The syndrome of inappropriate secretion of antidiuretic hormone associated with anaerobic thoracic empyema.

The syndrome of inappropriate secretion of antidiuretic hormone has been associated with many pulmonary diseases, including tuberculosis and bacterial and viral pneumonia: however, it has not been reported with anaerobic infections or empyema in the absence of pneumonia. We report a patient with empyema due to Bacteroides melaninogenicus, Bacteroides oralis, and Peptostreptococcus who developed the syndrome. Eight hours before the start of therapy, his serum sodium concentration was 127 mEq per liter; serum osmolality, 255 mOsm per kg; urine osmolality, 522 mOsm per kg; urinary sodium concentration, 39 mEq per liter. The creatinine clearance and the adrenocorticotropic hormone stimulation test were normal, and there was no evidence of dehydration. No other causes of the syndrome of inappropriate secretion of antidiuretic hormone were apparent. With drainage and antimicrobial drug therapy, the empyema cleared, and the syndrome resolved in 8 days. The patient has been well, without evidence of inappropriate secretion of antidiuretic hormone, for 9 months. Anaerobic infections and/or empyema without pneumonia can be associated with the syndrome of inappropriate secretion of antidiuretic hormone.