Wall v Cooper

[2008] WASCA 53

WALL -v- COOPER [2008] WASCA 53

Jurisdiction:	SUPREME COURT OF WESTERN AUSTRALIA	Citation No:	[2008] WASCA 53
Court:	THE COURT OF APPEAL (WA)
Case No:	CACV:71/2006	Heard:	4 DECEMBER 2007
Coram:	MARTIN CJ WHEELER JA McLURE JA	Delivered:	4/03/08
No of pages:	31	Judgment Part:	1 of 1
Result:	Appeal dismissed Cross-appeal dismissed
Category:	B
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Parties:	MELVYN LEE MAXWELL WALL TIMOTHY MICHAEL COOPER
Catchwords:	Appeal Medical negligence Causation General damages Turns on own facts
Legislation:	Uniform Civil Procedure Rules 2005 (NSW), r 31.35
Case References:	Amaca v Hannell [2007] WASCA 158; (2007) 34 WAR 109 Bennett v Minister of Community Welfare (1992) 176 CLR 408 City of Stirling v Tremeer [2006] WASCA 73; (2006) 32 WAR 155 Henville v Walker (2001) 206 CLR 459 March v E & MH Stramare Pty Ltd (1991) 171 CLR 506 Strempel v Wood [2005] WASCA 163 Thatcher v Charles (1961) 104 CLR 57 Wall v Cooper [2006] WADC 81; (2006) 43 SR (WA) 69

JURISDICTION : SUPREME COURT OF WESTERN AUSTRALIA TITLE OF COURT : THE COURT OF APPEAL (WA) CITATION : WALL -v- COOPER [2008] WASCA 53 CORAM : MARTIN CJ

WHEELER JA
McLURE JA

HEARD : 4 DECEMBER 2007 DELIVERED : 5 MARCH 2008 FILE NO/S : CACV 71 of 2006 BETWEEN : MELVYN LEE MAXWELL WALL

Appellant

AND

TIMOTHY MICHAEL COOPER
Respondent

ON APPEAL FROM:

Jurisdiction : DISTRICT COURT OF WESTERN AUSTRALIA

Coram : YEATS DCJ

Citation : WALL -v- COOPER [2006] WADC 81

File No : CIV 1187 of 2003

Catchwords:

Appeal - Medical negligence - Causation - General damages - Turns on own facts

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Legislation:

Uniform Civil Procedure Rules 2005 (NSW), r 31.35

Result:

Appeal dismissed

Cross-appeal dismissed

Category: B

Representation:

Counsel:

Appellant : Mr C L Zelestis QC & Mr N P Dobree
Respondent : Mr J R B Ley

Solicitors:

Appellant : Nicholas P Dobree
Respondent : Clayton Utz

Case(s) referred to in judgment(s):

Amaca v Hannell [2007] WASCA 158; (2007) 34 WAR 109
Bennett v Minister of Community Welfare (1992) 176 CLR 408
City of Stirling v Tremeer [2006] WASCA 73; (2006) 32 WAR 155
Henville v Walker (2001) 206 CLR 459
March v E & MH Stramare Pty Ltd (1991) 171 CLR 506
Strempel v Wood [2005] WASCA 163
Thatcher v Charles (1961) 104 CLR 57
Wall v Cooper [2006] WADC 81; (2006) 43 SR (WA) 69


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1 MARTIN CJ: I agree with Wheeler JA that the appeal and the cross-appeal should both be dismissed, for the reasons she gives. However, I wish to add a few observations of my own.

2 A significant plank of the appellant's argument rested upon the fact that, during cross-examination, Dr Golledge accepted that if the appellant's uncontradicted description of the wound was correct, it was not a superficial wound. The appellant argues that as a result of that acknowledgement, it should be concluded that, in the opinion of Dr Golledge, the wound was a high risk wound which should have been treated with antibiotics, and, in particular, a broad spectrum antibiotic. However, as Wheeler JA observes (at [44]), that proposition was never put to Dr Golledge in cross-examination.

3 During this examination-in-chief, Dr Golledge identified the factors which caused him to conclude that the appellant's wound was in the low risk category. Four factors were identified, namely (at ts 475):

it's superficial nature, the fact that Mr Cooper operated on the wound in a timely manner, under 8 hours, that it was adequately lavaged and was not heavily contaminated.

4 The significance of the wound being characterised as 'superficial' to the assessment of risk was explained by Dr Golledge in his examination-in-chief in the following terms (at ts 476):

Well it doesn't fall into the high risk [category] because it doesn't involve deep tissue structures.

5 In the context of that evidence, if the appellant's counsel wished to put the submission that the evidence of Dr Golledge was that if the wound was not superficial, it was, without more, properly characterised as high risk, it was essential for that proposition to be put to Dr Golledge in cross-examination. It was not. In this context, the observation by the trial judge that Dr Golledge's acknowledgement that the wound was not superficial led her to approach his opinion with caution (Wall v Cooper [2006] WADC 81; (2006) 43 SR (WA) 69 at [110]), appears to me to be, if anything, unduly favourable to the appellant. Long established principles of procedural fairness require that any proposition which is to be used to undermine the evidence of a witness must be put to that witness. That was not done in this case, with the consequence that it is impossible to conclude that Dr Golledge had changed his view as to the proper assessment of the risk associated with the appellant's wound.

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6 These observations lead me to a more general observation relating to the expert evidence adduced in this case. As Wheeler JA has pointed out (although perhaps not so graphically), the experts who gave evidence in this case were likes ships passing in the night without knowledge of each other, proceeding on varying factual assumptions, and in some instances, without being directly engaged to respond to a contrary view expressed by other experts. With the benefit of hindsight, it can be said that this is a case in which a less traditional approach to the leading of evidence would have had significant benefits.

7 In a number of jurisdictions it is now the established practice to lead evidence from expert witnesses who hold contrary views concurrently. Their evidence is usually taken together, after all the factual evidence has been led, so that the range of factual assumptions possibly open on the evidence can be put to them. The practice also involves the parties, the experts and the court agreeing upon a list of issues which are in contention. The oral evidence of the experts is then addressed to each of those issues, and in the course of their evidence, it is possible for each expert to directly engage with the other (see Uniform Civil Procedure Rules 2005 (NSW) r 31.35(c) - (i)).

8 This case provides a paradigm example of the potential advantages to be derived from expert evidence being taken concurrently (see Justice McClellan, 'Expert Evidence: Aces Up Your Sleeve?' (2007) 8 The Judicial Review 215, 222 - 224; New South Wales Law Reform Commission, Expert Witnesses, Report 109 (2005) [6.57] - [6.60]). It is a procedure which, in my opinion, should be encouraged.

9 The final observation I would make concerns the assessment of general damages which is challenged on the cross-appeal. Unless there is a further appeal, this issue is, of course, moot. The assessment is in the range normally reserved for cases in the worst category. At first sight, it is difficult to see how this case falls within that category. However, as Wheeler JA points out at [66] - [69], there is evidence which would sustain the conclusion that this case is comparable to cases in the worst category. Accordingly, and not without considerable reservation, I agree with Wheeler JA that appellate intervention with the assessment is not warranted.

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WHEELER JA:

The appellant's claim

10 The appellant had claimed damages from the respondent, who was a plastic surgeon, in relation to the respondent's treatment of the appellant for dog bites. Quantum was agreed, apart from general damages, which the primary judge provisionally assessed. Liability was the central issue. Her Honour found that the appellant had not established negligence, and made provisional findings that the respondent's actions did not cause or materially contribute to complications with the appellant's right leg following surgery for the dog bites.

