Pre-operative and anaesthesia-related risk factors for mortality in equine colic cases.
Authors: Proudman C J, Dugdale A H A, Senior J M, Edwards G B, Smith J E, Leuwer M L, French N P
Journal: Veterinary journal (London, England : 1997)
Summary
# Editorial Summary: Pre-operative and Anaesthesia-related Risk Factors for Mortality in Equine Colic Cases Horses undergoing emergency abdominal surgery for colic face substantially elevated mortality risk compared with other surgical procedures, yet the specific pre-operative and anaesthetic factors driving this outcome remain incompletely understood. Using multivariable analysis of 774 surgical colic cases, Proudman and colleagues identified several critical risk markers: elevated heart rate and packed cell volume (PCV) at admission predicted intra-operative death, whilst counterintuitively, horses displaying severe pain showed lower intra-operative mortality—likely reflecting that horses in extreme pain may have better-defined, more surgically addressable lesions. Post-operative mortality increased with advancing age and elevated PCV, and breed significantly influenced prognosis, with draught horses, Thoroughbreds, and Thoroughbred crosses demonstrating worse outcomes than other types. Notably, the choice of anaesthetic induction agent, inhalation maintenance drugs, or use of intermittent positive pressure ventilation had no significant bearing on mortality risk. For practitioners, these findings underscore the importance of assessing cardiovascular compensation at presentation—particularly tachycardia and haemoconcentration—as key indicators of perioperative risk, whilst highlighting that anaesthetic protocol itself appears less critical than managing the horse's underlying physiological status through the surgical and recovery periods.
Read the full abstract on PubMed
Practical Takeaways
- •Pre-operative cardiovascular status (heart rate and PCV) is a strong predictor of intra-operative mortality in surgical colic cases—assess these parameters carefully before committing to surgery
- •Age and breed significantly influence post-operative survival; older horses and certain breeds (Draught, Thoroughbred types) carry higher risk and may require more intensive post-operative monitoring
- •Anaesthetic choice itself appears less critical than other factors; focus on optimising cardiovascular stability and pain management rather than selecting specific anaesthetic agents
Key Findings
- •Intra-operative mortality was significantly associated with elevated heart rate and packed cell volume (PCV) at admission, and negatively associated with severity of pain
- •Post-operative mortality increased with increasing age and PCV at admission
- •Draught horses, Thoroughbreds, and Thoroughbred-cross horses had significantly worse prognosis than other breeds
- •Anaesthetic induction agents, inhalation maintenance agents, and use of intermittent positive pressure ventilation had no significant effect on mortality risk