Endocrine Disorders Flashcards
Hormones
natural chemicals that exert their effects on specific tissues known as target tissues
What is in place to prevent hormone accumulation?
negative feedback system
Positive Feedback Mechanisms
- changes from the normal point & amplifies it
- Blood clot formation: vessel damages, platelets start to cling to injured site & release chemicals that attract more platelets until clot is formed
- Milk production: suckling baby
- uterine contractions: oxytocin release intensifies contractions
- Fever: body heats self to get rid of bacteria
What does the Hypothalamus produce?
CRH, TRH, GHRH, GnRH, Somatostatin, Dopamine
What does the anterior Pituitary produce?
TSH, ACTH, LH, FSH, PRL (prolactin), GH, MSH
What does the posterior pituitary produce?
Vasopressin (ADH), oxytocin
Deficient GH
growth retardation: short stature, decreased bone density, truncal obesity
Deficient FSH & LH
Women: amenorrhea, breast atrophy, decreased axillary & pubic hair
Men: decreased facial & body hair, impotence, reduced muscle mass, & loss of bone density
Deficient TSH
decreased TSH: weight gain, hirsutism, slowed cognition, lethargy, decreased metabolism
Deficient ACTH
decreased cortisol levels: weakness, decrease resistance to infection, fasting hypoglycemia
Hyperpituitarism
a hormone oversecretion that occurs with pituitary tumors or hyperplasia
- most common cause is a pituitary adenoma
- Results in gigantism or acromegaly
Excess GH
Gigantism (before puberty)
Acromegaly (after puberty): Increase in lip & nose sizes, prominent brow ridge, increase in head, hand & foot size, protrusion of the lower jaw, enlarged organs
Excess prolactin
Galactorrhea: discharge of a milk like substance thats not associated with breast feeding
Excess ACTH
Cushings Disease
Excess TSH
Elevated plasma TSH levels: weight loss, tachy, heat intolerance, fine tremors
Hypophysectomy
removal of the pituitary gland & tumor by surgery, cryosurgery, or gamma knife
Posterior Pituitary Hypofunction: Diabetes Insipidus
deficiency of production or secretion of ADH, decreased renal response to ADH
- results in fluid & electrolyte imbalances
- excretion of large volumes of dilute urine
- Increased plasma osmolality (hypernatremia)
Symptoms of Posterior Pituitary hypofunction
Polyuria, Polydipsia, hypotension, tachycardia, poor turgor, drug mucous membranes, increased thirst, decreased cognition, weight loss, fatigue, weakness
Posterior Pituitary Hyperfunction
- Syndrome of Inappropriate antidiuretic Hormone (SIADH)
- an excessive amount of serum ADH resulting in water intoxication & dilutional hyponatremia
- Results in fluid retention: increased plasma volume inhibits the release of renin & aldosterone
Characteristics of Posterior Pituitary Hyperfunction
high intravascular volume, weight gain, pulmonary symptoms, lethargy, HA, changes in LOC, seizures, decreased DTR
What does the thyroid produce
T3, T4, and calcitonin
What is contained in the thyroid hormone?
iodine
What controls release of pituitary hormones?
TRH from the hypothalamus
What controls the release of thyroid hormone?
TSH from the anterior pituitary
What is the role of iodine?
taken from food and converts into T4 and T3 and thyroid cells are the only cells that can absorb iodine and they combine with amino acid and tyrosine to make T3 and T4
Hypothyroidism
a deficiency of thyroid hormone causing a general slowing of the metabolic rate
- causes: Hashimotos
- congenital: cretinism: deficient hormone during fetal/neonatal
What are symptoms of hypothyroid?
