Open-chest cardiac massage after closed-chest compression in a canine model: when to intervene.

Open-chest cardiac massage appears beneficial in improving hemodynamics during resuscitation efforts and in improving resuscitation success. The time between cardiac arrest and the initiation of open-chest cardiac massage is crucial. It would appear that if initiation of open chest cardiac massage is delayed for more than 20 min from the onset of cardiac arrest, little or no successful outcome can be expected. Further techniques for assessing the adequacy of closed-chest compression CPR are needed. Such techniques would allow early identification of ineffective resuscitation efforts and provide the opportunity for early change to other, presumably more effective, techniques.