Influences secretion of hormones by other endocrine glands.
Controlled by hypothalamus.
Located at the base of the brain
Follicle-stimulating hormone (fsh) and prolactin
FSH stimulates growth of ovarian follicle, and ovulation in women and in males it stimulates sperm production.
Prolactin prepares the breast for breast-feeding
FSH and LH activiate estrogen in the ovary and progesterone in the corpus luteum. In males, they produce testosterone in the testes.
ACTH, or adrenocorticotropic stimulates synthesis and secretion of adrenocortical hormones.
TSH or thyroid-stimulating hormone stimulates synthesis and secretion of thyroid stimulating hormone.
GH or somatropin is the growth hormone, which stimulates growth of bone, and muscle. It also decreases carbohydrate metabolism.
TSH, ACTH, FSH, and LH: main function is to release hormones from other endocrine glands.
Growth hormone: its secretion is increased by stress, exercise, and low blood glucose levels. Half life of 20-30 minutes in the blood.
The most common hormones to be over secreted are the ACTH and GH.
This oversecretion can cause cushing symdrome (ACTH) or acromegaly (GH)
Symptoms of acromegaly (caused by oversecretion of GH and eosinophilic turmors) are: 1. enlargement of peripheral body parts without an increase in height.
2. Gigantism in children ( a person may be 7 or 8 feet tall).
Cushing Syndrome ( too much ACTH)
Truncal obesity, moon face, acne, abdominal striae, and hypertension
Insufficient secretion of GH during childhood can lead to limited growth and dwarfism.
It commonly involves all of the anterior pituitary hormones and can happen because of destruction of the anterior lobe.
It is termed panhypopituitarism.
The thyroid gland, the adrenal cortex, and the gonads atrophy, or shrink because of loss of the TROPIC-STIMULATING HORMONE.
Most common disorder related to posterior lobe dysfunction is DIABETES INSIPIDUS
Diabetes Insipidus: abnormally large volumes of dilute urine are excreted as a result of deficient production of ADH. (vasopresin).
Causes: DI can happen because of surgical treatment of a brain tumor, secondary to nonsurgical brain tumors, traumatic brain injury, infections of the nervous system such as meningitis, encephalitis, or tuberculosis, post hypophysectomy, failure of renal tubals to respond to ADH because of hypokalemia or hypercalcemia, and the use of specific medications such as lithium. Can also happen because of metastatic disease, lymphoma of the breast or lung.
About 250 mL of urine per hour, and very diluted with no abnormal substances such as glucose or albumin.
Patient craves cold water and usually drinks about 2-20 L of fluid daily.
Could be insidious or abrupt in adults.
Excess urination will continue even with limiting fluid intake.
If you limit it, the patient can experience hypernatremia and severe dehydration.
A fluid deprivation test by withholding fluids for 8-12 hours or until 3 to 5 % of the body weight is lost.
Weight patient frequently.
Perform plasma and omsolality studies before and end of test.
Inability to increase the specific gravity and osmolality of the urine is a characteristic of DI.
1st hour-urine specific gravity assessed.
3rd hour- of stable urine osmolality administer vasopressin (5 units of arginine vasopressin or 1 nanogram desmopressin SQ or 10 nanogram desmopressin via nasal spray)
If UOP decreases and osmolality increases, no DI
If large volume dilute urine continues, DI is present.
Because the patient continues to excrete large volumes of urine with low specific gravity, he will experience water weight loss and the serum osmolality will increase. This leads to high serum sodium levels. The patient is not drinking water, but release it, therefore sodium content is higher in his body with a high osmolality. This will lead to tachycardia.
The test is stopped if tachycardia, excessive weight loss, or hypotension develops.
Goal of therapy of DI: 1. To replace ADH ( usually a long-term therapeutic program).
2. To ensure adequate fluid replacement
3. To identify and correct the underlying intracranial pathology.
Meds used for DI:
Desmopressin, a synthetic vasopressin without the vascular effects of natural ADH.
It has longer action and fewer adverse effects.
1 or 2 administrations daily every 12-24 hours.
Vasopressin causes vasoconstriction, so use it cautiously in patients with coronary artery disease.
