Effects of External Ventricular Drainage on Serum Sodium Levels in Adult Neurosurgical Patients

Objective: Hyponatremia is a common electrolyte abnormality observed in neurosurgical practice. The purpose of this article is to report the preliminary findings on the relationship between hyponatremia and continuous external ventricular drainage in adult neurosurgical patients. Methods: We retrospectively studied the mean serum sodium (Na+) levels of 67 patients (29 females, 38 males) who were operated for intracranial pathologies and underwent external ventricular drainage insertion to monitor and decrease the intracranial pressure. We correlated serum Na+ levels with cerebrospinal fluid (CSF) drainage in three time periods (early, medium, and late). Results: The mean duration of CSF drainage was 10±6.4 days. Fifteen patients experienced hyponatremia during CSF drainage. Thirteen of them (86.6%) had borderline hyponatremia. One patient with the diagnosis of pituitary macroadenoma and one with subarachnoid hemorrhage had the mean serum Na+ level of 129 mmol/L during the medium period. There was no significant correlation between the mean serum Na+ levels and the CSF drainage values in any of the periods. Conclusion: Our findings showed no association between hyponatremia and continuous CSF drainage in adult patients, indicating that external ventricular drainage can be safely used except in certain intracranial pathologies that require cautious observation for low Na+ levels.