal artery. I also accept that in that process the radiologist or intervening vascular surgeon would normally put a wire down through a tube to poke at the blockage to try and discover whether it was just thrombus or whether it was solid and not able to be fixed. Depending upon the vascular surgeon's assessment a Fogarty catheter may be used or an attempted aspiration may be made."

33 Mr Milne is a vascular surgeon who was called by the appellant. The trial Judge said that his evidence carried the greatest weight of the vascular surgeons who gave evidence. However, that does not relieve this Court of its duty to make its own assessment of the evidence: Fox v Percy [2003] HCA 22; (2003) 214 CLR 118 at [25].

34 At the hearing of the appeal the respondents contended that the trial Judge erred in finding that an angiogram should have been carried out on the ground that, although it would provide a clearer picture of blood flow in the arterial vessels, it would not determine the nature of the injury or assist the decision as to appropriate treatment.

35 An angiogram involves passing a catheter through an artery leading to the relevant area of interest in the body and a contrast material is injected to highlight the vessels when x-rays are taken. It provides a road map of how well blood is moving through the relevant vessels. The placement of wire down the catheter to assess whether the blockage is a soft thrombus or a chronic (hard) occlusion is, in effect, an opportunistic add-on. Further, an attempt can be made to aspirate the thrombus using the angiogram catheter. This is best explained in the evidence of Mr Milne. Before going to the specifics, it is best to provide the context. Mr Milne's evidence is to the following effect. As a result of the acute ischaemia, there was a grave risk of loss of the appellant's leg. A clinical judgment had to be made at the outset as to whether the limb was viable or unsalvageable. This can be a difficult judgment. If the view is that it is unsalvageable, it can be appropriate not to actively intervene. If it is still viable, it is necessary to assess whether there is a sudden (acute) occlusion or a chronic occlusion because that affects the available treatment options. Mr Milne assessed it to be obviously acute. The next matter to consider is the cause of the occlusion. According to Mr Milne, his presumptive diagnosis was arterial injury as a result of the knee surgery. Then the issue is the nature of the injury. There were a number of theoretical options, including complete or partial transection of the artery or otherwise breaching it; external pressure to the artery causing it to block; or a blunt injury to the wall or lining of the artery causing a thrombus (a stationary blood clot along the wall of a vessel). According to Mr Milne, it is for the purpose of determining the nature of the injury (which affects the possible treatment options) that it is necessary to investigate further by means of an angiogram. Mr Milne was asked about the appropriate response after having received the results of the duplex scan. He said:

"If one intends to give this limb the best chance of surviving, one would do an angiogram which is an insertion [indistinct] in the groin artery, injecting a contrast agent into the artery, following it down with x-ray equipment to delineate the anatomy and the status of the arteries beyond the damaged area.

If that was done in this case, what in your opinion would that have shown?---Well, I think there's very little doubt that it would confirm the occlusion of the popliteal artery which has already been seen on ultrasound. It may show a reasonable artery or it may show no arteries beyond the blockage depending on previous vessel status and whether the clot has extended beyond the area of injury. One would also use an angiogram to try and improve the situation in that a radiologist or intervening vascular surgeon would normally put a wire down under these circumstances and have a poke at the blockage to try and get an idea of whether it was just thrombus or whether it's very solid and not able to be fixed and you can in actual fact quite easily aspirate the clot through the catheter you put in to do the angiogram, thus improving the situation without resorting to surgery and this is normally the first step that we would introduce in this clinical picture and we would ask our radiologist, or if one is the vascular surgeon, to make an attempt to see if we can improve the situation as it stands without making the situation more complex by resorting to other surgical options."

36 Mr Milne also referred to angiograms performed on the appellant in 2000 and 2002 to identify the nature of the injury resulting in the ischaemia on 25 September. It appears he was shown the angiograms after he had provided his written reports that are in evidence. He said the angiograms provided information as to the nature of the anatomical obstruction and continued:

"... [I]n other words, and I mentioned before that the blockage could be a transection or ligation or a blunt injury to the artery producing lifting up of the lining, something like that, but the advantage of the hindsight here is that now that I have been shown the angiogram I can say that it's more likely that this was a soft thrombus in the artery rather than a transecting injury.

It's a deduction you've made from information that you now have recently available?---Correct.

Looking back as to what might have been the case had an angiogram been conducted in 1998?---That's correct."

37 I infer from the last question and answer that the same information would have been available if an angiogram had been conducted on 25 September. Further, it is clear from Mr Milne's evidence that his view was that regardless of any clinically based (provisional) assessment of the cause of the ischaemia, the appropriate course is to further investigate by way of angiogram.

38 It is difficult to clearly identify the conflict, if any, between the evidence of Mr Milne and that given by the respondents' expert vascular surgeon, Mr Lawrence-Brown. Mr Lawrence-Brown was also of the view that, based on the pre and immediate post-operative history, the occlusion was acute. His support for the second respondent's conservative management was based on assumptions that were not proven. Mr Lawrence-Brown assumed, firstly, that the second respondent had assessed the leg to be viable (that is, it would live) because of collateral circulation. In making that assessment, he assumed that the second respondent had detected movement in the appellant's ankle. He did so because he inferred from the second respondent's management of the appellant that he was not worried about the viability of the leg. In that factual context, he assumed the second respondent had assessed that the risks of surgery were greater than the perceived benefits.

39 In fact, the trial Judge found that the second respondent conservatively managed the appellant because he concluded that the popliteal occlusion was chronic, in which case it could not be removed by aspiration or a Fogarty catheter and a bypass was too risky. Further, the assumptions made by Mr Lawrence-Brown were at odds with the second respondent's explanation at trial for his conservative management. He said he assessed that the leg was non-viable.

40 Mr Lawrence-Brown said in cross-examination that an angiogram (or arteriogram) is indicated "if you have an action intention". The cross-examination continued:

"But if you're considering your options about whether or not to intervene, wouldn't an arteriogram tell you? I mean, if it's a localised occlusion of a particular spot which might be dealt with by stenting, bypassing or some similar process, wouldn't an arteriogram assist in that?---In most circumstances if you have an acute occlusion and you want to fix it then, yes, you would do an arteriogram and proceed immediately, but if you've already made the decision that you're not going to operate in this situation because the situation is such you can only make it worse, then there's no point in doing an arteriogram at that time.

I see, so the conclusion is: surgical intervention is completely out because I'm going to make it worse; there's no point doing an arteriogram ?---Yes.

But if there's a possibility that it may improve the situation, you proceed immediately to an arteriogram and then proceed according to what that shows?---Yes. You have to make that judgment as you see it - as the person there at the time."

41 Mr Lawrence-Brown was re-examined about the risks of using a Fogarty catheter and aspirating a clot. A Fogarty catheter is a tube with a balloon on the end which is able to be passed down an artery and inflated and is used to retrieve thrombotic material. He identified the risks by reference to the nature of the injury to the artery. If the thrombus was covering a hole in the artery, its removal could result in bleeding into the tissues and exacerbation of the problem. If the wall of the artery was damaged, a Fogarty catheter could disrupt it further. However, he does not say that if the circumstances do not favour conservative management, those risks outweigh the benefit of intervention. Mr Lawrence-Brown agreed with Mr Milne that the occlusion was a temporary phenomenon.

