130 Applying those principles, this submission by the plaintiffs fails to meet the test of factual causation. There is no evidence to support the submission. The proposition was never put in terms to any of the doctors. The submission is based on speculation not inference. In that regard, not only is it not known when the clot formed and when it broke off, but it is not capable of being known.
131 On causation questions the focus is a retrospective one and is concerned with what actually happened. The operation took place on 1 May and the fatal PE occurred on 27 May. The medical evidence is all one way. The medical experts say that one or two doses of Clexane given at the time of the operation would not have prevented the development of the fatal PE 27 days later. This evidence was not accompanied by any qualifications. Accordingly, although there was a breach of duty by Dr Newman in failing to ensure that a dose of Clexane was administered following the operation, that breach did not play a part in bringing about the fatal PE. This submission by the plaintiffs fails.
132 The plaintiffs' alternative submission was that Dr Newman breached the duty of care which he owed to the deceased in that having embarked upon the prescription of Clexane, he should have ensured that it was administered to the deceased for 7-10 days. In oral submissions the argument was put as follows:
"But the second limb of our argument is this; looked at from a practical point of view, if you decide you are going to do a dose then it has to be something which is based on rationality and dosage intervals. It is insufficient for Dr Newman to say look I went by the guidelines. I didn't have anything else to go by." (T.190.42)
133 In support of that submission, the plaintiffs relied upon the evidence of Dr McGrath that there was a certain logic in administering Clexane for that period of time [64]. The Court was referred to the distributor's recommendation and the recommendation of 7-10 days of treatment in the 2004 edition of MIMS. The plaintiffs submitted that having decided that there was a prophylactic benefit to be gained from Clexane in relation to the risk of DVT and VTE, it was illogical of Dr Newman not to have ensured that an appropriate dose was administered to the deceased, i.e. 40 mg per day for 7-10 days.
134 In considering this submission and the question of breach of duty generally, it is useful to have regard to two statements of principle by the High Court.
"In the way in which litigation proceeds, the conduct of the parties is seen through the prism of hindsight. A foreseeable risk has eventuated, and harm has resulted. The particular risk becomes the focus of attention. But at the time of the allegedly tortious conduct, there may have been no reason to single it out from a number of adverse contingencies, or to attach to it the significance it later assumes. Recent judgments of this Court have drawn attention to the danger of a failure, after the event, to take account of the context, before or at the time of the event, in which a contingency was to be evaluated." ( Rosenberg v Percival [2001] HCA 18, (2001) 205 CLR 434 Gleeson CJ at [16])
"Again, because the inquiry is prospective, it would be wrong to focus exclusively upon the particular way in which the accident that has happened came about. In an action in which a plaintiff claims damages for personal injury it is inevitable that much attention will be directed to investigating how the plaintiff came to be injured. The results of those investigations may be of particular importance in considering questions of contributory negligence. But the apparent precision of investigations into what happened to the particular plaintiff must not be permitted to obscure the nature of the questions that are presented in connection with the inquiry into breach of duty. In particular, the examination of the causes of an accident that has happened cannot be equated with the examination that is to be undertaken when asking whether there was a breach of duty of care which was a cause of the plaintiff's injury. The inquiry into the causes of an accident is wholly retrospective. It seeks to identify what happened and why. The inquiry into breach, although made after the accident, must attempt to answer what response a reasonable person, confronted with a foreseeable risk of injury, would have made to that risk. And one of the possible answers to that inquiry must be "nothing". ( Vairy v Wyong Shire Council [2005] HCA 62, (2005) 223 CLR 422 Hayne J at [124]).
135 Doctor Newman set out his reasons for prescribing one or two doses of Clexane ([28] - [31]). I have already indicated why I accept Dr Newman as a truthful witness. The reasons why I have found that the content of the duty of care did not include an obligation to administer Clexane to the deceased apply equally to this issue. There are additional reasons.
