Lack of association between arterial oxygen tensions in horses during exploratory coeliotomy and post-operative incisional complications: A retrospective study.

The aim of this retrospective study was to determine if there was an association between the lowest arterial blood oxygen tensions (PaO2) measured during anaesthesia and post-operative incisional complications in horses. Clinical records of 278 horses undergoing ventral midline coeliotomy from 1 January 2010 to 31 December 2013 were examined. The frequency of incisional complications was 32.0% (n = 89). In a multivariable model, intra-operative arterial blood oxygen tensions (PaO2) were not significantly associated with development of an incisional complication (P = 0.351). Using hypertonic (7.2%) saline (P = 0.028, OR 3.167, 95% CI 1.132-8.861), increasing total plasma protein concentration (TP) (P = 0.002, OR 1.061 per g/L, 95% CI 1.021-1.102), an intestinal resection (P <0.001, OR 4.056, 95% CI 2.231-9.323), increasing body mass (P = 0.004, OR 1.004 per kg, 95% CI 1.001-1.006) and the use of penicillin alone compared with penicillin and gentamicin pre-operatively (P = 0.009, OR 4.145, 95% CI 1.568-10.958) increased the risk of incisional complications. The study was unable to demonstrate a link between low intra-operative PaO2 and increased risk of post-operative incisional complications.