Does intraoperative low arterial partial pressure of oxygen increase the risk of surgical site infection following emergency exploratory laparotomy in horses?

This study investigates the impact of oxygen pressure in the arteries during surgery (PaO2) on the risk of infection at the surgical site (SSI) in horses undergoing emergency abdominal surgery. The research found that low PaO2 during the operation, longer anesthesia time, and specific suture material could contribute to a higher risk of post-operative infections.

Research Methodology

• This inquiry was a prospective case series aiming to evaluate the effects of intraoperative arterial partial pressure of oxygen (PaO2) on the surgical site infection (SSI) rate in horses that underwent emergency exploratory laparotomy due to acute gastrointestinal diseases.
• The protocols for anesthesia and antibiotics were consistent across all examined cases.
• The researchers collected various data, including demographic information, potential surgical risk factors, and PaO2 values obtained one hour after the induction of anesthesia.
• Post-surgery, the researchers monitored all surgical wounds daily during the hospital stay to detect any signs of infection and collected follow-up information after the horses were discharged.

Research Findings

• The research included a total of 84 adult horses and found that 34 of those (or 40.4%) developed SSIs.
• A multivariate logistic regression pointed to three main predictors of SSIs: PaO2 levels, the duration of anesthesia, and the type of subcutaneous suture material used.
• Horses that were anesthetized for more than 2 hours, and those that had a PaO2 level of fewer than 80 mm Hg, were identified as having the greatest risk of developing an SSI.
• The life of polyglycolic acid sutures was also found to contribute to a higher risk of infection.

Conclusion

• This study confirms the initial hypothesis that a low level of oxygen in the arteries during surgery can increase the likelihood of a horse developing an infection in the surgical site following an abdominal surgery.
• The study also identified two other significant factors that contribute to the increased risk of SSIs: anesthesia time and the type of suture material used.