Resuscitative endovascular balloon occlusion of the aorta in zone I versus zone III in a porcine model of non-traumatic cardiac arrest and cardiopulmonary resuscitation: A randomized study

Introduction: Resuscitative endovascular balloon occlusion of the aorta (REBOA) in zone I increases systemic blood pressure during cardiopulmonary resuscitation (CPR), while also obstructing the blood flow to distal organs. The aim of the study was to compare the effects on systemic blood pressure and visceral blood flow of REBOA-III (zone III, infrarenal) and REBOA-I (zone I, supraceliac) during non-traumatic cardiac arrest and CPR. Methods: Cardiac arrest was induced in 61 anesthetized pigs. Thirty-two pigs were allocated to a hemodynamic study group where the primary outcomes were systemic arterial pressures and 29 pigs were allocated to a blood flow study group where the primary outcomes were superior mesenteric arterial (SMA) and internal carotid arterial (ICA) blood flow. After 7-8 min of CPR with a mechanical compression device, REBOA-I, REBOA-III or no aortic occlusion (control group) were initiated after randomization. Results: Systemic mean and diastolic arterial pressures were statistically higher during CPR with REBOA-I compared to REBOA-III (50 mmHg and 16 mmHg in REBOA-I vs 38 mmHg and 1 mmHg in REBOA-III). Systemic systolic, mean and diastolic arterial pressures were statistically elevated during CPR in the REBOA-I group compared to the controls. The SMA blood flow increased by 49% in REBOA-III but dropped to the levels of the controls within minutes. The ICA blood flow increased the most in REBOA-I compared to REBOA-III and the control group (54%, 19% and 0%, respectively). Conclusion: In experimental non-traumatic cardiac arrest and CPR, REBOA-I increased systemic blood pressures more than REBOA-III, and the potential enhancement of visceral organ blood flow by REBOA-III was short-lived.