ADH mod 5 Flashcards
what is SIADH?
SIADH = Syndrome of Inappropriate AntiDiuretic Hormone
Definition: An abnormal production or sustained secretion of ADH
Characterized by:
Fluid retention
Serum hypoosmolality and hyponatremia
Concentrated urine
SIADH etiology
Malignant Tumors
Example = Small cell carcinoma of the lung
- secrete ADH
Central Nervous System Disorders
Ex = Head trauma, stroke, brain tumors
Drug Therapy
Ex = morphine, SSRI’s, some chemotherapy drugs
Miscellaneous conditions
Ex = Hypothyroidism, Infection
**acute - self limiting
chronic - lung cancer, metabolic disorder
SIADH pathogenesis
renal distal tubule increased permeability
dilutional hyponatremia
song to remember:
Lung tumors, trauma, and bad bugs a complication might be-
- SIADH, SIADH, SIADH, this hormone stops the pee pee.
Low output, sodium; gained weight and high specific gravity
- SIADH, SIADH, SIADH, this hormone stops the pee pee.
SIADH and osmolarity
**hyponatremia
Serum osmolality = LOW - nyponatremia Urine osmolality and specific gravity = HIGH Serum sodium = LOW Urine output = LOW Weight = GAIN
Remember, your patient is retaining pure water without salt!
SIADH clinical manifestations
Manifestations depend on:
Severity and rate of onset of hyponatremia - ***hypovolemia shock
Sx of Hyponatremia: Dyspnea, Fatigue Neurologic Dulled sensorium, confusion, lethargy Muscle twitching, convulsions
GI:
Impaired taste, anorexia, vomiting, cramps
Severe Sx @ Na+ < 100-115 mEq/L
Possible irreversible neurologic damage
can your pt die of water intoxications?
yes, serum Na is lower than cell Na, caused cell swelling, which leads to brain swelling
pharm for SAIDH
Pharmacotherapy is not the first line of treatment
Treatment is instead directed at the underlying cause
Ex., Discontinue offending medication
Chronic SIADH = Demeclocycline (Declomycin)
***tetracycline
s/s
mild - fluid restriction
severe- hypertonic solution
loop diuretics for FVE w/ salt tablets
demeclocycline (Declomycin)
- *chronic SIADH
- *not 1st line tx
classification: tetracycline broad-spectrum ABX
drug usage:
- ABX therapy
- tx chronic SIADH
MOA- interferes with renal response to ADH
AE:
- photosensitivity - avoid sun
teeth staining
nephrotoxic - monitor kidney (BUN/Cr)
what is diabetes insipidus (DI)
**decreased ADH
Definition:
A deficiency of ADH or a decreased renal response to ADH
Characterized by:
Excessive loss of water in the urine
Two forms:
Neurogenic (Central) - lesion in brain
***most common
Nephrogenic- kidney not responding to ADH, has enough ADH
nephrogenic DI etiology
**renal
Renal origin
**enough ADH, but kidneys insensitive to ADH
Cause
- Loss of kidney function
- Often drug-related (e.g., Lithium)
Associated disorders
Chronic kidney disease
Onset? Slow
Course of disease? Progressive
** increase CKD = increased nephrogenic DI
neurogenic DI etiology
**brain, sudden
Neuro origin (Central DI)
Cause
- Hypothalamus or pituitary gland damage
Associated disorders
- Stroke, traumatic brain injury
- Brain surgery
- Cerebral infections
Onset? Sudden
Permanent? Usually Yes
**destroys part of pituitary gland
diabetes insipidus pathogenesis
decreased ADH
decreased water reabsorption in renal tubules
decreased intravascular fluid volume
- increased serum osmolality (hypernatremia)
- excessive urine output
diabetes insipidus osmolality
Serum osmolality = HIGH Urine osmolality and specific gravity = LOW Serum sodium = HIGH Urine output = HIGH Weight = LOSS
clinical manifestations diabetes insipidus
Polyuria
Polydipsia
Dehydration
Others based on severity
- Electrolyte imbalances
- Hypovolemic shock death
pharm DI
Neurogenic DI = synthetic ADH replacement
Nephrogenic DI tx = thiazide diuretics
