Use of desmopressin acetate in severe hyponatremia in the intensive care unit.

BACKGROUND AND OBJECTIVES: Excessive correction of chronic and profound hyponatremia may result in central pontine myelinolysis and cause permanent brain damage. In the case of foreseeable or established hyponatremia overcorrection, slowing down the correction rate of sodium plasma levels (PNa) or reinducing mild hyponatremia may prevent this neurologic complication.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This retrospective and observational study was performed with 20 consecutive patients admitted to two intensive care units for severe hyponatremia, defined by PNa <120 mmol/L and/or neurologic complications ascribable to hyponatremia and subsequently treated by desmopressin acetate (DDAVP) during correction of hyponatremia when the rate of correction was overtly or predictably excessive. The primary endpoint was the effectiveness of DDAVP on PNa control.

RESULTS: DDAVP dramatically decreased the rate of PNa correction (median 0.81 mmol/L per hour [interquartile range, 0.46, 1.48] versus -0.02 mmol/L per hour [-0.16, 0.22] before and after DDAVP, respectively; P<0.001) along with a concurrent decrease in urine output (650 ml/h [214, 1200] versus 93.5 ml/h [43, 143]; P=0.003), and a rise in urine osmolarity (86 mmol/L [66, 180] versus 209 mmol/L [149, 318]; P=0.002). The maximal magnitude of PNa variations was also markedly reduced after DDAVP administration (11.5 mmol/L [8.25, 14.5] versus 5 mmol/L [4, 6.75]; P<0.001). No patient developed seizures after DDAVP or after subsequent relowering of PNa that occurred in 11 patients.

CONCLUSIONS: Desmopressin acetate is effective in curbing the rise of PNa in patients admitted in the intensive care unit for severe hyponatremia, when the initial rate of correction is excessive.