Gastrografin-induced hypertonicity. The pathogenesis of a neonatal hazard

Operative mortality in meconium ileus approaches 50 per cent. Recently, operation has been obviated by the administration of high Gastrografin enemas. However, the nonoperative therapy causes hypertonicity, manifested by rising hematocrit and serum osmolality and a decreased cardiac output and pulse rate. The suggested mechanism for hypertonicity is the attraction of plasma water into the gut by the concentrated “nonabsorbable” material. An alternate explanation involves absorption into the vascular system of osmolar active substances from Gastrografin. The purpose of this study is to clarify the pathogenesis of acute hyperosmolality.High Gastrografin enemas were administered to twenty-one neonatal puppies and serial blood studies were performed. A disproportionate rise in measured osmolality as compared to the calculated osmolality suggested significant absorption of the contrast material or its components through the puppy's intact gut wall. The results indicate that the hyperosmolar state is due to a combination of agent absorption and plasma water decrease.