Introduction: Whole blood (WB) or blood products are not always immediately available for repletion of lost intravascular volume in trauma/hemorrhagic shock (T/HS), and thus, resuscitation with crystalloid solutions is often necessary. Recently, we have shown enteral tranexamic acid (TXA) to be effective as a mild protease inhibitor in blood-resuscitated T/HS by counteracting proteolytic activity in and leaking from the gut with resultant preservation of systemic vascular integrity. We hypothesized that enteral TXA would improve hemodynamic stability after T/HS in the absence of blood reperfusion.
Methods: We directly compared resuscitation with enteral TXA versus intravenous (IV) TXA in conjunction with lactated Ringer's solution (LR) or WB reperfusion in an experimental T/HS model. Rats were subjected to laparotomy and exsanguinated to a mean arterial blood pressure of 35-40 mm Hg for 90 min, followed by LR or WB reperfusion and monitored for 120 min. TXA was administered via IV (10 mg/kg) or enteral infusion (150 mM) 20 min after establishment of hemorrhage for 150 min.
Results: Animals resuscitated with LR were unable to restore or maintain a survivable mean arterial blood pressure (>65 mm Hg), regardless of TXA treatment route. In contrast, rats reperfused with WB and given TXA either enterally or IV displayed hemodynamic improvements superior to WB controls.
Conclusions: Results suggest that the beneficial hemodynamic responses to enteral or IV TXA after experimental T/HS depend upon reperfusion of WB or components present in WB as TXA, regardless of delivery mode, does not have appreciable hemodynamic effects when paired with LR reperfusion.
Keywords: Enteral protease inhibition; Hemorrhagic shock; Tranexamic acid; Trauma.
Published by Elsevier Inc.