Pediatric Hypernatremia Workup

Updated: Dec 16, 2020
  • Author: Ewa Elenberg, MD, MEd; Chief Editor: Timothy E Corden, MD  more...
  • Print

Laboratory Studies

Studies indicated in patients with suspected hypernatremia are listed below.

Serum tests

Obtain levels of sodium, osmolality, BUN, and creatinine.

Other laboratory measurements include aldosterone, cortisol, antidiuretic hormone (ADH), and corticotropin (ACTH) levels

Urine sodium concentration and osmolality

In cases of hypovolemic hypernatremia, extrarenal losses show urine sodium levels of less than 20 mEq/L, and in cases of renal losses, urine sodium values are more than 20 mEq/L.

In euvolemic hypernatremia, urine sodium data vary.

In hypervolemic hypernatremia, the urine sodium level is more than 20 mEq/L.


Imaging Studies

Imaging studies of the head should be considered in alert patients with severe hypernatremia to rule out a hypothalamic lesion affecting the thirst center.

CT scans may help in diagnosing intracranial tumors, granulomatous diseases (eg, sarcoid, tuberculosis, histiocytosis), and other intracranial pathologies.

MRI further delineates the pathology.