The Impact of Intraoperative Fluid Therapy and Body Temperature on Surgical Site Infection - Re-Assessment of a Randomized Trial.

Background: Use of supplemental oxygen during surgery to reduce the incidence of SSI was investigated in the PROXI trial, which found no reduced frequency of SSI. Subsequently, it has been suggested that a restrictive fluid regimen and hypothermia in some patients could explain why no beneficial effect of supplemental oxygen was found. We evaluated the association between the occurrence of SSI and two perioperative factors, volume of infused fluid and body temperature (BT). Methods: We used data from the PROXI trial including 1,386 patients undergoing laparotomy randomly assigned to receive 80% or 30% oxygen during surgery. A fluid infusion index (FII) was calculated for each patient as the volume of infused fluids/body weight/duration of surgery. Results: SSI occurred in 18.9% of the patients in the lower FII tertile group (OR=0.86; P=0.41), in 20.4% in the upper FII tertile group (OR=1.49; P=0.05), in 19.7% of the patients with hypothermia (OR=1.28; P=0.25) and in 25.0% with hyperthermia (OR=1.26; P=0.52). An increased risk of SSI (OR=3.15; P=0.01) was found in patients having both hypothermia and emergency surgery. CONCLUSION: A trend towards an increased risk of SSI was seen in patients who received a greater volume of intravenous fluid. No association was found between BT and SSI.

Timing of surgical site infection and pulmonary complications after laparotomy.

BACKGROUND: Surgical site infection (SSI) and other postoperative complications are associated with high costs, morbidity, secondary surgery, and mortality. Many studies have identified factors that may prevent SSI and pulmonary complications, but it is important to know when they in fact occur. The aim of this study was to investigate the diagnostic timing of surgical site infections and pulmonary complications after laparotomy. MATERIAL AND METHODS: This is a secondary analysis of the PROXI trial which was a randomized clinical trial conducted in 1400 patients undergoing elective or emergent laparotomy. Patients were randomly allocated to either 80% or 30% perioperative inspiratory oxygen fraction. RESULTS: SSI or pulmonary complications were diagnosed in 24.2% (95% CI: 22.0%-26.5%) of the patients at a median of 9 days [IQR: 5-15] after surgery. Most common was surgical site infection (19.6%); median time 10 days after surgery [IQR: 7-18]. The corresponding figures for anastomotic leakage was 5.7%, 8 days [IQR: 6-10]; pneumonia 3.5%, 5 days [IQR: 3-9]; and respiratory failure 2.3%, 3 days [IQR: 1-8]. The oxygen allocation was not significantly related to time of diagnosis for postoperative surgical site infections or pulmonary complications. CONCLUSION: A high percentage of patients undergoing laparotomy develop a postoperative complication. This study adds new knowledge by identifying time intervals within which medical professionals should be aware of surgical site infections and pulmonary complications in order to initiate appropriate treatment of the patients.