Abstract 12177: Inhaled Nitric Oxide During Cardiopulmonary Resuscitation Improves Functional Outcome and Increases 7-Day-Survival After Prolonged Cardiac Arrest in Rats

Abstract

Introduction: Precordial compressions during cardiac arrest (CA) increase pulmonary vascular resistance (PVR), potentially impeding survival by limiting left ventricular preload. Although used as selective pulmonary vasodilator there is accumulating evidence that inhaled nitric oxide (iNO) also attenuates I/R injury. Hypothesis: Applying iNO during cardiopulmonary resuscitation (CPR) increases resuscitation rates and improves functional outcome after cardiac arrest in rats. Methods: Thirty male Sprague-Dawley rats were subjected to 10 mins of CA and 3 mins of CPR. Animals were randomized to receive either 20 ppm or 40 ppm iNO during CPR until 30 mins after ROSC (return of spontaneous circulation) or no iNO treatment. For all animals a neurological deficit score (NDS) was calculated daily for seven days following the experiment. Results: Inhalation of 20 ppm iNO increased ROSC rates in comparison to animals treated with 40 ppm or without iNO treatment, however this failed to reach statistical significance (control: 7/10; 20ppm iNO: 10/10; 40ppm iNO 6/10). 20 ppm iNO significantly decreased time to ROSC, resulting in a significant reduction of post-arrest lactate levels. Also, significantly higher mean arterial pressures in comparison to control animals were observed. Furthermore, 20 ppm iNO resulted in a significantly higher seven-day-survival in comparison to controls (control: 4/10; 20 ppm iNO: 10/10). All iNO treated animals showed better neurological outcomes, being significant in animals treated with 20 ppm iNO on postoperative day 2- 7. Conclusions: Our study demonstrates that 20 ppm but not 40 ppm iNO during CPR significantly decreases time to ROSC. Furthermore, significantly better seven-day-survival and neurological outcome was noted for 20 ppm iNO in comparison to controls.