Neonatal ascites and hyponatraemia following umbilical venous catheterization.

The complications associated with umbilical venous catheterization in neonates range from pericardial effusion, portal hypertension, and peritoneal perforation with ascites, to Wharton's jelly embolism. The case of a term neonate who developed ascites and severe hyponatraemia (serum sodium 119 mmol/L) most probably following peritoneal perforation by an umbilical venous catheter is reported. The presenting feature was convulsions associated with dilutional hyponatraemia, probably following absorption of a large quantity of ascitic fluid across the peritoneum. Conservative management was associated with gradual recovery over 24 h. The case highlights that, irrespective of the route, excessive administration of salt-free fluids can lead to dilutional hyponatraemia with adverse consequences. The present case illustrates the importance of confirming intravascular positioning of umbilical catheters by ensuring free flow of blood on aspiration, to prevent/detect inadvertent peritoneal perforation. Ideally, echocardiographic confirmation of optimal intravascular placement of such catheters is preferred as radiographic confirmation is reported to be unreliable.