Abstract 43: Comparison of Periodic Acceleration and Thumper CPR in an Asphyxial Cardiac Arrest Model in Pigs
Background: Whole body periodic acceleration (pGz) is a novel method of CPR. Back and forth motion of the supine body, provides ventilation and blood flow to vital organs during arrest. We showed that pGz produces superior post resuscitation outcomes and less myocardial stunning compared to an automated chest compression device (Thumper) in a model of VF cardiac arrest. Asphyxia (ASPX) is the leading cause of cardiac arrest in newborns and children. The mechanisms for cardiac arrest during asphyxia are different from sudden cardiac arrest, and primarily induced by airway obstruction with progressive acidosis, and hypoxia that eventually lead to pulseless electrical activity (PEA) or VF. We compared Thumper (TH) to pGz CPR with regards to acute outcomes, hemodynamics and heart function in an ASPX model.
Methods: We monitored 16 anesthetized pigs (4 ± 1 kg) for hemodynamic and echocardiographic parameters. ASPX arrest was induced by paralysis and airway obstruction. Upon cessation of aortic pulsations (pulse pressure < 5 mm Hg for 10–13 min), animals were randomized to:
TH viz., chest compression and ventilation with FiO2 of 1.0 or
pGz for 10 mins followed by epinephrine, sodium bicarbonate and defibrillation attempts.
Results: ROSC occurred in 4/8 animals in each group, only 1/8 in each group survived to 180 min. Severe myocardial stunning occurred in all survivors of both groups. %EF decreased from baseline (BL) of 54 to 32% and 56 to 31% in pGz and TH, respectively (p < 0.01 BL vs ROSC) There were no significant differences in hemodynamics at BL, during ASPX and during CPR between groups. † All values different from BL ( p < 0.01) but not different between groups. BPm = mean blood pressure CPPm = mean Coronary Perfusion Pressure, both mmHg.[X ± (SD)].
Conclusion: In this severe model of ASPX arrest, pGz is equivalent to TH with regards to acute ROSC and hemodynamics. Unlike the VF model of cardiac arrest, pGz does not appear to confer early protection from myocardial stunning.