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

Abstract

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-hour) 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 minutes. Basic life support was performed for 10 minutes. At minute 10 (EMS arrival), animals received either SNPeCPR (n=8) or standard ACLS (n=8). Defibrillation (200J) occurred every 3 minutes. CPR continued for a total of 45 minutes, then the balloon was deflated simulating revascularization. CPR continued until return of spontaneous circulation (ROSC) or a total of 60 minutes, if unsuccessful. SNPeCPR animals received 2 mg of SNP at minute 10 followed by 1 mg every 5 minutes until ROSC. Standard ACLS animals received 0.5 mg epinephrine every 5 minutes until ROSC. Primary endpoints were ROSC and 4-hour 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-hour 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-hour survival compared with standard ACLS CPR in a porcine model of prolonged ischemic, refractory VF cardiac arrest.

Role of Epinephrine and Extracorporeal Membrane Oxygenation in the Management of Ischemic Refractory Ventricular Fibrillation

“…This would likely limit the observed effectiveness of ECMO. Prior studies performing standard ACLS in this same model of ischemic VF have demonstrated a low ROSC rate, suggesting a minimal impact in this study (3) . This may also eliminate the injury typically caused by repeated defibrillation in clinical situations.…”

“…We used 33 pigs with an average weight of 44 ± 3 kg. The surgical preparation under aseptic conditions, anesthesia, data monitoring, and recording procedures used in the present study have been described elsewhere 3 , 4 , 5 . Briefly, pigs were anesthetized with intramuscular ketamine (1,000 mg) followed by inhaled isoflurane at a dose of 0.8% to 1.2%.…”

“…The coronary occlusion protocol has been described previously 3 , 6 , 7 . A 6-F Amplatz Left 0.75 short-tipped guide catheter was engaged into the left main coronary artery under fluoroscopic guidance.…”

“…Therefore, we developed a porcine model of prolonged CPR with refractory ischemic VF that simulated our MRC clinical protocol (3) and implemented a randomized 2 × 2 factorial design to test 2 hypotheses: 1) use of EPI in prolonged resuscitation improves short-term 4-h survival; and 2) ECMO-facilitated reperfusion improves short-term 4-h survival and cardiac function compared with CPR-facilitated reperfusion with no ECMO support.…”

Personalized physiology-guided resuscitation in highly monitored patients with cardiac arrest—the PERSEUS resuscitation protocol

“…In addition to the primarily vascular activity, it may also have antioxidant effects through the release of NO, which is a potent antioxidant and is capable of rendering neuroprotection against oxidative stress-induced neurotoxicity [23]. Besides nitroglycerin, sodium nitroprusside-enhanced CPR has been shown to improve myocardial, carotid, and cerebral blood flow, postresuscitation left ventricular global function, and 24-h survival with good neurological function in porcine models of cardiac arrest [24,25]. Also, the addition of inhaled NO to hemodynamic-directed CPR may improve short-term survival and intra-arrest hemodynamics [26].…”