Continuous chest compression resuscitation in arrested swine with upper airway inspiratory obstruction

This study was designed to compare 24-h survival rates and neurological function of swine in cardiac arrest treated with one of three forms of simulated basic life support CPR.

Thirty swine were randomized equally among three experimental groups to receive either 30:2 CPR with an unobstructed endotracheal tube (ET) or continuous chest compression (CCC) CPR with an unobstructed ET or CCC CPR with a collapsable rubber sleeve on the ET allowing air outflow but completely restricting air inflow. The swine were anesthetized but not paralyzed. Two min of untreated VF was followed by 9 min of simulated single rescuer bystander CPR. In the 30:2 CPR group, each set of 30 chest compressions was followed by a 15-s pause to simulate the realistic duration of interrupted chest compressions required for a single rescuer to deliver 2 mouth-to-mouth ventilations. The other two groups were provided continuous chest compressions (CCC) without assisted ventilations. At 11 min post-arrest a biphasic defibrillation shock (150 J) was administered followed by a period of advanced cardiac life support.

In the 30:2 group, 8 of 10 animals had good neurological function at 24-h post-resuscitation. In the CCC open airway group, 10 of 10, and in the CCC inspiratory obstructed group, 9 of 10. The number of shocks (P<0.05) and epinephrine doses (P<0.05) required for ROSC was greater in the 30:2 CPR group than in the other two groups.

There were no differences in 24-h survival with good neurological function among these three different CPR protocols.