For mild DI, you can also use chlorpropamide and thiazide diuretics, but hyperglycemia is possible.
If the DI is renal in origin (nephrogenic)
thiazide diuretics, mild salt depletion, and prostaglandin inhibitors such as ibuprofen and indomethacin and aspirin are used.
Physical assessment and patient education are key to the nurse.
We have give written specifications of medications, prevention of complications, side effects, and signs and symptoms of HYPONATHREMIA.
Patient should wear medical identification bracelet and carry medication and information about DI at all times.
This is excessive ADH secretion from the pituitary gland.
Patients with SIADH retain fluids, develop hyponathremia.
SIADH is often of NONENDOCRINE ORIGIN.
Example of nonendocrine origin: it can occur in patients with malignant lung cells that synthesize and release ADH.
Can also occur in patients with severe pneumonia, pneumothrorax, and other disorders of the lung.
Medical management of SIADH
Correct underlying cause
restrict fluid intake ( serum sodium concentration gradually increases)
If severe hyponathremia, use diuretic agent with fluid restriction
Close monitoring of I&O
Three types that represent an overgrowth
1. Eosinophilic cells
They produce eosinophilic tumors that may
develop early in life. Causes gigantism . The
person may be tall and have large
proportions, but will be weak and lethargic.
He or she can hardly stand.
If it starts in adulthood, the growth occurs
only in the feet, hands, the superciliary ridge
molar eminences, nose and chin
Gives rise to ACROMEGALY
Severe headaches, visual disturbances because of pressure on the optic nerves.
Assessment of central vision may reveal loss of color discrimination, diplopia which is double vision, or blindness in a portion of a field of vision.
Decalsification and disturbances similar to hyperthyroidism are associated with this type of tumor.
2. Basophilic tumors cause Cushing syndrome ( with features attributable to hyperadrenalism)
masculinization and amenorrhea in females, truncal obesity, hypertension, osteoporosis, and polycythemia.
3. Chromophobic turmors represent 90 % of pituitary turmors.
They produce no hormones.
They destroy the rest of the pituitary gland and cause hypopituitarism.
People with this disease are often obese and somnolent. Fine scanty hair, dry soft skin, pasty complexion and small bones.
Experience headaches, loss of libido, and visual defects progressing to blindness. Other symptoms can include polyuria, polyphagia, lowering of the basal metabolic rate, and subnormal body temperature.
Assessment and Diagnostic Findings
1. Careful history and physical
2. Visual acuity and visual fields
3. CT and MRI to diagnose presence of tumors.
4. Serum levels of pituitary hormones along with measurements of hormones of target organs such as measurements of the thyroid or adrenal gland.
Surgical removal of the pituitary gland, which is called a HYPOPHYSECTOMY.
Choice of treatment for cushing syndrome patients.
Hypophysectomy may also be performed on occasion as a palliative measure to relieve bone pain secondary to metastasis of malignant lesions of the breast and prostate.
Stereotactic radiation therapy, with the use of a neurosurgery-type frame. this causes little effect on normal tissue.
Conventional radiation therapy with bromociptine, which is a dopamine antagonist and octreotide, which is a synthetic analogue of GH.
These medications may improve symptoms by inhibiting the production or release of GH. The brand names are parlodel and sandostatin, respectively.
To shrink the tumor preop, you can also use octreotide and lancretide.
Removal of the tumor will not affect symptoms of acromegaly.
The removal of the pituitary gland requires hormone treatment with corticosteroids and thyroid hormone. It will menstruation to cease and infertility.
Trauma, tumor, vascular lesion, radiation therapy to the head and neck area, or disease of the hypothalamus can result in destruction of the pituitary gland and removes all stimuli that are normally received.
Symptoms: Extreme weightloss, emaciation, atrophy of all endocrine glands and organs, hair loss, impotence, amenorrhea, hypometabolism, and hypoglycemia.
If missing hormones are not replaced, coma and death occur.
The largest endocrine gland
Has a lot of blood flow to it.
Produces 3 hormones: T4, T3, and Calcitonin.
