Continuous Chest Compressions vs AHA Standard CPR of 30:2 (CCC)

National Heart, Lung, and Blood Institute (NHLBI), Canadian Institutes of Health Research (CIHR), Heart and Stroke Foundation of Canada, American Heart Association, Defence Research and Development Canada, U.S. Army Medical Research and Development Command

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). The primary null hypothesis will be that the rate of survival to hospital discharge is not affected by use of continuous compressions with passive or positive pressure ventilation (intervention group) versus CPR with compressions interrupted for ventilation at a ratio of 30:2 (control group).

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.

American Heart Association (AHA)recommended cardiopulmonary resuscitation (CPR) of 30 compressions with brief pause for 2 ventilations

30:2 CPR consists of 3 cycles of standard CPR with each cycle consisting of 30 chest compressions with a pause for 2 ventilations at a compression:ventilation ratio of 30:2. CCC consists of a series of three cycles of continuous chest compressions without pauses for ventilation. In either group, each cycle will be followed by rhythm analysis until three cycles are completed or restoration of spontaneous circulation (ROSC), whichever occurs first.

Patients may die in the field (outside of the hospital at the time of the cardiac arrest), at the emergency room, in the hospital, or they are discharged alive from the hospital.

Patients will be followed from the time of the cardiac arrest until death or hospital discharge, whichever occurs first.

Neurologic status at discharge will be assessed using the modified Rankin Score (MRS). A higher value indicates a worse outcome. 0-No symptoms at all; 1-No significant disability despite symptoms; able to carry out all usual duties and activities, 2-Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance, 3-Moderate disability; requiring some help, but able to walk without assistance; 4-Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance, 5-Severe disability; bedridden, incontinent and requiring constant nursing care and attention; 6-Dead

Patients will be followed from the time of the cardiac arrest until death or hospital discharge, whichever occurs first.

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

Nichol G, Leroux B, Wang H, Callaway CW, Sopko G, Weisfeldt M, Stiell I, Morrison LJ, Aufderheide TP, Cheskes S, Christenson J, Kudenchuk P, Vaillancourt C, Rea TD, Idris AH, Colella R, Isaacs M, Straight R, Stephens S, Richardson J, Condle J, Schmicker RH, Egan D, May S, Ornato JP; ROC Investigators. Trial of Continuous or Interrupted Chest Compressions during CPR. N Engl J Med. 2015 Dec 3;373(23):2203-14. doi: 10.1056/NEJMoa1509139. Epub 2015 Nov 9.

Brown SP, Wang H, Aufderheide TP, Vaillancourt C, Schmicker RH, Cheskes S, Straight R, Kudenchuk P, Morrison L, Colella MR, Condle J, Gamez G, Hostler D, Kayea T, Ragsdale S, Stephens S, Nichol G; ROC Investigators. A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest: rationale for and design of the Resuscitation Outcomes Consortium Continuous Chest Compressions Trial. Am Heart J. 2015 Mar;169(3):334-341.e5. doi: 10.1016/j.ahj.2014.11.011. Epub 2014 Nov 20.