BACKGROUNDThe effects of chest compressions to hemodynamic and respiratory parameters during hands-only cardiopulmonary resuscitation (CPR) in a non-arrested patient who suddenly collapses are confusing. In this research, we investigated the effects of chest compressions in a non-arrested porcine model.

METHODSFourteen male domestic pigs were randomized into sham control group (SHAM group, only anesthetized and instrumented without chest compression, n = 6) or chest compression group (CC group, 2 minutes of chest compressions, n = 8). Continuous hemodynamic parameters, dynamic lung compliance (Cdyn), and blood gas analysis outcomes were recorded. Serum levels of catecholamine were measured at baseline and 2 minutes, 30 minutes, 4 hours, and 24 hours after chest compressions. Chest computed tomography (CT) was performed at 30 minutes and 24 hours. Conventional histopathology evaluation was performed.

RESULTSAfter two minutes of chest compressions in the CC group, heart rate and extravascular lung water increased significantly; mean arterial pressure, stroke volume, and global ejection fraction significantly decreased. Cdyn significantly decreased to valley levels at 30 minutes and slowly recovered. Compared with the baseline, serum levels of catecholamine significantly increased at 2 minutes and rapidly decreased 24 hours later. At 30 minutes after chest compressions, chest CT showed local exudation, which was absorbed 24 hours later.

CONCLUSIONSThis research showed that 2 minutes of chest compressions causes various heart and lung tissue damage in the normal a normal porcine model. It also impacts the hemodynamic and Cdyn.