ADH Disorders Flashcards
ADH
anti-diuretic hor; released in response to high serum osmolality and/or hypotensive
- causes water retention in the kidneys
SIADH
syndrome of inappropriate ADH
- abnormal production or sus sec of ADH
SIADH CM
retention, hyponatremia and hypoosmolality, concentrated urine, low solutes in the blood; neuro, dyspnea, fatigue, lethargy, muscle twitches, convulse, anorexia, vom, cramp, impaired taste
Causes of SIADH
**malignant tumor - small cell carcinoma of the ling (adenocarcinoma)
- CNS dx - stroke, tumor, **head trauma
- drugs - morph, SSRI, chemo
- hypothyroidism, infx
SIADH patho
inc ADH which causes increased H2O reabsorption in tubules, inc Intravascular fluid vol, dilutional hyponatremia and dec serum osmolality
Labs for SIADH
- dec serum osmolality
- inc urine osmolality and inc sp, gravity
- dec serum sodium
- dec urine output
- wt gain
- retain pure water w/o salt
Severe sx of SIADH
IRREVERSIBLE neuro damage with Na 100-115
Water intoxication with SIADH
when serum NA is lower than what is inside the cells; cells swell causing neuro, confusion, lethargy, coma, death
SIADH tx
- stop meds that cause it
- may need to wait out head trauma
- meds is lung cancer is the cause
- loop diuretics if Na over 125 and may give Na tabs with
Drug for SIADH from lung cancer
demeclocycline
Diabetes inspidus
Lack ADH or dec renal response to ADH causing excess water loss thru urine
Types of DI
Neurogenic (central) and nephrogenic
Neurogenic (central) DI
- hypothalamus or pituitary damage from TBI, stroke, cerebral infx
- often after injury or surgery
- permanent bc pit often destroyed
- sudden onset
Nephrogenic DI
- often r/t loss of kidney fxn from ESRF or chronic RF
- kidneys can’t preserve water or respond to ADH
- also can be r/t lithium
- slow onset and progressive
Labs for DI
- inc serum osmolality
- dec urine osmolality and sp gravity
- inc serum Na
- inc urine output
- wt loss
