In 1990, a survey of 20 814 dogs and 20 103 cats undergoing general anaesthesia in the UK reported a mortality of 0.23% in dogs and 0.29% in cats.(20) However, when they were divided into two groups, on the basis of the absence or presence of pathology, a different situation was observed. In dogs, the figure was 3.12% with pathology and 0.11% without. In cats, a similar pattern was observed with a mortality of 3.33% with pathology and 0.29% without. There were few factors that could be highlighted as the main cause of death. However, the administration of xylazine was again associated with an exceptionally high mortality rate. Complications following tracheal intubation in the cats appeared to be associated with several deaths.
In a survey involving some 30 000 anaesthetics reported in 1992, a mortality rate of 0.11% was reported in dogs and 0.06% in cats.(21) The most common cause of death was cardiopulmonary arrest. A further single institution survey published in 1994 recorded a death rate of 0.43% in dogs and cats.(22) Most of the deaths were associated with cardiac arrest and, due to the nature of the surgical condition, resuscitation was not attempted in some of these animals. A more recent survey was published in 1998 on anaesthesia in the dog and cat.(23) Death occurred in 0.11% of 8087 dogs and in 0.1% of 8702 cats. Significant odds ratios were calculated for a number of factors including the association of cardiac arrest with xylazine administration in dogs. A modified ASA classification of patient status was adopted, and a classification of 3, 4, or 5 was also associated with an increased incidence of cardiac arrest in both species.
It would appear that the incidence of death associated with anaesthesia over a number of years has shown a reduction in most species. Whilst this may well have been associated with the development of ââ‚¬Ëœsafer anaesthetic techniquesââ‚¬â„¢, it is most likely also to have been associated with attempts to reduce human error by improved training and wider use of sophisticated monitoring methods. However, with the developments in surgery, which have presented greater challenges to the anaesthetist, it remains to be seen whether further major improvements in mortality figures will occur in the foreseeable future.
20 Clarke KC, Hall LW. A survey of anaesthesia in small animal practice. AVA/BSAVA report. J Ass Vet Anaesth 1990; 17: 4ââ‚¬â€œ10
21 Dodman NH, Lamb LA. Survey of small animal anesthetic practice in Vermont. J Anim Hosp Ass 1992; 28: 439ââ‚¬â€œ45[ISI]
22 Gaynor JS, Dunlop CI, Wagner AE, Wertz EM, Golden AE, Demme WC. Complications and mortality associated with anesthesia in dogs and cats. J Anim Hosp Ass 1994; 35: 13ââ‚¬â€œ7
23 Dyson DH, Maxi MG. Morbidity and mortality associated with anesthetic management in small animal veterinary practice in Ontario. J Anim Hosp Ass 1998; 35: 325ââ‚¬â€œ35[/b]