Abstract 2663: The Importance of Gasping During Ventricular Fibrillation Cardiac Arrest for 24-hr Neurologically Normal Survival
Background: Gasping following cardiac arrest is not uncommon. Gasping or agonal breathing has been reported in 56% of out-of-hospital cardiac arrests with ventricular fibrillation (VF) by Clark and associates and was highly correlated with survival. Many resuscitation research laboratories utilize paralysis, which precludes gasping, as part of their model of cardiac arrest. The purpose of this study was to determine if gasping in a swine model of VF cardiac arrest was associated with 24-hr neurologically normal survival.
Methods: Domestic swine (n=27) were anesthetized, instrumented, and electrically fibrillated. After unassisted VF for 3– 4 min, CPR was administered for 8–9 min using either continuous chest compressions or 30:2 chest compressions to ventilation ratio. Following 12 min of VF, ACLS, including defibrillation, was provided followed by 1 hr of critical care monitoring. Animals were assessed for neurologically intact survival at 24 hrs post-VF using a standard scale. Gasping was measured using a pneumotachometer and direct observation; more than10 gasps/min was designated as continuous gasping.
Results: Overall 18 of 27 swine had 24-hr neurologically normal survival. Neurologically normal survival was found in 80% (17/21) of animals that had continuous gasping compared to 16% (1/6) that did not (p < 0.01). In response to the first defibrillation shock, 93% (14/15) with continuous chest compression CPR converted to a perfusing rhythm compared with only 50% (6/12) (p < 0.05) of those with 30:2 CPR.
Conclusions 1: Animals that gasp following the onset of VF are more likely to have neurologically normal survival at 24-hr post-resuscitation. Research laboratories that use paralysis as part of their protocol eliminate this physiologically important reflex.
Conclusion 2: Animals receiving continuous chest compressions CPR were more likely to have a perfusing rhythm after a defibrillation shock that those who received 30:2 CPR.