New Versus Old External Cardiopulmonary Resuscitation

Since standard cardiopulmonary resuscitation (SCPR) cannot reliably preserve the brain during resuscitation, a “New” CPR has been proposed, which seeks to augment blood flow by increasing peak intrathoracic pressure (ITP) during chest compression. This “New” CPR (NCPR) consists of a) high pressure ventilation (70-110 cmH2O) simultaneous with chest compression, b) compression rate of 40/min, c) compression duration of 60% of the compression relaxation cycle, and d) abdominal binding. Although laboratory evidence suggests that NCPR may be capable of augmenting cerebral blood flow (1), the effect on cerebral outcome remains to be demonstrated.Although the hemodynamic superiority of open-chest CPR has long been recognized, its advantages with respect to the brain have only recently been recognized. It can reliably sustain EEC activity and pupillary light reflexes during CPR (2) as well as providing better cerebral blood flow (3,4). The objective of this two phase study was to establish the relative efficacy of standard, “new,” and open-chest CPR with respect to preserving the brain during CPR.The objective of phase I of this study was to compare standard and “New” CPR with respect to maintenance of hemodynamic, respiratory, and cerebral variables during prolonged resuscitation. Methods: Ten 10-15 kg dogs were anesthetized with halothane and 50% N2O/O2. Catheters were placed in the carotid artery, aortic arch, right atrium, external jugular vein and the sagittal sinus. An electromagnetic flowprobe was placed on the common carotid artery. Intracranial pressure was monitored with a subdural catheter. EEG electrodes were secured to the skull.