Estate of Otter v Accident Rehabilitation and Compensation Insurance Corporation

IN THE DISTRICT COURT Decision Ne. 154 /96 AT WELLINGTON UNDER THE Accident Rehabilitation and Compensation Insurance Act 1992 AND IN THE MATTER of an appeal pursuant to Section 91 of the Act BETWEEN THE ESTATE OF JENNIFER ANNE OTTER APPELLANT (DCANO, 8/95) AND ACCIDENT REHABILITATION AND COMPENSATION INSURANCE CORPORATION a body corporate duly constituted under the provisions of the said Act RESPONDENT Date of Hearing: 24 July 1996 Date of Decision: 18 December 1996 Counsel for Appellant: M Mclennan Counsel for Respondent: R F Irving DECISION OF JUDGE J.H. LOVELL-SMITH INTRODUCTION The issue in this appeal is whether the Appellant's wife's death was as a result of medical misadventure. 2 There is no dispute that there was an error in the treatment of the Appellant when she was administered a double dose of insulin on 11 July 1992. The issue is whether that medical error caused her death. There is a further issue as to whether Mrs Otter's care following the administration of the double dose of the insulin was a medical error and, if so, whether it was causative of her death. THE COURSE OF THE HEARING A medical assessor, Professor D Beaven, was appointed pursuant to Section 93 of the Accident Rehabilitation and Compensation Insurance Act 1992 ("the Act"). I am indebted to him for all his help. Mr Otter and Professor Ian Holloway gave evidence. BACKGROUND Mr Otter lodged a claim on behalf of his late wife on 23 December 1992 stating that the Appellant had been given a "double dosage of insulin in error" and that she died later that same day. The medical certificate stated "Given double dose insulin in error. Post-mortem showed heart disease". The claim was referred to the Medical Misadventure Advisory Committee ("MMAC") comprising Ms S Moran, Ms S Cole and Dr C Burgess, a pharmacologist. w The committee considered the evidence and concluded on 28 April 1994: "This claim, involving death following the administration of a double dose of insulin given in error cannot be considered under the provisions of medical misadventure. This is because, in the committee's view, there is no medical evidence to support the claim that Mrs Otter's death could be attributed to the double dose of insulin. The committee noted that Mrs Otter's health was already compromised and that at no time during the day following the double dose of insulin, was the level of sugar in Mrs Otter's blood low." The Respondent declined the claim on the basis of the Committee's recommendation. THE REVIEW OFFICER'S DECISION Mr Otter applied for a review of that decision. The hearing commenced on 16 August 1994 and resumed on 1 November 1994. The Review Officer obtained additional medical evidence from Dr Cutfield, a specialist physician, diabetologist and endocronologist together with a further report from Dr T Koelmeyer, Associate Professor of Forensic Pathology. The review hearing resumed in the presence of Mr Otter and Dr Cutfield. 4 In his decision of 22 December 1992, the Review Officer concluded that the evidence did not establish that medical error, namely the double dose of insulin, caused Mr Otter's death. The Review Officer, however, posed a series of questions about the care of Mrs Otter following the administration of the double dose of insulin. In particular, was there any negligence and if so, whether that contributed to Mrs Otter's death. The Review Officer considered that this was not a matter within the scope of the enquiry but invited the Respondent to conduct its own further enquiry should it decide to do so. The Respondent did not pursue any further enquiries forming the view that the matter had been fully investigated and that any further enquiry would be superfluous. The manager of the Medical Misadventure Unit advised Mr Otter of the Respondent's decision on 16 January 1996. THE LAW Section 8(2) of the Act provides that the Act shall cover personal injury which is medical misadventure. Medical misadventure is defined in section 5 of the Act to mean: "Personal injury resulting from medical error or medical mishap". Section 5 also defined medical error to mean: "The failure of a registered health professional to observe the standard of care and skill reasonably to be expected in the circumstances. It is not medical 5 error solely because desired results are not achieved or because subsequent events show that different decisions might have produced better results". Section 4 defines personal injury: "... and means the death of, or physical injuries to, a person, and any mental injury suffered by that person which is an outcome of those physical injuries to that person. No cardiovascular or cerebrovascular episode (a heart attack or a stroke) is to be regarded as personal injury for the purposes of the Act unless it is a result of medical misadventure; or it is a work injury by virtue of section 6(1) of the Act". SUBMISSIONS (i) The Overdose Of Insulin It is accepted by the Respondent the administration of the double of insulin on 11 July 1992 was medical error. The question is one of causation. The onus of proof is upon the Appellant. The Appellant is required to prove on the balance of probabilities that Mrs Otter's death was due to medical error. It was submitted on behalf of the Respondent that the reports from Dr Koelmeyer, Dr Cutfield and Dr Holdaway do not support a finding that the double dose of insulin was causative of Mrs Otter's death or a cardiac episode. 