Hyponatremia Complicates Outcomes for Kids After Neurosurgery

A study finds that children who develop hyponatremia after surgery for intracranial tumors are at heightened risk for a range of negative outcomes.

Children who develop hyponatremia after neurosurgery for intracranial tumors are more likely to have longer and more complicated recoveries and to have worse neurological outcomes, according to the results of a recent study.

Children with neurological disorders are at an elevated risk for developing hyponatremia, and the condition is associated with longer hospital stays and poor outcomes. However, little is known about the effects of hyponatremia in children undergoing brain tumor resection. The study authors previously attempted to analyze the risk factors for hyponatremia among children undergoing malignant intracranial tumor resections, but their data was limited. The current study, published online on January 10, 2014, in the Journal of Neurosurgery: Pediatrics, aims to expand on this research by estimating the prevalence of hyponatremia, identifying characteristics associated with hyponatremia, and analyzing the relationship between the condition and outcomes among children who have undergone surgery for intracranial tumors.

The retrospective study included children up to 19 years old who were admitted to Primary Children’s Medical Center in Salt Lake City, Utah, between January 2001 and February 2012 for their first intracranial neoplasm surgery. Children with serum sodium levels less than or equal to 130 mEq/l were considered to have hyponatremia. Using medical records, the researchers identified seizures and periods of decreased mental status caused by hyponatremia. At discharge, patients underwent physical examinations to calculate their Pediatric Cerebral Performance Category (PCPC) score. Depending on this score, patients were categorized as having normal or mild disability or as having moderate disability, severe disability, coma or vegetative state, or brain death.

Hyponatremia was diagnosed in 39 (12%) of the 319 patients included in the study. Younger children, those with tumors that overlapped multiple anatomical regions, and those with obstructive hydrocephalus were more likely to have hyponatremia than were other patients. Of the children with hyponatremia, 8 (21%) had seizures and 16 (41%) had altered mental status associated with the condition. Hyponatremia was also significantly associated with longer hospital stays and higher hospital costs. In addition, children with hyponatremia were more likely to develop infections and to need mechanical ventilation, physical therapy, and supplemental nutrition.

Hyponatremia was associated with a greater risk of disability at discharge. Based on PCPC scores, children with hyponatremia had 5 times the risk of being moderately or severely disabled compared with children without hyponatremia.

Although the results of the study suggest an association between hyponatremia and surgery for intracranial tumors, the authors note that they are unsure of what causes the complication or how to improve outcomes in these children.

“Prospective studies to develop targeted monitoring and intervention strategies to decrease hyponatremia are needed to determine if this decreases complications and improves outcomes,” they conclude.