Endocrine Flashcards
What is the range for normal serum TSH levels?
0.4-6.15 u/ml
What is the endocrine system composed of?
The endocrine system is composed of the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreatic islets, ovaries, and testes.
What 4 categories are hormones classified into?
1) Amines and Amino acids (epinephrine, norepinephrine & Thyroid hormones)
2) Peptides, Polypeptides, Proteins and Glycoproteins (Thyrotropin releasing hormone, follicle stimulating hormone & growth hormone)
3) Steroids (corticosteroids - produced in adrenal cortex)
4) Fatty Acid derivatives (retinoids)
Explain paracrine action.
Paracrine action refers to a type of cell signaling where a cell releases chemical messengers (hormones or signaling molecules) that act on neighboring or nearby target cells rather than traveling through the bloodstream to distant sites.
Explain autocrine action.
Autocrine action refers to a type of cell signaling where a cell releases chemical messengers (hormones or signaling molecules) that act on the same cell that produced them. - the cell responds to its own signal.
Which gland plays an important role in regulating the endocrine system.
The pituitary gland.
What is the primary role of the pituitary gland?
To secrete hormones into the blood stream.
The disorders of the endocrine gland are manifested as __________ & ____________
Hyper & Hypofunction
What is acromegaly?
Progressive enlargement of peripheral body parts resulting from excessive secretion of growth hormone
Acromegaly is often caused by a pituitary adenoma.
Define Addison’s disease.
Chronic adrenocortical insufficiency due to inadequate adrenal cortex function
It can lead to fatigue, weight loss, and low blood pressure.
What characterizes an Addisonian crisis?
Acute adrenocortical insufficiency; characterized by hypotension, cyanosis, fever, nausea/vomiting, and signs of shock
This is a medical emergency requiring immediate treatment.
What is adrenalectomy?
Surgical removal of one or both adrenal glands
It may be performed to treat tumors or conditions affecting adrenal function.
What is adrenocorticotropic hormone (ACTH)?
Hormone secreted by the anterior pituitary, essential for growth and development
ACTH stimulates the adrenal cortex to produce cortisol.
What are androgens?
Male sex hormones
Examples include testosterone and dehydroepiandrosterone (DHEA).
What does basal metabolic rate refer to?
Chemical reactions occurring when the body is at rest
It is a measure of energy expenditure in a neutrally temperate environment.
What is calcitonin?
Hormone secreted by the thyroid gland; participates in calcium regulation
It helps lower blood calcium levels by inhibiting osteoclast activity.
Describe Chvostek sign.
Spasm of the facial muscles produced by sharply tapping over the facial nerve; suggestive of latent tetany in patients with hypocalcemia
It indicates neuromuscular excitability due to low calcium levels.
What are corticosteroids?
Hormones produced by the adrenal cortex or their synthetic equivalents
They are used to treat inflammation and autoimmune conditions.
What is Cushing’s syndrome?
Group of symptoms produced by an oversecretion of adrenocorticotropic hormone; characterized by truncal obesity, “moon face,” acne, abdominal striae, and hypertension
It can result from a tumor or prolonged use of corticosteroids.
Define diabetes insipidus.
Condition in which abnormally large volumes of dilute urine are excreted as a result of deficient production of vasopressin
It leads to excessive thirst and frequent urination.
What does euthyroid mean?
State of normal thyroid hormone production
This indicates that the thyroid gland is functioning properly.
What is exophthalmos?
Abnormal protrusion of one or both eyeballs
It is commonly associated with Graves’ disease.
What are glucocorticoids?
Steroid hormones secreted by the adrenal cortex in response to ACTH; produce a rise of liver glycogen and blood glucose
Cortisol is the primary glucocorticoid.
Define goiter.
Enlargement of the thyroid gland
It can result from iodine deficiency or autoimmune diseases.
What is Graves disease?
A form of hyperthyroidism; characterized by a diffuse goiter and exophthalmos
It is an autoimmune disorder where the immune system stimulates the thyroid.
What are hormones?
Chemical transmitter substances produced in one organ or part of the body and carried by the bloodstream to other cells or organs
They have specific regulatory effects on various bodily functions.
What are mineralocorticoids?
Steroid hormones secreted by the adrenal cortex
They are involved in the regulation of sodium and potassium balance.
Define myxedema.
