Sodium nitroprusside enhanced cardiopulmonary resuscitation improves short term survival in a porcine model of ischemic refractory ventricular fibrillation

Introduction Sodium nitroprusside (SNP) enhanced CPR (SNPeCPR) demonstrates increased vital organ blood flow and survival in multiple porcine models. We developed a new, coronary occlusion/ischemia model of prolonged resuscitation, mimicking the majority of out-of-hospital cardiac arrests presenting with shockable rhythms. Hypothesis SNPeCPR will increase short term (4-h) survival compared to standard 2015 Advanced Cardiac Life Support (ACLS) guidelines in an ischemic refractory ventricular fibrillation (VF), prolonged CPR model. Methods Sixteen anesthetized pigs had the ostial left anterior descending artery occluded leading to ischemic VF arrest. VF was untreated for 5 min. Basic life support was performed for 10 min. At minute 10 (EMS arrival), animals received either SNPeCPR (n = 8) or standard ACLS (n = 8). Defibrillation (200J) occurred every 3 min. CPR continued for a total of 45 min, then the balloon was deflated simulating revascularization. CPR continued until return of spontaneous circulation (ROSC) or a total of 60 min, if unsuccessful. SNPeCPR animals received 2 mg of SNP at minute 10 followed by 1 mg every 5 min until ROSC. Standard ACLS animals received 0.5 mg epinephrine every 5 min until ROSC. Primary endpoints were ROSC and 4-h survival. Results All SNPeCPR animals (8/8) achieved sustained ROSC versus 2/8 standard ACLS animals within one hour of resuscitation (p = 0.04). The 4-h survival was significantly improved with SNPeCPR compared to standard ACLS, 7/8 versus 1/8 respectively, p = 0.0019. Conclusion SNPeCPR significantly improved ROSC and 4-h survival compared with standard ACLS CPR in a porcine model of prolonged ischemic, refractory VF cardiac arrest.