Abstract 11244: Active Decompression During Device Assisted Elevation of the Head and Thorax, an Impedance Threshold Device, and Active Compression Decompression Cardiopulmonary Resuscitation is Needed for Sustained Hemodynamic Benefit in a Porcine Model of Prolonged Cardiac Arrest

Abstract

Introduction: Active compression decompression cardiopulmonary resuscitation (CPR), an impedance threshold device (ITD), and automated device-assisted controlled head up positioning, collectively termed AHUP CPR, work synergistically to lower intracranial pressure, augment venous return to the heart and significantly improve neurological survival versus conventional (C)-CPR in animals and patients in cardiac arrest. The current study focused on the role of active decompression (AD) during prolonged AHUP CPR, since AD can be difficult to perform manually for an extended period. Hypothesis: Full AD is needed to optimize hemodynamics during prolonged AHUP CPR Methods: Six female and male farm pigs (~40 kg) were sedated, intubated, anesthetized, and monitored. After 8 min of untreated ventricular fibrillation followed by ≥ 30 min of AHUP CPR with an automated device, AHUP CPR was continued except that AD was intentionally reduced from an average of 3.33 ± 0.37 cm of lift to 0 cm lift above the resting neutral position as this is the amount of decompression that occurs with C-CPR and passive chest wall recoil. After 1 min of AHUP CPR with 0 cm lift, AD was progressively increased back to 3 cm of lift over 3 min. Hemodynamics (mean ± SD) were compared using Student’s t test, where p<0.05 was considered statistically significant. Results Coronary perfusion pressure (CorPP) (p<0.005), cerebral perfusion pressure (CerPP) (p<0.001), and ETCO2 (p<0.0001) significantly decreased after AD was discontinued (Fig.1). With restoration of AD to 3 cm, CorPP (p<0.009) and ETCO2 (p<0.001) significantly improved and CerPP trended higher (p=0.084). Conclusion During prolonged (≥ 30 min) AHUP CPR in pigs, active lift of the chest wall is essential to maintain stable hemodynamics. Hemodynamics deteriorated rapidly with intentional loss of AD, but could be partially restored with resumption of AD.