T3 ( triiodythyronine) and T4 ( thyroxine) are the energy hormones. They make you want to get up in the morning and do stuff. Increase metabolic rate, increase protein and bone turnover, increase responsiveness to catecholamines ( epinephrine, dopamine), necessary for fetal and infant growth and development.
Calcitonin lowers blood calcium and phosphate levels. This is Thyroid C cell.
T3 and T4 are amino acids.
They are stored bound to protein in the cells of the thyroid gland until needed for release into the blood stream.
Thyroxine-binding globulin (TBG), transthyretin, and albumin- transport T3 and T4.
IODINE= essential to the thyroid gland for synthesis of its hormones.
Major use of IODINE in the body is by the thyroid.
Major derangement of iodine deficiency can lead to thyroid malfunction (iodine deficiency)
It needs it to work properly.
You dont make iodine. It is a mineral. You get it in your diet.
So, you ingest iodide from diet, thyroid gland takes it up from blood and converts it to iodine, and together with tyrosine, it makes thyroid hormone.
REGULATION OF THYROID HORMONE
TSH, which are released by anterior pituitary gland, control T3 and T4.
TSH controls the rate of thyroid hormone release through negative feedback mechanism, and in turn the level of thyroid hormone in the blood determines the release of TSH. They work together.
TRH is thryroid releasing hormone release by the hypothalamus and controls the release of TSH.
If increase in TRH, you have an increase in TSH.
Environmental factors: Lower temperature can increase TRH, therefore increase TSH.
Main function of Thyroid Hormone
Control cellular metabolic activity, pretty much metabolic rate.
Also important in brain development and cell replication.
T4, a weak hormone, maintains body metabolism in a steady state.
T3, stronger than T4, has a more rapid metabolic action. So t3 related to faster metabolic rate.
Together increase the level of oxygen consumption and responsiveness of tissues to other hormones.
Secreted in response to high plasma levels of calcium.
Inadequate secretion of thyroid hormone during fetal and neonatal development= stunted physical and mental growth.
In adults, hypothyroidism= lethargy, slow mentation, and generalized slowing of body functions.
Increased metabolic rate
All the other symptoms are related to the increase in circulating cathecholamines such as epinephrine and norepinephrine.
Increased metabolic rate
Goiter (also common in iodine deficiency)
Iodine deficiency results in low levels of circulating thyroid hormones, which then causes increased release of TSH that causes overproduction of globulin, causing hypertrophy of the thyroid gland.
So, iodine deficiency creates low levels of circulating thyroid hormones, which in turn causes increase of TSH, which causes overproduction of globulin leading to hypertrophy of the thyroid gland.
Inspect and palpate thyroid gland routinely in all patients.
Landmarks: lower neck region between the sternocleidomastoid muscles is inspected for swelling or asymmetry.
Ask the patient to extend neck and swallow.
Thyroid tissue should rise normally with swallowing.
Then, palpate for size, shape, consistency, symmetry, and the presence of tenderness.
If enlarged gland, use stethoscope to auscultate both lobes.
If you hear a bruit, or feel soft texture or firmness and tenderness, refer to doctor.
Palpation and auscultation with laboratory measurement of thyroid hormones, thyroid scanning, bipsy, and ultrasonography.
Widely used tests: Serum immunoassay for TSH and free T4.
Measurement of the TSH concentration is the single best screening test of thyroid function in outpatients because of high sensitivity.
Recommendations for testing
Starting at 35 and every five years
Who is at risk for thyroid dysfunction
Postpartum women, persons with high levels of radiation exposure, patients with down syndrome
Some contraceptives and corticosteroids can interfere with test results.
T3 and T4 generally increase or decrease together.
T3 level is a better indicator of hyperthyroidism, which in increased a bit more than T4 levels.
During Thyroid tests
When thyroid tests are scheduled:
Check if the patient is allergic to iodine (shellfish)
Ask if the patient has taken medications or agents that contain iodine because they may alter test results (example are contrast agents or iodine containing medications to treat thyroid disorders such as radioactive iodine).
Les obvious sources of iodine are: topical antiseptics, multivitamin preparations, food supplements that contain kelp, seaweed and amiodarone.
Estrogens, salicylates, and amphetamines as well as chemotherapeutic agents, and antibiotics, corticosteroids and mercurial diuretics may alter test results.
