The Adverse Effects of High Oral Osmolal Mixtures in Neonates: A Review and a Study of the Osmolality of Calcium Preparations

In both animals and humans, there are numerous clinical, physiologic, and morphologic al terations that occur when hypertonic solutions are introduced into the alimentary tract. The most serious adverse effect observed in the human infant is necrotizing enterocolitis. A short in vitro study analyzing osmolalities of drug-formula mixtures at various dilutions, conducted by the authors, showed that an unacceptable degree of high osmolality may be achieved in the preparation of common medications used in newborn nurseries. Although review of the literature confirms that, in general, the osmolalities of mixtures fed to newborns should not exceed 460 mOsm/kg H₂O, lower levels would be preferable in ill and low birth weight newborns. When possible, consideration should be given to the use of parenteral medication for the critically ill neonate. Ideally, the osmolalities of mixtures fed to newborns should be measured if they are not known or cannot be calculated.