42 Mr Milne said that the relevant clinical judgment is in determining whether the limb is at risk and if the answer is yes, then you can do riskier things to save it than if the limb is not at risk. I do not understand Mr Lawrence-Brown to have a different view. It is at the stage of clinical judgment as to whether the limb is beyond salvation that Mr Milne referred to the differences in ability, intent and "daring-do" which results in different decisions by different people.

43 Like Mr Milne, Professor Nade concluded that, as there was no excessive bleeding during surgery, the occlusion occurred through a thrombosis as a result of blunt injury to the wall or lining of the artery during the surgery. He was also of the opinion that the appropriate treatment was to attempt to restore the blood supply to the leg which would be done by surgical exploration and a procedure.

44 I am satisfied that the weight of the evidence is that an angiogram can be used to assist in identifying the nature of the injury to the artery. The respondents' contentions too narrowly focus on the primary purpose of an angiogram rather than the associated use to which it can be put. The weight of the evidence also supports the trial Judge's conclusion that the failure to conduct an angiogram (or arrange for an angiogram to be conducted) and to use the catheter for the purposes of probing the occlusion is a breach of the standard of care required of an ordinary skilled vascular surgeon.

45 Before going further, it is appropriate to deal with a pleading point raised by the respondents. They contend the appellant did not plead that the second respondent was negligent in failing to perform an angiogram and in failing to diagnose an acutely occluded popliteal artery. Although that is correct, the issues were in substance joined and litigated in the action and required determination notwithstanding the absence of a formal amendment to the pleadings: see Water Board v Moustakas [1988] HCA 12; (1988) 180 CLR 491 at 496, 497.

46 There is a further step in the trial Judge's analysis and that concerns the appropriateness and results of "surgical" intervention. She addresses that issue correctly, in my view, in the context of causation.

47 Different legal principles may apply if the issue is related to whether there is a breach or whether the breach caused the damage. When considering whether there has been a breach, knowledge obtained in hindsight (that is, not available at the material time) should form no part of the assessment of what is reasonable in all the circumstances: Rosenberg v Percival [2001] HCA 18; (2001) 205 CLR 434 at 441 per Gleeson CJ and 456 per Gummow J. That principle has no application to the question whether the breach caused the damage. However, for the purposes of determining whether there has been a breach, regard can properly be had to what the respondents knew or ought to have known. That includes matters which they would have known if an angiogram had been undertaken on 25 September. To the extent that, as stated by Mr Milne, the results of the angiograms conducted in 2000/2002 are indicative of what an angiogram conducted at the relevant time would have disclosed about the nature of the occlusion, that is not hindsight. In any event, the nature of the injury would be ascertained from the use of the wire in the way indicated by Mr Milne.

48 Where, as here, causation arises in the context of an omission, the correct approach is described by Gaudron J in Bennett v Minister of Community Welfare [1992] HCA 27; (1992) 176 CLR 408 (at 422 - 443) as follows:

"... where questions of causation depend on hypothetical considerations, allowance should be made, as in the assessment of damages, for the possibility that some event would not have occurred. Possibilities, if they are not fanciful, must be taken into account, at least in a general way, when ever causation or the related issue of prevention is in issue. But questions of that kind are not answered 'maybe' or, even, 'more probably than not'. They are answered 'yes' or 'no' depending on the probabilities for or against. In this respect, they are indistinguishable from the question whether an event happened where possibilities are taken into account but, once the question has been answered, those possibilities have no further bearing on the matter."

49 If an injury occurs within an area of foreseeable risk, then, in the absence of evidence that the breach had no effect, or that the injury would have occurred even if the duty had been performed, it will be taken that the breach of the common law duty caused or materially contributed to the injury: Bennett v Minister of Community Welfare at 420 - 421; Chappel v Hart (1998) 195 CLR 232 at 257 per Gummow J, 273 per Kirby J; Naxakis v Western General Hospital at 279 per Gaudron J.

50 The trial Judge found that there were, relevantly, three possible types of surgical interventions, being, in order of increasing degrees of invasiveness, aspiration of the clot (in the course of conducting the angiogram), use of a Fogarty catheter or bypass surgery. The trial Judge found that it would not have been appropriate to attempt to bypass. There is no challenge to that finding. On the question of causation, the trial Judge's reasons are as follows (at [298] to [300]):

"However, the second [respondent] should have performed an angiogram and should have assessed, from the result of the angiogram, the prospects of achieving a positive result from the use of the Fogarty catheter or aspiration. I cannot say whether the results of the angiogram would have been such to justify surgical intervention. Further, after considering all the evidence I am not satisfied that it can be said that the second [respondent's] failure to perform the angiogram and intervene has caused the [appellant's] injuries.

At the time the [appellant] developed ischaemia he had at least a 50 per cent chance of losing his leg whether or not there was surgical intervention. The conservative treatment has resulted in him keeping his leg. There is no doubt he has suffered damage to his leg as a result of the fasciotomy not healing. There is however insufficient evidence before me to prove that those injuries would have been avoided if the second [respondent] had attempted surgical intervention some time after the duplex scan result was obtained. First, revascularising the leg would have led to a greater chance of compartment syndrome occurring through reperfusion. Secondly, if as I accept the leg was gradually becoming ischaemic throughout 24 September and was ischaemic at around 10.30 am on 25 September, the damage to the plaintiff's muscle had in all likelihood occurred by the time the second [respondent] was in a position to revascularise the leg. Thirdly, I accept that any of the techniques that were available to the second [respondent] to use in an attempt to revascularise the leg carried with them their own risks of serious damage to, and even loss of, the leg. These risks were referred to by the second [respondent] and also by Mr Lawrence-Brown who regarded them as significant enough to warrant a vascular surgeon deciding not to intervene to revascularise a leg.

I also accept the possibility that if an angiogram had been performed it may have revealed to the second [respondent] an occlusion that could not be safely removed. For example, he may have decided that there was such a suspicion that the clot was blocking a hole in the artery that an attempt to remove it was fraught with too much danger. The real possibility that an angiogram and preliminary investigations may have revealed a situation that could not be improved was recognised by Mr Milne and certainly by Mr Lawrence-Brown."

51 The trial Judge concluded that she was not satisfied on the balance of probabilities that the failure to conduct an angiogram caused the appellant's injuries. There is no merit in the contention that the trial Judge gave inadequate reasons for her conclusion on causation. They meet the functions and purposes they are required to serve (see Tran v Claydon [2003] WASCA 318 at [35] - [37]).

52 The opening sentence of the third paragraph above has the potential to be misleading. If it is intended to suggest that the prospects of the appellant losing his leg after the onset of acute ischaemia would remain the same regardless of surgical intervention, the evidence does not support such a finding. The evidence goes no further than that the appellant had a 50 per cent chance of losing his leg if nothing was done.

53 There are four strands in the trial Judge's analysis that need to be untangled. The first relates to the likelihood of surgical intervention if an angiogram had been performed; the second to the prospects of the intervention being successful; the third to the likelihood of progressive damage; and the fourth is whether, if the occlusion could have been removed and blood flow re-established, compartment syndrome would have been avoided. This arises because most of the personal injuries the subject of the claim are directly related to the consequences of the compartment syndrome and the surgery (fasciotomy) to address that problem.