Example: amiodarone, aspirin, cimetidine, diazepam, furosemide, heparin, lithium, dilantin and propranolol.
Single nodule: can be cancer
multiple nodules: can be hashimotos thyroiditis
diffuse goiter: graves disease or hashimotos thyroiditis
Also thyroid lymphoma
Tenderness: Subacute thyroiditis
Hemmorrhagic or infarcted adenoma
Low thyroid hormone
Myxedema is an abvanced life threatening form.
1. Autoimmune disease such as hashimoto's thyroiditis, post grave's disease
2. Atrophy of thyroid gland with aging
3. Therapy for hyperthyroidism such as radioactive iodine and thyroidectomy
4. Medications such as lithium, iodine compounds, and anithyroid medications
5. Radioation to head, neck in treatment for head and neck cancers, lymphoma
6. Infiltrative diseases of the thyroid such as amyloidosis, scleroderma, and lymphona
7. Iodine dificiency and excess.
Symptoms of hyperthyroidism may later be followed by those of hypopthyroidism.
Patients that had hyperthyroidism and treated it with radioiodine or antithyroid medications of got a thyroidectomy are at risk for hypothyroid.
Extreme fatigue (unable or difficult to complete a full day's work or participate in usual activities).
Hairloss, brittle nails, and dry skin are common
Numbness and tingling of the fingers may occur.
Voice may become husky, and patient may complain of hoarseness.
Menorrhagia, or amenorrhea, and loss of libido.
Women more common than men.
Usually between 40 and 70.
In severe hypothyroidism,
patient might feel cold even in warm environment.
subnormal body temperature and pulse rate.
The speech is slow, the tongue enlarges, hands and feet increase in size, deafness may occur, constipation may happen, mental processes become dulled.
Advanced hypothyroidism may produce personality and cognitive changes characteristic of dementia. Sleep apnea, and pleural effusion. Pericardial effusion, and respiratory muscle weakness may also occur.
Severe is associated with an elevated serum cholesterol level, atherosclerosis, coronary artery disease, and poor left ventricular function. Abnormally sensitive to sedative, opioid, and anesthetic agents.
It is a form of thyrotoxicosis
Excessive synthesis of endogenous or exogenous thyroid hormones by the Thyroid.
Grave's disease, toxic multinodular goiter, and toxic adenoma.
Graves disease is an autoimmune disorder from too much output of thyroid hormones by annormal stimulation of the thyroid.
Happens more in women than men.
onset between the second and fourth decades.
Disorder may appear after an emotional shock, stress, or an infection
Presenting symptom is often NERVOUSNESS
Irritable, apprehensive, cannot sit quietly, palpitations, pulse is abnormally rapid at rest as well as on exertion.
Tolerate heat poorly and perspire unusually freely.
The skin is flushed continuously
Salmon color in caucasians
Tremor of the hands
exophthalmos- which produces a startled facial expression because of the abnormal protrusion of one or both eyeballs.
Increased appetite and dietary intake, weight loss, fatigability and weakness
If sever hyperthyroidism and untreated, MI and heart failure may occur.
Labs will show decrease in TSH, increased T4, and increase in radioactive iodine uptake
Raioactive iodine can be used for the treatment for graves disease.
Beta blocking agents, atenolol, metoprolol are adjunctive therapy meds used for symptomatic relief.
iodine therapy, antithyroid medications and surgery all share the same complications of relapse or recurrent hyperthyroidism and permanent hypothyroidism.
For treatment using radioactive iodine, pregnancy test given 48 hours before, and should not get pregnant 6 months following treatment
Thyroid storm: a lifethreatning condition manifested by cardiac dysrhthmias, fever, and neurologic impairment.
When a patient is using ablatie dose of radioactive iodine initially it causes an acute release of thyroid hormone from the thyroid gland and may cause increased symptoms, so thyroid storm can happen.
This happens in patients with cardiovascular disease or older patients that may need pretreatment with antithyroid medications 4-6 weeks prior to administration of radioactive iodine. Stop the meds three days before the radioation and then start them again 3 days after them for about 4-6 weeks.
