Exothermic reaction in zeolite hemostatic dressings: QuikClot ACS and ACS+^®

Background Zeolites have hemostatic properties used to stop bleeding in severe hemorrhage. Manufactured QuikClot® is an approved zeolite-based hemostatic agent for battlefield use. The exothermic reaction associated with QuikClot as loose granules or as granules packaged in a mesh bag has potential burn effects; this led to the development of a formulation of "cooler" non-exothermic QuikClot. The goal of this study was to compare the elevation of temperature of these formulations upon contact with blood. Methods Following full transection of the femoral vasculature, anesthetized Yorkshire pigs (n = 15) (28.8 ± 1.5 kg) were hemorrhaged for 2 min and treated with 100 g of bagged QuikClot (Advanced Clotting Sponge (ACS) (n = 4)) or a modified non-exothermic formulation (ACS+ (n = 11)). Vital signs and temperature at the dressing/tissue interface were continuously recorded for 3 h. Additional procedures were used to examine effects of different ratios of blood to zeolite on temperature elevation. Results Total post-treatment blood loss was comparable for ACS+_E and ACS_E groups (overall average: 18.6 ± 10.5% EBV). Temperature recorded at the dressing/tissue interface was significantly lower with ACS+ vs. ACS (40.3 ± 1.8 vs. 61.4 ± 10.7°C, respectively, p < 0.01) and was 3.2 ± 2.6°C higher than rectal temperature (38.0 ± 0.7°C, p < 0.01). Survival at endpoint (7/11 vs. 4/4) and average survival time (134 ± 64 vs. 180 min) were greater for both ACS+ and ACS in comparison to Standard Dressing. The wound temperature with ACS was reduced with greater blood to product ratios and this pattern was paralleled with in vitro measurements. Conclusions The lower heat release with ACS+ compared to ACS was confirmed in an animal model and ACS+ had similar efficacy in arresting bleeding when compared to Standard Dressing.