In 2004 we reported results of relationships between oxygen saturation of skin (SSO2) and muscle (MSO2) (measured by visible lightguide and near-infrared spectrophotometry respectively) and physiological characteristics. We now present results of a trial measuring tissue oxygen saturation (StO2), using the same methods, to predict surgical site infections (SSI).
StO2 was measured at the wound pre-operatively and at 12, 24 and 48 hours post-operatively in patients undergoing major surgery. Age, body mass index (BMI) and triceps skinfold thickness (TST) were recorded. Signs of infection were assessed for independently at one month using the Control of Diseases Centre definition: those who healed were classified into Group A and those who developed a wound infection into Group B.
Of 59 patients (38M, 21F), 42 healed and 17 developed SSI. There were no significant differences in sex, age, TST or BMI between the two groups. Wound SSO2 was not significantly different between the groups at any stage. At 12 hours post-operatively there was a significant difference in wound MSO2 between the two groups (A= 58.3±21.6%, B=42.2±16.6%, p=0.005). Chi-squared tables for differing values of wound MSO2 showed that the test performs best when a value of 53% was chosen as the threshold to classify potential infection (chi-squared test, p=0.002). This correlated to a sensitivity of 70.6% and a specificity of 76.2%. The use of the near-infrared spectrophotometer as a tool to predict wound infections should be further evaluated and advocated.
Ives CL, Harrison DK, Stansby G. Tissue oxygen saturation may predict healing of surgical site wounds. Microcirculation 13: 511-534.
Dr. David K. Harrison, Durham Unit, Durham. Tel: +44 (0)191-333-2215.
Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne, NE7 7DN, UK.
Tel: +44 (0)191-233-6161 E-mail: webmaster@rmpd.org.uk Web: http://www.rmpd.org.uk
By using this site you agree to our Terms and Conditions of Use. Please read our legal page.
Regional Medical Physics Department, a Clinical Directorate of the Newcastle upon Tyne Hospitals NHS Foundation Trust.
Copyright ©1999-2008 All Rights Reserved. Revised 7 November, 2008.
