710 likes | 866 Views
INTERFERENCES TO NUTRITIONAL NEEDS DUE TO REGULATORY MECHANISM DYSFUNCTION:. ENDOCRINE DISORDERS Adrenal and Pituitary Dysfunction 2009. ENDOCRINE SYSTEM. FUNCTION: Works with the nervous system Coordinates the response of the body to internal and external stimuli
E N D
INTERFERENCES TO NUTRITIONAL NEEDS DUE TO REGULATORY MECHANISM DYSFUNCTION: ENDOCRINE DISORDERS Adrenal and Pituitary Dysfunction 2009
ENDOCRINE SYSTEM • FUNCTION: • Works with the nervous system • Coordinates the response of the body to internal and external stimuli • Goal: to maintain homeostasis
ENDOCRINE GLANDS • Pituitary • Thyroid • Parathyroid • Adrenals • Islets of Langerhans in pancreas • Ovaries • testes
WHAT DO ENDOCRINE GLANDS DO? • Secrete their products directly into the bloodstream • Differ from EXOCRINE GLANDS which secrete through ducts onto epithelial surface or into the GI tract
HORMONES DEFINED: Chemical substances secreted by the endocrine glands WHAT DO THEY DO? • Hormones help regulate organ function • They work with the nervous system
GOAL OF HORMONES • Keep concentration of hormones in bloodstream constant • When levels drop: rate of production increases • When levels are high: rate of production decreases • NEGATIVE FEEDBACK SYSTEM: mechanism for regulation of hormone concentration in the bloodstream
EXAMPLE OF NEGATIVE FEEDBACK SYSTEM CONTROL OF INSULIN SECRETION: • When blood glucose levels hormone insulin secreted • Insulin glucose uptake by the cells blood glucose levels • THUS: the action of insulin ( blood glucose levels) is the opposite of the condition that stimulated insulin secretion ( blood glucose levels)
HYPOTHALMUS • Link between the nervous system and endocrine system • It controls both the posterior and the anterior pituitary gland
ABNORMALITIES • Based on overproduction and underproduction
PITUITARY GLAND: ANTERIOR AND POSTERIOR • ANOTHER NAME: hypophysis • Master gland of endocrine system • Secretes hormones that control the secretion of hormones by other endocrine glands • It is controlled by the hypothalmus
POSTERIOR PITUITARY HORMONES SECRETED: • Vasopressin (or ADH or antidiuretic hormone) STIMULATED BY: • Increase in osmolality of the blood • Decrease in blood pressure PRIMARY FUNCTION: • To control the excretion of water by the kidney
POSTERIOR PITUITARY HORMONES SECRETED: • Oxytocin STIMULATED BY: • Pregnancy • childbirth PRIMARY FUNCTION: • Facilitate milk ejection during lactation • Increase force of uterine contractions during L&D
POSTERIOR PITUITARY: QUICK SUMMARY • DI (Diabetes Insipidus) ADH urine • SIADH (syndrome of inappropriate antidiuretic hormone) ADH • Dilute urine • Water retained • Low sodium
ANTERIOR PITUITARY HORMONES SECRETED control growth, metabolic activity and sexual development: • FSH – Follicle Stimulating Hormone • LH – Luteinizing Hormone • Prolactin • ACTH - Adrenocorticotropic hormone • TSH – Thyroid stimulating hormone • GH – Growth hormone,or somatotropin • MSH - Melanocyte stimulating hormone
PITUITARY: QUICK SUMMARY ANTERIOR PITUITARY: • Hypopituitarism: deficiency of one or more hormones resulting in metabolic and sexual dysfunction • Panhypopituitarism: decreased production of all anterior pituitary hormones • Hyperpituitarism: hormone oversecretion • ACTH secretion of MSH • PRL(prolactin) inhibits secretion of gonadotropins and sex hormones galactorrhea , amenorrhea, infertility • GH gigantism and acromegaly
ADRENAL GLANDS There are two glands Each has two parts • Adrenal medulla • Adrenal cortex HORMONE SECRETION: is regulated by the pituitary ACTH
ADRENAL GLANDS Adrenal medulla at the center of the gland secretes catecholamines Catecholamines regulate metabolic pathways to promote catabolism of stored fuels to meet caloric needs • (dopamine, epinephrine, and norepinephrine) • EPINEPHRINE: fight or flight response
