NURS271 - Endocrine Problems

hyperthyroidism

- the production and release of excess thyroid hormones

> T3/Triiodothyronine and T4/Thyroxine

- cause: antibodies stimulate thyroid receptors on gland which decreases TSH, increases T3 and T4

- s/sx: everything is sped up, increased metabolism, increased HR and BP, insulin resistance, resp dysfunction, goiter

graves disease

- autoimmune disorder, most common form of hyperthyroidism

- cause unknown, but likely genetic link

T3 and T4

- controls metabolism

- excessive production in hyperthyroidism

- lack of production in hypothyroidism

thyroid hormones overview

-TRH/Thyroid Releasing Hormone

- TSH/Thyroid Stimulating Hormone

- T3/Triiodothyronine

- T4/Thyroxine

- hypothalamus produces TRH → anterior pituitary gland produces TSH → thyroid gland produces T3/T4

> controls metabolism, excessive production in hyperthyroidism and vice versa

thyrotoxicosis (thyroid storm)

- complication of hyperthyroidism, only occurs if hyperthyroidism is not treated properly

- rare sudden worsening of s/sx due to trauma, stress, and manipulation of the thyroid gland itself during surgery

hyperthyroidism/thyrotoxicosis (thyroid storm) s/sx

- tachycardia (HR>200), problematic d/t decreased blood perfusion

- hypertension

- heat intolerance (hallmark), due to increased T4

- exophthalmos (bulging eyeballs)

- diarrhea d/t sped up digestion

- fever d/t heat intolerance

somatotropin (STH)

- growth hormone

- secreted by the anterior pituitary gland

pathophysiology of hyperthyroidism

- types: primary, secondary, tertiary

- thyroid produces T3//T4 (primary)

- pituitary gland produces TSH (secondary)

- hypothalamus produces TRH (tertiary)

primary hyperthyroidism

problem stems from a dysfunctional thyroid gland, increases antibodies trick the thyroid/nodule on gland to increase T3 and T4 secretion

secondary hyperthyroidism

problem stems from an issue with the pituitary gland (such as a tumor on the gland) which causes an increase in TSH and the thyroid gland producing excess T3 and T4

tertiary hyperthyroidism

problem stems from an issue/dysfunction with the hypothalamus, causing an increase in TRH → increased TSH → increased T3 and T4

exophthalmos

- caused by edema and accumulation of fatty tissue causing abnormal protrusion of the eyeballs

> common with Graves Disease

- those with it can not see it

- pts may complain of blurred vision, diplopia (double vision), eye pain, photophobia (sensitivity to light), dry eyes, lid lag

lid lag

- the eyelids stay open when a person looks down

- associated with hyperthyroidism

photophobia

eye sensitivity to light

pharmacological tx of hyperthyroidism

- propylthiouracil (PTU) or methimazole (tapazole)

> anti-thyroid drugs

- radioactive iodine therapy

> preferred treatment

> oral intake of radioactive iodine which damages the cells absorb the ioding which damages the cells

- beta-adrenergic blocking drugs (same as beta blockers)

> propranolol (non-selective)

> metoprolol (cardio-selective)

propylthiouracil (PTU) or methimazole (tapazole)

- anti-thyroid drugs to treat hyperthyroidism

- decreases thyroid hormone production

- takes 6-12 weeks to work, taken for >1 yr to correct problem

radioactive iodine therapy

- preferred treatment for hyperthyroidism

- oral intake of radioactive iodine which damages the cells absorb the ioding which damages the cells

> destroys thyroid tissue → decreases T3 and T4

> too much leads to hypothyroidism

> takes 6 months to see affects, Dr monitors levels periodically

beta-adrenergic blocking drugs

- tx for hyperthyroidism

- same as beta blockers

> propranolol (non-selective → can cause bronchoconstriction and decreased RR)

> metoprolol (cardio-selective)

- look at the pts hx to choose correct beta blocker

surgical tx for hyperthyroidism

- partial or total thyroidectomy

> total only done if large nodules or thyroid cancer

> may cause hypothyroidism which requires lifelong tx of levothyroxine

- removes part of gland to decrease thyroid hormone synthesis and secretion

> only done if drug tx does not work

hypothyroidism

- extremely decreased production of thyroid hormones

- cause: dysfunctional thyroid, malnutrition (decreased iodine or tyrosine consumption), or thyroidectomy which increases TSH, decreases T3 and T4

- s/sx: decreased metabolism, everything slows down, goiter

- hashimoto thyroiditis, myxedema, myxedema coma

- more common in women, risk increases w/ age

hashimoto thyroiditis (autoimmune thyroiditis)

- most common type of primary hypothyroidism

- immune system attacks the thyroid gland → fibrous tissue grows → inflammation and reduced thyroid hormone production (decreased T3 and T4) → hypothyroidism

myxedema

- mucus, fluid, and protein build up in the skin and organs due to extreme hypothyroidism

- rare and life threatening

myxedema coma

- rare/extreme complication of hypothyroidism when it is poorly or completely untreated

> triggered by illness or trauma

- decreased cardiac output → decreased tissue perfusion → brain and organ depletion → multi-organ failure → death

goiter

- enlargement of the thyroid gland due to abnormality

> most common cause: iodine deficiency

hypothyroidism s/sx

- decreased metabolism

- cold intolerance

- extreme fatigue (hallmark)

- constipation

- bradycardia

- weight gain

- mental challenges/deficiencies

- decreased growth

pharmacological tx of hypothyroidism

- levothyroxine (synthroid)

