Resuscitative Endovascular Balloon Occlusion of the Aorta in Experimental Cardiopulmonary Resuscitation: Aortic Occlusion Level Matters

INTRODUCTION: Aortic occlusion during cardiopulmonary resuscitation (CPR) increases systemic arterial pressures. Correct thoracic placement during the resuscitative endovascular balloon occlusion of the aorta (REBOA) may be important for achieving effective CPR. HYPOTHESIS: The positioning of the REBOA in the thoracic aorta during CPR will affect systemic arterial pressures. METHODS: Cardiac arrest was induced in 27 anesthetized pigs. After 7 min of CPR with a mechanical compression device, REBOA in the thoracic descending aorta at heart level (zone Ib, REBOA-Ib, n = 9), at diaphragmatic level (zone Ic, REBOA-Ic, n = 9) or no occlusion (control, n = 9) was initiated. The primary outcome was systemic arterial pressures during CPR. RESULTS: During CPR, REBOA-Ic increased systolic blood pressure from 86 mmHg (confidence interval [CI] 71–101) to 128 mmHg (CI 107–150, P < 0.001). Simultaneously, mean and diastolic blood pressures increased significantly in REBOA-Ic (P < 0.001 and P = 0.006, respectively), and were higher than in REBOA-Ib (P = 0.04 and P = 0.02, respectively) and control (P = 0.005 and P = 0.003, respectively). REBOA-Ib did not significantly affect systemic blood pressures. Arterial pH decreased more in control than in REBOA-Ib and REBOA-Ic after occlusion (P = 0.004 and P = 0.005, respectively). Arterial lactate concentrations were lower in REBOA-Ic compared with control and REBOA-Ib (P = 0.04 and P < 0.001, respectively). CONCLUSIONS: Thoracic aortic occlusion in zone Ic during CPR may be more effective in increasing systemic arterial pressures than occlusion in zone Ib. REBOA during CPR was found to be associated with a more favorable acid–base status of circulating blood. If REBOA is used as an adjunct in CPR, it may be of importance to carefully determine the aortic occlusion level. The study was performed following approval of the Regional Animal Ethics Committee in Linköping, Sweden (application ID 418).