title: Tissue oxygen saturation, measured by near-infrared spectroscopy, and its relationship to surgical-site infections.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Medical Physics, University Hospital of North Durham, Durham, UK.
authors.forename: C L
authors.initials: CL
authors.lastname: Ives
authors.forename: D K
authors.initials: DK
authors.lastname: Harrison
authors.forename: G S
authors.initials: GS
authors.lastname: Stansby
mesh_terms: D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D006119:Groin / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared; D013530:Surgical Wound Infection / Q000517:prevention & control*
chemical_list: D010100:Oxygen