Time Matters in Severe Frostbite: Assessment of Limb/Digit Salvage on the Individual Patient Level

Abstract

Severe frostbite is associated with high levels of morbidity through loss of digits or limbs. The aim of this study was to examine the salvage rate following severe frostbite injury. Frostbite patients from 2006 to 2014 were identified in the prospectively maintained database at a single urban burn and trauma center. Patients with imaging demonstrating a lack of blood flow in limbs/digits were included in the analysis (N = 73). The Hennepin Frostbite Score was used to quantify frostbite injury and salvage. This score provides a single value to assess each individual patient's salvage rate. The majority of patients with perfusion deficits were male (80%) with an average age of 42 years (range 11-83 years). Patients requiring amputation tended to be older (P = .002), have more tissue impacted by frostbite (P < .001), and experienced a longer time from rewarming to thrombolytic therapy (P = .001). A majority of patients (62%) received thrombolytic treatment. The percentage of patients requiring amputation was lower and the salvage rate was higher in patients treated with thrombolytics; however, the differences failed to reach statistical significance (P = .092 and P = .061, respectively). The rate of salvage decreases as the time from rewarming to thrombolytic therapy increases. Regression analysis demonstrates an additional 26.8% salvage loss with each hour of delayed treatment (P = .006). When the amount of tissue at risk for amputation is included in the model, each hour delay in thrombolytic treatment results in a 28.1% decrease in salvage (P = .011). This study demonstrates a significant decrease in limb/digit salvage with each hour of delayed administration of thrombolytics in patients with severe frostbite.