11 The relevant background is as follows. On 21 June 1997, the appellant, a paediatrician, was bitten by two dogs during a home visit to a patient. One attached itself below the appellant's right knee and outside his calf, resulting in a wound which ran like a hinge wound parallel with the main bone. He was also bitten on his right middle finger, causing a puncture wound. The incident occurred between 2.00 pm and 4.00 pm, but closer to 4.00 pm than to 2.00 pm. At approximately 5.00 pm, the appellant was seen in the emergency department of St John of God Hospital in Murdoch. After his examination by the casualty medical officer, the respondent then recommended that the appellant have emergency surgery to clean and repair the wound. The appellant consented to a procedure involving a skin graft for his leg. Because of the unavailability of an appropriate operating room at Murdoch, the appellant was taken to the Mount Hospital where the respondent treated his leg between 7.15 pm and 8.15 pm.

12 The treatment given by the respondent consisted of washing the wounds and inspecting them more closely using loupe magnification. This magnification was effected by the means of glasses which magnified by three. The respondent removed contamination from the leg wound by "debriding" (that is, removing) what appeared to be dead tissue and cleaning the area using a machine which gave intermittent bursts of saline under pressure ("pulse lavage"). The respondent harvested a split skin graft from the thigh of the injured limb and inserted it into the skin deficit with staples. The wound was then sutured and the appellant's leg was completely bandaged from ankle to groin before being immobilised with a plaster of Paris back slab to support it. The respondent left instructions for intravenous Flucloxacillin while the appellant remained in hospital.

13 On 23 June, the respondent arranged for the appellant's discharge. He advised the appellant that he was going to be working overseas until

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6 July and arranged for a consultation upon his return, on 7 July. There was some conflicting evidence about the date from which he had told the appellant his absence would commence, but that does not seem to be material. The respondent told the appellant that, in the meantime, the dressings would remain intact and he was to continue oral Flucloxacillin for five days. As her Honour found, he also gave the appellant instructions about the use of crutches and about what he should do if he noticed certain symptoms which might be indicative of infection.

14 On 29 or 30 June, the appellant started to experience a severe penetrating, aching pain. On 1 July at approximately 4.00 pm, he tried to contact the respondent's consulting rooms but was unable to speak to anyone. He also telephoned the Mount Hospital, hoping to learn the name of the respondent's deputy, but was told there was no record of a deputy. The pain became worse and the appellant noticed a very unpleasant smell in the early hours of the following morning. Pulling back the bandage, he discovered that the wound was running with green pus. He tried to contact the respondent's consulting rooms at 8.00 am but was unable to speak to anyone. There was evidence, which her Honour accepted, that the respondent's secretary attended the rooms from 9.00 am on Monday through Thursday, and that there was an answering machine which was switched on after hours.

15 At 9.00 am, the appellant was seen by a general practitioner who noted that the appellant was suffering from secondary wound infection and breakdown after the initial graft. A swab taken from the wound later found a pseudomonas infection. The appellant was treated by irrigation of the wound, further debriding, bed rest, dressings and the administration of broad spectrum antibiotics. In due course, a second skin graft was laid on 15 July by a different plastic surgeon. The appellant was later diagnosed with complex regional pain syndrome (CRPS).

Trial evidence concerning infection

16 There was at trial a considerable amount of evidence about the danger of infection which would arise from organisms to be found in a dog's mouth. The evidence was that all such wounds should be regarded as potentially heavily contaminated by a variety of different organisms. There was conflicting evidence about the appropriate treatment of dog bite wounds in order to avoid infection which might result from those contaminants. The two most significant disputes appeared to revolve around the question of what were termed "primary" and "secondary" closure, and around antibiotic use. "Primary" closure, which was the

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procedure effected by the respondent, involved suturing and/or grafting of the wound relatively soon after it had been received, while "secondary" closure involved treating the wound in other ways, monitoring it for a number of days, and then closing it when it was clear that potential dog bite contaminants had been removed. The second issue concerned the question of whether it was necessary to prescribe antibiotics in all dog bite cases, because of the potential contaminants, and, if it was appropriate to provide antibiotics, whether broad spectrum antibiotics or some other sort of antibiotics should be prescribed.

17 Despite the focus on the proper treatment of dog bites, and the need to prevent infection which stemmed from contaminants potentially present in the dog's mouth, it was also plain from the evidence that the infection from which the appellant suffered had not resulted from a contaminant to be found in a dog's mouth. Dr Golledge, a senior consultant in clinical microbiology and infectious diseases, said that pseudomonas "is not found" as a pathogen in a dog's mouth, and said that the pseudomonas was a secondary contamination, with infection from that organism probably starting to occur somewhere between day three and day five after the wound (ts 479). In evidence-in-chief he explained that he thought that perhaps "day four, five or six would have been the start of the replication of the organism" (ts 483). Dr Golledge's evidence was also that it was possible, but unlikely, that the pseudomonas had been introduced at operation. He said that an operating theatre with aseptic clean air and copious lavage would be an unusual environment for pseudomonas to be introduced (ts 479). His view was that it was more likely to have been part of the appellant's skin flora. Dr Baldwin, a plastic and reconstructive surgeon, gave evidence that the pseudomonas was "by way of a contaminant" and that the skin flap necrosis, which was also found, was a direct consequence of the original injury (green AB 256). Professor Spicer, a consultant medical microbiologist and infectious diseases physician, called by the appellant, said that it would be "extremely unusual" for pseudomonas to have come from the dog's mouth (ts 300). He considered that it was likely that it was either introduced at operation or was a subsequent contaminant, and does not seem to have expressed a view about which of those was more likely. He described it as "a renowned pathogen causing infections" (green AB 93).

Trial evidence concerning pseudomonas prevention

18 It is, it seems to me, fair to say that all of the witnesses called by the appellant who gave evidence concerning the correct treatment of dog bites, gave evidence primarily directed at the question of what was an

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appropriate treatment which would minimise or eliminate the risk of infection caused by pathogens in a dog's mouth. To the extent that they dealt with the question of infection by pseudomonas specifically, their evidence seems only to have been that, had a broad spectrum antibiotic been prescribed (that being the treatment which they considered to be appropriate in relation to dog bite pathogens), that broad spectrum antibiotic would also have had the additional benefit of reducing the likelihood of the severe growth of pseudomonas infection which the appellant in due course suffered.

19 There was almost no evidence directed to the question of what pseudomonas was, how the risk of infection by that organism arose, and the way in which a patient should be treated in order to minimise the risk of that specific infection. So far as one can discern from the evidence, however, it appears that pseudomonas is an "opportunistic" organism, commonly encountered in hospitals, and it is an organism which appears to infect not just dog bite wounds, but any wounds or skin injuries, including burns. It is described as a "multi-resistant" organism, and although there were differing medical views about the likelihood of it being inhibited by appropriate drug therapy, there was some evidence that at least some drugs which are used specifically to target pseudomonas would not necessarily be effective in eradicating it on all occasions. Pseudomonas is apparently a very common cause of the loss of skin grafts.

20 The only evidence about whether it was desirable or appropriate for a broad spectrum antibiotic to be prescribed for a patient in order to prevent a pseudomonas infection, rather than an infection from some of the contaminants likely to be found in a dog's mouth, was the evidence of the respondent himself. As to one of the drugs which had been suggested as being an appropriate broad spectrum antibiotic for dog bites, Ticarcillin, it was the respondent's understanding that it required a positive wound swab which demonstrated the presence of pseudomonas and which had to be the subject of specific approval under the pharmaceutical benefits scheme (PBS). Therefore, it could not be prescribed as a preventative measure.

21 The respondent was also asked about Ciprofloxacin and, as to that drug, which was said by some witnesses to be active against most strains of pseudomonas, he said that he did not use that in order to avert the risk of such an infection because "… we [presumably surgeons, or plastic surgeons] don't give antibiotics to prevent pseudomonas". The reason for that was "[w]e're not allowed to" (ts 457). That answer was not explored further with him by cross-examining counsel. The context of that

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evidence was that it followed an explanation that certain drugs were restricted because "if all of us had access to broad spectrum potent antibiotics with high risk - with side effect profiles, then the community would be awash with resistant organisms" (ts 456). In that context, the respondent's evidence must be understood as conveying either that the pharmaceutical benefits scheme positively prevented him from prescribing a drug in order to deal with a risk of pseudomonas, rather than with a demonstrated infection, or that alternatively as a matter of good medical practice, because of the potency of the drugs and the risk of creating resistant organisms, it would be improper to prescribe a broad spectrum antibiotic for the purpose of preventing a pseudomonas infection where none had been demonstrated to exist.

