Exam 5: Chapter 42 - Endocrine Flashcards
Pituitary Gland and Hormones Secreted
Posterior pituitary —> Antidiuretic hormone (ADH, vasopressin) —-> Kidney
Anterior Pituitary —> ACTH —-> Adrenal Cortex —-> Adrenocorticosteroids
Anterior Pituitary —> TSH —> Thyroid gland —> Thyroid hormones
Anterior Pituitary Hormones
FSH, LH, prolactin, ACTH, TSH, GH- somatotropin
Effects of anterior pituitary hormones being in excess (hyper)
Cushing syndrome (ACTH)
Gigantism (GH)
Acromegaly (GH)
Effects of anterior pituitary hormones being insufficient (hypo)
dwarfism (GH)
Condition caused by hyposecretion of all of the anterior pituitary hormones
Panhypopituitarism
The cause of panhypopituitarism:
loss of the stimulating hormones leading to shrinking of the target organs.
Posterior Pituitary Hormones
ADH or Vasopressin
Oxytocin
Effects of posterior pituitary hormones being in excess (hyper)
SIADH
Effects of posterior pituitary hormones being insufficient (hypo)
Diabetes insipidus - most common condition r/t decrease in vasopressin
Pituitary tumors
- 95% are benign
- Primary or 2ndary: functional/nonfunctional - don’t secrete hormones
- Surgery: hypophysectomy: removal of the pituitary gland
Diabetes Insipidus (DI) Causes:
- decreased amounts of ADH
- CAUSE:
- *head trauma, brain tumor, surgical interventions r/t pituitary gland, infections (meningitis, encephalitis, TB), tumors
- *Nephrogenic: failure of the renal tubules to respond to ADH
- *Drug-induced: Lithium, Declomycin
Clinical manifestations of DI
Increased amounts of dilute urine
Management/treatment of DI
- Replace ADH, fluids, and correct underlying pathology
- Desmopressin (DDAVP) is synthetic vasopressin
- Diabinese/thiazide - potentiate the action of vasopressin - used in mild disease
- Nephrogenic: Thiazide diuretics, ibuprofen, aspirin (prostaglandin inhibitors), Na restriction
The nurse is caring for a patient with DI. What nursing intervention should be implemented?
-Assess skin turgor every 2 to 4 hours.
The cause of SIADH
- Head injury, craniotomy, CNS infections, lung cancer
- Medications: Oncovin (chemo drug), Phenothiazines, TCA’s thiazide diuretics, nicotine.
Clinical manifestations of SIADH
- fluid retention
Test results:
urine = increased sodium, increased osmolarity
Blood = decreased sodium, decreased osmolarity (radioimmunoassay = increased adh)
Management/treatment of SIADH
- Diuretics - Lasix
- Fluid restriction
Nursing management r/t SIADH
- monitor I&O
- daily weight
- urine and blood work
A patient with a pituitary tumor has developed SIADH. What interventions would the nurse implement?
-Assess neuro status and weight daily
Thyroid hormones
T3, T4, Calcitonin
-Iodine is contained in thyroid hormone; T3 = 3 atoms and T4 = 4 atoms
What is needed by the thyroid gland to make the thyroid hormones?
Iodine
_____ from the _____ ______ controls the release of thyroid hormone.
TSH
Anterior Pituitary
The thyroid controls
Cellular metabolic activity
Between T3 and T4, which is more rapid-acting?
T3 is more potent and rapid-acting than T4.
Calcitonin
-is secreted in response to high plasma calcium level and increases calcium deposit in the bone
Hypothalamic - Pituitary - Thyroid Axis: the mechanism for which the body makes thyroid hormones
TRH: Thyroid releasing hormone, from the hypothalamus, stimulates the pituitary gland to release TSH.
TSH stimulates the thyroid to produce T3 & T4 which will then inhibit further TSH secretion & thyroid hormone production
**Thyroid hormone levels in the blood determine the release of TSH
**When the thyroid concentration decreases, the release of TSH increases
Thyroid diagnostic tests
- TSH: this is the BEST test. It’s highly sensitive
- Serum free T4: unbound thyroxine. Measures for changes in T4 secretion during tx for hyperthyroidism
- T3/T4: total levels
- T3 resin uptake: tells the mount of thyroid hormone bound to TBG (thyroxine-binding globulin) and available binding sites
- Thyroid antibodies: autoimmune causes
- Radioactive iodine uptake: measures the rate of iodine uptake by the thyroid gland.
- Fine-needle biopsy: malignancies
- Thyroid scan, radioscan, or scintiscan: cold and hot spots
- Serum thyroglobulin: checks for recurrence of thyroid carcinoma
Partial list of Medications that may alter Thyroid Test Results (Chart 42-2)
Estrogens, sulfonylureas, corticosteroids, iodine, propranolol, Cimetidine, 5-Fluorouracil, Phenytoin, Heparin, Chloral hydrate, X-ray contrast agents, Opioids, Androgens, Salicylates, Lithium, Amiodarone, Clofibrate, Furosemide, Diazepam, Danazol, Dopamine antagonists, Propylthiouracil
Hypothyroidism: Causes
- Hashimoto’s Disease (autoimmune thyroiditis) - most common; Autoimmune, women 30-50 years old
- Atrophy of the thyroid gland: women over 50, women.
- Decreased iodine
Therapy/management for hypothyroidism
- primary objective is to restore a normal metabolic state by replacing the missing hormone.
- Meds: Synthroid or Levothroid (levothyroxine); meds are dosed based on the patient’s TSH concentration
- Support of cardiac function and respiratory function
- Prevention of complications
Hashimoto’s disease
- most common cause of hypothyroidism
- affects women 5x more frequently than men
- early symptoms may be nonspecific
Causes of hypothyroidism (Chart 42-3)
- Autoimmune disease
- Atrophy of the gland
- Therapy for hyperthyroidism
- Medications
- Radiation to head and neck for treatment of head and neck cancers, lymphoma
- Infiltrative diseases of the thyroid
- Iodine deficiency or excess
Complications of hypothyroidism
- Myxedema….may progress to stupor, coma and death
Hypothyroidism Signs and Symptoms (picture slide)
Hair loss, apathy, lethargy, dry skin (coarse & scaly), muscle aches & weakness, constipation, intolerance to cold, receding hairline, facial & eyelid edema, dull-blank expression, extreme fatigue, thick tongue/slow speech, anorexia, brittle nails & hair, menstrual disturbances
LATE S/S: subnormal temperature, bradycardia, weight gain, decreased LOC, thickened skin, cardiac complications