The transfer of sodium to the extracellular space and cerebrospinal fluid in a newborn infant.

In the course of experiments on the transmission of radioactive sodium across the human placenta it became necessary to examine the way in which sodium diffuses in the newly born infant. Studies of this problem have already been reported by Flexner, Wilde, Proctor, Cowie, Vosburgh and Hellman (1947) and by Perley, Forbes and Pennoyer (1951). It was thought that some additional information might be obtained concerning the equilibrium level of Na24 if specimens of other body fluids could be examined at the same time as the blood plasma. The birth of a living, apparently healthy child with an incurable meningo-myelocoele offered an opportunity to determine the equilibrium level of the plasma and the cerebrospinal fluid. The child, weighing 3 12 kg. (6 lb. 14 oz.), had an open myelocoele with the spinal cord and nerve trunks exposed. The opening through which the cerebrospinal fluid exuded was small, and during the experiment the opening was almost completely sealed with a pledget of vaseline gauze. As the -child was incurable and was certain to die within a fortnight, the mother readily gave consent to the obtaining of multiple blood and cerebrospinal fluid samples. Method