22 As I have noted, this evidence of the respondent was neither explored further nor challenged in cross-examination. It appeared from later evidence that he was incorrect in his understanding about the restrictions on the relevant drugs, but only in the sense that he may have confused Ciprofloxacin and Ticarcillin. It appears that Ciprofloxacin required express approval from Canberra pursuant to the PBS, while Ticarcillin was at the relevant time available without such approval. However, that does not affect the importance of the point which he was making.

23 The respondent's evidence in that respect was, to a degree, supported by the evidence of Dr Golledge. Dr Golledge's evidence was that, based on his understanding of the nature of the particular dog bite wound, it would not have been necessary for any antibiotic to have been prescribed. His evidence was that his "inherent bias" as an infectious diseases specialist, used to dealing with complications of infectious diseases, would have been to recommend, if an antibiotic were to be used, Ticarcillin. However, he went on to explain that:

The reason you don't use broad spectrum antibiotics all the time - and this would have involved having to keep the plaintiff in hospital, it would have required parenteral, so intravenous, administration of the antibiotic which has significant side-effects which can also run the risk of infected intravenous lines, chemical phlebitis from the intravenous preparation, it's inconvenient, it's quite costly. There are a number of reasons why we don't try to use, and of course there are greater side-effects too from broad spectrum antibiotics in terms of skin rashes, nausea, bacterial diarrhoea overgrowth, fungal super-infections. So there's a number of downsides to using broad spectrum antibiotics as well, so while it might sound microbiologically idealistic, there is a number of negatives as well that we need to consider. (ts 489)

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Trial evidence concerning Flucloxacillin

24 So far as the drug Flucloxacillin was concerned, the evidence was that it was a "narrow spectrum" antibiotic. However, there was also evidence that it was effective against certain of the pathogens likely to be found in the mouth of a dog, and in particular, Dr Golledge said, it would be effective against "particularly the common destructive early organism such as staphylococcus aureus, staphylococcus intermedius and pyogenic streptococci. So it has good activity against those three major pathogens found in the dog mouth" (ts 477). For that reason, Dr Golledge would have described it, although the term was not one commonly used medically, as "moderate spectrum".

25 Although there was evidence about the number of pathogens to be found in a dog's mouth, and about the effectiveness of various types of antibiotics against them, there was very little evidence about which of those pathogens were more likely to cause an infection, and there was no evidence about which of the infections which might result could have the most serious possible effects. That was presumably because there was no evidence that the appellant suffered from an infection caused by a pathogen introduced at the time of the dog bite.

26 There was, in a later swab taken from the appellant's wound, some evidence of a staphylococcus aureus infection as well as the very heavy pseudomonas infection, but the staphylococcus infection does not seem to have been regarded by anyone as a significant factor in the loss of the graft. In any event, apart perhaps from some speculation by Professor Spicer, there was no evidence suggesting that this staphylococcus aureus was an infection arising from a pathogen in the dog's mouth, as opposed to a later contaminant.

Trial judge's findings - antibiotics

27 In relation to the appropriateness of the respondent's choice of antibiotic, her Honour's conclusion was as follows (Wall v Cooper [2006] WADC 81):

There is no question that infection was a foreseeable risk of surgery. Dr Cooper admitted that there is a risk of infection with all surgery, and he admitted there was the risk of contracting a pseudomonas infection in all surgery, quite apart from the special risks associated with the 40 organisms found in a dog's mouth when treating dog bite. The issue is whether Dr Cooper's choice of Flucloxacillin in these particular circumstances breached the standard of reasonable care and skill in Dr Cooper's provision of professional treatment for Dr Wall's dog bites. While under

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Dr Cooper's care, Dr Wall did not develop any infection from any organism in the dog's mouth. That in itself would tend to indicate there was no breach of Dr Cooper's duty of care. But Dr Wall developed a heavy pseudomonas infection while under Dr Cooper's care. Was it a breach of Dr Cooper's duty of care to have prescribed Flucloxacillin in these circumstances? I do not accept that it was unreasonable for Dr Cooper to prescribe Flucloxacillin. While there is always a risk of pseudomonas infection, I do not accept that a surgeon's duty of care requires the giving of broad spectrum antibiotics to every patient undergoing surgery. It seems to me that could be the effect of an adverse finding about Dr Cooper's treatment on this issue. And that would be wrong. I accept that broad spectrum antibiotics are contra indicated for a number of reasons stated by both Dr Cooper and Dr Golledge. I accept Dr Cooper's evidence that among other factors, broad spectrum antibiotics are more prone to breed resistant bacteria. That in itself provides a compelling reason not to over prescribe broad spectrum antibiotics, and certainly not in every case involving surgery. Keeping Dr Wall immobilized in hospital longer for intravenous administration of a broad spectrum antibiotic with all the associated risks of side effects as Dr Golledge advised would be another important factor supporting the reasonableness of Dr Cooper's decision to prescribe Flucloxacillin. [184]

28 The evidence of the respondent which her Honour accepted was quoted at [120] of her reasons, and is the same evidence to which I have already referred. I would also note that her Honour's reference to the undesirability of keeping the appellant immobilised in hospital for intravenous administration of a broad spectrum antibiotic is of significance in the light of her Honour's factual conclusion about the cause of the appellant's CRPS. At [146], her Honour had referred to evidence that trauma is the most common cause, and immobilisation the second most common cause, for that pain syndrome, and had concluded that it was foreseeable that a risk of such an injury would arise from treatment which prolonged the appellant's immobilisation. Similarly, at [191], in dealing with issues of causation, albeit in a provisional way, her Honour had found "[i]t is not the pseudomonas infection, but the inevitable results of that infection, leading to prolonged immobilisation, that it is suggested caused or contributed to the onset of the pain syndrome". Her Honour accepted that suggestion. It would appear to follow logically that there would have been a potential risk of CRPS from broad spectrum antibiotic treatment which prolonged the appellant's initial immobilisation.

29 Although her Honour went on to consider evidence that other medical practitioners would have preferred to have prescribed a broad spectrum antibiotic, rather than Flucloxacillin, in cases of dog bite, and to describe the issue as "narrowly balanced" [186], in my view the issue with

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which her Honour dealt at [184] was the relevant one. Given that pseudomonas is not an organism likely to be found in a dog's mouth, and that it was a pseudomonas infection which led ultimately to the appellant's CRPS, the relevant questions appear to me to have been these (it being accepted that the respondent owed the appellant a duty to use reasonable care and skill to avoid foreseeable infection). The first question is whether it was foreseeable that a pseudomonas infection might result, not from the dog bite directly, but from the risk which pseudomonas poses in cases of wounds of (apparently) all kinds. Plainly, it was foreseeable. The second question is as to what reasonable care and skill required to reduce that risk, having regard to the likelihood of pseudomonas developing, the likely course of such an infection, and the drugs or other treatments available to reduce the risk. That question fell to be considered in the context of the risks, if any, posed by those drugs or other treatments, and of any restrictions which might arise legally or ethically in relation to their use. As to this question, as I have noted, the only direct evidence was that of the respondent himself, supported to a degree by the evidence of Dr Golledge. Not surprisingly, her Honour accepted that evidence.

30 Against that lengthy background, I turn to the grounds of appeal.

Ground 1 - Negligence

31 Broadly, ground 1 attacks certain aspects of her Honour's findings concerning the reasonableness of the decision to prescribe Flucloxacillin rather than a broad spectrum antibiotic. It is plain from the way this ground was developed, both in the written submissions and in particular in the oral submissions, that the "negligence" upon which the appellant seeks to rely in relation to this ground is negligence in relation to guarding against infection from the pathogens likely to be contained in the mouth of a dog. It, in effect, repeats the allegation made by the appellant's counsel at trial in his opening address; that was to the effect that it was negligent to use Flucloxacillin because that drug would not have eradicated all infection likely to be caused by the dog wound.