54 Starting with the first two strands. Although the trial Judge found that the second respondent ought to have conducted an angiogram and explored the nature of the occlusion (by placing a wire down the catheter), she said she was unable to conclude whether the results of the angiogram would have been such as to justify surgical intervention or what the prospects of achieving a positive result from an attempt to aspirate the clot or the use of a Fogarty catheter would be, having regard to the risks identified by Mr Lawrence-Brown.

55 Mr Milne's evidence was that the post-arthroplasty angiogram reinforced his impression that the arterial injury was relatively minor in terms of anatomical disruption, that the cause of the anaemia was largely a thrombotic event and therefore would be more than likely amenable to endovascular technology to alleviate it such as sucking the clot out at the time of the angiogram. This evidence supports a finding that aspiration was appropriate and would on the balance of probabilities have been successful. The conclusion is consistent with Professor Nade's evidence referred to earlier. Further, although Mr Lawrence-Brown referred in general terms to the risks of aspiration, he did not quantify the risk or state that it justified inaction if his assumptions that justified conservative action were misplaced. The mere identification and existence of the possibilities on which the trial Judge relies does not answer the relevant question which is whether the breach did, on the balance of probabilities, cause the damage.

56 In my view, it was open to the trial Judge and the weight of the evidence supports a finding that, on the balance of probabilities, the nature of the arterial injury and the cause of the occlusion (thrombus) was such that it could have been successfully aspirated in the course of the angiogram.

57 The third strand relied on by the trial Judge was that progressive ischaemia would have resulted in damage to the leg by the time the second respondent was in a position to revascularise it. I assume that is shortly after the receipt of the results of the duplex scan and ABI. There is no evidence to support a finding (and no finding made) that irreversible damage had occurred to the appellant's muscle by around 4.30 pm on 25 September. The evidence is to the contrary. Irreversible damage can occur after six to eight hours from the onset of acute ischaemia. There were no indications of ischaemia at 7 am when the appellant was reviewed by the first respondent. The first indications were at 10 am on 25 September and the symptoms were acute by about 1 pm on that day. There is no reasonable basis for a finding that irreversible damage had occurred by the time the second respondent ought to have acted.

58 The next issue is whether the failure to intervene and restore blood flow caused or materially contributed to the compartment syndrome. The trial Judge accepted Mr Lawrence-Brown's evidence that the appellant's compartment syndrome was caused by the acute ischaemia precipitated by the occlusion of the popliteal artery. There is no challenge to that finding.

59 The trial Judge relies on the risk of compartment syndrome from reperfusion. There is no evidence that the risk of reperfusion-caused compartment syndrome was such as to justify inaction. Mr Lawrence-Brown's evidence was that it was necessary to be alive to, and watch for, symptoms of the syndrome but that it is uncommon to get compartment syndrome where blood flow is re-established in an acute situation. In this case, the trial Judge noted that the care and attention given by hospital staff to the appellant on the evening and night leading to the development of compartment syndrome was inadequate. The weight of the expert evidence (and that of the second respondent) was that active intervention was the normal course in the case of an acute occlusion. That being the case, it is more likely than not that restoration of blood flow could be achieved without causing compartment syndrome.

60 It was not suggested that the failure to re-establish blood flow within a reasonable time after 4.30 pm on 25 September did not increase the risk of developing ischaemia-caused compartment syndrome. Further, I do not understand the second respondent to contend that the injuries could not be relevantly caused by the negligent omissions if (as is the case) the purpose of the active management contended for was to save the leg which was achieved by natural means. That would seem to be consistent with Chappel v Hart (1998) 195 CLR 232.

61 I am satisfied that the weight of the evidence justifies a finding that the breaches by the second respondent caused the injuries the subject of the action.

62 The pleaded breach is to the effect that the first respondent failed to have due regard to the appellant's leg symptoms on 24 and 25 September 1998 which required investigations and/or surgery to restore blood supply.

63 The trial Judge's findings are as follows (at [275]):

"I find that once the first [respondent] had obtained the second [respondent's] opinion he was almost bound to follow the second [respondent's] advice with respect to vascular treatment as he was the expert. I accept Professor Nade's view in this regard. I do not accept that the first [respondent] could not question the second [respondent's] proposed treatment and it is a mystery to me why there was not further discussion between them as to possible treatment to increase the [appellant's] chances of keeping his leg and avoiding complications of the ischaemia. Nonetheless I am not persuaded that the first [respondent's] reliance upon the second [respondent's] advice which was not to surgically intervene, was negligent."

64 In dismissing the claim against the first respondent, the trial Judge also relied on her conclusion that the second respondent was not negligent in failing to investigate and surgically intervene. The second ground for dismissing the claim against the first respondent falls away.

65 The first respondent's evidence was that in his conversations with the second respondent on the afternoon of 25 September the second respondent said he thought the appellant's ischaemia was due to old trauma and that he did not think a bypass was a viable option. The first respondent said he accepted the second respondent's view because, in his opinion, the vascular management of the appellant was the second respondent's responsibility. Further, because he was of the view that vascular management was the second respondent's responsibility, he did not explore other options with the second respondent as to the treatment of the ischaemia or question the second respondent's opinion or institute any vascular treatment of his own. The first respondent did not give his opinion as to the cause of the ischaemia or the compartment syndrome.

66 There are obvious difficulties with the first respondent's evidence concerning his alleged transfer of responsibility for the vascular management for the appellant to the second respondent. The second respondent ordered Clexane and that was countermanded by the first respondent. The first respondent reviewed the appellant with the second respondent at around 4.30 pm and then later that evening. It was the first respondent who took responsibility for, and carried out, the fasciotomy in the early hours of 26 September.

67 Further, it is evident from the extent of the evidence of the orthopaedic surgeons, Professor Nade and Mr Hill, that the identification of the existence and cause of vascular problems following orthopaedic surgery is within the skill and expertise of an orthopaedic surgeon. That is to be expected having regard to the trial Judge's finding that there was a five per cent risk of serious thrombosis following arthroplasty. Further, it was the first respondent who had a great deal of information obtained before, during and after the surgery that was relevant to an assessment of the cause and nature of the ischaemia. For example, his pre-operative work-up did not disclose arterial insufficiency or anaemia, there was no bleeding during surgery which would indicate that an artery had been cut and, finally, on the morning of 25 September there were no symptoms of ischaemia.

68 In addition, Professor Nade's opinion is an inadequate foundation for a conclusion that the first respondent was bound to follow the second respondent's advice. In particular, Professor Nade's evidence is not to the effect that the first respondent was bound to follow the second respondent's "advice" with respect to vascular treatment. The clear thrust of his evidence is that it is preferable for the surgical procedures (that is, treatment, including a fasciotomy) to be carried out by a vascular surgeon. That falls well short of being almost bound to accept the vascular surgeon's assessment of the cause of the problem which, as the trial Judge found, dictated his action in this case.