> one pill for the rest of your life

> best taken in the morning on an empty stomach

levothyroxine (synthroid) side effects

- decreases the ability of insulin or anti-diabetic meds to function in pts w/ diabetes

> dosage of insulin or anti-diabetic rugs may need to be adjusted

hypothalamus

- a neural structure lying below the thalamus

- directs eating, drinking, body temperature, and is linked to emotion

- controls the pituitary gland through hormones secreted by neurosecretory cells

anterior pituitary gland

- an endocrine gland whose secretions are controlled by hypothalamic hormones

- secretes six different hormones: TSH, ACTH, FSH/LH, Growth hormone (GH), Prolactin (PRL), endorphins

anterior pituitary gland disorders

- primary pituitary dysfunction

- secondary pituitary dysfunction

- pituitary hypofunction

- pituitary hyperfunction

primary pituitary dysfunction

problems with the anterior pituitary gland itself

secondary pituitary dysfunction

problem with the hypothalamus that causes anterior pituitary gland dysfunction

pituitary hypofunction

- decreased secretion and production of anterior pituitary gland hormones

- can be caused by trauma, circulatory disturbances, congenital malformations, or tumors

- tx: hormone replacement therapy

pituitary hyperfunction

- excessive secretion and production of anterior pituitary gland hormones

- often presents as acromegaly or gigantism

cause of hypopituitarism

- benign or malignant tumors compress and destroy pituitary tissue

- anorexia nervosa → malnourished → rapid tissue loss

- shock or severe hypertension → decreased blood flow to PG → hypoxia → pituitary infarction

- Sheehan's syndrome

- postpartum hemorrhage

Sheehan's syndrome

- hypopituitarism caused by uterine hemorrhage during childbirth

- pituitary gland is unable to function due to blood loss.

patient assessment for hypopituitarism

- M/F s/sx: changes in peripheral vision, vision loss, diplopia, blurred vision, infertility, impotence, headache,stress/irritation

- LH and FSH deficiencies → change/loss of secondary sex characteristics

- Females: amenorrhea, painful sex, difficulty conceiving, decreased hair in armpits

- Males: decreased body hair, impotence, decreased libido

hypopituitarism tx

- replace deficient hormones, lifelong therapy

- androgen (testosterone), decreases LH for M, impacts reproduction for M/F

> preferred route: gel

>> cost effective, convenient, good at stabalizing hormones, libido, mood & energy

acromegaly

- hypersecretion of growth hormone (GH, secreted by APG) after puberty

- most common cause is pituitary adenoma

> tumor grows on APG, causing over secretion of GH

- increase in size of bones in hands and feet, bone deformities, splenomegaly, hypertrophy of skin

- no change in height

- takes years to develop, by the time people notice the damage to organs is already done

gigantism

hypersecretion of GH from the APG (usually a tumor) before puberty, leading to abnormal overgrowth of body tissues, especially long bones

pituitary tumor drug tx

- dopamine agonist → decrease tumor size

- cabergoline (dostinex)

> preferred tx

> taken 1-2x weekly, longer lasting, better tolerated

- bromocriptine (parlodel)

> more side effects, taken daily

dopamine agonist

- mimic dopamine by binding to D2 receptors on the tumor cells

- decrease prolactin production

- reduce pituitary tumor size

- restore normal gonadal function

preferred pharmacological tx for pituitary tumors?

cabergoline (dostinex)

transsphenoidal adenomectomy (TA)

- removal of a pituitary tumor through the sphenoid sinus

> most common s/sx for women is amenorrhea

- clip off tumor through nose, takes ~45 min

- if tumor is too large → open skull (rare)

- post-anesthesia recovery, post op-unit for a day

postoperative care for TA

- monitor neurologic response

- assess for postnasal drip

> monitor for presence of CSF/halo sign, indicates increased intracranial pressure

- HOB elevated, bed rest

- assess nasal drainage

- avoid bending

- avoid straining

diabetes insipidus (DI)

- damage to the APG or hypothalamus usually d/t tumor or manipulation

- ADH deficiency causes H2O metabolism problem → renal tubules can't reabsorb any water → large amts of urine secreted (polyuria) → rapid dehydration

DI drug tx

- desmopressin acetate (DDAVP)

- replaces vasopressin, works w/in an hour

- can be given PO, nasal, or IV

vasopressin

hormone normally produced in body to help balance amount of water and salt

diabetes insipidus s/sx

- DRY INSIDE

- up to 20L urine/day

- decreased specific gravity

- decreased osmolarity

- hypovolemia

- increased thirst

- tachycardia

- decreased BP

- edema, jugular distention, increased weight

- neurological issues, confusion, disorientation

syndrome of inappropriate antidiuretic hormone secretion (SIADH)

- over secretion of ADH/vasopressin, even when plasma osmolarity is low or normal

- feedback mechanisms do not function properly

- water is retained, resulting in hyponatremia

> dilutional hyponatremia

- soaked inside

causes of SIADH

- heart failure

- diseased hypothalamus

- lung cancers

- pneumonia

- tuberculosis

SIADH nursing interventions

- fluid restriction

- furosemide (lasix), loop diuretics to excrete water with solvents, NOT free water

- 3%NS, hypertonic saline to increase Na

- drug tx: vaptans

vaptans

- tolvaptan (samsca)

- vasopressin antagonist

> block V2 receptors and prevents vasopressin from exerting its effect

> blocks water reabsorption

> increases free water excretion

> results in increased serum concentration correcting hyponatremia