Abstract 20736: Ischemic Postconditioning Requires High-Quality CPR and Epinephrine to Improve Cardiac Mitochondrial Respiration After Prolonged Cardiac Arrest

Introduction: Ischemic postconditioning (IPC) has been shown to improve cardiac mitochondrial respiration during CPR and left ventricular ejection fraction post-ROSC in a porcine model of prolonged cardiac arrest compared to standard CPR. IPC during CPR (IPC-CPR) also increased coronary perfusion pressure (CPP) after bolus IV epinephrine. We investigated if the increased CPP obtained during IPC-CPR is required for improvement of cardiac mitochondrial respiration by: a) controlling CPP to <30mmHg via shallow chest compressions and, b) by withholding epinephrine during CPR. Methods: After 15 min of ventricular fibrillation, 36 intubated and isoflurane anesthetized female pigs were randomized to receive standard CPR (S-CPR, n=11), IPC (IPC, n=11), IPC with controlled CPP (IPC-ConCPP, n=8), or IPC without epinephrine (IPC-NoEpi, n=6). All groups, except IPC-NoEpi, received 0.5 mg of epinephrine at minute 3 of CPR. IPC consisted of 3 cycles of 20 sec compression / 20 sec pause for the first 2 min of CPR. Cardi...