32 However, that argument misses the point made by her Honour in [184], which I have already quoted. Whether one characterises it as an issue of classification of the duty which the respondent owed (which was, relevantly, a duty to protect so far as possible against a pseudomonas infection), or as one of causation, the same result follows, in my view, in either case. The failure of the respondent to prescribe the type of drug which the appellant's witnesses considered was required in the case of a

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dog bite, to protect against the organisms in a dog's mouth, either was not negligent, or the negligence caused no injury, since the appellant did not suffer from an infection resulting from the pathogens in the dog's mouth.

33 Only the crudest "but for" reasoning could lead to the view that the respondent's failure to prescribe a broad spectrum antibiotic at that stage "caused" the pseudomonas infection, in the sense that if a broad spectrum antibiotic had been prescribed, it might have had the beneficial side effect of reducing the risk of a pseudomonas infection developing. However, causation is not established merely by establishing that "but for" negligence of one type or another, an injury would not have been sustained: see March v E & MH Stramare Pty Ltd (1991) 171 CLR 506. As was noted during the course of argument, if the appellant had been injured crossing the road upon his discharge from hospital, it may have been correct in one sense to say that "but for" the respondent's failure to keep him in hospital in order to administer intravenous antibiotics, the appellant would not have been injured. However, it would not be correct to say that the respondent's negligence caused that injury.

34 It is perhaps desirable to add in this context that, although there was some criticism, at the hearing of this appeal, of the way in which the trial was conducted before her Honour by then counsel for the appellant, it appears that the difficulty with the appellant's case arose at the anterior stage of the conclusions or assumptions made by the appellant's experts, some of which were later found to be incorrect. If one looks, for example, at the first report of Dr Peter Conrad, a consulting surgeon, the primary focus of his report is upon damage which he considered had been sustained to the lateral popliteal nerve, and what he considered to be the failure of the respondent to thoroughly explore that nerve when he treated the appellant. It was the respondent's evidence, however, that he did inspect that nerve and that it was relevantly undamaged, and her Honour accepted that evidence. Dr Conrad also suggested that the respondent's treatment of the bite was inadequate in that he should not have performed primary closure. However, there is in that report no suggestion of a nexus between the failure to perform primary closure and the infection. Dr Conrad did not apparently comment at that stage upon the choice of antibiotic. Similarly, Professor Spicer's further report of 8 February 2006 concentrates entirely upon the desirability of using broad spectrum antibiotics in order to protect against dog bite pathogens. So far as the pseudomonas itself is concerned, the only reference to that seems to be in the paragraph in which he adds that "[f]urther, had broad spectrum antibiotics been used rather than narrow spectrum, infection in this case would have been less likely, +/or less severe" (green AB 93). As well as

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advocating the use of broad spectrum antibiotics, the appellant's expert witnesses either advocated secondary closure, or considered that the popliteal nerve had been damaged, or both. For reasons which I note shortly, her Honour rejected the evidence of those experts in relation to primary closure, found that the appellant's CRPS did not stem from damage to the popliteal nerve, and found that the respondent had adequately explored that nerve.

35 For the sake of completeness, I consider what the position would be if I accepted that it was appropriate to reason as the appellant contends. That reasoning involves asking: first, was it appropriate not to prescribe a broad spectrum antibiotic for this dog bite; and, second, was there any causal connection between the failure to prescribe a broad spectrum antibiotic and the development of pseudomonas (or, putting this last proposition differently, might the prescription of broad spectrum antibiotic have inhibited the development of pseudomonas)?

36 The appellant contends that her Honour effectively gave five reasons for the conclusion that the respondent was not negligent in failing to prescribe a broad spectrum antibiotic, they being:

(i) the fact that the appellant did not develop any infection from an organism in the dog's mouth tended to indicate that there was no carelessness regarding the antibiotic prescribed;

(ii) a finding that a broad spectrum antibiotic should have been prescribed would imply that all surgery patients should receive such drugs, which would be wrong;

(iii) the respondent's reasons for not using a broad spectrum antibiotic in this case;

(iv) there were contraindications for the use of a broad spectrum antibiotic;

(v) the judge was particularly persuaded by Dr Golledge's opinion that Flucloxacillin was a reasonable choice.

37 As to (i), I accept that the fact that the appellant did not develop a dog-related infection does not necessarily indicate that the respondent was not negligent. However, it seems to me that this was a factor which fortified her Honour's conclusion, rather than being a necessary step in her Honour's reasoning. Otherwise, I set out below in summary, in italics, the appellant's submission about each of these matters, together with my view of the appellant's submission.

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38 (ii) A judicial finding on the use of antibiotics in the present case would not establish a general rule for all surgeons in all cases. As I have noted earlier, the evidence suggests that pseudomonas is an organism which can arise following surgery generally; it must follow that a finding that it was negligent not to prescribe, for whatever reason, an antibiotic which might have marginally reduced the risk of pseudomonas, would involve the proposition that that antibiotic should be prescribed in all cases of surgery.

39 (iii) the respondent's reasons relating to cost and permission from Canberra were baseless, as her Honour found. They were not wholly baseless, but it should be accepted that there were drugs which could be described as broad spectrum antibiotics which were not particularly high cost and which could be prescribed without permission from Canberra. The respondent's other reasons (those relating to resistant organisms generally) are dealt with under (iv).

40 (iv) what the judge referred to as "contraindicators" were general reasons for not using broad spectrum antibiotics in all cases, not necessarily applicable to this case; and Dr Baldwin said there were no contraindicators to the use of broad spectrum antibiotics in the present circumstances. The appellant's submission in relation to the reasons which her Honour accepted as rendering the general prescription of broad spectrum antibiotics inappropriate, in every dog bite case, is founded in an ambiguous use of the word "contraindicators". The matters to which Dr Golledge and the appellant referred, and which the judge accepted, were reasons why caution should always be exercised in prescribing broad spectrum antibiotics, and for concluding that they should not be used except in cases where there was a clear requirement for their use. Those considerations applied to the case of the appellant, just as they applied to all surgical patients, and perhaps to all patients generally.

41 However, there was no evidence that there were any particular contraindicators, over and above those factors, in the case of the appellant, which would have made it inappropriate to have prescribed broad spectrum antibiotics for him. That is, there was no indication of any sensitivity, or allergy, or interference with the operation of other medication, or matters of that kind. The real question was, in this case, whether the nature of the appellant's wound was such as to outweigh the general considerations to which her Honour referred, and make it appropriate for broad spectrum antibiotics to be prescribed for him. There is no indication in her Honour's reasons that she did not understand this issue.

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42 (v) the opinion relied upon by the judge, and expressed by Dr Golledge, was based upon Dr Golledge's original understanding that the appellant had suffered a superficial, and thus low risk, wound. In order to understand this contention, it should be noted that the Antibiotic Guidelines, which seem to have been accepted on all sides as relevant, provided that, in relation to low risk bites, antibiotics may not be necessary "for mild wounds not involving tendons or joints that can be adequately debrided and irrigated and that are seen within 8 hours" (green AB 96). However, high risk wounds required more aggressive treatment. High risk wounds were said by the Guidelines to include wounds with delayed presentation (that is, greater than eight hours), puncture wounds (irrelevant here), wounds on hands, feet or face (irrelevant here), wounds with underlying structures involved (for example, bones, joints, tendons) and wounds in the immuno-compromised patient (also irrelevant here).

43 Professor Spicer conceded that the wound was not high risk, but contended it was also not low risk. His evidence was "this wound, because of its size, because of the delay in attending to it and, it might be argued, in view of the subsequent infection and perhaps the subsequent nerve involvement that shows it was not a straightforward low risk wound" (ts 297). However, only the size of the wound was, in the end, of potential relevance. Professor Spicer's view was that the wound had been seen "late" in the eight-hour period (ts 296). That was not consistent with the view which her Honour took of the evidence. The reference to "subsequent infection" is plainly hindsight and should, in my view, be disregarded. Further, it was not her Honour's finding that there was any "nerve involvement". It was the respondent's evidence that the peroneal nerve was able to be seen, that the respondent inspected it, and that it was undamaged (ts 369). Her Honour accepted that evidence, so that there was no evidence of the nerve, or any other structure, being "involved".

