First responder airway and compression rate cluster randomized controlled trial: rational and design.

Background: The specific components of professional first-responder CPR (chest compressions and ventilations) are associated with clinical outcomes following out-of-hospital cardiac arrest (OHCA). Yet, this understanding about best-practices CPR is largely informed by observational rather than randomized evaluation. The Design and setting: FACT is a factorial, cluster-randomized, cross-over trial conducted in a large metropolitan region in the United States by Emergency Medical Services (EMS). Study interventions are allocated according to EMS agency every 4 months. Study subjects: The study plans to enroll ∼4200 adults with nontraumatic OHCA treated by first responder firefighter emergency medical technicians (EMTs). Interventions: Randomized interventions will include the initial EMT airway (mask or i-gel supraglottic airway) and the professional rescuer compression rate (100 or 110 or 120 compressions per minute). Inspiratory and expiratory ventilation volume will be assessed in a subset of subjects. Compression rates will be directed by metronome and assessed through review of the defibrillator recording. Outcomes: The primary outcome is survival to hospital discharge; secondary outcomes include return of spontaneous circulation at the end of EMS care and survival with favorable neurological status classified as Cerebral Performance Category of 1 or 2 at hospital discharge. Subgroup analyses: Planned subgroup analyses include intervention comparisons according to sex, initial rhythm, and BLS CPR strategy (30:2 and 10:1). Inference: Results of the FACT study may inform fundamental approaches to first responder CPR.