Effect of Crew Size on Objective Measures of Resuscitation for Out-of-Hospital Cardiac Arrest

BACKGROUND: There is no consensus among emergency medical services (EMS) systems as to the optimal numbers and training of EMS providers who respond to the scene of prehospital cardiac arrests. Increased numbers of providers may improve the performance of cardiopulmonary resuscitation (CPR), but this has not been studied as part of a comprehensive resuscitation scenario. OBJECTIVE: To compare different all-paramedic crew size configurations on objective measures of patient resuscitation using a high-fidelity human simulator. METHODS: We compared two-, three-, and four-person all-paramedic crew configurations in the effectiveness and timeliness of performing basic life support (BLS) and advanced life support (ALS) skills during the first 8 minutes of a simulated cardiac arrest scenario. Crews were compared to determine differences in no-flow fraction (NFF) as a measure of effectiveness of CPR and time to defibrillation, endotracheal intubation, establishment of intravenous access, and medication administration. RESULTS: There was no significant difference in mean NFF among the two-, three-, and four-provider crew configurations (0.32, 0.26, and 0.27, respectively; p = 0.105). More three- and four-person groups completed ALS procedures during the scenario, but there was no significant difference in time to performance of BLS or ALS procedures among the crew size configurations for completed procedures. There was a trend toward lower time to intubation with increasing group size, though this was not significant using a Bonferroni-corrected p-value of 0.01 (379, 316, and 263 seconds, respectively; p = 0.018). CONCLUSION: This study found no significant difference in effectiveness of CPR or in time to performance of BLS or ALS procedures among crew size configurations, though there was a trend toward decreased time to intubation with increased crew size. Effectiveness of CPR may be hindered by distractions related to the performance of ALS procedures with increasing group size, particularly with an all-paramedic provider model. We suggest a renewed emphasis on the provision of effective CPR by designated providers independent of any ALS interventions being performed.