Canine anaesthetic death in Spain: a multicentre prospective cohort study of 2012 cases.

Objective: To study current perianaesthetic mortality in dogs in Spain and to identify the main risk factors predisposing to perianaesthetic mortality in our country.
Study Design: A multicentre prospective cohort study.
Animal Population: Dogs anaesthetised for different surgical and diagnostic procedures at 39 Spanish veterinary clinics between February 2007 and March 2008.
Methods: Data of patients, procedures and anaesthetic management were recorded. Anaesthetic death was defined as perioperative death within 24 hours of the procedure end. A multivariate study evaluated perinanaesthetic death using logistic binary regression models with the Wald technique.
Results: 2012 animals were included in the analyses. Twenty-six dogs died. The global mortality rate was 1.29% (95% Confidence interval (95% CI): 0.88-1.89%). ASA I-II was 0.33% (95 CI: 0.14-0.78%); ASA III-V was 4.06% (95% CI: 2.67-6.13%). Most deaths occurred during the post-operative period (20 dogs, 77%). The multivariate analysis revealed that high ASA grade was associated with an increased risk of mortality. The use of opioids plus NSAIDs during anaesthesia was related with a decrease of the risk.
Conclusions: Perianaesthetic mortality in dogs in Spain was 1.29% (95% CI: 0.88-1.89%). ASA grade was the main prognostic factor of likelihood of death. The use of some analgesics (opioids and NSAIDs) in the perioperative period was associated with reduced odds of death and may be protective.
Clinical Relevance: Evaluation and stabilisation of patients before interventions may help lower risk of death during the anaesthesia. In addition to their use for welfare purposes, analgesics may be beneficial in reducing anaesthetic-related deaths.
(© 2013 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.)