Rapid tissue viability evaluation using methemoglobin as a biomarker in burns

Burns are a frequent cause of traumatic injury, accounting for an average of 1,230 visits to the emergency department every day in the United States. While many of these injuries will heal spontaneously, nearly 1 in 10 are severe enough to require hospitalization or transfer to a specialized burn center. The early surgical management of a severe burn is critical to patient outcome, but few tools exist for triaging viable and non-viable tissue at early time-points post-injury. Without a validated outcome measure, even experienced burn surgeons diagnose tissue viability with an accuracy of only 50-70%, with significant consequences for patient morbidity, mortality and cost to the healthcare system. In this work, we have developed a non-invasive device that uses near-infrared spectroscopy to rapidly assess traumatic burns at the bedside. We report that near-infrared spectroscopy can detect methemoglobin non-invasively, and that this molecule increases in burned tissue immediately following injury in both a porcine model and in humans. Methemoglobin levels are highest in non-viable tissue, and correlate with tissue viability as early as 24 hours post-burn. Methemoglobin is the first reported objective outcome measure for use in the management of traumatic burn injury.