Efficacy of near-infrared spectroscopy in diagnosing skin and soft tissue infections: A single-center retrospective study

Abstract

Aim

Skin and soft tissue infection (SSTI) is classified as necrotizing fasciitis (NF) or cellulitis based on the invasion depth of the lesion. Cellulitis has a good prognosis and improves with conservative treatment, whereas NF has a poor prognosis with rapid progression requiring prompt debridement of the wound and intensive care control. Therefore, they should be differentiated quickly and accurately; however, a useful diagnostic method, except for the surgical test incision, remains to be established. This study aimed to verify the usefulness of near-infrared spectroscopy (NIRS) to measure regional oxygen saturation (rSO2) in diagnosing SSTI.

Methods

This was a single-center, retrospective, observational study. SSTI cases from October 2019 to April 2024 (4.5 years) were selected from medical records, and their characteristics, rSO2 levels, computed tomography findings, and Laboratory Risk Indicator for Necrotizing Fasciitis scores were collected. The primary endpoint was the rSO2 between cellulitis and NF lesions measured using NIRS, and the affected and unaffected sides in the same patient were compared.

Results

Eighteen patients were included: six with NF and 12 with cellulitis. There were no significant differences in patient characteristics between the groups. The primary endpoint of NIRS on the affected/unaffected side was significantly lower in patients with NF (0.6 [interquartile range, 0.5–0.7] vs. 1.4 [1.2–1.6]; p < 0.01).

Conclusion

NIRS has the potential to be a non-invasive and quantitative diagnostic tool for SSTI.