Supplemental Oxygen Reduces Surgical Infection

Not Applicable

Completed

Interventions: Procedure: Perioperative supplemental oxygen
Procedure: Standard oxygen

Brief Summary: Supplemental perioperative oxygen has been reported to halve or double the risk of surgical wound infection. We tested the hypothesis that supplemental oxygen reduces infection risk following colorectal surgery. Colorectal surgery patients (n=300) were randomly assigned to 30% or 80% FiO2 intraoperatively and 6 hours postoperatively. Wound infections were diagnosed by blinded investigators using Centers for Disease Control criteria. Baseline patient characteristics, anesthetic management, and potential confounding factors were recorded. Wound infection rates were compared with chi-square analysis. Logistic regression identified the contribution of potential confounding factors. Surgical wound infection occurred in 24.4% of patients receiving 30% oxygen, but only 14.9% of those receiving 80% oxygen (P\<0.039). According to logistic regression, the relative risk of infection in patients given supplemental oxygen was 0.46 (P=0.035). Supplemental inspired oxygen reduced wound infection risk by roughly a factor of two. We thus recommend that supplemental oxygen be provided to patients undergoing colorectal surgery.

Detailed Description: Context: Supplemental perioperative oxygen has been variously reported to halve or double the risk of surgical wound infection.

Objective: We tested the hypothesis that supplemental oxygen reduces infection risk following colorectal surgery.

Design: Randomized, controlled trial. Setting: Fourteen Spanish hospitals. Patients: Three hundred patients undergoing elective colorectal surgery. Interventions: Patients were randomly assigned to either 30% or 80% FiO2 intraoperatively and for 6 hours after surgery. Anesthetic management and antibiotic administration were standardized.

Main outcome measures: Wound infections were diagnosed by blinded investigators using Centers for Disease Control criteria. Baseline patient characteristics, anesthetic management, and potential confounding factors were recorded. The wound infection rate in the 30% and 80% oxygen groups was compared with chi-square analysis. A logistic regression was used to identify the contribution of potential confounding factors.

Recruitment & Eligibility

Inclusion Criteria

Elective colorectal resection,
Patients having abdominal-peritoneal reconstructions were included, but not those scheduled for minor colon surgery (e.g., polypectomy, isolated colostomy) or laparoscopic surgery.

Exclusion Criteria

Exclusion criteria included expected surgery time of less than one hour, fever or existing signs of infection, diabetes mellitus (type I or II), HIV infection, weight loss exceeding 20% in the previous three months, serum albumin concentration < 30 g/L, and a leukocyte count <2500 cells/ml.

Arm && Interventions

Group	Intervention	Description
80% perioperative oxygen	Perioperative supplemental oxygen	Perioperative supplemental oxygen: Patients were randomly assigned to 80% fraction of inspired oxygen (FIO2) intraoperatively and for 6 hours after surgery. Anesthetic treatment and antibiotic administration were standardized.
30% perioperative oxygen	Standard oxygen	Standard oxygen: Patients were randomly assigned to 30% fraction of inspired oxygen (FIO2) intraoperatively and for 6 hours after surgery. Anesthetic treatment and antibiotic administration were standardized.

Primary Outcome Measures

Name	Time	Method
Incisional Surgical Wound Infection	0 to 14 days after surgery	Surgical wounds were defined as infected if they met Centers for Disease Control and Prevention definitions.

Secondary Outcome Measures

Name	Time	Method
First Solid Food Intake	time to event after surgery	Time to restarting feeding after surgery, measured in days.
Hospital Length of Stay	time to hospital discharge after surgery	The number of days patient stayed in the hospital after surgery.
Return of Bowel Function	time to event after surgery to discharge from hospital	Time to return of bowel function, measured in days.
Return to Ambulation	time to event after surgery	time to return to ambulation after surgery, measured in days
Staples Removed	time to event after surgery	Time to staples removed, measured in days