No intravenous access, no problem: Intraosseous administration of tranexamic acid is as effective as intravenous in a porcine hemorrhage model.

BACKGROUND: The acute coagulopathy of trauma is often accompanied by hyperfibrinolysis. Tranexamic acid (TXA) can reverse this phenomenon, and, when given early, decreases mortality from bleeding. Establishing intravenous (IV) access can be difficult in trauma and intraosseous (IO) access is often preferred for drug administration. Currently, there are no data on the efficacy of IO administered TXA. Our objectives were to compare serum concentrations of TXA when given IV and IO and to compare the efficacy of IO administered TXA to IV at reversing hyperfibrinolysis. METHODS: Using a porcine hemorrhage and ischemia-reperfusion model, 18 swine underwent hemorrhagic shock followed by a tissue plasminogen activator infusion to induce hyperfibrinolysis. Animals then received an IV or tibial IO infusion of TXA over 10 minutes. Blood was then analyzed using rotational thromboelastometry to monitor reversal of hyperfibrinolysis. Serum was analyzed for drug concentrations. RESULTS: After hemorrhage and ischemia-reperfusion, there were no significant differences in mean arterial pressure (48 vs. 49.5), lactate (11.1 vs. 10.8), and pH (7.20 vs. 7.22) between groups. Intraosseous TXA corrected the lysis index at 30 minutes in EX-TEM and IN-TEM, like IV infusion. Peak serum levels of TXA after IV and IO administration show concentrations of 160.9 µg/mL and 132.57 µg/mL respectively (p = 0.053). Peak levels occurred at the completion of infusion. Drug levels were tracked for four hours. At the end of monitoring, plasma concentrations of TXA were equivalent. CONCLUSION: Intraosseous administration of TXA is as effective as IV in reversing hyperfibrinolysis in a porcine model of hemorrhagic shock. Intraosseous administration was associated with a similar peak levels, pharmacokinetics, and clearance. Intraosseous administration of TXA can be considered in hemorrhagic shock when IV access cannot be established.

Resuscitative endovascular balloon occlusion of the aorta for major abdominal venous injury in a porcine hemorrhagic shock model.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a rescue maneuver for unstable patients with noncompressible hemorrhage below the diaphragm. The efficacy of REBOA in the setting a major abdominal venous injury is unknown. Our objective was to examine the use of REBOA in a large animal model of major abdominal venous injury and characterize any impact on the hemodynamics, rate and volume of hemorrhage, and survival. METHODS: Ten swine (35-55 kg) underwent a controlled and validated hemorrhage and ischemia/reperfusion injury protocol to produce shock physiology. Animals were randomly assigned to a control arm (N = 5) or a treatment (REBOA) arm (N = 5). An injury was then created in the common iliac vein. Bleeding was allowed for 60 seconds and the balloon was then inflated in the REBOA arm. Hemodynamics were recorded for 45 minutes or until death. Blood loss was verified post-mortem and bleeding rate calculated. RESULTS: All animals demonstrated shock physiology at the time of randomization. There were no differences between control versus REBOA animals in baseline mean arterial pressure (42 vs. 50), pH (7.29 vs. 7.26), lactate (6.19 vs. 6.26), or INR (1.2 vs. 1.3, all p = NS). REBOA animals demonstrated immediate improvements in mean arterial pressure (50.6 vs. 97.2, p = 0.04). The mean survival time was 4.1 minutes for controls (100% died) versus 40.1 minutes for REBOA (p < 0.01). There was no difference in total blood loss (mean 630 mL for both). The rate of bleeding was significantly lower in the REBOA animals (control 197 mL/min vs. REBOA 14 mL/min, p = 0.02). CONCLUSION: In the setting of an abdominal venous injury, REBOA improved hemodynamics and lengthened survival time. Blood loss was similar between groups but the rate of bleeding was markedly decreased with REBOA. REBOA appears effective for central venous injuries and provides a sustained period of stabilization and window for surgical intervention.