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

This study examines the potential link between low arterial blood oxygen tensions (PaO2) during anesthesia in horse surgeries and post-operative complications at the incision site. The findings suggest there is no significant relation between the two, but identify other factors that may increase the risk of these complications.

Review of Study Methods and Participants

• This research is a retrospective analysis, meaning existing data from clinical records was studied and evaluated.
• The clinical records evaluated were of 278 horses that underwent a specific kind of abdominal surgery called ventral midline coeliotomy, within the period from January 1, 2010, to December 31, 2013.

Key Findings

• The incidence of post-operative incisional complications was noted to be 32%, involving 89 of the horses reviewed.
• Contrary to the initial hypothesis, intra-operative arterial blood oxygen tensions (PaO2) were found not to have a significant association with the development of post-operative incisional complications. This conclusion was reached as the statistical analysis returned a non-significant P-value (P= 0.351), indicating that the observed associations could have occurred by chance.
• Other factors did however show a statistically significant association with the likelihood of incisional complications, including using hypertonic saline during surgery, increased total plasma protein concentrations, an intestinal resection during the procedure, increased body mass, and the use of only penicillin as a preoperative prophylaxis as opposed to a combination of penicillin and gentamicin.
• It is important to bear in mind that a correlation does not imply causation, so while these factors were linked with an increased incidence of post-surgical complications, it is not clear whether these factors were the cause.

Conclusions and Implications

• This study suggests a lack of association between low PaO2 during anesthesia and post-operative incisional complications in horses. This finding is impactful as it negates the concern of maintaining optimal PaO2 during such surgical procedures to reduce post-operative complications.
• The identified associations with other factors do, however, suggest potential ways to further reduce the risk for post-operative complications in horses undergoing coeliotomy, such as reconsidering the use of hypertonic saline and the preoperative use of both penicillin and gentamicin.