Blood chemistry abnormalities in bacterial endocarditis of narcotic addicts

We recently treated two narcotic addicts with bacterial endocarditis who developed the syndrome of inappropriate antidiuretic hormone secretion (SIADH). This prompted a retrospective review of blood chemistry studies in all narcotic addicts admitted to our hospital over a 30-month period because of a clinical suspicion of bacterial endocarditis. Patients with culture-positive endocarditis (group 1) had significantly lower plasma osmolality, sodium, calcium and albumin values (P less than .02, .001, .005, and .005 respectively) than addicts without endocarditis (group 2). More than 90% of those in group 1 had hyponatremia, and 48% had plasma hypoosmolality. These findings may be of value in the initial evaluation of ill narcotic addicts for hospitalization.