Abstract Body: Background
Resuscitative endovascular balloon occlusion of the aorta (REBOA) therapy augments circulation to the heart and brain during cardiopulmonary resuscitation (CPR). However, once return of spontaneous circulation (ROSC) is achieved, immediate REBOA deflation can cause significant loss of blood pressure and other hemodynamics¹. Little is known about the potential harmful effects of REBOA deflation, under normal physiological conditions and low circulatory states.
Research Question
Does REBOA catheter deflation cause a significant decrease in mean arterial pressure (MAP) under normal physiological conditions and after ROSC following cardiac arrest? How long does it take to recover in the absence of additional treatment?
Methods
For the normal physiological conditions study, 6 pigs were anesthetized and instrumented. The REBOA was inflated to occlude the aorta at the level of the diaphragm for 7 minutes, then deflated completely. For the post-ROSC study, 8 pigs underwent head up (HUP) CPR with active compression decompression CPR, an impedance threshold device, and a head/thorax elevation device. A REBOA was placed after ~44 minutes of CPR. One minute after ROSC, the REBOA was deflated completely. In both studies, hemodynamic parameters were monitored continuously. Statistical comparisons were made using a paired samples t-test.
Results
Hemodynamic findings before, during, and after the REBOA inflation are shown in Table 1. With REBOA inflation, MAP increased from 95.4±14.6 to 118.0±18.1 mmHg (p=0.01), and following deflation, MAP decreased from 119.1±19.0 to 84.3±24.4 mmHg (p=0.01). Parallel changes were observed other hemodynamics as well. Following REBOA deflation MAP and other hemodynamic parameters required 15 min to return to pre-REBOA values. REBOA during HUP CPR increased key hemodynamic parameters, whereas REBOA deflation post ROSC resulted in a profound and dangerous decrease in MAP from 79.4±33.7 to 50.4±23.4, p=0.017 (Table 2).
Conclusion
REBOA deflation can lead to significant hypotension under normal conditions and life-threatening hypotension after ROSC. Strategies to maintain MAP during REBOA deflation will be needed to reduce these potentially harmful effects.

1. Segond, N., et al. (2024). Abstract Or108: Optimizing Post-resuscitation Care after Resuscitative Endovascular Balloon Occlusion of the Aorta and Automated Head-up Position Cardiopulmonary Resuscitation. Circulation, 150(Suppl_1), https://doi.org/10.1161/circ.150.suppl_1.or108