The Special Committee Investigating Deaths Under Anaesthesia (SCIDUA) reviews all deaths under or within 24 h of anaesthesia in the Australian state of New South Wales, with a population of 5.7 million. The Committee is appointed by the Minister for Health, is legally privileged and provides complete confidentiality of its investigations. Deaths are reported to SCIDU by the State Coroner's Office. The anaesthetist involved in each case then is asked to complete and voluntarily return a questionnaire on the event. There is a 92% response rate.In reviewing 1503 deaths in approximately 3.5 million surgical procedures between 1984 and 1990, the Committee concluded that factors under the control of the anaesthetist caused or significantly contributed to the deaths of 172 patients. No better alternative procedure was available in 11 of the cases and, in these, the procedure was carried out properly. The findings demonstrate a rate of one anaesthesia related death in 20 000 operations, compared with 1:5500 in 1960 and 1:lO 250 in 1970.In children under ten years of age, there were 76 deaths investigated, with approximately 280 000 operations in this age group. sixty-three percent of the children were less than one year. The operations involved were chiefly cardiothoracic, laparotomies for necrotising enterocolitis in premature neonates and trauma surgery. Anaesthetic factors were implicated in only one of the 76 deaths.While there are limitations to the study, in its 34 years SCIDUA has provided a credible estimate of anaesthesia related mortality and been able to highlight features of its incidence and pattern. The major anaesthetic factors relating to the deaths remain inadequate pre-and postoperative care, inappropriate choice of anaesthetic technique or drugs and overdosage with anaesthetic agents.

The Special Committee Investigating Deaths Under Anaesthesia (SCIDUA) reviews all deaths under or within 24 h of anaesthesia in the Australian state of New South Wales, with a population of 5.7 million. The Committee is appointed by the Minister for Health, is legally privileged and provides complete confidentiality of its investigations. Deaths are reported to SCIDU by the State Coroner's Office. The anaesthetist involved in each case then is asked to complete and voluntarily return a questionnaire on the event. There is a 92% response rate.In reviewing 1503 deaths in approximately 3.5 million surgical procedures between 1984 and 1990, the Committee concluded that factors under the control of the anaesthetist caused or significantly contributed to the deaths of 172 patients. No better alternative procedure was available in 11 of the cases and, in these, the procedure was carried out properly. The findings demonstrate a rate of one anaesthesia related death in 20 000 operations, compared with 1:5500 in 1960 and 1:lO 250 in 1970.In children under ten years of age, there were 76 deaths investigated, with approximately 280 000 operations in this age group. sixty-three percent of the children were less than one year. The operations involved were chiefly cardiothoracic, laparotomies for necrotising enterocolitis in premature neonates and trauma surgery. Anaesthetic factors were implicated in only one of the 76 deaths.While there are limitations to the study, in its 34 years SCIDUA has provided a credible estimate of anaesthesia related mortality and been able to highlight features of its incidence and pattern. The major anaesthetic factors relating to the deaths remain inadequate pre-and postoperative care, inappropriate choice of anaesthetic technique or drugs and overdosage with anaesthetic agents.

No abstract

Previous studies suggest that the muscles of the diaphragm are less sensitive to neuromuscular blocking agents than the limb muscles. However, this difference has not been characterized directly in terms of relaxant drug plasma concentrations. The pharmacodynamics of the non-depolarizing muscle relaxant alcuronium were therefore investigated in nine dogs using a constant-rate infusion regimen with simultaneous measurement of muscle paralysis in the limb and diaphragm. Maximum paralysis between 95 and 100% was achieved in both muscle groups, within approximately the same time interval. However, during onset of and offset of effect, the pharmacodynamic parameters ECp50 and ECp95 for the limb muscle were lower than in the diaphragm. From a pharmacodynamic effect model it was also predicted that Css(50) and Css(95) for the limb muscles are half those values for the diaphragm. Thus, the diaphragm is less sensitive to the action of alcuronium than are limb muscles. The half-time for equilibration of alcuronium between plasma and the effect site was two-fold lower for the diaphragm, and the rate of recovery from paralysis in diaphragmatic muscles was twice that observed in limb muscles. Collectively, these data suggest that there is a greater margin of safety in the diaphragmatic muscles and that the response of the peripheral limb muscles to nerve stimulation provides only a conservative index of recovery from competitive neuromuscular block in the diaphragmatic muscles.