69 In the circumstances as they occurred, the appellant should have had the benefit of the two specialists applying themselves to the issues and contributing to the assessment. The first respondent made no contribution. He had personal knowledge of matters relating to the cause of the occlusion. It can be inferred that the first respondent would know, like Professor Nade, that the usual treatment for an acute ischaemic event was an angiogram and active intervention. If he had acted reasonably, he would at the time of the 4.30 pm consultation have raised with the second respondent the relevant facts of which he was aware and the reasonableness of the second respondent reaching and acting on the conclusion that the occlusion was chronic without going the next step and obtaining an angiogram. There is no reason to believe that a professional colleague such as the second respondent would refuse to review or alter his position if cogent information was provided by the first respondent. It is unnecessary in this case to determine who has the ultimate responsibility in the event of a difference of opinion as to the appropriate course of action. I am satisfied that the first respondent was negligent in abdicating his shared responsibility to assess the appropriate response to the acute ischaemia.

70 The claim the subject of this ground of appeal was not pleaded. However, it was raised in closing as a result of evidence given by the first respondent to the effect that he offered to perform the total knee replacement surgery because he thought the applicant was severely disabled; in particular, he thought the appellant had constant, severe pain and a useless limb. The appellant contended in closing that the first respondent negligently overestimated his disability, the leg not being as severely disabled as the first respondent understood. The appellant says the trial Judge erred in failing to draw the inference that, if the first respondent had understood the appellant's actual degree of disability, he would not have offered the surgery to the appellant.

71 This goes beyond the question of the technical availability of the surgery. It goes to the question of whether a medical practitioner, having (as the trial Judge found) warned the patient of all of the relevant risks, should go further and, in effect, remove the decision-making from the patient because of a personal view that the risks outweigh the potential benefit of the procedure.

72 However, it is unnecessary to address that novel question because I am not persuaded that the issue was in substance joined and litigated by the parties such as to require determination (Water Board v Moustakas (above)). If it had been, the first respondent would have had the opportunity to give direct evidence on the issue. Further, what the trial Judge found as to the extent of the appellant's disability is not determinative. It is relevant to know whether the first respondent had reasonable grounds for his assessment, based on the history given to him by the appellant and his observations.

Gentamicin Damages - Appeal and Cross-Appeal

74 The trial Judge assessed damages at $131,846 for the admitted liability in respect of the negligent administration of gentamicin as follows:

Past Loss of earnings $ 7,751.00

Interest thereon $ 465.00

Future Loss of earnings $ 13,500.00

Past Gratuitous and paid services $ 20,465.00

Interest thereon $ 1,228.00

Future Gratuitous and Paid Services $ 26,437.00

Special Appliances $ 2,000.00

Home modifications $ 10,000.00

Rest and Recreational needs $ 10,000.00

General damages $ 40,000.00

Total $131,846.00

75 The appellant developed symptoms of giddiness, vertigo, imbalance, nausea, hearing loss and tinnitus as a result of gentamicin-induced toxicity. The effects are permanent and nothing can be done to alleviate them beyond teaching the appellant to be more dependent on other senses to help compensate for the loss of balance. In addition, failure of concentration can result in the breakdown of the compensatory mechanisms. It is more difficult for the appellant to walk, particularly if tired or distracted. The condition also affects his ability to negotiate steps and drive, particularly when tired, distracted or at night.

76 The appellant now uses two crutches to walk. But for the effects of gentamicin, the appellant would have learned to walk again without crutches. The use of crutches has resulted in symptoms in the appellant's wrists, arms and shoulders.

77 The appellant has a prosthetic left leg, and stiffness and foot drop in his right leg. Physical balance is difficult for him. These problems are exacerbated by the gentamicin-caused vestibular injuries. That is significant because damages depend on the consequences of the injuries for the individual rather than their anatomical nature: Halley v Chudleigh [1963] ALR 616 at 619. However, the trial Judge had regard to all of the relevant factors, including the impact of the compensable injuries in the context of his existing disabilities. I am not persuaded the award of $40,000 for general damages is so far outside the permissible range as to be manifestly inadequate or disproportionate to the injuries received (see Sharman v Evans [1977] HCA 8; (1977) 138 CLR 563 at 565).

78 The appellant and the second respondent challenged the award of damages of $21,251 for past and future loss of earning capacity. The appellant contends it is manifestly inadequate and the second respondent contends there was no, or no sufficient, evidence to warrant awarding any damages under this head.

79 As the trial Judge observed, she had difficulties differentiating between the appellant's problems related to his landmine injuries and the arthroplasty and its complications as opposed to the antibiotic-related injuries. The evidence relating to damages did not clearly differentiate between the gentamicin-related effects from the other causes. Although this made the Judge's task difficult, mere difficulty in making an assessment does not relieve the Court of its duty to do so. However, the difficulties make it harder for the appellant and the respondents to successfully challenge the award.

80 In May 2000, after his arthroplasty-related injuries but before the gentamicin-caused injuries, the appellant elected to seek early retirement from his then employer, the Department of Commerce and Trade. He retired from that employment on 25 August 2000.

81 The second respondent relies on the fact that Dr Merrick, a rehabilitation specialist called on behalf of the appellant, did not expressly attribute any loss of earning capacity to the effects of the gentamicin. The absence of expert evidence does not prevent an award for loss of earning capacity. The evidence was, and the trial Judge found, that although the appellant gave up his employment with the Department of Commerce and Trade on 25 August 2000 as a result of the arthroplasty-related injuries, he continued to work from home undertaking part-time consultancy work. The appellant has tertiary qualifications, is well motivated, determined and articulate. He was highly thought of by his previous employers. The trial Judge found that the gentamicin effects reduced the appellant's earning capacity by, inter alia, reducing his speed, mobility and concentration, as well as the amount of time he was able to devote to his consultancy. The finding is clearly open and reasonable.

82 The trial Judge concluded that the gentamicin-related disabilities resulted in a 20 per cent diminution in earning capacity which had already been greatly reduced after the arthroplasty. She expressed this in dollar figures by saying that, were it not for the injuries, the appellant would have been able to earn 20 per cent more than he actually earned. The Judge used the appellant's income for the year ending June 2001 (adjusted to reflect that he only had the gentamicin injuries for 83 per cent of that year) as the basis of the calculation for past and future loss of earning capacity. I am not persuaded there is any methodological error in the approach.

83 The appellant and the second respondent also challenge the award for paid and gratuitous services (past and future), home modifications and rest and recreation needs. The appellant additionally challenges the award for special appliances and future medical treatment. The appellant's challenge is based on a number of matters, the first of which relates to the Judge's rejection of a claim that the gentamicin injuries would result in the appellant using a wheelchair earlier than he otherwise might. The Judge said she was not persuaded the need for a wheelchair was caused by the appellant's antibiotic-caused injuries as opposed to his landmine injuries or his arthroplasty complications. She did not make a finding that polyarthralgia in his arms and shoulders would be aggravated by crutches so that he would not be able to use them and would have no alternative but to use a wheelchair. She accepted a rolled-up submission to that effect for the purposes of considering whether the use of a wheelchair would affect the appellant's earning capacity. The appellant's remaining submissions in relation to these matters are in the nature of assertions.