After the antithyroid med treatment took place 4-6 weeks, then you can do thyroid hormone replacement starting up to 18 weeks after antithyroid medications have stopped.
You have to test for T4 before giving the thyroid hormones because exams can be misleading during these weeks.
Once a normal thyroid state has been established, TSH should be measured every 6-12 months for life.
If T3 is elevated, persistent hyperthyroidism and T3 normal or low it is transient hypothyroidism.
recumbent position to observe sides of the back of the neck
Report signs of sensation of pressure or fullness at the incision site
report difficulty in respiration
Keep a tracheostomy set at the bedside of the patient in case of difficulty in respiration and call the surgeon.
When moving the patient, support the patient's head and avoid tension on the sutures.
The most comfortable position: Semi-fowelers with the head elevated and supported by pillows.
IV fluids immediately post op.
Water after nausea subsides and bowel sounds are present.
Cold fluids and ice.
Talk as little as possible.
A high calorie-diet may be prescribed once the patient is better.
Nonabsorbable sutures are usually removed within 5-7 days.
Following thyroid surgery, monitor the patient closely for signs of tetany (spasms, twitching), and hyperirritability of the nerves. Laryngospasm, although rare, can occur and obstruct the airway.
This happens after thyroid surgery because if the parathyroid is damaged during the surgery, or removed, it creates a fall in the blood calcium levels, causing hypocalcemia, which in this case is treated with IV calcium gluconate.
One attached to the upper portion of each kidney
They are pretty much two separate endocrine glands with independent functions.
The adrenal medulla, which is in the center of the gland, secretes catecholamines.
The outer portion, which is the cortex, secretes steroid hormones ( glucocorticoids, mineralocorticoids, and sex hormones).
Adrenal medulla functions as part of the autonomic nervous system.
Epinephrine is released by the adrenal medulla, and epinephrine is released when preparing to meet a challenge, for example the fight-or-flight response.
Secretion of epinephrine causes decreased blood flow to tissues that are not needed in emergency situations.
Adrenal Cortex: It is necessary for life: adrenocortical secretions important for the body to adapt to stress of all kinds.
Three types released by adrenal cortex:
mineralcorticoids, mainly aldosterone
sex hormones, mainly androgens, which are male sex hormones
Without adrenal cortex, circulatory failure, circulatory shock, and protration.
Survival is possible but only with nutritional, electrolyte, and fluid replacement
Increased cortisol levels= increased blood glucose levels.
Major effect on metabolism of almost all organs.
Large doses of exogenous glucocorticoids= inhibited release of acth and endogenous glucocorticoids.
This can cause the adrenal cortex to atrophy.
If exogenous glucocorticoid administration is discontinued suddenlty, adrenal insufficiency may result ( because of they atrophied cortex to respond adequately).
Exert their major effects on electrolyte metabolism.
Act on renal tubular and GI epitheleum.
When secreted in excess, they produce masculinization in women, feminization in men, or premature sexual development in children.
This is called the adrenogenital syndrome.
Turmor usually benign.
Causes hypertension, and it is the only form of hypertension cured by surgery.
formed by chromaffin cells of the adrenal medulla.
A possibility in patients iwth medullary thyroid carcinoma and parathyroid hyperplasia or tumor and those with this in their family history. They should be monitored.
Five H's signs:
hypertension, headache, hyperhidrosis, hypermetabolism, and hyperglycemia.
Diagnostic: Measurements of urine and plasma levels of catecholamines and metaneprhine
24 hour ruine specimen is good too
avoid chocolate, bananas, coffie, vanilla, aspirin, tea, coffee and other things before testing. Even decaffeinated teas and coffees can affect the results, so they should be avoided.
Urine that is collected over a 2-3 hour period after an attack of hypertension can be used.
The total plasma catecholamine concentration is measured with the patient supine and at rest for 30 minutes.
A butterfly needle might be inserted 30 minutes before the specimen is taken.
This is adrenocortical insuffiency
Occurs when adrenal cortex function is inadequate to meet the patient's needs for cortical hormones.
Autoiimune or idiopathic atrophy of the adrenal glands is common cause.
