[A case of hypernatremia treated with human atrial natriuretic peptide]

We describe a case of 65-year-old obese female patient with pulmonary embolism and life-threatening hypernatremia after removal of craniopharyngioma. On the 18th day after neurosurgical procedure, pulmonary embolism developed abruptly. Immediately after placement of inferior vena cava filter, surgical removal of the pulmonary thrombus was performed under cardiopulmonary bypass. Although mechanical ventilatory support and infusion of noradrenaline were required postoperatively, the trachea was extubated on the 10th postoperative day. Meanwhile, daily serum Na level increased gradually and reached 178 mEq x l(-1). We suspected that dehydration and pituitary dysfunction were mainly responsible for the hypernatremia. Human atrial natriuretic peptide (hANP) was infused from the 2nd to the 4th postoperative day, and her urinary Na excretion became increased and serum Na level became normal. After discontinuation of hANP, urinary Na excretion became decreased again and serum Na levels increased transiently. However, her consciousness level and cardiopulmonary condition improved and she was discharged from the ICU after twelve days of ICU stay. HANP may be useful for treatment of life-threatening hypernatremia.