Severe hypothyroidism; can be with or without coma
It presents with symptoms such as swelling, weight gain, and sensitivity to cold.
What is negative feedback?
Regulating mechanism in which an increase or decrease in the level of a substance decreases or increases the function of the organ producing the substance
This mechanism helps maintain homeostasis.
What is pheochromocytoma?
Adrenal medulla tumor
It can cause episodes of hypertension, palpitations, and sweating.
What does SIADH stand for?
Syndrome of inappropriate antidiuretic hormone
It involves excessive secretion of antidiuretic hormone despite low serum osmolality levels.
What is thyroidectomy?
Surgical removal of all or part of the thyroid gland
It is performed to treat conditions such as thyroid cancer or hyperthyroidism.
Define thyroiditis.
Inflammation of the thyroid gland; may lead to chronic hypothyroidism or may resolve spontaneously
Various types include Hashimoto’s thyroiditis and subacute thyroiditis.
What is thyroid-stimulating hormone (TSH)?
Released from the pituitary gland; causes stimulation of the thyroid, resulting in release of T3 and T4
TSH levels are used to assess thyroid function.
What is a thyroid storm?
Life-threatening condition of the thyroid due to untreated hyperthyroidism
It can cause fever, tachycardia, and altered mental status.
What is thyrotoxicosis?
Condition produced by excessive endogenous or exogenous thyroid hormone
It can lead to symptoms such as weight loss, anxiety, and heat intolerance.
What is thyroxine (T4)?
Thyroid hormone; active iodine compound formed and stored in the thyroid
T4 is converted to the more active T3 in peripheral tissues.
What is triiodothyronine (T3)?
Thyroid hormone; formed and stored in the thyroid; released in smaller quantities, biologically more active, and with faster onset of action than T4
T3 has widespread effects on cellular metabolism.
Describe Trousseau sign.
Carpopedal spasm induced when blood flow to the arm is occluded; suggestive sign for latent tetany in hypocalcemia
It indicates neuromuscular irritability due to low calcium levels.
What is vasopressin?
Antidiuretic hormone secreted by the posterior pituitary
It helps regulate water balance in the body.
When diagnosing a patient with an endocrine disorder, what information from their health history is important to obtain?
Patients should be asked if they have experienced changes in the following areas: energy level, tolerance to heat or cold, weight, thirst, frequency of urination, bowel function, body proportions, muscle mass, fat and fluid distribution, secondary sexual characteristics (e.g., loss or growth of hair), menstrual cycle, memory, concentration, sleep patterns, mood, vision, joint pain, and sexual dysfunction.
When diagnosing a patient with an endocrine disorder, what physical assessment should be done?
Physical, psychological, and behavioral changes should be noted. Examples of changes in physical characteristics on examination may include appearance of facial hair in women, “moon face,” “buffalo hump,” exophthalmos (abnormal protrusion of one or both eyeballs), vision changes, edema, thinning of the skin, obesity of the trunk, thinness of the extremities, increased size of the feet and hands, edema, and hypo- or hyperreflexia. The patient may also exhibit changes in mood and behavior such as nervousness, lethargy, and fatigue.
In terms of assessing for endocrine dysfunctions, why do we do blood tests?
Blood tests determine the levels of circulating hormones, the presence of autoantibodies, and the effect of a specific hormone on other substances (e.g., the effect of insulin on blood glucose levels). The serum levels of a specific hormone may provide information to determine the presence of hypo- or hyperfunction of the endocrine system and the site of dysfunction.
In terms of assessing for endocrine dysfunctions, why do we do urine tests?
Urine tests are used to measure the amount of hormones or the end products of hormones excreted by the kidneys.
Why would we do a 24 hr urine specimen?
A 24-hour urine specimen is collected to measure hormone levels and their metabolites over a full day, providing a more accurate assessment of endocrine function compared to a single blood test.
What are stimulations tests used for, how does it work?
Stimulation tests are used to confirm hypofunction of an endocrine organ. The tests determine how an endocrine gland responds to the administration of stimulating hormones that are normally produced or released by the hypothalamus or pituitary gland. If the endocrine gland responds to this stimulation, the specific disorder may be in the hypothalamus or pituitary. Failure of the endocrine gland to respond to this stimulation helps identify the problem as being in the endocrine gland itself.
Explain suppression tests, how does it work?
