Study on the Etiology of the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Among the Hospital Admitted Patient

Abstract

Background: The syndrome of inappropriate antidiuretic hormone (SIADH) is a clinical illness that increases antidiuretic hormone (ADH) production or activity due to different disease processes. Normal release of ADH, or arginine vasopressin (AVP), occurs in the posterior lobe of the pituitary gland. SIADH, a hemodynamic disturbance, does not cause secretion of ADH. It is mediated through no osmotic receptors, resulting in water retention and dilutional hyponatremia. Materials methods: This was a cross-sectional observational study carried out by the Department of Medicine, Shaheed Ziaur Rahman Medical College Hospital, Bogura. Total 100 consecutive patients had hyponatremia due to SIADH. All patients were interviewed using standardized questionnaires. Data were analyzed using the statistical packages for social sciences (SPSS) for windows version 16. Results: Most of the patients (42%) in the study were older people >60 years. The average age was 60.69 years. The male-female ratio was 1.43.1. The symptoms of hyponatremia were fever (32%), headache (34%), weakness (40%). confusion (48%), convulsion (19%) and coma (52%). Of them, 34% were hypertensive, and 51% of patients had a Glasgow coma scale of 3/15. It was observed that the most common etiology of SIADH was hemorrhagic stroke (46%) then ischemic (41%). Among the hemorrhagic strokes, 40% were intracerebral, 4% were subarachnoid hemorrhage, and 2% were brain stem hemorrhage. Another etiology was meningitis (4%). Encephalitis (4%). Pneumonia (3%) and pulmonary tuberculosis (2%). Serum Na+ <120 mmol/L was seen in 38% patients. Total plasma osmolality was 260.40±8.51 (mmol/Kg), urinary Na+ was 13465±55.81 mmol/L, urinary osmolality was 408.05±157.02 mmol/L. S. creatinine was 1.06±1.02 m/dl, and S. uric acid was 3.35±0.75 mg/dl. Conclusions: The most common symptoms were Coma, confusion, weakness, headache, fever, and convulsion by hemorrhagic stroke and ischemic stroke. Meningitis, encephalitis, pneumonia, and pulmon