The incidence of postoperative hyponatremia and associated neurological sequelae in children with intracranial neoplasms

Abstract

Intracranial tumors are common pediatric neoplasms and account for substantial morbidity among children with cancer. Hyponatremia is a known complication of neurosurgical procedures and is associated with higher morbidity among neurosurgical patients. The authors aimed to estimate the incidence of hyponatremia, identify clinical characteristics associated with hyponatremia, and assess the association between hyponatremia and patient outcome among children undergoing surgery for intracranial tumors. This is a retrospective cohort study of children ranging in age from 0 to 19 years who underwent an initial neurosurgical procedure for an intracranial tumor between January 2001 and February 2012. Hyponatremia was defined as serum sodium ≤ 130 mEq/L during admission. Hyponatremia during admission occurred in 39 (12%) of 319 patients and was associated with young age and obstructive hydrocephalus (relative risk [RR] 2.9 [95% CI 1.3-6.3]). Hyponatremic patients were frequently symptomatic; 21% had seizures and 41% had altered mental status. Hyponatremia was associated with complicated care including mechanical ventilation (RR 4.4 [95% CI 2.5-7.9]), physical therapy (RR 4 [95% CI 1.8-8.8]), supplemental nutrition (RR 5.7 [95% CI 3.3-9.8]), and infection (RR 5.7 [95% CI 3.3-9.5]). Hyponatremic patients had a 5-fold increased risk of moderate or severe disability on the basis of their Pediatric Cerebral Performance Category score at discharge (RR 5.3 [95% CI 2.9-9.8]). Obstructive hydrocephalus (adjusted odds ratio [aOR] 3.24 [95% CI 1.38-8.94]) and young age (aOR 0.92 [95% CI 0.85-0.99]) were independently associated with hyponatremia during admission. Hyponatremia was independently associated with moderate or worse disability by Pediatric Cerebral Performance Category score at discharge (aOR 6.2 [95% CI 3.0-13.03]). Hyponatremia was common, particularly among younger children and those with hydrocephalus. Hyponatremia was frequently symptomatic and was associated with more complicated hospital courses. Hyponatremia was independently associated with worse neurological outcome when adjusted for age and tumor factors. This study serves as an exploratory analysis identifying important risk factors for hyponatremia and associated sequelae. Further research into the causes of hyponatremia and the association with poor outcome is needed to determine if prevention and treatment of hyponatremia can improve outcomes in these children.