Defibrillation and biphasic shocks: Implications for perianesthesia nursing

Cardiac arrests, the majority of which are due to ventricular fibrillation (VF), are a significant threat to survival. The definitive therapy for cardiac arrests due to VF is rapid, early defibrillation. There have been several advances made to modern defibrillators to electively or emergently terminate lethal and nonlethal arrhythmias through external defibrillation. The most recent improvement is in the efficacy of the delivered shock. Biphasic shock waveforms have been shown to be superior to monophasic shocks and are recognized in the current Advanced Cardiac Life Support guidelines by the American Heart Association. Because hospitals are increasingly replacing older models of monophasic capability defibrillators with the newer biphasic capability models, it will be essential for perianesthesia nurses to understand the principles of biphasic technology.