84 The respondents, on the other hand, rely on the failure of the evidence as a whole to isolate the effect, if any, of the gentamicin-related

injuries. I am satisfied that those injuries do materially add to the extent of the appellant's requirements for the services and other needs. However, having regard to the obvious difficulties in quantifying these matters, I am not persuaded that either party has demonstrated appealable error. I would dismiss the appellant's challenge to the assessment of damages and the second respondent's cross-appeal.

85 I would allow the appellant's appeal on liability, dismiss the appellant's appeal from the assessment of damages and dismiss the cross-appeal. I would hear from the parties as to whether the matter can be remitted to the trial Judge, Jenkins J, for an assessment of damages.

86 LE MIERE AJA: This is an appeal from a judgment of a Judge of the District Court in an action in which the appellant claimed damages for personal injuries. The appellant alleged he received the injuries as a consequence of the negligence of the respondents in connection with right knee replacement surgery that the first respondent performed on 24 September 1998. Each of the respondents denied that he was negligent except that the second respondent admitted liability in respect to the negligent administration of the antibiotic, gentamicin, for the period 3 August to 3 October 2000. The learned trial Judge concluded that the appellant had not established any of the allegations of negligence other than the negligent administration of gentamicin by the second respondent. The learned trial Judge ordered that the appellant's claim against the first respondent be dismissed and there be judgment for the appellant against the second respondent in the sum of $131,846.

87 In the principal appeal, FUL 111 of 2003, the appellant appeals against the findings of the trial Judge that the appellant had not proved any of the allegations of negligence other than the negligent administration of gentamicin by the second respondent. The appellant submits that the learned trial Judge should have found that each of the respondents was negligent in the post-operative treatment of the appellant. The appellant submits that the judgment should be set aside and there should be judgment for the appellant against the respondents for damages to be assessed. The appellant further appeals against the award of damages made by the learned trial Judge in relation to the negligent administration of gentamicin. The appellant submits that the damages awarded were inadequate and below the range of a sound discretionary judgment.

88 The respondents' cross appeal on a number of grounds that collectively argue that the damages awarded in respect of the negligent administration of gentamicin were excessive.

89 In appeal FUL 12 of 2004 the appellant raised two issues. One concerned the learned trial Judge's award of costs. The second was in substance whether the learned trial Judge had jurisdiction to amend par 276 of her reasons and issues about the manner in which her Honour made the amendment. The appellant did not pursue that appeal and it is not necessary to say anything further about it.

90 The following facts were found by the trial Judge and are not challenged on appeal or are clearly established by the evidence and not in dispute.

91 The appellant was born on 22 February 1945. He joined the Royal Australian Army in 1964. He was posted to Vietnam as a Second Lieutenant. On 28 August 1967 he stepped on a landmine and suffered injuries to both his legs. His left leg was initially amputated at the knee. Later it was amputated above the knee to enable a prothesis to be more easily attached to it. The appellant also suffered permanent injuries to his right leg. His right knee was left with only a few degrees of flexion and he lost half his right calf muscle. Multiple pieces of shrapnel and other material remain within his right leg.

92 The appellant was repatriated to Perth and in 1968 he resumed normal duties with the Army. Over the next few years the appellant had two children to his first wife and graduated with a Bachelor of Commerce from the University of Western Australia. In the early 1970s the appellant was posted to Canberra. In 1973 he resigned his commission as a captain in the Army.

93 By this time he was able to walk using a prosthesis on his left leg and no other aids. Between 1973 and 1998 the appellant had a number of different occupations including working for the Swan Brewery as a market research manager and periods running his own liquor store and a tavern. By 1998 the appellant was working for the Western Australian government in the Department of Commerce and Trade as a Level 7 manager. This employment required the appellant to travel throughout the State and Australia, which he managed to do.

94 Throughout this period the appellant suffered varying amounts of pain in his right knee. Now and again he asked doctors whether there was any advancement in medical technology that would enable something to be done about his problems in his right knee. Up until 1997 the answer was "no" but at that time he asked a doctor and the doctor suggested that the appellant see the first respondent about having an arthrodesis, that is surgery to fuse the knee joint. The appellant saw his general practitioner who referred the appellant to the first respondent asking the first respondent to speak to the appellant about options for his knee.

95 The first respondent is the Professor of Orthopaedic Surgery at the University of Western Australia and is a consultant at Hollywood and Sir Charles Gairdner hospitals. He is a very well qualified and experienced orthopaedic surgeon.

96 The appellant consulted the first respondent on 2 September 1998. The appellant told the first respondent that pain would result from long standing and then the knee flexing. The appellant said that he coped with the swelling and pain by lying down and elevating the leg. The appellant said that after about 20 minutes of elevation the foot would become painful. The appellant said that he was exploring having the knee fused to prevent any flexion and thereby hopefully prevent any pain.

97 The first respondent told the appellant that a total knee replacement was an alternative to a fusion. The first respondent gave the appellant a booklet entitled "Total Knee Replacement Information Book" ("the booklet") which is a standard Hollywood Hospital publication for arthroplasty, that is joint replacement, candidates. The booklet explains that more than 90 per cent of arthroplasties are trouble free and successful. It states that in 5 per cent of patients the results are not satisfactory and that some complications can be put right by further surgery and some may not. Immediate complications include death (in about 1 per cent of patients), major post-operative illness such as pneumonia, reaction to drugs or some other generalised problem. There is no specific reference to vascular complications. The booklet says that thrombosis, that is the formation of a blood clot, in the leg occurs in between 25 to 50 per cent of patients but is usually trivial and can be ignored. Serious thrombosis, with major problems in the leg or in the lungs, occurs in about 5 per cent of cases. Death from thrombosis, or from fat getting into the bloodstream, or from a heart attack, or from some other reason occurs in about 1 to 2 per cent of patients having a knee replacement.

98 The first respondent did a neurovascular examination that included looking at the muscles and a vascular examination that involved feeling the pulses. The relevant pulses are the pedal pulses and the popliteal pulse. There are two pedal pulses. One is called the distalis pedis, which is in the front of the ankle bone. The other is called the posterior tibial, which is immediately behind the ankle bone. The popliteal pulse is in the popliteal artery which runs behind the knee. All three pulses can be difficult to palpate, that is perceive by touch, even by experienced practitioners. The first respondent found the pedal pulses and the popliteal pulse to be present.

99 The first respondent said that prior to a decision whether or not to have the operation the appellant would need to undergo some further tests. One of the tests was to check out the condition of the bone at the joint and the other test concerned the skin at the back of the knee. As a result of the landmine explosion the skin was adhered to the back of the knee and the first respondent was concerned that that skin would not rupture when the knee was flexed. The first respondent referred the appellant for an MRI scan and a consultation with Dr Fiona Wood, a plastic surgeon, for an opinion as to the relative value of a flap to use as a skin graft over the surgical incision and the possibility of cultured skin to improve his healing after an arthroplasty. This request was for an opinion about the value of the skin the first respondent thought he may need to use to close the surgical incision and not a request related to the general sufficiency of the vascularity of the appellant's right knee for surgery.

100 The first respondent also undertook, or arranged for, investigations to ascertain whether there would be a metal mismatch and electrolysis between the shrapnel in the appellant's leg and the metal used in the replacement knee.

