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chapter 44
pituitary and adrenal disorders exam 5
Question | Answer |
---|---|
negative feedback | ↑levels inhibit ↓levels stimulate |
positive feedback | ↑levels stimulate ↓levels inhibit |
pituitary gland is located | in stella turcica and is connected to hypothalamus via infundibular stalk |
anterior pituitary hormones | GH ACTH TSH FSH LH PROLACTIN MELANOCYTE STIM HORM (MSH) |
posterior pituitary hormones | ADH OXYTOCIN |
glucose tolerance test for GH suppression | give standard amount of glucose IV and measure levels for 120 minutes; glucose supresses GH in neg-feedback process; if large decrease in GH occurs then it is a positive sign of hyperpituitarism |
hyperpituitarism | excessive production of one or more anterior pituitary hormones |
hyperpituitarism leads to | prolactinemia gigantism acromegaly |
S&S of hyperpituitarism | visual deficits and HA; enlargement of hands, feet, paranasal and frontal sinuses, soft tissues; initially have increased strength progressing rapidly to weakness and fatigue |
elevation of any hormone | requires further evaluation and follow-up |
most reliable test for acromegaly | glucose tolerance test; normal results is for the level to fall during testing but it will remain unchanged in acromegaly |
tx for acromegaly | somatostatin analog - SE: suppresses insulin secretion removal of adenoma - |
skeletal changes seen in acromegaly | cannot be reversed with tx |
soft tissue hypertrophy | can improve with tx |
postop nursing care of pt with hyperpituitarism | monitor neurological status closely, strict doc of I&O and specific gravity due to risk of DI or SIADH, note any clear, colorless drainage and notify provider might be CSF leak, nuchal rigidity a sign of meningitis, pt might have a stereotactic frame for radiation therapy, pin care will be needed, emergency removal of frame may be required if pt has seizures, watch for ICP, avoid valsalva maneuvers - coughing, straining, vomiting, sneezing might disrupt surgical site and cause CSF leak, no heavy lifting |
postop nursing care of pt with hyperpituitarism continued | or bending from the waist for 2-3 months after surgery, notify surgeon of fluid retention or diuresis, electrolyte imbalances |
hypopituitarism | inadequate secretion of GH |
dwarfism definition | height that is 40% below normal children |
panhypopituitarism | inadequate secretion of GH in adults Sheehan syndrome, tumors, chronic recurrent infections, removal of pituitary gland, suppression of pituitary hormones from drug therapy |
s&s of hypopituitarism | depends on stage of life; early onset: short stature but proportional, delayed or absent sexual maturation, mental retardation, accelerated aging |
s&s of panhypopituitarism | Simmonds chachexia - muscle and organ wasting, disruption of digestion and metabolism, hypoglycemia, hypothyroidism, decreased pigmentation of skin, gonads may atrophy |
tx of panhypopituitarism | deficient hormones are replaced, men get testosterone women get estrogen unless they have hx of breast cancer or prostate cancer |
tx of hypopituitarism | GH is admin to children until the person reaches a height of 5 feet |
nursing care of hypopituitarism | be aware of mental acuity, emotional stability and affect |
disorders of posterior pituitary disorders | DI SIADH |
another name for ADH | vasopressin |
ADH maintains | fluid balance by promoting reabsorption of water in the renal tubules when body water is decreased or very concentrated |
ADH release causes | increased water retention; distal tubules and collecting ducts do not reabsorb sufficient water resulting in an increased plasma osmolarity, massive dehydration ensues; cardiac arrest and death if left untreated |
diabetes insipidus | DI; excessive output of dilute urine |
neprogenic DI | is an inherited defect |
neurogenic DI | is a defect in either the production or secretion of ADH |
dipsogenic DI | is a disorder of thirst stimulation |
S&S, DX and tx of DI | massive diuresis, dehydration, and thirst, irregular heart beat, can excrete up to 30 L of urine per day; dx: 24 hr urine test, specific gravity will be extremely low, osmolarity is also decreased; tx: IV fluid replacement, vasopressors, |
nursing care of DI | measure I&O q 15-30 minutes, fluid replacement is prescribed based on output, daily weight, if self-care is in doubt refer to home nursing care |
SIAHD | water imbalance related to increase in ADH synthesis, secretion or both; it is usually a temp condition |
S&S, DX and tx of SIAHD | dilutional hyponatremia and water retention, water retention, weight gain without edema; dx: serum and urine electrolytes and osmolality, urine that has higher osmolality than serum is positive; tx: typertonic saline given slowly over 4-6 hrs, fluid restriction of 800-1000 mL/day, diuretic can be used only if the serum sodium is at least 125 mEq/L; vasopressor receptor antagonist - vaptains |
nursing care of SIAHD | describe mental status q4h in the alert pt and hourly if there is evidence of impairment, for cerebral edema elevate HOB 30-45 degrees, report declining neurological status or weight gain of more than 2 lb/day |
adrenal glands | triangle shaped, located on the kidneys, medulla or cortex |