Other causes: surgical removal of both adrenal glands, infection of the adrenal glands, such as tuberculosis and histoplasmosis.
Inadequate secretion of ACTH from the pituitary gland also results in adrenal insuffieiency because of decreased stimulation of the adrenal cortex.
Also, the most common cause is therapeutic use of corticosteroids.
Any patient that has been treated with corticosteroids should be monitored for adrenal insufficiency.
Muscle weakness, anorexia, GI symptoms, fatigue, emaciation, dark pigmentation of the mucous membranes and the skin, especially of the knuckles, knees, and elbows
low blood glucose, low sodium, and high potassium
patient in recumbent position with legs elevated, restore blood circulation, administer fluids and corticosteroids, monitor vital signs. Hydrocortisone is administered IV followed by 5 % dextrose in normal saline.
Vasopressors may be required if hypotension persists.
Assess for patient's level of stress and focus on presence of symptoms of fluid inbalance.
Monitor BP and pulse rate as the patient moves from lying, sitting, and standing for inadequate fluid volume.
Blood pressure decrease of 20 in systolic may indicate depletion of fluid volume.
Assess skin for changes in color and turgor.
Weight, muscle weakness, fatigue, and any illness or stress that may have precipitated the acute crisis.
Excessive, adrenocortical activity.
Excessive corticosteroid production secondary to hyperplasia of the adrenal cortex.
Tumor in pituitary gland that produces ACTH and stimulates the adrenal cortex to increase its hormone secretion.
Commonly caused by the use of corticosteroid medications
IMBALANCED ADRENOCORTICAL HORMONE SECRETION CHARACTERIZES BOTH ADDISONS DISEASE, WHICH IS HYPOPRODUCTION, AND CUSHING SYNDROME, WHICH IS HYPERPRODUCTION
central-type obesity with buffalo hum in the neck and supraclavicular areas
relatively thin extremities
sleep is disturbed
excessive protein catabolism
muscle wasting and osteoporosis
kyphosis, backache, and compression fractures of the vertebrae may result.
hypertension and hear failure because of increased mineralcorticoid which increases retention of sodium and water.
hyperglycemia or overt diabetes may develop
women between 20-40 more likely than men
In women, virilization can result of excess androgens.
Hirsutism and breasts atrophy
libido is lost in men and women
Ophthalmic-cataracts and glaucoma
skeletal- osteoporosis, spontaneous fractures
Cardiovascular-hypertension, heart failure
truncal obesity, moon face, buffalo hump, sodium retention, hypokalemia, metabolic alkalosis, hyperglycemia
menstrual irregulaties, impotence, adrenal suppresion
Gastrointestinal-peptic ulcer, pancreatitis
Muscular- myopathy, muscle weakness
Immune function- decreased inflammatory responses
impaired wound healing
increased susceptibility to infections
dermatologic-thinning of skin
psychiatric-mood alterations, psychoses
If caused by turmor, remove turmor
Radioation of the pituitary gland
adrenalectomy is the treatment of choice in patients with adrenal hypertrophy ( primary)
Temporary replacement therapy with hydrocortisone may be needed for several months
if both adrenal glands were removed, lifetime treatment
meds: adrenal enzyme inhibitors such as metyrapone.
If cushing syndrome is a result of the administration of corticosteroids an attempt is made ot reduce or taper the medication to the minnimum dosage needed to reat the underlying disease process
Assessment for a patient with cushing
Health history focuses on the effects on the body of high concentration of adrenal cortex hormones and on the inability of the adrenal cortex to respond to changes in cortisol and aldosterone levels.
Patients level of activity, the skin is assessed for trauma, infection, breakdown, bruising, and edema. Changes in physical appearance such as hair. Mental function including mood, responses to questions, awareness of environment, and level of depression. Family is often a good source of information about gradual changes in the aptient's physical appearance as well as emotional status.
Decrease risk of injury
Give foods high in protein, calcium, and vitamin D
Avoid exposures to others with infections
Assess for subtle sings of infections
Prepare the patient for adrenalectomy, if indicated, and the postoperative course
If needed, insulin and peptic ulcer before surgery
blood glucose monitoring before, during and after surgery.
Do not use adhesive tape