Tissue oxygen saturation, measured by near-infrared spectroscopy, and its relationship to surgical-site infections.

Background: Surgical-site infections (SSIs) are common after major abdominal and groin bypass surgery. Tissue oxygen tension has been shown to predict these infections accurately. This study assessed whether a non-invasive measurement of tissue oxygenation, tissue oxygen saturation as measured by spectrophotometry, was as accurate.
Methods: Fifty-nine patients having major abdominal or groin bypass surgery had tissue oxygen saturation measured by near-infrared spectrophotometry at the incision site and in the arm before operation, and at 12, 24 and 48 h after surgery. Masked outcome assessments for SSI were made at 7 and 30 days after operation.
Results: In this retrospective analysis, 17 patients (29 per cent) developed an SSI. At 12 h after operation there was a significant difference in tissue oxygen saturation at the surgical site between patients who developed an SSI and those who did not (mean(s.d.) 43.4(18.1) versus 55.8(22.0) per cent; P = 0.032). These oxygen saturation readings were found to be more specific and sensitive in predicting SSIs than the National Nosocomial Infection Surveillance system.
Discussion: There is a difference in postoperative surgical-site oxygen saturation between patients who subsequently develop SSIs and those who do not. Prediction of SSIs provides opportunities for intervention and prevention.
(Copyright 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)