Continuous Chest Compressions vs AHA Standard CPR of 30:2

The primary aim of the trial is to compare survival to hospital discharge after continuous
chest compressions (CCC) versus standard American Heart Association (AHA) recommended
cardiopulmonary resuscitation (CPR) with interrupted chest compressions (ICC) in patients
with out-of-hospital cardiac arrest (OOHCA). For this study, CCC consists of a series of
three cycles of continuous chest compressions without pauses for ventilation followed by
rhythm analysis or until restoration of spontaneous circulation (ROSC), whichever occurs
first. ICC consists of series of three cycles of standard CPR each cycle comprised of chest
compressions with interposed ventilations at a compression:ventilation ratio of 30:2 (per
AHA guidelines) followed by rhythm analysis or until ROSC, whichever occurs first. In either
patient group, the duration of manual CPR before the first rhythm analysis will be 30
seconds or 120 seconds. This treatment period will be followed by two cycles of compressions
then rhythm analysis (i.e. each of approximately 2 minutes duration) in either group. Other
aims of the trial are to compare survival to discharge among patients grouped by
first-recorded rhythm or other a priori subgroups, as well as to compare neurological status
at discharge, mechanistic outcomes or adverse events between control and intervention
groups.

Inclusion Criteria:

- Age 18 years or more (or local age of consent);

- Initial fire/Emergency Medical Services (EMS) chest compressions provided by
Resuscitation Outcomes Consortium (ROC) study participating agency dispatched to the
scene;

- Lack of the exclusion criteria below

Exclusion Criteria:

- EMS witnessed arrest;

- Written do not attempt resuscitation (DNAR) orders;

- Obvious primary asphyxia or respiratory cause of arrest (drowning, strangulation,
hanging)

- Advanced airway placed prior to ROC EMS arrival, or pre-existing tracheostomy

- Traumatic cause (blunt, penetrating, burn) of arrest;

- Known prisoners;

- Known pregnancy;

- Uncontrolled bleeding or exsanguination

- Mechanical compression device used during study-assigned compression cycles