adrenal medulla | contains sympathetic ganglia, stimulation of SNS causes medulla to secrete epi and norepi (catecholamines, neurotransmitters), these bind to adrenergic receptors |
norepi binds to | alpha-adrenergic receptors |
epi binds to | beta-adrenergic receptors |
adrenal cortex | outer portion of gland; endocrine system, outer: zona glomerulosa middle: zona fasciculata inner: zona reticularis secretes the steroids mineralocroticoids, glucocorticoids, androgens and estrogens |
zona glomerulosa produces | mineralcorticoids, most abundant is aldosterone; maintains adequate extracellular fluid volume (ECF), |
aldosterone is regulated by | serum levels of K, renin-angiotensin mechanism and ACTH |
renin is produced by | juxtaglomerular cells of renal afferent arterioles, release is stimulated by decreased ECF |
renin acts of plasma proteins to release | angiotensin I which is catalyzed in the lungs to angiotensin II, |
angiotensin II stimulates the secretion of | aldosterone which results in sodium and water retention; compensatory mechanism that plays a very important role in shock states |
glucorticoids are produced by | zona reticularis and zona fasciculata, most abundant is cortisol; glucocorticoid must be present for other processes to occur |
glucocorticoid functions | control of carbs, lipid, fat metabolism, regulation of antiinflam and immune responses, control of emotional states |
adrenal androgens are produced in the | zona fasciculata and zona reticularis of adrenal cortex these are also produced there estrogens, progesterone; primary source of endogenous estrogen in postmenopausal women |
androgens primary function is | masculinization in men |
s&s of adrenal dysfunction | HA, lightheadedness with position changes, muscle weakness, N/V, abd pain, mentrual dysfunction, erectile dysfunction, fat pads under clavicles, buffalo hump, obesity of trunk |
vitiligo | loss of pigmentation |
age related changes | adrenal function remains adequate, cortisol secretion declines affecting ability to conserve sodium and adapt to position changes |
addison's disease | adrenal hypofunction; most common cause= idopathic atrophy, other causes: TB, hemorrhage, fungal infection, AIDS, gram-neg sepsis, abrupt withdrawal of exogenous steroids |
s&s of adrenal insufficiency | hypoglycemia, decreased production of gastric acid, glomerular filtration rate slows, hyperkalemia, hyponatremia, skin hyperpigmentation, unexplained abd pain |
hyperkalemia promotes | hydrogen ion retention causing metabolic acidosis |
skin hyperpigmentation is the result of | increased secretion of beta-lipoprotein or MSH, direct result of hypercortisolism and lack of negative feedback |
acute adrenal crisis (addisonian crisis) | any factor that causes stress can initiate a crisis; severe addison's disease symptoms (see other card, I'm not typing it again) |
s&s and dx of acute adrenal crisis (addisonian crisis) | low serum and urinary cortisol level, decreased fasting glucose, hyponatremia, hyperkalemia, increased BUN, abnormal ECG, salt craving, weight loss, |
most accurate measure of steroid secretion | 24 hr urine test |
tx of acute adrenal crisis (addisonian crisis) | replace deficient steroids; in divided doses, morning dose is 2/3 of daily dose; mimics normal human hormonal variations |
goal for tx of acute adrenal crisis (addisonian crisis) | restore the blood levels to normal |
nursing care for acute adrenal crisis (addisonian crisis) | monitor fluid and electrolyte balance, daily weights, monitor for inadequate tissue perfusion, IV NS, watch for postural hypotension, hypovolemia, exercise legs before standing to promote venous return, high protein, low carb diet, encourage rest to avoid depletion of glycogen supplies, |
adrenal hypersecretion Cushing's syndrome | excess amts of corticosteroids, particularly glucocorticoid; excess cortisol |
excess production of ACTH due to pituitary tumor | Cushing disease |
single exogenous cause of cushing syndrome | prolonged admin of high doses of corticosteroids |
s&s of hyperadrenalism | obesity, facial redness, hirsutism, menstrual disorders, hypertension, muscle wasting, moon face, striae on abd, breasts, buttocks or thighs, hypokalemia of uncertain cause |
small cell cancer of the lungs can secrete | ACTH which stimulates excess cortisol secretion |
promptly d/c drugs that supress adrenal function | if trauma or shock occurs b/c the pts ability to adapt is diminished |
nursing care of pts with Cushing Syndrome | avoid exposure to people with infections, skin is extremely fragile - inspect daily, fractures occur easily, low calorie diet that is sufficient in protein and calcium |
nursing care for adrenalectomy pt | monitor and correct any electrolyte imbalance, strict hand washing, high doses of cortisol are given IV for several days, |
s&s of acute adrenal insufficiency | vomiting, weakness, hypotension, joint pain, pruritus, emotional disturbances |
pheochromocytoma | is a benign tumor of the adrenal medulla that causes excessive secretion of catecholamines; s&s: hypertension, hypermetabolism, hyperglycemia; DBP 115 or greater, severe HA, diaphoresis; tx: removal of the tumor |
overall mission of the endocrine system | to maintain homeostasis |
main symptom of SIADH | water retention |