6 In his statement to the coroner Professor Koelmeyer said: "Insulin in excess causes a provide fall in blood sugar and this can lead to death. A level of vitreous glucose is determined at analysis (and this reflects the blood glucose levels) as high and thus I believe it is reasonable to state that the insulin did not cause (or, for that matter contribute significantly) to death" However in his conclusion he said: 'I believe that the cause of death is multifactorial with the muscular dystrophy and myocardial scarring contributing. I believe that the insulin excess did not contribute." Professor Koelmeyer confirmed his opinion in a further letter of 25 October 1994: "I believe that the "overdose of insulin" did not cause death. The blood sugar levels at the time of the autopsy (and this of course reflects the level present at the incident of death) is high and clearly the treatment procedures instituted to prevent a fall of blood-sugar due to excess insulin had had the desired effect." He suggested that matters relating to the implications of an overdose of insulin were best discussed with a specialist in this field. Dr R Cutfield, a specialist in this field, considered that at that time there was "insufficient evidence to suggest exact cause of death". In his report of 20 July 1994 he referred to Dr Koelmeyer's report of myocardial fibrosis and cerebral infarction 7 and wondered whether there may have been a small brain stem ischaemic event. He said he could "only guess as to whether she may have had a cardiac arrhythmia. Dr Cutfield said: "In conclusion there is no evidence of hypoglycaemia having caused this problem. Although hypoglycaemia really can cause death and may precipitate myocardial events, I do not believe it contributed to Mrs Otter's death. Insufficient evidence precludes a more accurate conclusion of the exact form of her demise." Dr Cutfield in a further report of 7 September 1994 said: "As it is unclear what actually caused Mrs Otter's death (for example arrhythmia perhaps most likely secondary to some myocardial damage, - less likely), it is very difficult to comment further. It is very unlikely that hypoglycaemia was implicated as I have mentioned in my letter and conversely, a blood-sugar advancing to 26 would not cause coma and would be a very unlikely cause of her death even indirectly. Many patients with diabetes have blood-sugars advancing in this range unfortunately and do not run into major problems that we are aware of." In his letter of 3 November 1994, Dr Cutfield said: "Firstly he [Mr Otter] is concerned about the effect of the overdose of insulin. I explained carefully to him that although a double does was given, that it did 8 not cause significant hypoglycaemia and while the blood sugars were variable during the day, in my opinion these were not responsible for his wife's death." I agree with the Respondent's submission that Dr Cutfield whilst uncertain as to the exact cause of death or any cardiac or cerebral episode, he excludes the likelihood of the double dose of insulin as being implicated. Professor Ian Holloway, an expert endocronologist, filed a report in June 1996 at the request of the Appellant. Dr Holdaway reviewed Mrs Otter's hospital case notes, her post-mortem report and the several reviews of her management while at St Margaret's Hospital. In his report he discussed the way in which the overdose of insulin and the consequent administration of glucose could potentially have contributed to Mrs Otter's death. He concluded as follows; "If these were not involved in her death (and one has to admit that their role is hypothetical), the most likely cause for her death is actually an increasing heart damage from the combination of muscular dystrophy and diabetes and that this led to arrhythmia plus-minus cardiac failure, coma and eventual cardiac arrest on the evening of 11.7.92. She was clearly at risk of this happening at any time, and whether or not the extra insulin and glucose administration during the day of 11.7.92 contributed or caused this problem remains uncertain." Professor Holdaway could not be certain as to whether Mrs Otter would have died on 11 July 1992 if she had not received the extra dose of insulin. He states that she 9 probably would still have died on this date, but it remains possible that she would have lived longer if the extra insulin had not been given. I accept that Professor Holdaway was unable to reach any conclusion as to whether or not the double dose of insulin played any part in Mrs Otter's death. In all the circumstances of this case I find that there was no, or no sufficient evidence to find on the balance of probabilities any cause or connection between the overdose of insulin and the death of Mrs Otter or any cardiac or cerebral events she suffered on 11 July 1992. (ii) Mrs Otters Medical Treatment And Hospital Care Following The Overdose Of Insulin. I turn now to consider the separate issue raised by the Appellant, namely the medical treatment of his wife following the overdose of insulin. I accept that to sustain a claim of personal injury by medical misadventure in this context would require proof of a medical error and that the medical error was causative of the personal injury. Again the question of causation is one to be determined largely on the medical evidence. 