Survival from perioperative anaphylaxis in Western Australia 2000-2009

The mortality from perioperative anaphylaxis has recently been quoted in a range between 3 and 9%. However, it was our impression in Western Australia that we had had no deaths from perioperative anaphylaxis for over a decade. As we have comprehensive processes in place to investigate both perioperative anaphylaxis and anaesthesia-related deaths, we undertook this study to determine our actual perioperative anaphylaxis mortality rate.

We obtained the number of deaths related to perioperative anaphylaxis for the decade 2000-2009 from the database of the West Australian Anaesthetic Mortality Committee; in Western Australia it is a legal requirement to report all deaths that occur within 48 h of an anaesthetic, and all deaths due to a complication of an anaesthetic. We obtained the number of cases of perioperative anaphylaxis for the same period from the database of the West Australian Anaesthetic Drug Reaction Clinic.

From 2000 to 2009, there were 45 anaesthesia-related deaths in Western Australia, but none of these involved anaphylaxis. Over this period, there were 264 cases classified by the West Australian Anaesthetic Drug Reaction Clinic as anaphylaxis. The 95% confidence interval for the observed 0/264 mortality rate is 0-1.4%. There were about three million anaesthetics administered in Western Australia over the decade, giving a perioperative anaphylaxis rate of ~1:11,000.

Our incidence of perioperative anaphylaxis was within expectations, but our mortality rate was lower than recently quoted figures. It is likely that the current true perioperative anaphylaxis mortality rate is within the range 0-1.4%.