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-rescuer bystander cardiopulmonary resuscitation (CPR) in a clinically relevant swine model of prehospital pediatric asphyxial cardiac arrest.


METHODS
Prospective, randomized study.


METHODS
Thirty-nine anesthetized domestic piglets.


METHODS
Asphyxial cardiac arrest was produced by clamping the endotracheal tubes of the piglets. For 8 mins of simulated bystander CPR, animals were randomly assigned to the following groups: group 1, chest compressions and simulated mouth-to-mouth ventilation (FI(O2) = 0.17, FI(CO2) = 0.04) (CC+V); group 2, chest compressions only (CC); group 3, simulated mouth-to-mouth ventilation only (V); and group 4, no CPR (control group). Standard advanced life support was then provided, simulating paramedic arrival. Animals that were successfully resuscitated received 1 hr of intensive care support and were observed for 24 hrs.


RESULTS
Electrocardiogram, aortic blood pressure, right atrial blood pressure, and end-tidal CO2 were monitored continuously until the intensive care period ended. Arterial and mixed venous blood gases were measured at baseline, 1 min after cardiac arrest, and 7 mins after cardiac arrest. Minute ventilation was determined during each minute of bystander 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 (CC) piglets (p < or = .01), one of seven group 3 (V) piglets (p < or = .05), and two of eight group 4 (control) piglets (p < or = .05). Twenty-four-hour neurologically normal survival occurred in seven of 10 group 1 (CC+V) piglets vs. one of 14 group 2 (CC) piglets (p < or = .01), one of seven group 3 (V) piglets (p < or = .05), and none of eight group 4 (control) piglets (p < or = .01). Arterial oxygenation and pH were markedly better during CPR in group 1 than in group 2. Within 5 mins of bystander CPR, six of 10 group 1 (CC+V) piglets attained sustained return of spontaneous circulation vs. only two of 14 group 2 (CC) piglets and none of the piglets in the other two groups (p < or = .05 for all groups).


CONCLUSIONS
In this pediatric asphyxial model of prehospital single-rescuer bystander CPR, chest compressions plus simulated mouth-to-mouth ventilation improved systemic oxygenation, coronary perfusion pressures, early return of spontaneous circulation, and 24-hr survival compared with the other three approaches.
Berg
R A
RA
University of Arizona Heart Center, Tucson, AZ, USA. rberg@peds.arizona.edu
Hilwig
R W
RW
Kern
K B
KB
Babar
I
I
Ewy
G A
GA
D000704:Analysis of Variance; D000818:Animals; D001237:Asphyxia / Q000150:complications*; D001925:Brain Damage, Chronic / Q000209:etiology / Q000517:prevention & control; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D002648:Child; D005392:First Aid / Q000379:methods*; D006323:Heart Arrest / Q000150:complications / Q000209:etiology / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D009460:Neurologic Examination; D011446:Prospective Studies; D011897:Random Allocation; D012121:Respiration, Artificial / Q000379:methods; D016019:Survival Analysis; D013552:Swine