642 The Use of Laser Speckle Contrast Imaging in Assessing Depth and Progression of Burn Wounds

Abstract

Abstract Introduction The ability of laser speckle contrast imaging (LSCI) to provide real-time images of blood flow makes this modality appealing in the assessment of burn wounds, particularly for clinicians making treatment decisions based on burn wound depth and presumed progression. Here we present 2 preclinical studies that used LSCI to assess wound progress, both immediately and months after injury. Methods LSCI images were taken 10-40cm away from the wound and captured with a 1388x1038-pixel CCD camera. In the first study, LSCI images were captured prior to and immediately following creation of superficial partial-thickness (SPTB, 10s), deep partial-thickness (DPTB, 15s), and full-thickness burns (FTB, 20s), and on post-burn day (PBD) 1, 2, and 3. In the second study, LSCI images were obtained before and after DPTB creation and on PBD 7, 14, 21, 28, 60, 90, and 120. Results 92 wounds from 9 swine were included. Speckle data was normalized to control sites and converted to percentages ([speckle wound/speckle control] x 100), producing speckle percentage of control (SPOC) which quantifies the relative decrease or increase in speckle output (vascularity). SPOC was significantly decreased for all burn times on PBD 0, 1, and 2. By PBD 3, only DPTB and FTB remained diminished (p=0.028 and p=0.005, respectively), and FTB SPOC was significantly less than the SPTB (p=0.015). In the second study, SPOC showed an increase post-debridement on PBD 7, noted as post-debridement day (PDD) 0. SPOC continued to increase significantly to a peak at PDD 7 (p< 0.0001) and remained elevated until PDD 28. By PDD 60, SPOC was no longer significantly increased. Conclusions LSCI is a reliable method for analyzing burn depth and wound progression in the preclinical setting. LSCI data shows an immediate decrease in vascularity at all burn depths immediately following burn creation, followed by a peak in vascularity on PDD 7, with a trend back to normal by PDD 60. Applicability of Research to Practice The correlation of wound bed vascularity based on LSCI to known data on burn depth and progression suggests that LSCI could be a useful measurement tool in the clinical setting for the provider determining wound viability.