新生児・小児医学

抽象的な

Neonatal Resuscitation at Birth with Intact Placental Circulation

David J R Hutchon

Neonatal asphyxia at birth is a major cause of mortality and long term disability. However the clinical diagnosis is imprecise and largely subjective. At the moment of birth it is usually the obstetrician or midwife who has to make the diagnosis within the first 60 seconds. Logically positive pressure ventilation is the treatment of the apneic neonate but in order for this to be carried out on the roomside resuscitation trolley, another intervention, the intervention of cord clamping is required. Cord clamping is therefore performed, by definition, before neonatal breathing is established, and it is now known that clamping the cord at this stage shocks the cardiovascular system. The shock of early cord clamping results in bradycardia, hypoxaemia, hypovolemia, reduced cerebral circulation and reduced muscular tone, and reduced activity of the respiratory centre. Permanent injury and long term disability is possible if these adverse factors cannot be reversed quickly during resuscitation after birth. Being prepared for and then providing effective ventilation close to the mother with an intact cord can prevent all these adverse events and also initiate a physiological transition from placental to pulmonary respiration.