Supplemental Oxygen Reduces Surgical Infection

Study Overview
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Brief Summary
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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
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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.

Official Title
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Supplemental Perioperative Oxygen Reduces the Risk of Surgical Wound Infection: A Randomized, Double-blind Trial

Conditions
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Wound Infection

Intervention / Treatment
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* Procedure: Perioperative supplemental oxygen
* Procedure: Standard oxygen


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 80% perioperative oxygen<br>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. | Procedure: Perioperative supplemental oxygen<br>* Patients were assigned to 80% fraction of inspired oxygen (FIO2) intraoperatively and for 6 hours after surgery. Anesthetic treatment and antibiotic administration were standardized.<br>|
| Placebo Comparator: 30% perioperative oxygen<br>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. | Procedure: Standard oxygen<br>* Patients were assigned to 30% fraction of inspired oxygen (FIO2) intraoperatively and for 6 hours after surgery. Anesthetic treatment and antibiotic administration were standardized.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incisional Surgical Wound Infection | Surgical wounds were defined as infected if they met Centers for Disease Control and Prevention definitions. | 0 to 14 days after surgery | 

Secondary Outcome Measures

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

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oxygen, surgical complications, colo-rectal resections