Efficacy of Hemostatic Gauzes in a Swine Model of Prolonged Field Care with Limb Movement.

INTRODUCTION: Prolonged field care for junctional wounds is challenging and involves limb movement to facilitate transport. No studies to date have explored the efficacy of gauze products to limit rebleeding in these scenarios. MATERIALS AND METHODS: We randomly assigned 48 swine to QuikClot Combat Gauze, ChitoGauze, NuStat Tactical, or Kerlix treatment groups (12 each) and then inflicted a severe groin injury by utilizing a modified Kheirabadi model of a 6-mm femoral artery punch followed by unrestricted bleeding for 60 seconds. We reassessed rebleed following limb movement at 30 minutes of stabilization and 4 hours after stabilization. RESULTS: Swine treated with Combat Gauze proved to have the lowest incidence of rebleeding, and conversely, NuStat Tactical had the highest incidence of rebleeding at wounds after limb movement. Importantly, rebleeds occurred at a rate of 25%-58% across all swine treatment groups at 30 minutes postinjury and 0%-42% at 270 minutes postinjury demonstrating that limb movements universally challenge hemostatic junctional wounds. CONCLUSIONS: Our findings highlight the difficulty of controlling hemorrhage from junctional wounds with hemostatic gauze in the context of prolonged field care and casualty transport. Our research can guide selection of hemorrhage control gauze when patients have prolonged field extraction or difficult transport. Our data demonstrates the frequency of junctional wound rebleeding after movement and thus the importance of frequent patient reassessment.

Safety of Pressurized Intraosseous Blood Infusion Strategies in a Swine Model of Hemorrhagic Shock.

BACKGROUND: Current guidelines support intraosseous access for trauma resuscitation when intravenous access is not readily available. However, safety of intraosseous blood transfusions with varying degrees of infusion pressure has not been previously characterized. MATERIALS AND METHODS: Adult female Yorkshire swine (Sus scrofa; n = 36; mean (M): 80 kg, 95% CI: 78-82 kg) were cannulated and then bled approximately 30% total blood volume. Swine were randomly assigned to proximal humerus intraosseous blood infusion with either Rapid Infuser, or Pressure Bag, or Push-Pull methods (n = 12 each). Flow rates, infusion pressures, vitals, biochemical variables, and pulmonary and renal tissue pathology were contrasted between groups. RESULTS: Flow rates were greater for the Push-Pull strategy than Pressure Bag (96.5 mL/min versus 72.6 mL/min, P = 0.02) or Rapid Infuser (96.5 mL/min versus 60 mL/min, P = 0.002) strategies. The pressures generated during the Push-Pull transfusion (3058 mmHg) were greater than the other strategies (≤360 mmHg). After the observation period, plasma-free hemoglobin levels were higher in the Push-Pull strategy than in the Rapid Infuser (40 mg/dL versus 12 mg/dL, P = 0.02) or Pressure Bag (40 mg/dL versus 12 mg/dL, P = 0.01). Groups did not significantly differ in vitals, biochemical variables, or tissue pathology. CONCLUSIONS: Push-Pull conferred the highest flow rates, but with higher infusion pressures and evidence of intravascular hemolysis. Rapid Infuser and Pressure Bag infusions had no increase from baseline in plasma-free hemoglobin. Pressure Bag infusion was noted to confer an advantage in flow rates over Rapid Infuser. Intraosseous blood transfusion with pressure bags can safely bridge toward central access in the early phases of trauma resuscitation.