- fatigue, apathy
- amenorrhea
- Hair loss, brittle nails, dry & thick skin
- slow speech, subdued emotional responses, cold intolerance
- weight gain, constipation
- Dyspnea, deafness
- Advanced symptoms: demetia type changes, sleep apnea
- Myxedema coma: hypothermic, unconscious, stupor, fluid accumulates causing pericardial & pleural effusions
What do the labs look like for hypothyroid
TSH increased
T3 and T4 decreased
elevated cholesterol & triglycerides
Management of Hypothyroid
replace hormones
levothyroxine (synthroid)
Symptoms of Hyperthyroid
- hyperexcitable, irritable, apprehensive
- cardiac symptoms
- weight loss, diarrhea, increased appetite
- fine tremors, insomnia, heat intolerance
- exophthalmos
- muscle fatigue, osteoporosis, fracture
- enlarged thyroid gland
What do the labs look like for hyperthyroid
decreased TSH
increased T3 and T4
Acute Thyrotoxicosis (Thyroid Storm)
acute & severe when excess amounts of thyroid hormones released into circulation: high fever, tachy, delirium pyschosis
Management of hyperthyroid
antithyroid: Propylthiouracil, methimazole
Iodine
Thyroid Medication: potassium Iodine
- salt of iodine (non-radioactive)
- protects thyroid gland against internal uptake of radioiodine released with a nuclear event
- Blocks absorption of radioactivity
Nursing Management for thyroid
- nutrition: high calorie diet (4000-5000 cal/day)
- General obsevations
- Eyes & skin
Thyroidectomy
- Subtotal thyroidectomy: remaining tissue supplies adequate hormone
- Hyperthyroidism
- goiter
- thyroid cancer
- Total thyroidectomy for some thyroid cancers
- requires life long thyroid replacement therapy
Thyroidectomy Preoperative
- may receive PTU or tapazole (antithyroid) 4-6 weeks priors to surgery
- monitor for hypothyroidsm
- Propranolol-blocks adrenergic effects
- Iodine for 10-14 days-reduces size & prevents excess bleeding
- Dietary information for metabolic needs & avoiding stimulants
- Medications to achieve euthyroid status
- Dietary information for metabolic needs & avoiding stimulants
- Routine pre-op instructions
Thyroidectomy Postoperative
- high fowlers position
- ask patient to talk to check for laryngeal nerve damage
- monitor for bleeding & hematoma; dressing
- avoid neck flexion or extension; neck support
- respiratory support
- monitor for hypocalcemia & tetany
Iodine deficiency
thyroid enlarges to obtain more iodine
Graves Disease
hypoerthyroidism-overstimulation causes the thyroid to swell
Hashimotos Disease
- Hypothyroidism-underactive thyroid
- sensing a low hormone level, the pituitary gland produces more TSH to stimulate the thyroid, which causes the gland the enlarge
Multinodular goiter
several solid or fluid filled lumps called nodules
Solitary thyroid nodule
a single nodule develops in one part of the thyroid-most are benign
Thyroid cancer
thyroid cancer can appear as an enlargement of one side of the gland
Inflammation
thyroiditis, an inflammation condition, that can cause pain and swelling in the thyroid
Parathyroid
- four glands on the posterior thyroid gland
- parathyroid hormone regluates calcium & phosphorus balance
What does PTH regulates
serum calcium & phosphorus by stimulating bone resorption of calcium, renal tubular reabsorption of calcium, & activation of vitamin D
what does parathormone do
lowers phosphorus level
Hyperparathyroidism
-characterized by increased secretion of PTH
Primary hyperparathyroidism
benign adenoma tumor in the gland
secondary hyperparathyroidism
compensatory response to hypocalcemia
- chronic renal failure - vitamin D deficiencies & malabsorption
Symptoms of hyperparathryroidism symptoms
- hypercalcemia (stones, bones, moans, groans, throne)
- CV: HTN, angina, arrhythmias
- GI: abdominal pain, constipation, PUD