44 So far as Dr Golledge was concerned, wounds were either low risk, or they were high risk. In his view, this wound was low risk, since it was operated on in a timely manner, adequately lavaged, and not heavily contaminated (ts 475). It did not involve deep tissue structures. So far as the size of the wound was concerned, Dr Golledge had originally described it as a "superficial degloving" injury (ts 475 - 476). In cross-examination, having regard to the description of the wound, he accepted that it was rather more than that. However, he was not asked, and did not say, whether that meant that he had changed his view of it as a "low risk wound" and whether there would be any consequence for his view that it was not necessary to prescribe any antibiotics in relation to this wound. Her Honour noted Dr Golledge's concession in relation to the

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nature of the wound, and concluded that therefore his opinion with respect to the appropriate antibiotic had to be approached "with caution" [110].

45 What her Honour was left with, then, was the conflicting testimony of two expert witnesses (taking Dr Golledge and Professor Spicer as each expressing the most extreme view on either side), each of which was, in some respects, erroneous in his understanding of the nature and treatment of the wound. Having heard Dr Golledge's evidence as a whole, it was, in my view, open to her Honour to conclude, notwithstanding the caution which she expressed, that she would rely upon the views which Dr Golledge expressed in relation to this particular wound.

46 Finally, in relation to this ground, I should note the appellant's submission that, apart from Dr Golledge, all of the experts who expressed opinions about the use of antibiotics in the present circumstances said that "a broad spectrum antibiotic was the appropriate treatment" (appellant's submissions par 8). Professor Spicer certainly did so. Dr Conrad did so. Her Honour gave less weight to the evidence of Dr Conrad because of what she regarded as a confusion and contradiction of his own prior evidence about the popliteal nerve [137]. Her Honour also gained the impression that he was not an unbiased objective witness, but one who was prepared to contradict the defendant's (respondent's) experts without full and careful consideration of their opinions [137]. The appellant submits that the contradiction in relation to the popliteal nerve was only a matter of terminology, concerning a nerve which had undergone a change in the name by which it was commonly referred to, but it appears to me that the important point about this aspect of Dr Conrad's evidence was that, once he had changed his terminology, he did not explain it and apparently did not reconsider what he had said earlier. Further, her Honour's finding concerning his lack of impartiality seems to be derived from his demeanour generally, and not just from this matter.

47 So far as Dr Baldwin is concerned, he did not suggest that broad spectrum antibiotics would have been the only appropriate choice. He described Flucloxacillin as being "of particular advantage against streptococcus and especially ... staphylococcus", and described it as "a good drug" (ts 548). He conceded that it lacked completeness against all the anaerobic organisms and some gram-negatives to be found in a dog bite, and accepted that broad spectrum antibiotics would have given greater cover against a multitude of organisms. However, those observations fall short of a suggestion that, either in relation to dog bites generally, or in relation to this particular case, the only appropriate drug would have been a broad spectrum antibiotic, rather than Flucloxacillin.

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48 It is my view, therefore, that it was open to her Honour to have found that it was not negligent of the respondent to prescribe the drug which he did, even if it was necessary to consider what was the appropriate standard of treatment of this wound in order to protect against the organisms to be found in the mouth of a dog.

Ground 2 - Secondary closure and delayed review

49 This ground asserts that her Honour erred in failing to consider the inter-related nature and compounding effects of the three main aspects of the respondent's management of the appellant, namely primary closure of the wound, narrow spectrum antibiotic and delayed review.

50 The evidence relating to primary closure appears to suffer from the same defect as the evidence relating to the use of antibiotics. That is, so far as one can discern from the evidence, the reason that those experts who support secondary closure suggest that it is the most appropriate choice of treatment is that, because of the contaminants likely to be found in the mouth of a dog, some period of time should be allowed to elapse in order to ensure that infection from those pathogens either has not been established or has been properly controlled.

51 There does not appear to have been any evidence directed to the question of whether primary or secondary closure was more or less likely to result in a pseudomonas infection developing. If pseudomonas is an opportunistic infection capable of being established in wounds generally, then as a matter of logic one might have considered that the longer the wound is open the more likely it is for that pathogen to be introduced, whether from the air or the patient's skin or from some other source. Any conclusion, however, would appear to be no more than speculation.

52 Her Honour dealt with the question of primary or secondary closure in the following way:

It is clear from the expert medical evidence that there is a difference of opinion among the medical experts on this topic. Dr Conrad and Professor Spicer are firmly of the view that primary closure is not appropriate for dog bite wounds to a leg. On the other hand Dr Baldwin, Dr Golledge and Dr Cooper maintain that debridement, lavage and immediate closure are the proper treatment of such a wound in the circumstances surrounding this injury.

In this case I have been ably assisted by expert medical opinions and I am satisfied that there is a division of approach in the treatment of dog bite wounds to an adult leg. I accept that at least formerly in Australia the practice was to delay closure of such wounds for a considerable time in

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order to ensure that all infection had been removed before the wound was closed (evidence of Dr Conrad and Professor Spicer). But I also accept that there is a newer but long standing practice in Australia and in Western Australia to use primary closure for dog bites after adequate debridement and lavage (evidence of Dr Baldwin, Dr Golledge and Dr Cooper). The issue for me is to judge whether Dr Cooper's primary closure of this dog bite wound in all the circumstances breached the standard of care he owed to Dr Wall. As alleged in the plaintiff's particulars of negligence I would need to be satisfied that Dr Cooper carried out primary closure 'before he had ensured that all infection was eradicated or controlled sufficiently'.

On the issue of primary closure I found Dr Baldwin's evidence highly persuasive. He is himself a plastic surgeon and his experience with dog bites was similar to, but more extensive than that of Dr Cooper. And Dr Baldwin's opinion about primary closure included a proviso - 'provided an adequate debridement to viable tissue has been carried out and provided the wound was cleansed' (exhibit 7.3, p 4) by adequate lavage. I accept and rely on Dr Golledge's opinion that debridement and lavage are the cornerstones of the treatment of dog bite [sic]. In this case there was compelling evidence that Dr Cooper adequately debrided and lavaged the dog bite. In some ways it could be said the proof was in the pudding. That is because none of the 40 organisms found in a dog's mouth caused Dr Wall's infection. If the wound had not been adequately washed and debrided I would have expected different infections to become established. Nothing from the dog's mouth infected Dr Wall's leg. The only reasonable inference is that all of the many organisms found in the dog's mouth had been removed by debridement and lavage. The infection to Dr Wall's leg was a pseudomonas infection. I accept Dr Golledge's opinion that the infection started on day three, four or five after the wound was closed and was not there at the time of surgery. I also accept Dr Golledge's opinion that the pseudomonas may have come from Dr Wall's own skin flora. [154] - [156]

53 In summary, although it appears to me that her Honour was not necessarily required to consider the question at all, her Honour formed the view that it was not negligent to treat a dog bite by way of primary closure. In any event, she found, correctly, that none of the organisms in a dog's mouth caused the appellant's infection. Although she did not say so expressly, it follows that even if the respondent had been negligent in resorting to primary rather than secondary closure, that negligence had no relevant consequence. The concluding three sentences of [156], although her Honour does not spell it out, appear to me to amount to the (correct) conclusion that there was no causal relationship between the method of closure adopted - either on its own or in conjunction with any other aspects of the treatment of the appellant - and the pseudomonas infection.

