Syndrome of inappropriate ADH: Difference between revisions
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Created page with "== Background == === Etiologies === * CNS: stroke, intracranial hemorrhage, infection, trauma, and psychosis * Malignancy: ectopic ADH production by small cell carcinoma or, even more rarely, with other lung cancers, head-and-neck cancer, olfactory neuroblastoma, and extrapulmonary small cell carcinoma * Medications: chlorpropamide, carbamazepine, oxcarbazepine, high-dose cyclophosphamide, SSRIs ** Others: vincristine, [[cinblastine]..." |
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== Differential Diagnosis == |
== Differential Diagnosis == |
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* [[Cerebral salt wasting]], which mimics SIADH and is most commonly caused by [[subarachnoid hemorrhage]] |
* [[Cerebral salt wasting]], which mimics SIADH and is most commonly caused by [[subarachnoid hemorrhage]], but requires fluid resuscitation rather than restriction |
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== Diagnostic Criteria == |
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* Essential criteria: |
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** Effective serum osmolality <275 mOsm/kg |
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** Urine osmolality >100 mOsm/kg at some level of decreased effective osmolality |
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** Clinical euvolaemia |
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** Urine sodium concentration >30 mmol/l with normal dietary salt and water intake |
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** Absence of adrenal, thyroid, pituitary or renal insufficiency |
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** No recent use of diuretic agents |
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* Supplemental criteria |
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** Serum uric acid <0.24 mmol/l (<4 mg/dl) |
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** Serum urea <3.6 mmol/l (<21.6 mg/dl) |
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** Failure to correct hyponatraemia after 0.9% saline infusion |
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** Fractional sodium excretion >0.5% |
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** Fractional urea excretion >55% |
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** Fractional uric acid excretion >12% |
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** Correction of hyponatraemia through fluid restriction |
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[[Category:Nephrology]] |
[[Category:Nephrology]] |
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Revision as of 14:07, 6 April 2026
Background
Etiologies
- CNS: stroke, intracranial hemorrhage, infection, trauma, and psychosis
- Malignancy: ectopic ADH production by small cell carcinoma or, even more rarely, with other lung cancers, head-and-neck cancer, olfactory neuroblastoma, and extrapulmonary small cell carcinoma
- Medications: chlorpropamide, carbamazepine, oxcarbazepine, high-dose cyclophosphamide, SSRIs
- Others: vincristine, cinblastine, cinorelbine, cisplatin, thiothixene, thioridazine, haloperidol, amitriptyline, MAO inhibitors, melphalan, ifosfamide, methotrexate, opiates, NSAIDs, interferon alpha, interferon gamma, sodium valproate, bromocriptine, lorcainide, amiodarone, ciprofloxacin, high-dose imatinib, and ecstasy
- Surgery, likely mediated by pain, but also specifically after transsphenoidal pituitary surgery
- Lung disease: pneumonia, occasionally also with asthma, atelectasis, respiratory failure, and pneumothorax
- Endocrinopathies: hypopituitarism and hypothyroidism
- Also exogenous vasopressin, desmopressin, and oxytocin
- HIV
- Hereditary SIADH
- Idiopathy, more common in older patients though occasionally found later to be from occult malignancy
Differential Diagnosis
- Cerebral salt wasting, which mimics SIADH and is most commonly caused by subarachnoid hemorrhage, but requires fluid resuscitation rather than restriction
Diagnostic Criteria
- Essential criteria:
- 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 (<4 mg/dl)
- Serum urea <3.6 mmol/l (<21.6 mg/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
