Near-Infrared Spectroscopy: Assessing Viability in Skin Tears
Summary: This single-center prospective cohort study at Madigan Army Medical Center (June 2023-July 2024) evaluated near-infrared spectroscopy (NIRS) using the SnapshotNIR device to assess tissue viability in 14 skin flaps from 11 patients (mean age 71 years) with comorbidities like diabetes and heart failure. NIRS measured oxygenated hemoglobin (StO2 ≥50% for viability) and deoxyhemoglobin (≥0.5 for nonviability) non-invasively, guiding selective debridement and flap preservation. Results showed a 78% relative wound area reduction (median 1.6 cm² vs. 9.1 cm² without preservation, P=0.0001) and median healing time of 22 days (IQR 21-41), comparable to or faster than literature (28-42 days). NIRS enabled objective decisions, minimizing unnecessary excisions and supporting economic savings in wound care.
Key Highlights:
- NIRS thresholds: StO2 ≥50% indicated viable flaps for reapproximation; deoxyhemoglobin ≥0.5 prompted debridement of nonviable eschar.
- Wound area reduction: 78% relative (IQR 63%-84%) and 6.2 cm² absolute (IQR 2.4-10.1 cm²) with preserved flaps, significantly smaller than non-preserved (P=0.0001).
- Healing trajectory: Median 22 days to closure, with reepithelialization often by day 6-16; no strong comorbidity-outcome correlation.
- Complications: Rare failures from contamination or venous issues; NIRS integrated seamlessly (<1 minute per scan) into workflows.
- Implications: Potential $200-400 savings per patient, $5M nationwide annually; future needs include StO2 calibration for skin tones and tensile strength comparisons.
Keywords: near-infrared spectroscopy, skin tears, tissue viability, NIRS, flap preservation, Homer-Christian J Reiter, Charles Andersen