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54 The "delayed review" aspect of the grounds is concerned with the fact that the respondent arranged to review the appellant after a period of two weeks, rather than at some earlier time. Her Honour found that the respondent arranged a review for two weeks after surgery, and not earlier. The evidence in relation to the appropriate time for a review was limited. The respondent explained that he did not want a review before he left to travel overseas because he did not want to disturb the skin graft on the leg and did not want to disturb the re-epithelialisation of the thigh donor site.

55 The only expert evidence concerning the appropriate time for a review appears to be that of Dr Baldwin, which her Honour accepted [166]. Dr Baldwin said that it would not be appropriate to review within a week (apparently of discharge, ie, from 23 June) because "[y]ou wouldn't want to disturb the dressing. You don't want to disturb the graft. The graft needs to be kept intact for a period of two weeks to become consolidated so that it can withstand the trauma of interference" (ts 548). Dr Baldwin said that he personally would have waited two weeks to review, and that was what he did with skin grafts of the leg, even in relation to dog bites. However, he also was asked, "Are there any risks about taking off the dressing and examining the wound say after a week?" He said that there were not, although earlier than that was difficult because of the possibility of disturbing the graft. He did not at any time positively agree that it would have been preferable to have reviewed the wound after one week. He did agree that, as a matter of logic, an inspection after one rather than two weeks would have given a better chance of picking up the onset of infection at an earlier time, and there was some evidence that the earlier such an infection is detected, the better the chance of saving the graft (ts 558).

56 In circumstances where there was clear evidence that too early an inspection would have given rise to certain risks, and that those risks would be present for "about" a week, it was, in my view, open to her Honour to find, as she did, that the respondent's decision to review in two weeks was a reasonable one.

57 The ground also attacks, in this context, her Honour's observation that the appellant "was a medical practitioner who would be expected to look after himself" [166]. The appellant was a paediatrician, not a plastic surgeon, so that skin grafts were not within his particular area of expertise. However, all it seems to me that her Honour meant by that observation was that the appellant, as a medical practitioner, must have had a basic understanding of the existence of the risk of an infection after a surgical procedure, and of the usual symptoms of infection (such as

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pain, smell, and so on). The respondent had instructed the appellant to seek assistance if he noticed any indications of infection and, having regard particularly to the nature of the appellant's profession, the respondent might well have expected him to take such an instruction seriously.

Grounds 3 to 7 - Causation

58 These grounds are concerned with her Honour's provisional finding that, even if there was negligence with respect to primary closure and delayed review, materially contributing to the onset of the appellant's CRPS, the failure to prescribe a broad spectrum antibiotic did not contribute to the onset of that syndrome. Having regard to the view I have formed concerning grounds 1 and 2, it is possible to deal with these grounds reasonably briefly. I should note that it is accepted on both sides that her Honour was incorrect in apparently accepting that Dr Golledge's evidence was that, at least in laboratory conditions, pseudomonas is susceptible to Flucloxacillin [201]. It is accepted that the relevant pathology reports make it clear that pseudomonas is not susceptible to Flucloxacillin. However, the error is of no relevance, since her Honour expressly said, of this evidence, "I do not rely on that part of Dr Golledge's evidence" [201].

59 Her Honour's findings, relevantly, are at [200] and [202] which read as follows:

The position is somewhat different with the alleged wrongful act of failing to prescribe a broad spectrum antibiotic. Professor Spicer's opinion was that if broad spectrum antibiotics had been given, that would have made it 'much less likely that pseudomonas would have been present on 2 July'. Dr Golledge said it would have been less likely but it probably would have made no difference. I accept and rely on Dr Golledge's expert evidence about the nature of pseudomonas, what he called a 'super–infection' infecting the wound later down the line even in patients' [sic] given aggressive antipseudomonal antibiotics. I accept his opinion that 'in roughly half the cases even despite aggressive pseudomonal therapy, pseudomonas can still occur' (T478). And I note this happened in this case when Dr Wall experienced another heavy growth of pseudomonas infection in August, despite aggressive antipseudomonal treatment during July. I also accept Dr Golledge's evidence that a pseudomonas infection is not a rare event. It happens 'almost on a daily basis' (T487) at a big teaching hospital like Sir Charles Gairdner where patients develop pseudomonas infections despite what would be deemed 'appropriate antibiotic cover' (T487).

...

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Taking account of the nature of the pseudomonas super-bug and relying on Dr Golledge's opinions, I am satisfied on the balance of probabilities that Dr Cooper's failure to give a broad spectrum antibiotic increased his risk of the onset of a pseudomonas infection but I am satisfied that the risk remained irrespective of the giving of a broad spectrum antibiotic, and that Dr Wall was just as likely to develop a pseudomonas infection whatever antibiotic was given. In this case there is evidence the injury would have occurred even if the duty had been performed and therefore the evidential onus did not shift (Strempel v Wood [49]).

60 It is submitted that it makes no sense to suggest that if broad spectrum antibiotics had been prescribed, the development of a pseudomonas infection would have been less likely, but that such a prescription probably would have made "no difference". However, it does make sense, if the reduction in risk resulting from broad spectrum antibiotics would have been marginal. It appears to me that, on a fair reading of Dr Golledge's evidence, her Honour was correct in characterising his view as being that, in the particular case of the appellant at least, it is likely that the giving of a broad spectrum antibiotic, instead of Flucloxacillin, would have made no difference to the development of the pseudomonas infection. As I understand it, that evidence was based in part upon his view about the nature of pseudomonas as an aggressive opportunistic organism which can often be resistant to even appropriate broad spectrum drugs, and in part upon the particular course of infection in the appellant's case, where there was apparently a pseudomonas infection found to be present at the time of a later swab, even after aggressive anti-pseudomonal treatment.

61 It is also submitted that her Honour wrongly suggested in [202] that the conclusion that the failure to prescribe a broad spectrum antibiotic materially contributed to the pseudomonas infection could be displaced by "evidence" that the injury would have occurred even if the duty had been performed. However, it appears to me that, having regard to her Honour's acceptance of the evidence of Dr Golledge in [200] and [202], her Honour intended to indicate that she, relying upon that evidence, had made a finding that the injury would have occurred even if the duty had been performed.

The cross-appeal

62 There are three grounds of the respondent's cross-appeal. I think it is possible to deal with them briefly.

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Cross-appeal ground 1 - Increased risk of pseudomonas

63 Ground 1 is concerned with the proposition that if her Honour found that the failure to prescribe a broad spectrum antibiotic increased the risk of pseudomonas, her Honour erred in so finding. However, it appears to me that the evidence of Dr Golledge, which her Honour accepted, and upon which the respondent relies for this ground, accepts that there was some, albeit marginal, reduction in the risk of a pseudomonal infection in cases where broad spectrum antibiotics are used. It appears to me that her Honour was correct in characterising his evidence as suggesting that there was, in general terms, some increase in risk (or, more correctly, that there would have been some marginal reduction in risk if such antibiotics had been prescribed), but that the outcome would have been unaffected, at least in this case, if a broad spectrum antibiotic had been prescribed.

Cross-appeal ground 2 - Causation of CRPS

64 This ground suggests that her Honour should have found that the appellant had not proved, on the balance of probabilities, that the pseudomonal infection caused, or materially contributed to, the appellant's CRPS. Her Honour found, the respondent accepts correctly, that there was no evidence which proved that the pseudomonal infection, standing alone, caused or contributed to CRPS.

65 However, her Honour did find that the infection was the first link in a chain of events which led to the appellant's prolonged immobilisation, which, in turn, led to the onset of CRPS. The submissions in support of this ground set out a variety of medical views which were expressed about the causation of this complex syndrome. The short answer to these submissions, in my view, is that at [194] to [198], in particular, her Honour carefully examined the relevant medical evidence which she found to be of particular assistance. Relying upon that evidence, she concluded at [199] that prolonged pain and immobilisation can cause or contribute to the onset of CRPS. She was satisfied that the pseudomonas infection led to the breakdown of the skin graft and that that, in turn, led to prolonged immobilisation of the appellant's leg during July. In my view, the evidence which she discussed and appeared to accept was capable of supporting that conclusion.

