Physiologic tolerance of descending thoracic aortic balloon occlusion in a swine model of hemorrhagic shock.

BACKGROUND Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technique in trauma; however, the physiologic sequelae have not been well quantified. The objectives of this study were to characterize the burden of reperfusion and organ dysfunction of REBOA incurred during 30 or 90 min of class IV shock in a survivable porcine model of hemorrhage. METHODS After induction of shock, animals were randomized into 4 groups (n = 6): 30 min of shock alone (30-Shock) or with REBOA (30-REBOA) and 90 min of shock alone (90-Shock) or with REBOA (90-REBOA). Cardiovascular homeostasis was then restored with blood, fluid, and vasopressors for 48 h. Outcomes included mean central aortic pressure (MCAP), lactate concentration, organ dysfunction, histologic evaluation, and resuscitation requirements. RESULTS Both REBOA groups had greater MCAPs throughout their shock phase compared to controls (P < .05) but accumulated a significantly greater serum lactate burden, which returned to control levels by 150 min in the 30-REBOA groups and 320 min in the 90-REBOA group. There was a greater level of renal dysfunction and evidence of liver necrosis seen in the 90-REBOA group compared to the 90-Shock group. There was no evidence of cerebral or spinal cord necrosis in any group. The 90-REBOA group required more fluid resuscitation than the 90-Shock group (P = .05). CONCLUSION REBOA in shock improves MCAP and is associated with a greater lactate burden; however, this lactate burden returned to control levels within the study period. Ultimately, prolonged REBOA is a survivable and potentially life-saving intervention in the setting of hemorrhagic shock and cardiovascular collapse in the pig.