Abstract 164: Sodium Nitroprusside Improves Carotid Blood Flow and 24-Hour Neurological Intact Survival in a Porcine Model of Prolonged CPR.
Introduction: Sodium nitroprusside (SNP) is a powerful vasodilator. In an effort to improve vital organ blood flow during CPR and optimize microcirculation, we tested the hypothesis that high doses of SNP would be beneficial for treating cardiac arrest when administered with devices and techniques known to enhance blood pressure and circulation during CPR.
Methods: Twenty one (30±1Kg) pigs, intubated and isofluorane anesthetized, had 6 minutes of untreated ventricular. Group A: 5 animals received standard (S-) cardiopulmonary resuscitation (CPR). Group B: 8 received active compression decompression (ACD) CPR plus an inspiratory impedance threshold device (ITD) plus abdominal binding (AB). Group C: 8 received ACD+ITD+AB+SNP CPR for 25 minutes before defibrillation was attempted. SNP (1mg iv) was given every 5 minutes. Animals in groups A and B received epinephrine based on the 2005 AHA guidelines before defibrillation. Right atrial, aortic pressure and carotid blood flow were recorded. Successfully resuscitated animals were recovered and evaluated 24 hours later for cerebral performance category score. Statistical comparisons were performed by ANOVA and Fisher's exact test.
Results: Systolic/diastolic pressures (mmHg) were significantly higher in groups B and C compared to A (mean± SD: 82±7/34±3 and 78±11/38±5 vs 42±6/18±5, respectively, <0.05). Coronary perfusion pressure (mmHg)(diastolic aortic — right atrial) over 25 minutes for groups A, B, and C was 14±4, 26±6 and 28±5 mmHg, respectively, p<0.05) Carotid blood flow (ml/min) was highest with the use of SNP (mean values over 25 min, A: 55±28; B:155±49; C: 285±83, p<0.01). End-tidal CO2 at the end of 25 m of CPR was 8±2, 23±5 and 31±3 mmHg respectively (p<0.01). 24 hour survival was, A:0/5, B: 2/8 and C:7/8 (p<0.01,C vs A; p=0.04, B vs C). Cerebral performance category (CPC) for group C was 1.87±0.5. The two animals in group B had a CPC of 2 and 3.
Conclusions: SNP can safely be used in pigs to significantly improve vital organ perfusion and 24 hour survival when used in conjunction with ACD CPR+ITD+AB. This mechano-pharmacological therapy maintains vital organ viability during prolonged CPR.
- © 2010 by American Heart Association, Inc.