Use of Physiologic and Arterial Blood Gas Variables to Predict Short‐Term Survival in Horses with Large Colon Volvulus

Objective To determine if preoperative physical examination and blood work values, intraoperative physiologic variables, and intraoperative treatments can be correlated with survival to anesthetic recovery and short‐term survival to hospital discharge in horses that undergo exploratory celiotomy for large colon volvulus (LCV) with and without colon resection. Study Design Retrospective case series. Animals Horses (n = 156) undergoing exploratory celiotomy for correction of LCV ≥ 360 ο . Methods Medical records (January 2000–December 2009) of horses that had surgical correction of LCV ≥ 360 ο were reviewed. Data collection included signalment, preoperative physical examination variables and hematologic values as well as intraoperative physiologic variables, intraoperative treatments, and arterial blood gas values. Risk factors for survival to anesthetic recovery and hospital discharge were determined using exact logistic regression. Results High preoperative heart rate and packed cell volume were associated with not surviving to anesthetic recovery or hospital discharge. A low intraoperative total serum protein concentration was associated with not surviving to anesthetic recovery or to hospital discharge. Intraoperative tachycardia and hypercapnia were associated with not surviving to hospital discharge. Intraoperative hypotension was a negative predictor of survival to anesthetic recovery. There was no increase in death for horses in which a resection and anastomosis was performed compared with those having manual correction. Conclusions Several hematologic and cardiorespiratory variables that are easily measured preoperatively and intraoperatively show good correlation with postanesthetic survival in horses undergoing surgical correction of LCV. These measurements might be useful for prognosticating survival in horses admitted for correction of LCV ≥ 360 ο .