Cross-appeal ground 3 - Quantum of damages

66 Her Honour made a provisional assessment of general damages and awarded an amount of $450,000 under that head. That is, I accept, a very large award. I accept that it is of the order usually awarded to claimants

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who are totally incapacitated by their injuries and have no prospect whatever of recovery. The question which arises, however, is whether the award is so unreasonably high, for the respondent's condition, that the court should infer that error was made.

67 Her Honour found that the appellant had experienced severe pain in his right leg since 1997, with similar symptoms developing in his left leg, which she described as "excruciating pain" [205]. Her Honour found that the appellant can look forward to living with that pain for the rest of his life. She accepted his evidence that the severity of his pain was such that he had considered amputation of his leg, but, following medical advice, had not adopted that course. She accepted that the pain syndrome has had a devastating effect on his personal life and on his career, which was formerly that of a leading specialist paediatrician, looking after youngsters with ADHD. It meant he was unable to write papers and a book because he could not sit and type, and could not concentrate sufficiently to complete his book or research. Her Honour concluded that the appellant "is left with a very limited existence and is dependent on heavy doses of morphine based pain killers with little time or energy to enjoy any of the normal day to day pleasures of life" [208]. As the appellant's counsel points out, there was evidence which compared the appellant's condition with that of "chronic unremitting pain of end stage malignant disease" (Professor Riley, exhibit 3.19).

68 In my view, the findings of fact which her Honour made would justify a very substantial award of general damages. While the appellant's condition is not perhaps the "usual" type of case in which such a large award would be made, it seems to me that this is an appropriate case in which to apply the observations of Windeyer J in Thatcher v Charles (1961) 104 CLR 57 at 71:

In theory it might seem that the most serious physical injures should always attract the heaviest damages. Therefore it is sometimes suggested that damages given in cases of paraplegia should be regarded as at the top of the scale and used as a basis for other estimations. But that involves an erroneous hypothesis. Compensable loss depends not only on the severity of the physical injury but on the consequences for the individual. No two injuries are really the same; and the consequences of apparently similar injuries vary infinitely for different individuals. Thus amounts given in different cases may be harmonious in principle, although appearing disproportionate when the physical injuries alone are regarded.

69 It is plain that her Honour was careful in this case to have regard to the consequences of the appellant's injuries for him and I am not

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persuaded that the award of general damages, although high, was so disproportionate as to require appellate intervention.

Conclusion

70 I would dismiss both the appeal and the cross-appeal.

71 McLURE JA: I agree with Wheeler JA that the appeal and cross-appeal should be dismissed. I agree with her reasons in the cross-appeal and in relation to ground 2 of the appeal. I propose to state my own reasons in relation to the issues of breach and causation.

72 The primary issues in the appeal are whether the respondent plastic surgeon breached his duty of care to the appellant in failing to treat him with broad spectrum antibiotics and whether the breach caused the relevant damage.

73 On 21 June 1997 the respondent conducted emergency surgery to clean and repair a wound just below the back of the knee of the appellant's right leg. The wound was caused by a dog bite. The respondent lavaged and debrided the leg wound and laid a skin graft to cover skin loss.

74 The unchallenged facts are as follows. On the respondent's instructions, the appellant was given the antibiotic flucloxacillin intravenously for the period he remained in hospital. The appellant was discharged from hospital on 23 June 1997 and prescribed oral flucloxacillin. On 29 June 1997 the appellant started to experience aches and pains in his right leg. He attended his general practitioner on 2 July 1997. He was diagnosed with a secondary wound infection resulting in the breakdown of the skin graft. A pathology report of a swab collected on that day revealed that the appellant had a pseudomonas infection. The appellant was admitted to Gosnells Hospital and broad spectrum antibiotic treatment (ciprofloxacin) was commenced. He received further lavage and debridement and a second skin graft was laid on 15 July 1997. A pathology report of a swab collected on 4 August 1997 revealed that, notwithstanding his treatment with broad spectrum antibiotics, the appellant had a further pseudomonas infection. The appellant's aches and pains continued and he was subsequently diagnosed as suffering from complex regional pain syndrome (CRPS). The appellant claimed that the respondent's negligent failure to treat him with broad spectrum antibiotics caused his CRPS.

75 There are 40 or more organisms in a dog's mouth capable of causing an infection. The organisms fall into three main groups: gram-positive,

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gram-negative and anaerobes. The antibiotic flucloxacillin is effective against gram-positive organisms but has reduced effectiveness against the other groups of organisms. Flucloxacillin is not a broad spectrum antibiotic and is not effective against a pseudomonas infection. A pseudomonas infection is susceptible to some, but not all, broad spectrum antibiotics. Pseudomonas is an aggressive virulent pathogen. It can be part of skin flora. There is a risk of contracting a pseudomonas infection in all surgery.

76 It was common cause that the respondent owed the appellant a duty of care. The trial judge found that the respondent had not breached his duty of care in prescribing flucloxacillin or in failing to prescribe a broad spectrum antibiotic. The trial judge made the following provisional findings on causation:

1. the prolonged immobilisation of the appellant in hospital as a result of the pseudomonas infection and the breakdown of the skin graft materially contributed to the onset of the appellant's CRPS;

2. the failure to prescribe a broad spectrum antibiotic did not cause or materially contribute to the appellant's pseudomonas infection.

77 There is an overlap between breach and causation in the law of negligence. The claimant bears the onus of proving that the breach in question caused the relevant damage. It is convenient at this stage to summarise the relevant legal principles on causation.

78 A breach of duty does not have to be the sole cause of the damage. It is sufficient if the negligent act or omission materially contributed to the damage. Generally, the issue of causation is divided into two questions: a question of causation in fact which is generally determined by the application of the 'but for' test and a further question of whether the defendant is in law causally responsible for the damage: Bennett v Minister of Community Welfare (1992) 176 CLR 408, 412 - 413. The law and its application on this subject are discussed by McHugh J in Henville v Walker (2001) 206 CLR 459 as follows:

In some situations, the legal framework may require a finding that, despite a causal connection in a physical sense between the breach and damage, no causal connection exists for legal purposes …

…

Exceptionally … the policy or rationale of the legal norm that has been breached will require the court to disregard the physical connection and to make a finding of no causal connection.

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Thus in Gorris v Scott, in the course of a voyage on the defendant's ship, the plaintiff's sheep were washed overboard because the defendant neglected his statutory duty to provide pens on the deck of the ship. The action was dismissed because the statute was aimed at preventing disease and was not directed to the events that had happened. Thus in spite of the existence of a breach of duty that resulted in damage to the plaintiff, there was no relevant causal connection because the damage was outside the contemplation of the statute. Similarly, in Close v Steel Company of Wales Ltd, the defendant, in breach of its duty, had failed to fence a dangerous drilling machine. The plaintiff was injured when the drill bit fragmented. His action failed because the House of Lords held that the duty to fence was limited to keeping the worker from coming into contact with the dangerous machinery and did not extend to protecting the worker from injury caused by ejected pieces of the machine (491 - 492).

79 In summary, there must be a causal connection between the rationale or basis for the act or omission that constitutes the breach and the damage sustained: City of Stirling v Tremeer [2006] WASCA 73; (2006) 32 WAR 155 [95]. Causation is not established in this case if the evidence goes no further than establishing that the respondent should have treated the appellant with broad spectrum antibiotics because of the risk of infection from one or more of the many pathogens in a dog's mouth. That is because the pathogens in a dog's mouth did not cause the appellant's pseudomonas infection. Thus, I do not accept the appellant's submission that causation is established if the exercise of reasonable care to protect against the risk of infection from dog pathogens provided a collateral benefit in reducing the risk of a pseudomonas infection. The appellant conducted its case at trial on this erroneous basis.

