A focused investigation of expedited, stack of three shocks versus chest compressions first followed by single shocks for monitored ventricular fibrillation/ventricular tachycardia cardiopulmonary arrest in an in-hospital setting.

Background: In cases of in-hospital-witnessed ventricular fibrillation/ventricular tachycardia (VF/VT) arrest, it is unclear whether cardiopulmonary resuscitation prior to defibrillation attempt or expedited stacked defibrillation attempt is superior.

Methods: Retrospective, observational study of all admitted patients with continuous cardiac monitoring who suffered VF/VT arrest between July 2005 and June 2013. In the stacked shock period (2005-2008), institutional protocols advocated early defibrillation with administration of 3 stacked shocks with brief pauses between each single defibrillation attempt to confirm sustained VF/VT. During the initial chest compression period (2008-2011), the protocol was modified to perform a 2-minute period of chest compressions prior to each defibrillation, including the initial. In the modified stack shock period (2011-2013), for a monitored arrest, defibrillation attempts were expedited with up to 3 successive shocks administered for persistent VF/VT. In unmonitored arrest, chest compressions and ventilations were initiated prior to defibrillation. The primary outcome measure was survival to hospital discharge.

Results: Six hundred sixty-one cardiopulmonary arrests were recorded during the study period, with 106 patients (16%) representing primary VF/VT. The incidence of VF/VT arrest did not vary significantly between the study periods (P= 0.16) Survival to hospital discharge for all primary VF/VT arrest victims decreased, then increased significantly from the stacked shock period to initial chest compression period to modified stacked shock period (58%, 18%, 71%, respectively, P < 0.01). Specific group differences were significant between the initial chest compression versus the stacked and modified stacked shock groups (all P < 0.01).

Conclusion: Data suggest that monitored VF/VT should undergo expeditious defibrillation with use of stacked shocks.