Hemodynamic Mechanisms of Prone Versus Supine CPR: A Cadaver-Based Pilot Study

This crossover cadaveric pilot investigation will quantify hemodynamic effects of prone versus supine cardiopulmonary resuscitation (CPR) and identify underlying pressure-transmission mechanisms. This crossover design using fresh, unembalmed donors at the MTSA cadaver laboratory, standardized mechanical chest compressions (LUCAS) will be applied in both positions while continuously acquiring intra-abdominal, intrathoracic, and arterial pressures via high-fidelity catheters. Primary endpoints are systolic, diastolic, and mean arterial pressures. Secondary analyses examine within-subject associations linking abdominal, thoracic, and arterial pressure waveforms across compression cycles. We hypothesize that prone positioning elevates intra-abdominal pressure, thereby enhancing thoracic pump efficiency and yielding perfusion pressures that are equal to or greater than those achieved in the supine position. As a mechanistic, non?human-subjects experiment, this study isolates physiologic pathways without patient risk, provides preliminary effect-size estimates to power subsequent investigations, and generates actionable data for settings where rapid supination is impractical (e.g., operating rooms, ICUs). Findings will inform protocol development, training priorities, and the design of prospective clinical studies evaluating prone CPR.

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