Neonatal cardiopulmonary resuscitation: Critical hemodynamics

Following asphyxia-induced severe bradycardia or asystole, a critical diastolic blood pressure must be attained during resuscitation to achieve return of spontaneous circulation. Although unknown in asphyxiated neonates, adult ventricular fibrillation models suggest that this critical pressure is approximately 15 to 20 mm Hg. Based on adult model data, chest compressions with coordinated ventilation at a ratio of 3:1 are unlikely to produce a sufficient diastolic blood pressure to achieve return of spontaneous circulation. Other compression-to-ventilation ratios that are potentially more effective at attaining an adequate diastolic blood pressure while maintaining adequate ventilation during neonatal resuscitation should be investigated. In addition, development of strategies to decrease hands-off time during newborn cardiac compressions are needed, including further investigation of capnography to guide cardiopulmonary resuscitation efforts rather than stopping to listen every 30 seconds. Administration of intravenous epinephrine often is needed once chest compressions are initiated for rapid achievement of the diastolic blood pressure necessary for a successful resuscitation. However, few data are available to allow determination of the most efficacious/safe epinephrine dosing and route of administration.