136 Although Dr McGrath said that there was a certain logic in administering Clexane for 7-10 days, it is clear from other evidence that there was an equally compelling logic in restricting the dosage to the time which a patient spent in hospital. This was the time when a patient's immobility was at its greatest and therefore the risk of a clot developing was at its greatest. Doctor McGrath said that such a practice had a prophylactic value and it was the practice followed by Dr Sullivan. It also reduced the risk of the development of one of the well-known side effects of Clexane, such as haemorrhage.
137 Apart from the MIMS publication and the recommendations of the distributor of Clexane, Aventis, the medical literature was all one way. It did not recommend the routine administration of LMWH or Clexane for this kind of surgery. Some particular risk factor had to be identified in a patient. None were identified in the deceased. There is no basis for Dr Conrad's assessment of the deceased as a high-risk patient or of this operation as a high-risk operation. The opinion of the defendants' medical experts was to the contrary as were the conclusions in the medical literature available at the time. The only specific risk identified in the evidence was that of immobility. This was a risk inherent in the operation itself and one would have thought, inherent in any foot or ankle operation.
138 The medical literature did not specify any particular dosage of Clexane or LMWH. The literature set out the advantages and disadvantages of the administration of LMWH and made recommendations. It was generally acknowledged that the medical literature provided little guidance as to the time over which LMWH was to be administered. Because of this lack of clear guidance and the real risks associated with the administration of LMWH, the consensus of the defendants' medical experts was that it was for the treating clinician to decide the period over which LMWH should be administered, having regard to the particular circumstances of the patient.
139 Against that evidentiary background, and keeping in mind that the question of breach of duty is a prospective analysis based on the state of knowledge and the circumstances at the time, it was well open to Dr Newman to adopt the compromise which he did, i.e. to administer LMWH in the case of an Achilles tendon operation only while the patient was in hospital. This was his practice if there were no special risk factors associated with the development of a DVT or VTE. The rationale for such a compromise was obvious. While providing a prophylactic benefit during a patient's period of most immobility, it also reduced the risk of dangerous complications such as haemorrhage. It also avoided the difficulties associated with self-administered Clexane outside the hospital. I am not persuaded that the failure by Dr Newman to administer Clexane or other LMWH for 7-10 days following the operation constituted a failure to comply with the appropriate professional standards.
140 If I am wrong in that conclusion, the evidence clearly establishes the defence in s 5O of the Civil Liability Act 2002.
"5O Standard of care for professionals
(1) A person practising a profession ( a professional ) does not incur a liability in negligence arising from the provision of a professional service if it is established that the professional acted in a manner that (at the time the service was provided) was widely accepted in Australia by peer professional opinion as competent professional practice.
(2) However, peer professional opinion cannot be relied on for the purposes of this section if the court considers that the opinion is irrational.
(3) The fact that there are differing peer professional opinions widely accepted in Australia concerning a matter does not prevent any one or more (or all) of those opinions being relied on for the purposes of this section.
(4) Peer professional opinion does not have to be universally accepted to be considered widely accepted."
141 In relation to the application of s 5O I respectfully adopt the approach of McClellan CJ at CL in Halverson v Dobler [2006] NSWSC 1307, that the section is intended to operate as a defence. This approach was approved by the Court of Appeal in Dobler v Kenneth Halverson [2007] NSWCA 335 at [59] - 60] where Giles JA said:
"59 Section 5O was amongst the tort law reforms consequent on the Review of Law of Negligence Final Report, September 2002 ("the Review "). It was intended to introduce a modified Bolam principle. Its importance does not lie so much in questions of onus of proof as in who determines the standard of care. Commonly, as in the present case, there will be expert evidence called by the plaintiff to the effect that the defendant's conduct fell short of acceptable professional practice and expert evidence called by the defendant that it did not; the expert evidence may or may not recognise that the opposing professional practice is one which has some currency. Apart from s 5O the Court would determine the standard of care, guided by the evidence of acceptable professional practice. It would not be obliged to hold against the plaintiff if the defendant's conduct accorded with professional practice regarded as acceptable by some although not by others. Section 5O has the effect that, if the defendant's conduct accorded with professional practice regarded as acceptable by some (more fully, if he "acted in a manner that … was widely accepted … by peer professional opinion as competent professional practice"), then subject to rationality that professional practice sets the standard of care.