Abstract
BACKGROUND: The recovery period is associated with the greatest risk of injury for horses undergoing anaesthesia. Recovery quality and duration can be influenced by the volatile agent. METHODS: This prospective, randomised blinded clinical investigation recruited 101 healthy client-owned horses undergoing elective surgery at one UK equine hospital. Anaesthesia was standardised, and horses were randomly assigned to receive desflurane or isoflurane for maintenance. Horses were ventilated to normocapnia and received dobutamine to maintain mean arterial blood pressure above 60 mmHg. All the patients received romifidine intravenously prior to recovery, which was timed and video recorded to allow offline blinded evaluation by two experienced clinicians. RESULTS: There was no significant difference between groups in haemodynamic support during anaesthesia or recovery quality. Desflurane horses recovered faster and made fewer attempts to stand. LIMITATIONS: Nonlinearity and lack of validation of the recovery scale limit reliability; however, in the absence of a validated instrument, this scoring system is widely used. CONCLUSION: Haemodynamic support required during anaesthesia and recovery quality were similar between agents. Desflurane horses recovered faster and required fewer attempts to stand, suggesting that this anaesthetic may lead to fewer recovery injuries and optimise workflow in the equine theatre.