- MS: skeletal pain, fractures, weakness
- Neuro: lethargy, psychosis, irritability
- Renal: stones, UTI, polyuria
Parathyroidectomy
- partial/complete per endoscopy
- may have auto transplantation of normal parathyroid tissue
Nonsurgical Therapy
- asymptomatic or mild symptoms
- regular exams & PTH measurements
- Diuretics or Bisphosponates (Fosamax)
Hypoparathyroidism
- uncommon associated with iadequate circulating PTH
- Causes: most common from surgical removal, may be associated with hypothyroidism & hypogonadism
- Symptoms: Tetany, painful tonic muscle spasms -> laryngospasms, irritability, cardiac arrhythmias, labs
Management of hypoparathyroid
- replacement: IV calcium gluconate cautiously
- maintain airway
- PTH replacements not recommended
- oral calcium, Mg and vitamin D
- diet: high in calcium, low phosphorus, vitamin D
- lab monitoring follow up
- low calcium potentiates effects of Digoxin
Adrenal Medulla
- functions as part of the ANS
- catecholamines, epinephrine & norepinephrine
Adrenal Cortex
- mineralcorticoids: aldosterone
- glucocorticoids: Cortisol
- sex hormones: androgens & estrogens
Cushings Syndrome
- excessive adrenocortical activity, particularly glucocorticoids
- Endogenous causes of increased cortisol
- ACTH secreting pituitary adenoma
- ACTH production by tumors usually of the lung or pancreas
- Adrenal adenoma
- Exogenous from therapeutic use of corticosteroid medications
Symptoms of Cushings syndrome
- weak, fatigue
- back & joint pain, fractures
- altered emotional state
- increased incidence of infection
- Fragile skin & blood vessels
- Changes in fat distribution (moon face, truncal obesity, buffalo hump)
- muscle wasting, hirsutism
Cushings management
- pituitary adenoma: transsphenoidal resection, radiation therapy
- Prolonged use of corticosteroids: gradually discontinuing, reduce dosage, alternate day dosing
- Adrenocortical adenoma, cancer, hyperplasia
- adrenalectomy
Addisons Disease
- Adrenocortical insufficiency
- Hypofunction of the adrenal cortex
- primary cause (Addisons disease)
- autoimmune or idopathic atrophy
- Glucocorticoids, mineralocorticoids, and androgens all reduced
- Secondary: inadequate secretion of ACTH from pituitary gland: resulting from decreased stimulation of the adrenal cortex
- Common cause: suppression of the hypothalamic-pituitary axis because of use of exogenous corticosteroids
Symptoms of Addisons disease
- Hyperpigmentation
- Hypotension & hypovolemia
- Muscle weakness & fatigue
- N/V
- Depression, apathy & emotional lability
Hyperpigmentation
low cortisol levels, increase secretion of ACTH with increased melanin synthesis
Addisonian crisis
insufficient adrenocortical hormones or sudden sharp decrease in these hormones
Complications
addisonian crisis
abrupt discontinuation of a glucocorticoid medication or with a trauma, infection, stress-> circulatory shock
Complications
Hypoglycemia
decrease glucocorticoids causes increase insulin sensitivity & decrease glycogen
Complication
Hyponatremia/Hyperkalemia
increase excretion of sodium & decrease of potassium
Pheochromocytoma
-a catecholamine producing tumor of the adrenal medulla: rare & usually benign
-epinephrine & norepinephrine secreted
-produce SNS effects
Cause is unknown
-Riks factors: endocrine neoplasia, anesthesia, opiates, radiographic dye, foods high in tyramine
Symptoms of Pheochromocytoma
- hypertension
- HA
- hyperhidrosis
- ypermetabolism
- hyperglycemia
- chest pain
Corticosteroid Therapy
- corticosteroids are therapeutic for
- adrenal insufficiency
- suppress inflammation & autoimmune response
- control allergic reactions
- reduce trasplant rejection
- Common corticosteroids
- patient teaching
- timing of doses
- take as prescribed, tapering required, side effects
