The Confidential Enquiry into Perioperative Equine Fatalities: phase 4 (CEPEF4) - a worldwide observational, prospective, multicentre cohort study in 2025.

Abstract

OBJECTIVE: To report on the Confidential Enquiry into Perioperative Equine Fatalities 4 (CEPEF4). STUDY DESIGN: Confidential, observational, prospective, multicentre, cohort study. ANIMALS: 47,396 horses/ponies undergoing general anaesthesia (GA). METHODS: Characteristics of each GA (249 variables) were collected. Outcomes after seven days were ALIVE (or discharged), EUTHANASIA or DEAD. Logistic regression analysed patient demographics and the anaesthetic drugs (p < 0.05). RESULTS: Data were collected from 47,396 GAs in 93 centres in 28 countries. Death rates were 1.2% overall, 0.6% for cases classified as NON-COLIC and 4.2% for COLIC. For NON-COLICs (227 deaths from 39,798 NON-COLICs), the main three causes of death were fractures (35.7%), abdominal complications (18.1%) and central nervous system problems (13.2%). Logistic regression analyses revealed an increase in the odds of death for pregnant mares, geriatrics, thin horses, those with a higher American Society of Anesthesiologists grade, urgent procedures and those lasting < 1 hour or > 2 hours. Ketamine infusions and plasma lactate measurement during maintenance were associated with elevated risk. By contrast, monitoring invasive arterial pressure, end-tidal CO, blood gases and body temperature were each associated with reduced odds of death. Premedication with agonist-antagonist/partial-agonist opioids with non-steroidal anti-inflammatory drugs and administration of &#x3b1;-adrenoceptor agonists during recovery, alone or with acepromazine, were associated with reduced odds of death. CONCLUSIONS AND CLINICAL RELEVANCE: CEPEF4 reports a reduction in the death rate compared with CEPEF2 in 2002: overall 1.2% versus 1.9%, colic death rate 4.2% versus 7.8% and non-colic death rate 0.6% versus 0.9%. Healthy horses still die, the majority because of fractures during recovery. We identified factors that may influence clinical decision-making and enhance patient safety. The CEPEF4 database will continue to provide clinically applicable information, with potential for further insights and improvements in equine anaesthesia.