ADRENAL GLANDS Adrenal cortex at the outer portion of the gland secretes steroids and sex hormones: STEROIDS: • Glucocorticoids (cortisol) • Mineralocorticoids (aldosterone) PURPOSE OF STEROIDS: • Regulate body’s response to physical and psychological stress
ADRENAL CORTEX HORMONES AND WHAT THEY DO GLUCOCORTICOIDS: important to glucose metabolism • Eg: increased secretion results in elevated blood glucose Glucocorticoids are often administered to patients to reduce inflammatory response to tissue injury and to suppress allergic manifestations • SE: diabetes, osteoporosis, peptic ulcer, poor wound healing
ADRENAL CORTEX HORMONES AND WHAT THEY DO MINERALOCORTICOIDS (aldosterone): • Acts on the kidney and GI tract to increase Na absorption in exchange for excretion of K or hydrogen ions • Secretion occurs in the presence of angiotensin II
ADRENAL CORTEX HORMONES AND WHAT THEY DO SECRETION OF ADRENAL SEX HORMONES are controlled by ACTH ANDROGENS: Exerts effects similar to those of male sex hormones ESTROGEN: Adrenal gland secretes small amounts of female sex hormones
ADRENAL GLAND: QUICK SUMMARY OF DYSFUNCTION ADRENAL CORTEX • function adrenal insufficiency adrenal crisis, Addison’s crisis loss of aldosterone and cortisol • function cortisol (hypercortisolism or Cushings) • Mineralocorticoids hyperaldosteronism • androgens ADRENAL MEDULLA • Pheochromocytoma: catecholamines
PHEOCHROMOCYTOMA • Tumor, usually benign on the adrenal medulla, unknown cause • Affects men and women equally, runs in families • Causes *****hypertension • Severity of symptoms depends on the amount of epinephrine and nor-epinephrine secretion
Tremor Headache Flushing Anxiety Hyperglycemia palpitations Profuse diaphoresis Chest pain N & V Heat intolerance Wgt loss PHEOCHROMOCYTOMA S&S
DRUGS WHICH PROMOTE HYPERTENSIVE CRISIS IN PHEOCROMOCYTOMA • Trycyclic antidepressants • droperidol (Inapsine): sedative/hypnotic • glucagon (GlucaGen) • metoclopramide (Clopra): antiemetic • phenothiazines (Melloril): antipsychotic • Naloxone (Narcan): opiod antagonist • Foods high in tyramine
PREPARE FOR SURGERY • Stabalize BP with IV antihypertensives of long acting alpha adrenergic blockers: phenoxybenzamine (Dibenzyline) • Control tachycardia and dysrhythmias: propanolol (Inderal) • Suppress catecholamine synthesis: calcium channel blockers: nicardipine (Cardene)
DIAGNOSTIC EVALUATIONSFOR PHEOCROMOCYTOMA • Measurement of urine and plasma levels of catecholamines: elevated with pheochromocytoma 24 hour urine for • VMA (vanillylmandelic acid - product of catecholamine metabolism) • Metanephrine • Catecholamines All are elevated with pheochromocytoma PREP FOR 24 HOUR URINE TEST FOR VMA: Avoid for 2-3 days: coffee,tea,cola,cocoa,bananas,citrus fruits, chocolate, vanilla,licorice,aspirin,antihypertensives prior to the VMA test
SURGICAL REMOVAL OF PHEOCROMOCYTOMA TUMOR REMOVAL OF TUMOR WITH ADRENALECTOMY • Anesthesia and Manipulation of the tumor during surgery may cause release of stored epinephrine and norepinephrine hypertensive crisis and changes of HR • If both adrenal glands are removed: corticosteroids replacement is necessary
POSTOP AFTER REMOVAL OF PHEOCHROMOCYTOMA • Hypotension, hypoglycemia may occur because of the sudden withdrawal of excessive amounts of catecholamines • Urine and plasma levels of catecholamines are measured to determine whether surgery has been successful • Receive volumn expanders for possible hypovolemia, hemorrhage and shock
ADDISON’S DISEASE • Adrenocortical insufficiency • Results when adrenal cortex function is inadequate to meet the patient’s need for cortical hormones CAUSED BY: • Decrease secretion of ACTH • Dysfunction of hypothalamic-pituitary control • Dysfunction of adrenal gland tissue • Removal of both adrenal glands