10 Medical error is ultimately a question of law but it does depend upon the medical evidence as to "the standard of care and skill reasonably to be expected in the circumstances". The Respondent's file discloses considerable disquiet regarding the inadequacy of the hospital notes. The medical advisory committee's also expressed concern that an emergency doctor was not called in. However, it was counsel for the Respondent's submission that neither the committee nor the medical specialist express an opinion that would support a finding that there was a failure to "observe a standard and skill reasonably to be expected in the circumstances". Dr Cutfield in his letter of 20 July reported: "The nurses when realising their error closely monitored the blood glucose and levels were taken at 08:30 (26.2), 09:50 (17) and 11:45 (13.8). She was given a glucose drink. At 12.45 her glucose level was measured at 7. Her blood glucose was 17.1 at 12:30 hours and at 12.2 at 14:00 hours. If the blood glucose levels are accurate then the level of 23.1 at 16:30 hours argues against any remote possibility of hypoglycaemia from the extra does of Mixtard." In his letter of 3 November 1994 Dr Cutfield says: "His [Mr Otter] other main concern is that he felt that there was considerable delay in the nursing home when his wife became comatose before transferring her to hospital. As you know, she died in the ambulance. I really could not 11 comment any further on that at this stage and that may need to be the basis of a subsequent enquiry by Mr Otter through you." Counsel for the Respondent contended that Professor Koelmeyer in his capacity of the pathologist reporting to the coroner had to be alert to any possible mishandling of the Appellant's care. In his sworn statement he states "appropriate steps were taken". It was contended therefore on behalf of the Respondent that there is no evidence upon which any conclusion can be drawn that the medical care following the overdose of insulin was insufficient, or amounted to medical error. Mrs Otter developed muscular dystrophy in 1982 and non-insulin dependent diabetes was diagnosed about the same time. Mr Otter gave evidence that on tablet treatment prior to her admission to North Shore Hospital with serious pneumonia in 1992, that he monitored her blood sugar levels, aiming to "not let these get into double figures". During her two month stay in North Shore Hospital Mrs Otter had at least one documented evidence of arrhythmia. The case notes record a low blood pressure (of the order of 70/45) due to a 2:1 heart block following a trial flutter. This was treated with a rhythm stabilising drug called 'amioderone', which reverted the rhythm to normal. 12 Mrs Otter had already had one serious rhythm change clearly documented in North Shore Hospital, and could reasonably have been expected to be monitored for others after transfer to St Margaret's Hospital. On 11th July the second dose of 12 units of Mixtard as Professor Ian Holdaway concedes, would have led to considerable transport of potassium ions out of the blood stream into the cells. This would have led to variations in serum potassium, undoubtedly increasing the known risk of arrhythmias in an at-risk person. Subsequent to the double dose of insulin, Professor Holdaway could not find any written record in the St Margaret clinical case record of: (i) What food, glucose or fluids given on the day (11.7.92) of her death. (ii) No note is recorded by any attending, visiting or resident medical staff during the day. (iii) No nursing observations are recorded during the day or at changeover of shifts. (iv) No blood pressure is recorded either during the day or when she was found in a coma. 13 Professor Holdaway comments adversely on the lack of confirmation of finger prick glucose values (well known to be subject to error) by venous glucose and in particular, the lack of serum potassium values. Professor Koelmyer in his autopsy report to the Coroner, whilst excluding hypoglycaemia as the immediate cause of death, quotes a potassium figure which Professor Holdaway translates back to a possibly low value at death. (vi) Professor Holdaway comments adversely on the lack of any medical record or ECG at the time of the presumed onset of coma approximately 1 to 1 1/2 hours prior to the death of Mrs Otter in the ambulance. The Review Officer, in his decision, does raise serious questions himself about the fact that there were no clinical records from St Margaret's Hospital. It has now been established that none existed. There is no dispute that the medical and nursing staff responsible for Mrs Otter's care were registered health professionals. I accept Mr Otter's evidence that he tried to keep home blood sugars in single and not double figures (normal blood glucose values 3.6 - 6.8 mls/litre - mean of 4.9, and this range = 2 standard deviations from normal). 14 Mrs Otter's blood sugars varied widely at St Margaret's, her finger prick values (if accurate) fluctuating between 7 and 26.7. Professor Holdaway's evidence was that he would be unhappy to have several values in the 20s in his ward. Indeed, North Shore Hospital clinical notes request in writing by the medical officer to keep sugars between 10 and 14 mis/litre in Mrs Otter's case. People with muscular dystrophy die early usually of arrhythmia. Fluctuating potassium levels are likely when blood sugars swing so much. On balance of probabilities, it seems likely that Mrs Otter had an arrhythmic episode some time during the afternoon. Such a condition had been previously diagnosed and treated at North Shore Hospital. Most of the difficulty in attempts by health professionals and the Respondent to unravel the sequence of events in this case stems from the complete lack of a clinical record including any record of simple blood tests for glucose and electolytes, lack of documentation and information about the clinical status, and no record or comment by any doctor on the day of Mrs Otter's death. In my view these omissions by medical and nursing staff constitute a failure to observe the standard of care and reasonably to be expected in the circumstances and there is no evidence to displace my conclusion from proven facts that the death of Mrs Otter was due to such failure. 15 The appeal is allowed. If costs cannot be agreed then the parties may file further written submissions. Jane H. Lovell-Smith District Court Judge