Suppression tests are used to detect hyperfunction of an endocrine organ. They determine if the organ is not responding to the negative feedback mechanisms that normally control secretion of hormones from the hypothalamus or pituitary gland. Suppression tests measure the effect of a given exogenous dose of the hormone on the endogenous secretion of the hormone or on the secretion of stimulation hormones from the hypothalamus or pituitary gland.
Which hormones does the posterior pituitary gland secrete?
ADH (Vasopressin)
Oxytocin
Which hormones does the anterior pituitary gland secrete?
Growth Hormone
ACTH
Thyroid Stimulating Hormone (TSH)
FSH & LH
Prolactin
What controls the Pituitary gland?
The Hypothalamus.
What are the main functions of the hormones TSH, ACTH, FSH and LH?
The main function of TSH, ACTH, FSH, and LH is the release of hormones from other endocrine glands
What is an imbalance in Adrenocorticotropic Hormone (ACTH) secretion characterized by?
Imbalanced ACTH secretion characterizes both Addison’s disease (hypoproduction) and Cushing’s syndrome (hyperproduction).
What does ADH/Vasopressin control?
the excretion of water by the kidney; its secretion is stimulated by an increase in the osmolality of the blood or by a decrease in blood pressure.
What will happen if a total destruction of the pituitary gland occur as a result of a tumor, trauma or vascular lesion?
This will remove all stimuli that are normally received by the thyroid, the gonads, and the adrenal glands. This leads to extreme weight loss, emaciation, atrophy of all endocrine glands and organs, hair loss, impotence, amenorrhea, hypometabolism, and hypoglycemia. Coma and death occur if the missing hormones are not replaced
Explain Diabetes Insipidus.
The most common disorder related to posterior lobe dysfunction is diabetes insipidus (DI), a condition in which abnormally large volumes of dilute urine are excreted as a result of deficient production of vasopressin
What factors may have an effect on the occurrence of DI?
DI may occur following surgical treatment of a brain tumor, secondary to nonsurgical brain tumors, traumatic brain injury, infections of the nervous system, post hypophysectomy (removal of the pituitary), failure of renal tubules to respond to ADH, and the use of specific medications
Almost all pituitary tumors are benign and are _____ _______ .
slow growing
What is the difference between functional pituitary tumors and non-functioning pituitary tumors?
Functional tumors secrete pituitary hormones, whereas nonfunctional tumors do not
Name the principal types of pituitary tumors.
The principal types of pituitary tumors represent an overgrowth of Eosinophilic cells,
Basophilic cells, or Chromophobic cells (i.e., cells with no affinity for either eosinophilic or basophilic stains).
Eosinophilic tumors that develop early in life result in ___________.
Gigantism
How does gigantism developed in adulthood present itself?
If the disorder begins during adult life, the excessive skeletal growth occurs only in the feet, the hands, the superciliary ridge, the molar eminences, the nose, and the chin, giving rise to the clinical picture called acromegaly. However, enlargement involves all tissues and organs of the body, and many of these patients suffer from severe headaches and visual disturbances because the tumors exert pressure on the optic nerves
Basophilic tumors give rise to ____________ .
Cushing’s syndrome
How does Cushing’s syndrome present itself?
Its features largely attributable to hyperadrenalism, including masculinization and amenorrhea in females, truncal obesity, hypertension, osteoporosis, and polycythemia.
Which tumors represent 90% of pituitary tumours?
Chromophobic tumors
How does Chromophobic tumors present themselves?
These tumors usually produce no hormones but destroy the rest of the pituitary gland, causing hypopituitarism.
People with this disease often have obesity, are somnolent, and exhibit fine, scanty hair; dry, soft skin; a pasty complexion; and small bones. They also experience headaches, loss of libido, and visual defects progressing to blindness. Other signs and symptoms include polyuria, polyphagia, a lowering of the basal metabolic rate.
What is the name of the surgery used to remove the pituitary gland?
Hypophysectomy.
Hypophysectomy is the treatment of choice in patients with Cushing’s disease resulting from excessive production of ACTH by a pituitary tumor.
What scans are used to diagnose pituitary tumors?
CT & MRI
What are 4 ways to characterize Diabetes insipidus?
central, nephrogenic, or dipsogenic, as well as gestational
Explain the etiology of nephrogenic DI.
Nephrogenic DI etiologic factors include kidney injury, medications such as lithium, hypokalemia, and hypercalcemia.
