[Death under anesthesia. Definition, causes, risk factors and prevention]

Death associated with anaesthetic procedures is rare, 1-4 deaths per 10,000 anaesthesias. However, each case gives rise to discussion about causality and who is to blame. Prospective studies are few, and comparison between them is difficult because of the use of different definitions of anaesthesia related death. A critically ill patient with impaired function of multiple organs seems to be at a higher risk of anaesthesia related death than a more healthy patient. However, no study has so far identified preoperative risk factors of anaesthesia related death. This is probably due to the low incidence of anaesthesia related death. The most common causes of anaesthesia related deaths are: 1) circulatory failure due to hypovolaemia in combination with overdosage of anaesthetic agents such as thiopentone, opioids, benzodiazepines or regional anaesthesia; 2) hypoxia and hypoventilation after for instance undetected oesophageal intubation, difficult intubation, technical failure in the anaesthetic equipment, or aspiration of gastric content, 3) anaphylactoid reactions including malignant hyperthermia, and 4) human negligence such as lack of vigilance or errors in the administration of drugs and in the maintenance and control of the anaesthetic equipment. We discuss the importance of continuing education for anaesthesiologists, development of a standard for surveillance during anaesthesia and quality control of the anaesthetic procedure with registration of undesired incidents. National registration of serious incidents will make it possible to determine the incidence of serious complications and death associated with anaesthesia. Hopefully this registration will provide information about causality and thereby facilitate prevention and improve patient safety during anaesthesia.