<prompt> All are true regarding SIADH, except -Increased level of ADH AHMS Nov 93Urine hvpoosmolarHyponatremiaAdequate hydration status  <response>: Ans. is b i.e., Urine hypoosmolar Cardinal features of SIADH include:o Hyponatremia dilutional hyponatremia with Na 135 m mold.o Decreased plasma osmolality 280 m osmkg with inappropriately increased urine osmolality 150 m osm.o High urine sodium over 20 meql.o Low blood urea Nitrogen 10 mgL.o Hypouricemia 4 mgdL.o Clinical Euvolemia.Absence of signs of hypervolemia edema, ascitis.Absence of signs of hypovolemia orthostatic hypotension, tachycardia, features of dehydration,o Absence of cardiac, liver or renal disease.o Normal thyroid and adrenal function.o A high BUN suggests a vloume contracted state and excludes a diagnosis of SIADH2.Syndrome of Inappropriate ADH Secretion SIADH :CRITERIA FOR DLAGNOSISCriteria for the diagnosis of syndrome of inappropriate antidiuretic hormone secretionEssentialo Decreased effective osmolality of the extracellular fluid POSM 275 m Osmolkg H,0. True hypoosmolality must be present and hyponatremia secondary to pseudohypomatremia or hyperglycemia must be excluded.o Inappropriate urinary concentration Uosm 100 mOsmokg H2O with normal renal function at some level of hypoosmolarity. Urinary concentration must be inappropriate for Plasma Hypos molality,o Clinical envolemia, as defined by the absence of signs of hypovolemia orthostasis, tachycardia, decreased skin rurgor, dry mucous membranes or hypervolemia subcutaneous edema, ascites,o Elevated urinary sodium excretion while on normal salt and water intake.o Absence of other potential causes of euvolemic hypoosmolality: Hypothyroidism, hypocortisolism Addisons disease or pituitary adrenocorticotropic hormone insufficiency and diuretic use.Supplementalo Abnormal water load test inability to excrete at least 90 of a 20 mlkg water load in 4 hours andor failure to dilute Uosm to 100 mOsmolkg H2O.o Plasma AVP level inappropriately elevated relative to plasma osmolality.o No significant correction of serum with volume expansion but improvement after fluid restriction. 