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Syndrome of Inappropriate Antidiuretic Hormone Secretion
From WikEM
Contents
Background
- Inappropriate or continued action of ADH despite normal/increased plasma volume→ impaired water excretion→ hyponatremia and hypo-osmolality
Causes
- Inappropriate or hypersecretion from hypothalamus
- Infectious
- Vascular/hemorrhagic
- Stroke, hypoxic ischemic encephalopathy, perinatal hypoxia
- Cavernous sinus thrombosis
- Subarachnoid hemorrhage
- Subdural hematoma
- Other
- Acute intermittent porphyria
- Cerebellar and cerebral atrophy
- CNS lupus
- Epilepsy, Delirium tremens
- Multiple sclerosis, Guillain-Barré Syndrome
- Hydrocephalus, ventriculoatrial shunt obstruction
- Wernicke encephalopathy
- Head trauma
- Ectopic ADH secretion due to neoplastic source
- Lung carcinoma, mesothelioma
- Duodenal, pancreatic, and colonic carcinomas
- Adrenocortical, bladder/urothelial, ovarian, prostate, and cervical cancers
- Brain tumor, leukemia/lymphoma, carcinoid, neuroblastoma, thymoma, Ewing's sarcoma
- Pulmonary disorders
- Drugs
- ADH-stimulating
- Acetylcholine, histamine
- Antineoplastic agents - Adenine arabinoside, cyclophosphamide, ifosfamide, vincristine, vinblastine
- Barbiturates, thiopental, MAOIs, tricyclic antidepressants
- Opioids
- Haloperidol, phenothiazines
- Carbamazepine, oxcarbazepine
- Halothane, nitrous oxide
- Bromocriptine
- Carbachol
- Chlorpropamide
- Isoproterenol
- Nicotine
- ADH-potentiating
- Griseofulvin
- Hypoglycemic agents – Metformin, phenformin, tolbutamide
- Oxytocin (large doses)
- Indomethacin, aspirin, NSAIDs
- Theophylline
- Vasopressin analogs (eg, AVP, DDAVP)
- ADH-stimulating
Clinical Features
Evaluation
Essential Criteria[1]
- Effective serum osmolality <275 mOsm/kg
- Urine osmolality >100 mOsm/kg at some level of decreased effective osmolality
- Clinical euvolaemia
- Urine sodium concentration >30 mmol/l with normal dietary salt and water intake
- Absence of adrenal, thyroid, pituitary or renal insufficiency
- No recent use of diuretic agents
Supplemental criteria
- Serum uric acid <0.24 mmol/l (<4mg/dl)
- Serum urea <3.6 mmol/l (<21.6mg/dl)
- Failure to correct hyponatraemia after 0.9% saline infusion
- Fractional sodium excretion >0.5%
- Fractional urea excretion >55%
- Fractional uric acid excretion >12%
- Correction of hyponatraemia through fluid restriction
Etiology
- Extensive differential to include categories in CNS disorders, neoplastic, pulmonary, drug-induced
- See more here - eMedicine, etiologies
References
- ↑ Schwartz WB, Bennett W, Curelop S, Bartter FC. A syndrome of renal sodium loss and hyponatremia probably resulting from inappropriate secretion of antidiuretic hormone. American Journal of Medicine 1957 23 529–542
