Increase in pre-shock pause caused by drug administration before defibrillation: An observational, full-scale simulation study☆

Abstract 

Background

The importance of circulation during cardiopulmonary resuscitation has led to efforts to decrease time without chest compressions (“no-flow time”). The no-flow time from the interruption of chest compressions until defibrillation is referred to as the “pre-shock pause”. A shorter pre-shock pause increases the chance of successful defibrillation. It is unclear whether drug administration affects the length of the pre-shock pause. Our study compares pre-shock pause with and without drug administration in a full-scale simulation.

Methods

This was an observational study in an ambulance including 72 junior physicians and a cardiac arrest scenario. Data were extracted by reviewing video recordings of the resuscitation. Sequences including defibrillation and/or drug administration were identified and assigned to one out of four categories: Defibrillation only (DC-only) and drug administration just prior to defibrillation (Drug+DC) for which the pre-shock pause was calculated, and drug administration alone (Drug-only) for which pre-drug time was calculated.

Results

DC-only sequences were identified in 68/72 simulations, Drug+DC in 24/72, and Drug-only in 33/72. Median pre-shock pauses were 18s (DC-only) and 32 (Drug+DC), and median pre-drug pause 6. The variation between pauses was statistically significant (p≪0.001). DC-only and Drug+DC sequences was found in 22/72 simulations. A statistically significant difference of 8s was found between the median pre-shock pauses: 17s (DC-only) and 25 (Drug+DC) (p≪0.001). For un-paired observations, the pre-shock pause increased with 78% and for paired observations 47%.

Conclusions

Drug administration prior to defibrillation was associated with significant increases in pre-shock pauses in this full-scale simulation study.

Keywords: Information overload, Advanced life support (ALS), Ambulance, Cardiac arrest, Cardiac massage, Cardiopulmonary resuscitation (CPR), Chest compression, Circulation, Defibrillation, Education, Emergency treatment, Guidelines, Manikin, Resuscitation, Transport, Drugs, Pharmacokinetics, Crisis resource management