Published online Aug 16, 2013. doi: 10.12998/wjcc.v1.i5.155
Revised: April 19, 2013
Accepted: May 18, 2013
Published online: August 16, 2013
Processing time: 148 Days and 23.5 Hours
We report a case of a 50-year-old malnourished African American male with hiccups, nausea and vomiting who was brought to the Emergency Department after repeated seizures at home. Laboratory evaluations revealed sodium (Na+) 107 mmol/L, unmeasurably low potassium, chloride < 60 mmol/L, bicarbonate of 38 mmol/L and serum osmolality 217 mOsm/kg. Seizures were controlled with 3% saline IV. Once nausea was controlled with iv antiemetics, he developed large volume free water diuresis with 6 L of dilute urine in 8 h (urine osmolality 40-60 mOsm/kg) and serum sodium rapidly rose to 126 mmol/L in 12 h. Both intravenous desmopressin and 5% dextrose in water was given to achieve a concentrated urine and to temporarily reverse the acute rise of sodium, respectively. Serum Na+ was gradually re-corrected in 2-3 mmol/L daily increments from 118 mmol/L until 130 mmol/L. Hypokalemia was slowly corrected with resultant auto-correction of metabolic alkalosis. The patient discharged home with no neurologic sequaele on the 11th hospital day. In euvolemic hyponatremic patients, controlling nausea may contribute to unpredictable free water diuresis. The addition of an antidiuretic hormone analog, such as desmopressin can limit urine output and prevent an unpredictable rise of the serum sodium.
Core tip: In euvolemic hyponatremic patients, controlling the underlying reason of excessive vasopressin secretion may lead to sudden, large-volume free water diuresis and rise of serum sodium exceeding 12 mmol/L per day. Polyuria after presentation with symptomatic hyponatremia is a serious warning sign and should not be ignored. These patients need frequent electrolyte monitoring and, in case of excessive rise of serum sodium, pure water replacement with 5% dextrose in water to achieve a targeted reduction in serum sodium levels. Early addition of an antidiuretic hormone analog, such as desmopressin, can limit urine output and improve patient outcome.