A cardiopulmonary resuscitation (CPR) compression force indicator includes circuitry (20, 26, 28, 30) for monitoring a patients transthoracic impedance while the patient is being given CPR and generating a corresponding impedance signal, circuitry (32, 34, 36) for processing the impedance signal to provide an ongoing measurement of cardiac hemodynamic output, a microprocessor (24) for determining if the measurement falls outside pre-set limits, and indicator(s) (38) for indicating such determination externally to the person giving the CPR.
