Crystalloids as an alternative to whole blood in pREBOA resuscitation for hemorrhagic shock

Trauma is a leading global health challenge, with hemorrhage being a major cause of preventable death. Resuscitative endovascular balloon occlusion of the aorta (REBOA) effectively halts hemorrhage but poses risks such as ischemic injury, especially to the kidneys. Partial REBOA (pREBOA) mitigates these effects by allowing limited distal blood flow. This study investigates crystalloid resuscitation as an alternative to whole blood during pREBOA release in a swine model, where all groups received an additional 2000 mL of Ringer's acetate prior to balloon deflation.

15 castrated male swine weighing 51-65 kg underwent controlled mean (SD) hemorrhage of 1200 (233) mL, followed by 60 minutes of pREBOA application and a 20-minute resuscitation phase, where the animals were randomized into three groups: low Ringer's acetate (0 mL) (n=5), high Ringer's acetate (2000 mL) (n=5), or whole blood transfusion (1000 mL)+ Ringer's acetate (1000 mL) (n=5). Hemodynamic variables, metabolic parameters, and renal blood flow were continuously monitored. Animals were observed for 60 minutes post-REBOA deflation.

High-volume Ringer's acetate improved stroke volume compared to low-volume crystalloids (p<0.001) and reduced heart rate (p<0.005) and systemic vascular resistance (p<0.01) immediately post-resuscitation. Hemoglobin levels were lower in the high-volume group than in the low-volume group (p<0.01), persisting for 40 minutes. Potassium remained within physiological limits.

Crystalloid resuscitation during pREBOA maintained mean arterial pressure and cardiac output comparable to whole blood, with high-volume crystalloids offering superior hemodynamic support compared to low-volume resuscitation. High-volume crystalloids improved stroke volume. Metabolic stability was preserved across groups, with no severe derangements observed. These findings highlight crystalloids as a potential alternative in resource-limited settings, although reduced renal perfusion warrants further investigation to optimize outcomes and ensure broader clinical applicability.