pituitary gland or hypophysis (master gland
controlled by hypothalamus, ,…
controlled by secreting factors of hypothalamus.
- hormones:FSH,LH, prolactin,ACTH, TSH, GH(somatropin)
- other hormones: melanocyte stimulating hormone, beta- lipotropin
insufficient: GH= dwarfism
hyposecretion= panhypopituitarism- thyroid, adrenal cortex, and gonads atrophy.
diabetes insipidus > large volumes of dilute urine excreted > deficient vasopressin ADH.
may occur after:
- sx treatment of brain tumor, nonsx brain tumors
- traumatic brain injury
- infection NS (meningitis, encephalitis, TB)
- post hypophysectomy (removal of pituitary)
- renal tubules not responding to ADH (r/t hypokalemia, hypercalcemia), specific
- pregnancy- increase vasopressin ace=decrease ADH
- meds (lithium, demclocycline (Declomycin)) inhibits ADH
- excessive thirst (polydipsia)
- excess dilute urine (>250mL/hr) specific gravity 1.001- 1.005 no abnormal substances
- drinks 2L- 20L/ daily cold water. CANNOT BE CONTROLLED BY LIMITING FLUIDS will just lead to hypernatremia and severe dehydration.(>Na+, < H2O) polydipsia.
- increase skin turgor (>3sec)
- hypotension (dilated vessels)
- fluid depravation test (withhold fluids for 8-12hrs or until 3-5% of body weight loss)
- inability to increase specific gravity and osmolality = DI
- plasma levels measured
- desmopressin therapy and IV infusion hypertonic solution
- assess for tumors if head injury isnt obvious
- to replace ADH (long term program)
- adequate fluid replacement
- correct underlying intracranial pathology
- desmopressin (DDAVP) SYNTHETIC VASOPRESSIN.
- longer duration action
- fewer SE
- route: intranasally
- 1-2 administration daily (q12-24h)
- causes vasoconstriction :warning: IN PT WITH CAD
- chlorpropamide (Diabinese) and thiazide diuretics
- DI renal:
- thiazide diuretics
- mild salt depletion
- prostaglandin inhibitors (ibuprofen (Advil, Motrin)
- indomethacin (Indocin) and aspirin
- declomycin (inhibits ADH) promotes diuresis
- No Ca+ foods (milk, antacids)
- spironolactone (k+- sparing diuretic)
- physical assessment
- patients history
- educate: follow- up care, prevent complications, emergency measures.
- daily weights
- NO FOODS THAT PROMOTE NATURAL DIURESIS (Watermelon, lemon, grapes, teas, coffee, energy drinks)
- written instructions for meds.
- S/S of hyponatremia.
- demonstrate med administration
- medical bracelet/ carry meds and info about DI ALWAYS.
SIADH: excessive ADH
- cannot excrete dilute urine(increased specific gravity)
- retain fluids(water intoxication)
- fluid overload
- weight gain
- increased BP(HTN)
- increased HR
- confusion (brain swelling)
- anorexia (too full)
- decreased urine output (corticosteroids)
- sodium deficiency (dilution hyponatremia)
- bronchogenic carcinoma
- severe pneumonia
- disorders of the lungs
- malignant other organs
- head/brain injury as well
- water intoxication S&S: crackles, dyspnea, decrease O2 sat.
- meds: vincristine (oncovin), phenothiazines, tricyclic, antidepressants, thiazide diuretics, nicotine
- restrict fluid intake
- loop diuretics: furosemide (Lasix),possible decrease K+
- hypertonic saline (3% NS)
slowly, through central line (hard on veins)
- daily wieghts
- urine/blood chemistries
- Neuro status
- vasopressin (ADH):controls excretion of water by the kidney. secretion stimulated by an increase in the osmolality of the blood, or decrease in BP.
- oxytocin:during pregnancy and childbirth.Facilitates milk ejection during lactation, increase uterine contraction during L/D
- synthesizes in hypothalamus.
GH. regulates growth and energy/ metabolism in children and adults.
- increases blood glucose levels, >protein synthesis in tissues
- GH secretion increased by deep sleep, stress, exercise, fasting, malnutrition, hypoglycemia, trauma, hypovolemic shock, sepsis
- decreased with obesity, depression, hypothyroidism.