80 The appellant also submitted the trial judge erred in failing to draw an inference from the independent expert evidence that the risk of a pseudomonas infection was a reason for the weight of expert evidence that the respondent should have treated the appellant with a broad spectrum antibiotic. It would be sufficient to establish causation if the weight of the evidence was that:

1. the risk of a pseudomonas infection was itself sufficient to require a broad spectrum antibiotic;

2. the risk of a pseudomonas infection in combination with the risk of infection from the pathogens in a dog's mouth required a broad spectrum antibiotic which was effective against all possible infections.

81 As I understand the expert evidence, all relevant infections were susceptible to ticarcillin clavulanate (a broad spectrum antibiotic
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combined with an enzyme inhibitor). That drug was on the pharmaceutical benefit scheme, was not terribly expensive and was readily available at the relevant time.

82 In submitting that the court should draw an inference of causation, the appellant relied on the respondent's evidence that the second most common reason for loss of a skin graft was a pseudomonas infection.

83 There is no evidence from any expert witness that directly or indirectly supports the inference contended for. To the contrary, such an inference is inconsistent with the express reasoning of the experts. They were aware that the appellant had contracted a pseudomonas infection which was not caused by the organisms in a dog's mouth. Against that background, they expressed their opinion as to the appropriate category of antibiotic solely by reference to the infection risks associated with the organisms in a dog's mouth. Their reasoning impliedly negatives an inference that a pseudomonas infection was a reason for determining the category and type of antibiotic that should have been prescribed. There are two additional factors which prevent such an inference arising from Dr Golledge's evidence. First, his evidence on breach is positively inconsistent with an opinion that reasonable care required antibiotic cover for, inter alia, the risk of a pseudomonas infection. The second factor, related to the first, is his opinion that a broad spectrum antibiotic would not in all probability have prevented the pseudomonas infection. Professor Spicer's contrary view on causation arguably provides some support for an inference that he regarded the risk of a pseudomonas infection as a reason for prescribing a broad spectrum antibiotic but it is not determinative and does not outweigh the other indicators to which I have referred. It is not determinative as there can be causation without a breach of duty but ordinarily there is no breach of duty without causation because a precaution would not be classified as reasonable unless its performance would in the ordinary course of events avert the risk that called it into existence: Bennett [422]. The most compelling inference is that Professor Spicer's reasoning reflects the collateral benefit approach to causation that has no relevant connection with breach. In summary, the appellant failed to prove that there was any breach of the respondent's duty of care relating to antibiotic coverage for the risk of a pseudomonas infection.

84 Whether or not flucloxacillin was an appropriate antibiotic for the range of organisms in a dog's mouth is of no consequence because there is no causal connection between that claimed breach and the damage. In any event, I agree with Wheeler JA that it was open to the trial judge to

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conclude that the respondent did not breach his duty of care in prescribing flucloxacillin for the risk of infection from organisms in a dog's mouth. The appellant placed primary emphasis on the evidence of all the independent experts, including Dr Golledge, that they would have given the appellant a broad spectrum antibiotic. However, that is not determinative. The central question is whether the exercise of reasonable care required that the appellant be given broad spectrum antibiotic cover. Professor Spicer and Dr Golledge are specialists in the relevant area. They disagreed as to what reasonable cover required. There were reasonable grounds for preferring the evidence of Dr Golledge. The Antibiotic Guidelines were silent on the question as the wound did not fall within the high or low risk categories. The differing opinions of Professor Spicer and Dr Golledge were sourced in their assessment of the extent of the risk of infection which is also reflected in their opinions on the issue of primary and secondary closure. Primary closure involves suturing the skin or laying a skin graft after lavage and debridement of the wound without further delay. Secondary closure involves delaying the closure of the wound, usually for a period of eight to 10 days, until all infection or potential infection is controlled. Dr Spicer was of the opinion that the appellant's risk of infection was sufficiently high to require secondary closure of the wound. Dr Golledge accepted that secondary closure was appropriate if there was a significant risk of infection. However, he supported primary closure in this case on the basis that lavage and debridement was the primary management tool and should be effective to remove from the wound all contamination that was the potential source of infection. The trial judge accepted Dr Golledge's opinion and concluded that primary closure was appropriate. Dr Golledge supported the use of flucloxacillin because it was effective against what he described as the primary pathogens in a dog's mouth being staphylococcus auereus and intermedius. He explained the reasons for not using a broad spectrum antibiotic as follows (ts 489):

But you would agree presumably then with Prof Spicer's view which is why wouldn't you use a broad spectrum antibiotic knowing that it will cover far more bacteria than a narrow spectrum antibiotic? … The reason you don't use broad spectrum antibiotics all the time - and this would have involved having to keep the plaintiff in hospital, it would have required parenteral, so intravenous, administration of the antibiotic which has significant side-effects which can also run the risk of infected intravenous lines, chemical phlebitis from the intravenous preparation, it's inconvenient, it's quite costly. There are a number of reasons why we don't try to use, and of course there are greater side-effects too from broad spectrum antibiotics in terms of skin rashes, nausea, bacterial diarrhoea overgrowth, fungal super-infections. So there's a number of downsides to

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using broad spectrum antibiotics as well, so while it might sound microbiologically idealistic, there is a number of negatives as well that we need to consider.

85 In addition to those negatives, the primary judge accepted Dr Cooper's evidence that broad spectrum antibiotics are more prone to breed resistant bacteria. The evidence establishes that the question of the appropriate antibiotic cover in this case was a matter of medical judgment on which views could legitimately differ.

86 I turn now to the trial judge's provisional finding that the failure to prescribe a broad spectrum antibiotic did not cause or materially contribute to the appellant's pseudomonas infection. After referring to the relevant evidence the trial judge said [202]:

Taking account of the nature of the pseudomonas super-bug and relying on Dr Golledge's opinions, I am satisfied on the balance of probabilities that Dr Cooper's failure to give a broad spectrum antibiotic increased his risk of the onset of a pseudomonas infection but I am satisfied that the risk remained irrespective of the giving of a broad spectrum antibiotic, and that Dr Wall was just as likely to develop a pseudomonas infection whatever antibiotic was given. In this case there is evidence the injury would have occurred even if the duty had been performed and therefore the evidential onus did not shift (Strempel v Wood [49]).

87 There are two points I wish to make on this subject. The first relates to the acceptance of Dr Golledge's evidence on causation which on my assessment is to the effect that a pseudomonas infection would on the balance of probabilities have developed even if broad spectrum antibiotics had been given. The provisional finding on causation presumes a finding that there was a breach of duty to treat for the risk of a pseudomonas infection which would necessitate the rejection of Dr Golledge's evidence relating to breach. In my assessment, Dr Golledge's evidence on causation is inextricably linked with his evidence on breach with the consequence that it would not be open to accept Dr Golledge's evidence on causation and reject his evidence on breach. The same is not the case for Professor Spicer who gave evidence which supports a finding that the failure to give an effective broad spectrum antibiotic caused or materially contributed to the contraction or extent of the infection and thus the period of immobilisation.

88 Secondly, the trial judge misunderstood the application of the Bennett principle of causation referred to in Strempel v Wood [2005] WASCA 163 [49]. That principle is to the effect that if a plaintiff has established a prima facie causal connection between the breach and the

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injury, a defendant has an evidential burden to adduce evidence that the breach had no effect or that the injury would have occurred even if the duty had been performed. If there is evidence sufficient to displace the prima facie case, it remains for the plaintiff upon the whole of the evidence to satisfy the tribunal of fact that the injury was caused by the defendant's negligence: City of Stirling v Tremeer [80]; Amaca v Hannell [2007] WASCA 158; (2007) 34 WAR 109 [395]. Thus, if the appellant in this case had established that the respondent breached his duty to provide antibiotic cover for the risk of contracting a pseudomonas infection then because the risk of that infection had materialised the appellant would have established a prima facie case that the breach caused the injury. However, the respondent adduced evidence that satisfied the evidential burden and the trial judge accepted that evidence. I agree with Wheeler JA that the trial judge made in effect a positive finding that the damage would have occurred even if the respondent had not breached his duty. However, I have concluded that it would not be open to accept Dr Golledge's evidence on causation whilst (notionally) rejecting his evidence on breach.