An apparatus and method is provided for a defibrillator that specifies treatment protocols in terms of number of chest compressions instead of time intervals. The defibrillator includes a connection port that is configured to attach with a plurality of electrodes that are capable of delivery of a defibrillation shock and/or sensing one or more physical parameters. An energy storage device capable of storing a charge is attached to the plurality of electrodes. A controller is coupled to the plurality of electrodes and the energy storage device, the controller is configured to provide CPR chest compression instructions in terms of the numbers of CPR chest compressions.