Development of a classification system for equine postoperative complications and its application in a cohort of 190 horses undergoing emergency laparotomy

Background: Accurate reporting of postoperative complications is paramount to understanding procedural outcomes, comparing procedures and assuring quality improvement. Standardising definitions of complications in equine surgeries will improve the evidence of their outcomes. To this end, we proposed a classification for postoperative complications and applied it to a cohort of 190 horses undergoing emergency laparotomy. Methods: A classification system for postoperative complications in equine surgery was developed. Medical records of horses that underwent equine emergency laparotomy and recovered from anaesthesia were analysed. Reported complications pre-discharge were classified as per the new classification system, and the cost and days of hospitalisation were correlated with the equine postoperative complication score (EPOCS). Results: Of the 190 horses that underwent emergency laparotomy, 14 (7.4%) did not survive to discharge (class 6 complications), and 47 (24.7%) did not develop complications. The remaining horses were classified as follows: 43 (22.6%) had class 1 complications, 30 (15.8%) had class 2, 42 (22%) had class 3, 11 (5.8%) had class 4; and three (1.5%) had class 5. The proposed classification system and EPOCS correlated with the cost and length of hospitalisation. Limitations: This was a single-centre study and the definition of scores was arbitrary. Conclusions: Reporting and grading all complications will help surgeons better understand the patients' postoperative course, thereby reducing subjective interpretation.