Risk factors for anaesthetic-related death in cats: results from the confidential enquiry into perioperative small animal fatalities (CEPSAF)

Background. Cats are commonly anaesthetized in veterinary practice, but recent figures describing the frequency of or risk factors for anaesthetic-related death are not available. The aims of this study were to address these deficiencies. Methods. A nested case-control study was undertaken in 117 UK veterinary centres. All anaesthetic and sedation procedures and anaesthetic and sedation-related deaths (i.e. 'cases') occurring within 48 h were recorded. Details of patient, procedure, and perioperative management were recorded for all cases and randomly selected non-deaths (controls). A detailed statistical model of factors associated with anaesthetic and sedation-related death was constructed. Results. Between June 2002 and June 2004, 175 deaths were classified as anaesthetic and sedation-related and 14 additional deaths (with insufficient information to be excluded) were included for the estimation of risk. During the study, 79 178 anaesthetic and sedation procedures were recorded and the overall risk of anaesthetic and sedation-related death was 0.24% (95% CI 0.20-0.27). Factors associated with increased odds of anaesthetic-related death were poor health status (ASA physical status classification), increasing age, extremes of weight, increasing procedural urgency and complexity, endotracheal intubation, and fluid therapy. Pulse monitoring and pulse oximetry were associated with reduced odds. Conclusions. The risk of anaesthetic-related death in cats appears to have decreased since the last published study in the UK. The results should aid the preoperative identification of cats at greatest risk. Greater care with endotracheal intubation and fluid administration are recommended, and pulse and pulse oximetry monitoring should be routinely implemented in cats.