- An association has been proposed between perioperative administration of 80% oxygen and a lower incidence of wound infection after colorectal surgery. The present study was conducted to assess this hypothesis. Thirty-eight patients (ASA classification 1 and 2) undergoing elective colorectal cancer surgery were allocated at random to 2 groups. Group 1 consisted of 19 patients who received an admixture of 80% oxygen and 20% nitrogen during anesthesia through an orotracheal tube and during the 2 first hours in the recovery room through a tight facemask with reservoir. Group 2 consisted of 19 patients who received an admixture of 70% nitrous oxide and 30% oxygen during anesthesia, followed by administration of 30% oxygen delivered by a blender through a tight facemask with reservoir in the same manner than group 1, during the first 2 hours in the recovery room. Wound infection was evaluated daily during hospital stay and after 7 days, 2 weeks, and 1 month. The incidence of wound infection was 12.5% in group 1 and 17.6% in group 2 (p=0.53). The results of this study showed no reduction in the incidence of wound infection following elective colorectal surgery in patients receiving 80% oxygen during the perioperative period.