Pulmonary Gas Exchange and Plasma Lactate in Horses with Gastrointestinal Disease Undergoing Emergency Exploratory Laparotomy: A Comparison with an Elective Surgery Horse Population

摘要

Objective: To characterize pulmonary gas exchange and arterial lactate in horses with gastrointestinal disease undergoing anesthesia, compared with elective surgical horses, and to correlate these variables with postoperative complications and mortality.Study Design: Prospective clinical study.Animals: Horses undergoing emergency laparotomy for acute intestinal disease (n = 50) and healthy horses undergoing elective surgery in dorsal recumbency (n - 20).Methods: Arterial blood gas analysis was performed at predetermined intervals on horses undergoing a standardized anesthetic protocol. Alveolar-arterial oxygen gradient was calculated. Predictive factors for postoperative complications and death in colic horses were determined.Results: Arterial oxygen tension (PaO2) varied widely among horses in both groups. PaO2 significantly increased in the colic group after exteriorization of the ascending colon. PaO2 and alveolar-arterial oxygen gradient were not significantly different between groups, and neither were correlated with horse outcome. Arterial lactate in recovery >= 5 mmol/L was associated with a 2.25 times greater relative risk of complications and lactate >= 7 mmol/L was associated with a 10.5 times higher relative risk of death.Conclusion: Colic horses in this population were not more likely to be hypoxemic than elective horses, nor was gas exchange impaired to a greater degree in colic horses relative to controls. Arterial lactate sampled immediately after anesthetic recovery was predictive for postoperative complications and death.