HYPERNATREMIA IN THE ACUTELY ILL ELDERLY PATIENTS - ROLE OF IMPAIRED ARGININE-VASOPRESSIN SECRETION

Hypernatremia, a common finding among the elderly, is believed to be d ue to water deficit. In the present study, in 12 consecutive hospitali zed elderly patients (mean age 82.2 years) with moderate to severe hyp ernatremia (mean serum sodium 166.9 mEq/l), inappropriately low plasma levels of vasopressin were found in relation to serum osmolality (mea n 1.8 pg/ml and 3 43 mosmol/l, respectively). All patients but 1 were hospitalized with acute febrile disease and all but 2 had underlying n eurological disease. Hypernatremia persisted for at least 3 days despi te the patients' rehydration. It seems, therefore, that temporary hype rnatremia in elderly patients with acute febrile disease, especially i n the presence of underlying neurological disorder, reflects an inadeq uate vasopressin response to the hyperosmolar state.