Peri-anaesthetic adverse events and their risk factors in 316 pet rabbits undergoing general anaesthesia: A multicentric, retrospective study

Rabbit anaesthesia carries higher risk or morbidity and mortality than anaesthesia of more conventional small animal species. This retrospective study investigated the occurrence of peri-anaesthetic adverse events and their risk factors in a population of pet rabbits. Data from 316 rabbits anaesthetised at three different veterinary centres were obtained from the anaesthetic record database systems and transferred to an excel spreadsheet. Keywords used for the database search were "rabbit/rabbits", "anaesthesia/general anaesthesia", and "GA". Variables related to demographics and anaesthetic protocol were categorized to be used for univariable and multivariable logistic regression. Risk factors for hypoxaemia were identified as delayed establishment of airway access, hypoventilation requiring intervention, and use of anaesthetic protocols that did not include an α2-adrenoreceptor-agonist. Surgical procedures lasting more than 30 min and use of anaesthetic protocols that did not include an α2-adrenoreceptor-agonist significantly increased the risk of surgical nociception requiring the administration of rescue analgesics. Not including an opioid or α2-adrenoreceptor agonist in the anaesthetic protocol, as well as hypothermia and surgical nociception requiring intervention, increased the risk of poor quality of recovery. The risk of peri-operative cardiopulmonary arrest was significantly increased when ASA physical status classification was higher than II, and when hypoventilation requiring intervention occurred. Prevention or mitigation of the risk factors identified in this study may help the clinicians to make evidence-based clinical decision, thus improving safety and outcome when performing rabbit anaesthesia.