101 A second consultation between the appellant and the first respondent took place on 11 September 1998. The first respondent informed the appellant that the metals remaining in his right knee were not incompatible with those in the proposed replacement knee and that the scans and x-rays had revealed that the operation was feasible. The first respondent mentioned to the appellant that he was at greater risk of complications because of the existing injuries to his right leg.

102 The first respondent considered that the vascular examination of the appellant was normal and therefore there was no need to get a vascular opinion. The first respondent considered but did not explore the possibility that the appellant may have had arterial disease because he looked in the notes of the Department of Veteran Affairs on the appellant to see if there was any indication that he had had popliteal artery damage and found none. He also could feel the appellant's pulses. Further, he was given no history of arterial disease. The first respondent did not offer the appellant an arthroplasty at the time of the second consultation. He was still awaiting the opinion of Ms Fiona Wood.

103 On 17 September 1998 Ms Wood gave an opinion. She said that she did not think that an arteriogram (also called an angiogram), that is radiographic exploration of the arteries, was necessary as the flap should not affect the vascularity of the area.

104 During a telephone conversation between the appellant and the first respondent prior to 23 September 1998 the first respondent offered an arthroplasty to the appellant and the appellant said that he wanted to proceed with the surgery.

105 The appellant was admitted to hospital on 23 September 1998. On the morning of 24 September, the first respondent performed an arthroplasty on the appellant's right knee. The surgery itself was relatively uneventful. The surgery was performed under an epidural anaesthetic which remained in place upon the appellant's return to the ward. This was to enable the appellant to receive anaesthetic pain relieving medication following the surgery. After surgery the appellant's pedal pulses were palpable and recorded as being strong. The appellant's right knee was on a continuous passive motion ("cpm") machine. This moved the appellant's right leg in an arc of 30 to 60 degrees.

106 In accordance with the usual procedure, upon the appellant's return to the ward a vascular observation chart of his right leg was kept by the nursing staff. On the morning of 24 September the first entry records the pedal pulses as faint. Then through to 2.00 pm the appellant's pedal pulses were recorded as strong. At 3.00 pm they are recorded as faint. The vascular observation chart also records observations of skin colour, skin temperature, sensation, movement and a pain score. At all relevant times the appellant was receiving epidural pain relief and the epidural drugs may have affected his appreciation of pain. However, the recorded observations tended to a conclusion that despite the presence of epidural pain relief the appellant was experiencing pain in his knee or leg.

107 The observations of the pedal pulses being faint, even when measured with a Doppler, continued from 3.00 pm on 24 September through to 9.00 pm that evening. A Doppler is a hand held instrument used to examine the blood flow in arteries and veins in the leg using ultrasound. No observations of the pedal pulses were recorded between 9.00 pm on 24 September and 2.10 am on the morning of 25 September. At that time the pedal pulses were again recorded as being faint with Doppler. There is no further recording until 4.50 am when the words "very hard" and "Doppler not available" are recorded on the chart. The words "very hard" mean that the nurse found the pedal pulses very hard to find by palpation because they were either very faint or absent. The next recording on the vascular chart is at 6.10 am. At that time there is no entry for the pedal pulses.

108 The first time the first respondent saw the appellant after surgery was at approximately 7.00 am on 25 September. The appellant told the first respondent that the leg was very comfortable. The first respondent adjusted the angle of the cpm machine so that it was further flexing the knee. The first respondent felt the appellant's pulses and they were present. The first respondent thought that the appellant had venous return and his foot was warm. In his evidence, the first respondent said that if the pedal pulses were able to be palpated then this would have amounted to an ABI (ankle brachial index) of about 1 which is normal. It was his view that whether or not the pulses were hard to palpate or faint was irrelevant as long as they were present and there were other positive signs such as venous return and warmth. The first respondent was not told by the appellant, the nursing staff or the junior doctors of any problems.

109 The next entry in the vascular chart on 25 September is at 10.00 am when it is noted that the toes were cool, there was 3 out of 10 pain on movement and the pedal pulses were absent. The epidural nursing notes indicate that that level of pain continued until 12.45 pm when the pain was 10 out of 10 on movement. Dr Boris Brankov, a registrar and resident medical officer, was informed. There are entries for 10.30, 10.50 and 10.55 am. However, at these times there are no observations regarding colour, temperature, movement, sensation and pain. There are two entries recording that the pedal pulses were again absent. Dr Brankov felt the popliteal artery and heard it on Doppler. The popliteal artery runs down the back of the leg from approximately two-thirds of the way down the femur. It continues behind the knee joint and below the knee it bifurcates into the anterior tibial artery and the posterior tibial artery. The posterior tibial artery quickly gives off another branch called the peroneal artery. The palpation of a pulse in the popliteal artery is not inconsistent with a blockage in the popliteal artery if Dr Brankov felt the popliteal pulse above the blockage. The learned trial Judge found that that is what occurred.

110 Dr Brankov did not inform the first respondent at this time of any problem with the appellant's right leg.

111 The hospital notes record that on 25 September at noon and 1.00 pm the colour of the appellant's leg was pale, toes cool, movement present, sensation absent and pedal pulses absent.

112 At approximately 1.00 pm the nursing staff rang the first respondent whilst he was in the operating theatre at Hollywood Hospital and advised him that the appellant was in excruciating pain. The first respondent sent Dr Brankov to see the appellant. Dr Brankov examined the appellant. Dr Brankov reported back to the first respondent that he was concerned about the blood supply to the appellant's leg and he thought that it might be ischaemic, that is affected by insufficient blood supply. The first respondent told Dr Brankov to get a specialist vascular opinion, preferably from the second respondent.

113 The second respondent is a surgeon practising in general and vascular surgery. He is a consultant at Hollywood Hospital. He is a very well qualified and experienced surgeon. His specific areas of interest include collateral circulation and stimulation of the collateral circulation.

114 Within an appropriately short period of time the second respondent examined the appellant. There is a written referral to and reply from the second respondent on the hospital file. The request to the second respondent was to "review his vascular supply to the lower leg, if it has been compromised?" When the second respondent first examined the appellant's leg in the afternoon it was white and cold. There was a lack of movement, sensation and no pedal pulses. His view was that because the appellant had a popliteal pulse and no pedal pulses there had to be discontinuity of blood flow between those two levels. To find out the nature and extent of that he suggested a duplex scan. The written reply of the second respondent dated 25 September states as follows:

"I suspect that he has major arterial discontinuity in the calf from his old injury.

Suggest:

1. Duplex scan and ABI.

2. Keep foot down.

3. Clexane 40 mgm bd.

Microvascular thrombosis after protracted elevation is a real possibility and must be prevented at all costs."

115 Dr Brankov reported to the first respondent that he had put the leg down flat and that he was organising the duplex scan. A duplex scan is a diagnostic ultrasound examination. The first respondent told Dr Brankov not to implement the Clexane treatment until the first respondent had reviewed the appellant. This was because the first respondent was concerned about the effect of Clexane, an anticoagulant, on the epidural site. Whilst an epidural is in place Clexane may produce bleeding at the epidural site.

116 The hospital notes record that at 2.00 pm the colour of the appellant's leg was pale, the temperature warm, movement present, sensation absent and no entry for the pedal pulses and a remark that there was popliteal on Doppler.

