exCeSSive water ingeStion and repeated SeizureS

A 34-year-old male, previously healthy, was admitted in ICU of the Hospital da Cidade (Salvador BA, Brazil). The patient was transferred from the emergency department with a history of ingestion of 40 glasses of potable water, equivalent to approxi-mately 8 liters, during a period of a few hours. The patient was playing domino and the players bet that one who loses a game should drink a full glass of water. The unlucky patient lost one game after the other and started to become sleepy, culminating with a generalized tonic-clonic seizure. Taken to the hospital, he developed new episode of seizure, lingered, requiring intubation and mechanical ventilation. The admission tests revealed plas-ma sodium of 123 mmol/L and mild cerebral edema at CT scan. The diagnosis of hypovolemic hyposmolar hyponatremia with low urinary osmolality (“the marathon runner’s hyponatremia”) was made based on plasmatic osmolality (262 mmol/L), urinary osmolality, urinary sodium (undetectable) and the volemic sta-tus was estimated by pre-load pressures. Since the installation of hyponatremia was rapid with severe symptoms, 3% saline so-lution was started with infusion rate of 0.5 mL/kg/h. Plasma so-dium was measured hourly, aiming for an elevation of sodium level by 0.5 mEq/L/hour. After discontinuing sedation he gradu-ally recovered, being disconnected from mechanical ventilation in the third day of hospitalization. He was discharged from ICU after five days without any neurological deficit.