Venous thromboembolism and severe hypernatremia in a patient with lithium-induced nephrogenic diabetes insipidus and acute kidney injury: a case report.

We report a case of thromboembolism in a patient with hypernatremia resulting from lithiuminduced nephrogenic diabetes insipidus (NDI). A 49-year-old female patient on chronic lithium therapy due to bipolar disorder was transferred to the emergency department with signs of dehydration, altered mental status, and increased oxygen demand. She was admitted to a local psychiatric clinic first because of an exacerbation of a manic episode. When she was transferred to our clinic, her blood pressure was 130/80 mmHg, she was tachycardic (110 beats/min), had tachypnea (24 breaths/min), normal body temperature (36.5 ℃), and an oxygen saturation of 94% via a face mask (10 L/min). Laboratory results showed hypertonic hypernatremia (osmolality, 363 mOsm/kg; sodium, 171 mEq/L), low urine osmolality (osmolality, 231 mOsm/kg), and normal urine sodium (Na, 63 mEq/L). Her serum lithium concentration was above the therapeutic range (1.52 mmol/L). An increase in cardiac markers and changes in electrocardiogram were detected; therefore, echocardiography was performed, which showed right ventricular dysfunction and small left ventricular chamber size. Computed tomography of the chest and lower extremities showed pulmonary thromboembolism (PTE) and deep venous thrombosis (DVT). She was treated with hypotonic fluid to correct hypernatremia and intravenous heparin for thromboembolism. The size of the thromboembolism decreased, and hypernatremia was corrected. She was discharged with a direct oral anticoagulant (DOAC). Here, we report a case of severe hypernatremia and venous thromboembolism in lithium-induced NDI.