STEROIDS AND ADRENAL INSUFFICIENCY • MOST COMMONLY CAUSED BY therapeutic use of corticosteroids • Corticosteroids therapy suppresses production of glucocorticoids through negative feedback by causing atrophy of the adrenal cortex • Glucocorticoids MUST BE WITHDRAWN gradually to allow for pituitary production of ACTH and activation of adrenal cells to produce cortisol
WHAT HAPPENS WITH ADDISON’S DISEASE? • Insufficiency of adrenocortical steroids causes problems through loss of aldosterone and cortisol
WHAT HAPPENS WITH CORTISOL IN ADDISONS Cortisol • gluconeogenesis (making of glucose from proteins) hypoglycemia • depletion of liver and muscle glycogen
WHAT HAPPENS WITH DECREASED ALDOSTERONE? • ALDOSTERONE • K EXCRETION HYPERKALEMIA DYSRRHYTMIAS AND CARDIAC ARREST • Na and water excretion • Hyponatremia; craves salt, low BP • Hypovolemia • Hyperkalemia reabsorption of hydrogen ions acidosis
S&S OF ADDISON’S DISEASE • ****Muscular weakness, fatigue, emaciation • Anorexia, GI symptoms(N,V,D) dehydration/wgt loss • melanocyte stimulating hormone • Dark pigmentation of skin, knuckles, knees, elbows and mucous membranes • c/o BEING TIRED AND WEAK (CARDINAL SYMPTOM) – increased during stress from hypoglycemia
LABORATORY EVAL FOR ADDISON’S DISEASE • Low blood glucose • Low serum sodium • elevated serum potassium • High WBC (leukocytosis) • ***low levels of adrenocortical hormones in bld/urine • Low serum cortisol levels
TEACHING PT WITH ADDISON’S DISEASE • Teach increase Na to prevent hyponatremia: illness/heat/stress • Lifelong hormone replacement • Teach to prevent stress, prevent fatigue • Teach to increase CHO and protein to prevent hypoglycemia • Lifelong problem
ADDISONIAN CRISIS Disease at it’s worst • Severe hypotension and shock • Fever • N/V, abdominal pain, diarrhea WITH SLIGHT OVEREXERTION, EXPOSURE TO COLD, INFECTIONS OR DECREASE IN SALT: leads to circulatory collapse, shock, death
TO PREVENT CRISIS • Must replace corticosteroids • No salt restriction - leads to crisis • No diuretics - leads to crisis
IV fluids, glucose and electrolytes and sodium for dehydration Replace missing cortisol and aldosterone deficiency: hydrocortisone For Na and K imbalance give mineralocorticoids hormone: fludrocortisone (Florinef) Glucagon for hypoglycemia MANAGEMENT OF ADDISON’S CRISIS
CUSHINGS SYNDROME (Hypercortisolism) Increased production of ACTH DISEASE RESULTS from too much corticosteroids being secreted by the adrenal cortex CAUSE; adrenocortical tumors, or pituitary tumor secreting ACTH causing increased secretion of glucocortiocoids
IF CAUSE OF CUSHINGS IS PITUITARY TUMOR • Pituitary tumor causes increased production of ACTH • treatment of choice is removal of pituitary gland
WHAT IS HAPPENING IN CUSHINGS? • Problems with nitrogen, CHO, mineral metabolism • Slow turnover of fatty acids: • total body fat • Truncal obesity, thin arms and legs • Buffalo hump: fat pads on neck, back, shoulders • Moon face • Pendulous abdomen
PROBLEMS IN CUSHINGS • BREAKDOWN OF TISSUE PROTEIN urine nitrogen excretion • muscle mass (muscle wasting, weakness), edema • Thin skin • Bone density loss
PROBLEMS IN CUSHINGS: • levels corticosteroids • killing of lymphocytes • Shrinks organs • eosinophils and macrophages ALL IMMUNE RESPONSE; leading to increased infections
PROBLEMS IN CUSHINGS: • ANDROGEN PRODUCTION • Acne • Hirsuitism ( hair growth) • Masculination of women • Oligomenorrhea • Decreased libido
PROBLEMS IN CUSHINGS: • SKIN CHANGES FROM BLOOD VESSEL FRAGILITY: • Bruises • Thin skin • Wound won’t heal • Reddish striae on abdomen, thighs, and upper arms from degrading effect of cortisol on collagen
PROBLEMS IN CUSHINGS: PSYCHOSOCIAL: • Emotional lability
PROBLEMS IN CUSHINGS: • Hypertension from water and sodium retention
DIAGNOSIS OF CUSHINGS SYNDROME • Cortisol levels • Hypernatremia – increased Na leads to fluid retention • Hypokalemia – leads to arrhythmias • Hyperglycemia from cortisol • 24 hour urine test measure cortisol levels: