syndrome of inappropriate antidiuretic hormone secretion
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SIADHSyndrome of inappropriate antidiuretic hormone secretion. A condition characterised by increased vasopressin/ADH secretion (despite low plasma osmolarity), water retention and dilutional hyponatraemia.
Addison’s disease, ACTH deficiency, AIDS, hypopituitarism, paraneoplastic hormone production (small cell carcinoma of lung, bronchogenic, pancreas, uterine, bladder or prostate), lymphoproliferative disorders, mesothelioma, thymoma, CNS disease (trauma, infection, chromophobe adenoma), metastases, lung disease (TB, pneumonia, PEEP ventilation), porphyria, drugs (e.g., chlorpropamide, vincristine, etc.).
Hypervolemia, hypouricaemia, decreased creatinine, hyponatraemia, natriuresis (urinary sodium > 20 mEq/L with decreased BUN), no symptoms of volume depletion, decreased maximum urinary dilution, increased ADH, normal renal and adrenal function.
Corticosteroids to suppress ADH secretion.