Relationship between healing time and mean perfusion units of laser Doppler imaging (LDI) in pediatric burns

Background: Laser Doppler imaging (LDI) is a noninvasive technique used to assess burn depth. However, there have been no studies regarding the use of LDI in predicting burn healing time. Objectives: The aims of this study are to evaluate the relationship between healing time and the amount of perfusion seen on LDI and to determine a cut-off value for LDI that predicts if a burn will heal within 14 days. Study design: Consecutive patients younger than 15 years old with partial-thickness burns were recruited from May to November 2006 for this prospective observational study. The mean number of perfusion units (PU) as determined by LDI (Periscan PIM 3 system) was obtained within 2-3 days following injury. Healing time was estimated clinically by two physicians and marked by the observation of reepithelization. The mean PU was compared between the early (healed with 14 days) and late healing groups (healed later than 14 days). The usefulness of the mean PU in predicting healing time within 14 days was estimated by receiver operating characteristic curve analysis. Results: A total of 103 patients with 181 partial-thickness burn wounds were enrolled in this study. The mean PU from LDI was higher in the early healing group compared to the late healing group (380.2 +/- 157.8 vs. 185.8 +/- 115.8, p < 0.001). When using 250 PUS as a cut-off value to predict early healing, the sensitivity and specificity were 80.6% and 76.9%, respectively. The area under the ROC curve was 0.844 (p < 0.001, 95% CI = 0.780-0.908). Conclusions: This study suggests the mean PU as determined by LDI can be used as a valuable tool in predicting the healing time of burn wounds. (C) 2008 Elsevier Ltd and ISBI. All rights reserved.