117 The appellant had the duplex scan in reasonable time some time after 2.00 pm. The person who conducted the scan provided a report. The report says, in effect, that the superficial femoral artery, the main artery to the leg, and the first part of the popliteal artery were of normal calibre and size and had a normal wave form, suggesting they had normal soft walls. There was fairly minor arterial disease present in the middle section of the popliteal artery, causing a 40 per cent narrowing of its calibre. At the end of the popliteal artery, it was completely blocked. There was no blood flow within all three of the main arteries to the leg below the knee. Collateral vessels, known as the geniculate vessels, which are the small arteries around the knee, were pitted. There was flow reconstitution in the right posterior tibial artery at the ankle joint. The report commented on the different wave form created by perfusion, that is a flow of blood to reach tissue, by collateral blood vessels and there was no arterial flow. If blood flow was not restored to the ischaemic tissue the tissue would die.

118 The radiologist advised the second respondent by telephone of the results of the duplex scan because of "the gravity of the findings". The second respondent's provisional treatment was to put the leg down in order to use gravity to encourage blood flow and to suggest anticoagulant treatment, that is Clexane.

119 The second respondent regarded his suggested treatment as a standard, conservative course. He discussed it with the first respondent around 4.30 pm. The second respondent acknowledged that there were complications with using Clexane as it may result in bleeding into the site of surgery and in the epidural space if the appellant still had an epidural catheter inserted. The second respondent considered that it was not up to him to decide whether, for example, to remove the epidural catheter as the appellant was not his patient, he was only providing a vascular opinion.

120 The second respondent explained his reference to microvascular thrombosis in his written note to be a reference to thrombosis of the smaller arteries coming from the tibial arteries. He said that once thrombosis occurred in these arteries and eventually also on the venous side there was an irretrievable situation. I take that to mean irreversible loss of blood flow to the tissue leading to death of the tissue. He said that this process occurred within hours.

121 The learned trial Judge found that this is consistent with the second respondent believing that the popliteal artery was chronically occluded and therefore placing importance on the collateral system.

122 As to whether it was appropriate to surgically intervene, the second respondent gave evidence that he thought that the only way to save what was not irretrievably damaged in the leg, was by a conservative approach. This was because the benefit he saw in surgical intervention was zero and the risk was very high. He thought that the benefit was zero because at the time what was damaged was already damaged irreversibly because of the 30 hours or thereabouts time lapse since the arthroplasty. Nerve and muscle which had been deprived of blood would have only survived for six hours once the blood flow was stopped. The risk he regarded as high because it would have required a surgical incision behind the knee straight through the area where the collaterals existed which in his view were sustaining the leg. He believed the result of that would have been that the appellant would have lost his leg because it would have divided his collaterals which were the only vessels that sustained the leg in the presence of the tibial artery occlusions.

123 As for bypass surgery, that is surgery to bypass the occluded area, the second respondent said his view was that as the duplex scan indicated there was reconstitution of flow within the posterior tibial artery at the ankle joint the bypass would have had to have been plugged in at the ankle. His view was that this would have had the result of saving his foot but losing the calf as the surgery would have required a cutting of the collaterals which supplied blood to the calf.

124 The second respondent said he gave consideration to a Fogarty catheter, which is a tube with a balloon on the end which is able to be passed down an artery and inflated and used to retrieve thrombotic material. The second respondent said that a Fogarty catheter is fairly rigid and will only go down an artery and will not traverse vessels. Therefore in this situation he considered that it would be necessary to insert it into the popliteal fossa behind the knee in order to approach the smaller vessels. However, this would not have cleared the thrombotic material in the tiny branches and microvascular system. He said that is why it fails after a few hours. He also referred to the complication of arterial damage from the catheter itself.

125 With respect to the use of a catheter to aspirate the clot in the popliteal artery, the second respondent said that "we" have not had particularly good results with the use of the method. He referred to the large diameter of the catheter and the fact that it had similar limitations as the Fogarty catheter.

126 The second respondent said he also considered the use of clot dissolving treatment as opposed to anticoagulant treatment which prevents further clotting. However, he dismissed this because of the risk of "torrential haemorrhage" at the site of the operation.

127 The first respondent left the operating theatre at about 3.30 pm and tried to find the appellant but at that time he was undergoing the duplex scan.

128 At 4.00 pm an observer recorded that the colour of the appellant's leg was pink, temperature warm, movement present, sensation absent and the columns for pedal pulses and remarks are blank.

129 The second respondent saw the appellant for a second time after he received the results of the duplex scan at approximately 4.30 pm and again at around 6.00 pm.

130 During the 4.30 pm consultation the second respondent thought that there had been a slight improvement in the perfusion of the leg in that the colour was somewhat better and the pain was somewhat less.

131 The first respondent was present during the 4.30 pm consultation. After reviewing the written advice of the second respondent the first respondent discussed the appellant with the second respondent. The second respondent advised the first respondent that he was concerned about the appellant's leg in that the duplex scan had shown no run off but that a bypass operation in his view was contraindicated.

132 The hospital notes record that at 4.45 pm the first respondent gave instructions to cease the cpm machine and only to commence Clexane after the epidural and other drains had been removed. The notes also record a requirement for "regular neurovascular obs 4 hourly" on the right leg. The first respondent also gave instructions to elevate the head of the bed above the heart at night and to use a space blanket. This was to keep the leg warm. The note concludes with "review in am". After leaving the instructions, the first respondent considered that he had done all that was required at that time.

133 At 5.30 pm the colour is recorded as pink, toes cool, movement slight, sensation absent, pain nil and the pedal pulses were faint with Doppler. Underneath the words "toes cool" was written the word "warm". The learned trial Judge found that comment to relate to the leg generally. There were no observations recorded on the vascular chart between 5.30 pm and 11.00 pm.

134 During the course of the evening of 25 September the appellant's condition deteriorated. The pain increased substantially. At 11.00 pm the vascular chart has no entry in the pain column but notes that the pedal pulses are absent with Doppler. At midnight the vascular chart notes that the pain is nil, across the pulses column there is a comment "leg is swollen" and in the remarks column it states "popliteal on Doppler". At 1.00 am on 26 September an observer recorded as follows; colour: pale, temperature: cool, movement: slight, sensation: (illegible) to mid-calf, nil below, and pain: severe. There is no entry for the pedal pulses. Regular observations were made between then and 2.00 am. However, no pain observation was made except at 1.15 am where it says "pain calf 9 on 10".

135 The epidural infusion notes for the same period have observations hourly from 5.30 pm on 25 September to 1.00 am on 26 September. On these the pain is noted as zero up until midnight and severe at 1.00 am.

136 The integrated progress notes have an entry for 1.00 am on 26 September indicating that the appellant had complained of severe pain in his right calf, that the leg was very swollen and there was no sensation and movement.

137 The first respondent was notified and came to the hospital and examined the appellant. The first respondent noted that the anterolateral aspect of his lower leg was swollen, woody hard and quite tender. The appellant's foot was white and passive dolciflexion of his toes increased the pain. The first respondent diagnosed compartment syndrome, arranged for an emergency fasciotomy and arranged for the appellant to sign consent papers for a fasciotomy and a bypass procedure. He explained that this was because he thought the appellant's leg was at risk. From the time the ABI was confirmed as being zero there was known to be a significant risk of necrosis and amputation. The first respondent contacted the second respondent and the appellant's wife. There were no delays in the first respondent's response after having been advised of the deterioration of the appellant's condition at around 1.00 am on 26 September.

