Simulated mouth-to-mouth ventilation and chest compressions (bystander cardiopulmonary resuscitation) improves outcome in a swine model of prehospital pediatric asphyxial cardiac arrest

Objective: To compare the efficacy of four methods of simulated single-resc uer bystander cardiopulmonary resuscitation (CPR) in a clinically relevant swine model of prehospital pediatric asphyxial cardiac arrest. Design: Prospective, randomized study. Subjects: Thirty-nine anesthetized domestic piglets. Interventions: Asphyxial cardiac arrest was produced by clamping the endotr acheal tubes of the piglets. For 8 mins of simulated bystander CPR, animals were randomly assigned to the following groups: group 1, chest compression s and simulated mouth-to-mouth ventilation (FIO2 = 0.17, FICO2 = 0.04) (CCV); group 2, chest compressions only (CC); group 3, simulated mouth-to-mout h ventilation only (V); and group 4, no CPR (control group). Standard advan ced life support was then provided, simulating paramedic arrival. Animals t hat were successfully resuscitated received 1 hr of intensive care support and were observed for 24 hrs. Measurements and Main Results: Electrocardiogram, aortic blood pressure, ri ght atrial blood pressure, and end-tidal CO2 were monitored continuously un til the intensive care period ended. Arterial and mixed venous blood gases were measured at baseline, 1 min after cardiac arrest, and 7 mins after car diac arrest. Minute ventilation was determined during each minute of bystan der CPR. Survival and neurologic outcome were determined. Twenty-four-hour survival was attained in eight of 10 group 1 (CC+V) piglets vs. three of 14 group 2 (CG) piglets (p less than or equal to .01), one of seven group 3 ( V) piglets (p less than or equal to .05), and two of eight group 4 (control ) piglets (p less than or equal to .05). Twenty-four-hour neurologically no rmal survival occurred in seven of 10 group 1 (CC+V) piglets vs. one of 14 group 2 (CC) piglets (p less than or equal to .01), one of seven group 3 (V ) piglets (p less than or equal to .05), and none of eight group 4 (control ) piglets (p less than or equal to .01). Arterial oxygenation and pH were m arkedly better during CPR in group 1 than in group 2. Within 5 mins of byst ander CPR, six of 10 group 1 (CC+V) piglets attained sustained return of sp ontaneous circulation vs, only two of 14 group 2 (CC) piglets and none of t he piglets in the other two groups (p less than or equal to .05 for all gro ups). Conclusions: In this pediatric asphyxial model of prehospital single-rescue r bystander CPR, chest compressions plus simulated mouth-to-mouth ventilati on improved systemic oxygenation, coronary perfusion pressures, early retur n of spontaneous circulation, and 24-hr survival compared with the other th ree approaches.