DDAVP to prevent rapid correction in hyponatremia

Correction of hyponatremia can be complicated by brisk free water diuresis with a rise in the serum sodium (s-Na) in excess of the generally accepted rate of 10-15 mmol/l/24 hours. We describe this complication and its treatm ent with desmopressin (dD-AVP), in a 56-year-old female with severe hyponat ermia secondary to polydypsia and antidiuretic (ADH) activity. The patient developed a large free water diuresis with a markedly dilute urine (urine o smolality 61 mmol/kg) and a rise in the serum sodium of 19 mmol/l in 19 hou rs despite the addition of large volumes of free water intravenously and or ally. To reduce the free water excretion, desmopressin (dD-AVP) 8 mu g was given intravenously. This resulted in a rise in the urinary osmolality, a r eduction in the urine volume, and a 2 mmol/l reduction in the serum sodium. Thereafter, the serum sodium rose 4 mmol/l in 24 hours. There were no neur ological sequellae. In cases of appropriate bur rapid correction of hyponat remia secondary to rapid free water diuresis, dD-AVP can safely reduce the free water excretion, slow the rate of correction of the serum sodium and s implify the fluid therapy of the patient.