138 As soon as the theatre was ready the first respondent commenced the fasciotomy. A fasciotomy is an operation to release the build up of pressure within a fixed compartment by dividing the fascia of the compartment. A compartment is a sheet of connected tissue which encloses groups of muscles or other organs. They separate muscles into groups. Compartments are dense and they do not give way. So if there is swelling within a compartment, for any cause, pressure within the compartment rises and it is unable to be released because of the layer of membranes surrounding it. Thus the swelling prevents the blood from circulating normally through the compartment and the muscles can thereby be deprived of essential blood and they can die. This is called a compartment syndrome. In the lower leg there is a compartment below the knee at the front called the anterior tibial compartment. It was in this compartment that a compartment syndrome developed.

139 There are a number of different causes of the build up of pressure that causes a compartment syndrome. Among those causes are exudation of tissue fluid, haemorrhage or the restoration of blood flow after a protracted period of ischaemia beyond six to 12 hours.

140 The learned trial Judge accepted that the compartment syndrome developed in the way explained by Mr Lawrence-Brown, a vascular surgeon called by the respondents to give expert opinion evidence.

141 Mr Lawrence-Brown considered that the popliteal artery was patent at the time of the knee replacement surgery and became occluded on the morning of 25 September. That led to ischaemia which developed on the morning of 25 September. Those views are consistent with the findings of the trial Judge. In his written opinion Mr Lawrence-Brown said that the compartment syndrome developed because of the acute ischaemia precipitated by the popliteal artery occlusion and the trauma of recent surgery. In cross-examination Mr Lawrence-Brown said that the compartment syndrome developed as a result of a combination of reduced blood inflow and increased swelling. There was reduced blood inflow because the popliteal artery was occluded and there was swelling and oedema from traumatic surgery.

142 In the fasciotomy the first respondent did a skin incision and then divided the fascia of the interior, posterior, deep posterior and perineal compartments of the lower leg. Although upon division there was muscle inside the anterior compartment which looked abnormal it twitched upon the first respondent testing it and so he decided not to do any debridement of the tissue, that is surgical excision of dead tissue, in the hope that it would all survive.

143 After the fasciotomy the wound was dressed. There was some bleeding after the fasciotomy had been performed which suggested to the first respondent that he had restored some blood flow to the compartment by performing the fasciotomy. The vascular chart showed slow improvement in the circulation of the lower leg. It took until October sometime for the pedal pulses to be recorded.

144 The appellant was commenced on Heparin, an anti-coagulant, immediately after the fasciotomy. The epidural catheter was removed at approximately 2.00 pm on 26 September.

145 On 1 October the appellant was taken back to surgery to have necrotic tissue in his lower leg removed. Further debridement, of the fasciotomy site occurred on 6, 14 and 19 October. On 5 November he had a further debridement of the fasciotomy site and a skin graft. Similar procedures followed. The appellant was discharged from Hollywood Hospital on 15 December 1998.

146 The following year the appellant was in and out of hospital having debridement and skin grafts. He also had manipulation of the knee under anaesthetic to improve its mobility which was affected by the long periods of immobilisation required after the skin graft.

147 In April 2000 the appellant had a scan which showed that his popliteal artery was patent. The trial Judge concluded that the occlusion had dissolved. In the words of Mr Lawrence-Brown the occlusion of the artery was a temporary phenomenon of short duration.

148 Within days of the fasciotomy the appellant noted that he had foot drop and this has continued to the date of trial. The learned trial Judge found that as a result of the arthroplasty and its complications the appellant has had and continues to suffer from loss of muscle in his right leg, foot drop, recurrent infection in his right leg and lymphedema. On the positive side, he now has increased movement in his knee of about 30 degrees.

149 As a result of the compartment syndrome and the subsequent fasciotomy the appellant had open wounds on his leg which did not heal well. The second respondent continued to manage this problem. On 3 August 2000 the second respondent caused gentamicin to be given intravenously to the appellant to deal with the infection. Gentamicin should not be given for any longer than 10 days because it involves a risk of permanent side effects. The known risks include permanent loss of hearing and permanent vestibular dysfunction symptoms including nausea and dizziness. Approximately four to five weeks after his initial prescription, the appellant started developing side effects. Principally these were loss of hearing and loss of balance. The second respondent failed to monitor the development of the side effects or to stop the administration of gentamicin which was continued for a period of approximately two months.

150 The learned trial Judge accepted that the appellant had suffered a permanent loss of hearing in the left ear but found that it was not a significant disability. The learned trial Judge accepted that the appellant had suffered a permanent loss of balance that has caused the appellant difficulty in getting around and made him clumsy and slow. He has also suffered nausea, dizziness and tinnitus.

151 The second respondent admitted liability for damages caused by the administration of gentamicin from 3 August to 3 October 2000. The learned trial Judge assessed damages for the loss and damage to the appellant resulting from that negligence.

Conclusions of Trial Judge with Respect to Credibility of Medical Experts

152 The appellant called evidence from Professor Tracy, a general and vascular surgeon, Mr Peter Milne, a vascular surgeon and Professor Nade, an orthopaedic surgeon. The respondents called evidence from Mr Lawrence-Brown a vascular surgeon and Mr Hill, an orthopaedic surgeon.

153 The learned trial Judge accepted and relied on the evidence of Professor Tracy in some respects but her Honour rejected the evidence of Professor Tracy that the occlusion was a result of the landmine injury. The learned trial Judge found that the occlusion of the popliteal artery occurred as a result of trauma at the time of the arthroplasty.

154 The learned trial Judge preferred the evidence of Mr Milne to that of the other two vascular surgeons, Professor Tracy and Mr Lawrence-Brown. However, her Honour held that Mr Lawrence-Brown's evidence still carries weight and referred to it when dealing with individual allegations of negligence.

155 The learned trial Judge preferred the evidence of Professor Nade to that of Mr Hill.

Conclusions of Trial Judge with Respect to Opinions of Respondents

156 The learned trial Judge found that on 25 September the second respondent believed that the occlusion was chronic and therefore he did not believe that he could remove the occlusion in the popliteal artery. He believed that he could not bypass it because the risk of failure of the bypass was significant and the risk of cutting the collateral circulation when performing the bypass was too high. Her Honour found that the second respondent acted on the basis that the occlusion was chronic. Her Honour found that the second respondent narrowed his options by his view that this was a chronic popliteal occlusion. Her Honour concluded that if he had been thinking more broadly then the second respondent may well have done an angiogram to explore whether there was any chance of removing the popliteal occlusion.

Strempel v Wood & Anor [2005] WASCA 163

At a glance

Court

Decision date

Before

Catchwords

Source

Catchwords

Judgment (326 paragraphs)

Strempel v Wood & Anor [2005] WASCA 163 (29 August 2005)

STREMPEL -v- WOOD & ANOR [2005] WASCA 163 (29 August 2005)

Parties

Cases Cited (16)