Comparing oxygenation assessment methods for the interventional management of hard-to-heal wounds

OBJECTIVE: To compare transcutaneous oxygen measurement (TCOM) and near infrared spectroscopy (NIRS) measurement of tissue oxygen levels in hard-to-heal (chronic) wounds. METHOD: Patients aged 18-85 years presenting with hard-to-heal lower extremity wounds between 1 December 2019 and 31 July 2020 were included in this cross-sectional study. TCOM and NIRS measurements of tissue oxygenation were obtained. Data were stratified by wound severity (Wagner score), skin pigmentation (Fitzpatrick skin type), and use of melanin correction for NIRS measurement. RESULTS: A total of 76 patients were included. Correlation coefficients between TCOM and NIRS with melanin correction were obtained for: Fitzpatrick I-III (p=0.41); Fitzpatrick IV-VI (p=0.08); Wagner 0-2 (p=0.22); Wagner 3-5 (p=0.34). Results without melanin correction were: Fitzpatrick I-III (p=0.19); Fitzpatrick IV-VI (p=0.08); Wagner 0-2 (p=0.05); and Wagner 3-5 (p=0.34). CONCLUSION: There was only one significant correlation between TCOM and NIRS measurements of tissue oxygenation in patients with hard-to-heal lower extremity wounds and that was for patients with Wagner scores of 0-2 without melanin correction. Further investigation is needed on the application of NIRS to guide the interventional management of hard-to-heal wounds.