Osmolality as a measure of dehydration in the neonatal period

Abstract

Plasma osmolality and sodium levels were estimated at birth and daily thereafter in a number of healthy full-term infants and in a series of feverish infants. There was only a slight correlation between serum sodium and plasma osmolality readings. A series of feverish babies without signs of infection showed a significant rise in osmolality but not in sodium levels. Implications are discussed.