Sandbox:Vindhya
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [2]
Epidemiology and demographics
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3] ; Associate Editor(s)-in-Chief: Vindhya BellamKonda, M.B.B.S [4] SIADH
Definition :The syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by the excessive release of serum antidiuretic hormone (ADH) relative to serum osmolality. It typically results in excessive water reabsorption in the collecting ducts and hyponatremia
Historical perspective:
Described by researchers from Boston, Massachusetts and Bethesda, Maryland (including Dr Frederic Bartter) in two patients with lung cancer.[1] Criteria were developed by Schwartz and Bartter in 1967,[2].
Pathogenesis:
Causes: CNS disturbances:
- Stroke
- trauma
- infection
- psychosis
- hemorrhage
Drugs :
- amiodarone
- amitryptyline
- bromocriptine
- ciprpfloxacin
- chlorpropamide
- carbamazapine
- cyclophosphamide
- cisplatine
- SSRI
- Vincristine
- Vinblastine
- thioridazine
- thiothixene
- haloperidol
- MAOI
- melphalan
- methotrexate
- opiates
- NSAID
- IFN-alpha
- IFN-gamma
Surgery: associated with hyper secretion of ADH, a response that is mediated by pain afferents.
Pulmonary disease: particularly pneumonia (viral, bacterial, tuberculous), can lead to the SIADH, although the mechanism by which this occurs is not clear.A similar response may infrequently be seen with asthma, atelectasis, acute respiratory failure, and pneumothorax.
Hormone deficiency: Hypopituitarism, hypothyroidism
HIV infection
Genetics: clinical picture of SIADH may result from genetic disorders that result in antidiuresis. A mutation affecting the gene for the renal V2 receptor, which some investigators have named nephrogenic syndrome of inappropriate antidiuresis, has been found to cause clinically significant hyponatremia. ongenital nephrogenic diabetes insipidus is characterized by a resistance of the renal collecting duct to the action of the arginine vasopressin hormone responsible for the inability of the kidney to concentrate urine.he X-linked form is due to inactivating mutations of the vasopressin 2 receptor gene leading to a loss of function of the mutated receptors.onversely, the nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is linked to a constitutive activation of the V(2)-receptor due to activating mutations with clinical and biological features of inappropriate antidiuresis but with low or undetectable plasma arginine vasopressin hormone levels.