A Retrospective Study on Pre- and Intraoperative Predictors on the Recovery Quality of Horses After General Anesthesia

Equine anesthesia is related to high morbidity and mortality rates and recent studies suggested that the period of recovery remains the phase associated with the greatest risk of mortality in horses. Intraoperative hypotension, hypoxemia, and hypercapnia are recognized as potential determinants of recovery quality. This study, conducted at the Equine University Hospital of Liege, aimed to explore how these factors influence recovery outcomes and compare complications between non-emergency and emergency procedures. We analyzed data from 1057 horses, with a mean weight of 498 kg (ranging from 150 to 850 kg) and a mean age of 10.7 (ranging from 0.5 to 37 years), undergoing standardized general anesthesia for non-emergency and emergency procedures to assess which factors influence recovery quality. Recoveries were graded as 'good' or 'bad' and age, sex, breed, American Society of Anesthesiologists (ASA) physical status classification, weight, anesthesia duration, presence of hypotension, hypoxemia, and hypercapnia were compared with a logistic regression analysis. Our findings highlight the multifactorial nature of anesthetic recovery in horses, with breed, age, anesthesia and recovery duration, and emergency status emerging as significant influencing factors. Additionally, monitoring and managing hypoxemia and hypotension remain critical due to their recognized impact on recovery quality. However, despite their clinical relevance, the specific effects of these variables on anesthetic recovery in horses remain insufficiently studied, emphasizing the need for further research to refine perioperative management strategies and improve outcomes.