Explain the etiology of central DI.
The primary etiology for central DI is head trauma but other causes include surgery, infection, inflammation, brain tumors, or cerebral vascular disease; it also may be idiopathic
Explain the etiology of Dipsogenic DI.
Dipsogenic DI is caused by a defect in the hypothalamus and may be the result of damage to the pituitary gland from a head injury, surgery, infection, inflammatory process, or a tumor
What happens when the kidneys are not receiving ADH?
Without the action of ADH on the distal nephron of the kidney, an enormous daily output (greater than 250 mL per hour) of very dilute urine with a specific gravity of 1.001 to 1.005 occurs. It also contains abnormal substances such as albumin and/or glucose.
Because of the intense thirst, the patient tends to drink 2 to 20 L of fluid daily and craves cold water
True/False
We can treat DI with restriction of fluids. Why/Why not?
FALSE.
The disease cannot be controlled by limiting fluid intake, because the high-volume loss of urine continues even without fluid replacement. Attempts to restrict fluids cause the patient to experience an insatiable craving for fluid and to develop hypernatremia and severe dehydration
What is the fluid depravation test, how is it done?
✔ Fluids are withheld for 8–12 hours or until the patient loses 3%–5% of body weight.
✔ The patient is weighed frequently during the test.
✔ Urine and blood tests (osmolality) are done at the start and end of the test.
✔ If the urine remains dilute (low specific gravity and osmolality) despite dehydration, it indicates Diabetes Insipidus (DI)
How do we treat DI?
The objectives of therapy are to replace ADH (which is usually a long-term therapeutic program), ensure adequate fluid replacement, and identify and correct the underlying intracranial pathology. Nephrogenic causes require different management approaches.
What is the drug of choice for central DI treatment?
Desmopressin, a synthetic vasopressin without the vascular effects of natural ADH, is the drug of choice for central DI. The drug may be given orally or intranasally.
Chlorpropamide and thiazide diuretics are also used in mild forms of the disease because they potentiate the action of vasopressin but are used with caution due to the risk for hypoglycemia.
Can we use Desmopressin to treat nephrogenic DI?
No -Nephrogenic DI occurs due to the kidneys’ resistance to antidiuretic hormone (ADH), not a deficiency of ADH.
If the DI is renal in origin, the previously described treatments are ineffective. Thiazide diuretics, mild salt depletion, and prostaglandin inhibitors (e.g., indomethacin and aspirin) are used to treat the nephrogenic form of DI.
How does the nursing management look like for patients with DI?
- assess for dehydration - Severe dehydration can lead to decreased cardiac output and, therefore, decreased perfusion of the vital organs, specifically the brain and kidneys.
- Ongoing monitoring of vital signs as well as intake and output (I&O) is essential
Explain SIADH and what does it stand for?
The syndrome of inappropriate antidiuretic hormone (SIADH) results from a failure of the negative feedback system that regulates the release and inhibition of ADH. Patients with SIADH cannot excrete a dilute urine, retain fluids, and develop a sodium deficiency known as dilutional hyponatremia.
True/False
SIADH is always and endocrine dysfunction.
False.
SIADH is often of nonendocrine origin; for instance, the syndrome may occur in patients with bronchogenic carcinoma in which malignant lung cells synthesize and release ADH. SIADH has also occurred in patients with severe pneumonia, pneumothorax, and other disorders of the lungs, as well as malignant tumors that affect other organs
What are other reasons for developing SIADH?
Disorders of the central nervous system, such as head injury, brain surgery or tumor, and infection, are thought to produce SIADH by direct stimulation of the pituitary gland. Some medications such as vincristine, phenothiazines, tricyclic antidepressants, thiazide diuretics and nicotine have been implicated in SIAD as they either directly stimulate the pituitary gland or increase the sensitivity of renal tubules to circulating ADH.
How do we medically manage SIADH?
Treatment is focused on eliminating the underlying cause, if possible, and restricting fluid intake. Because retained water is excreted slowly through the kidneys, the extracellular fluid volume contracts and the serum sodium concentration gradually increases toward normal.
Diuretic agents such as furosemide may be used along with fluid restriction. In severe hyponatremia sometimes a hypertonic NaCl (3%) may be prescribed and administered IV
What is the nursing management like for SIADH?
Close monitoring of fluid I&O, daily weight, urine and blood chemistries, and neurologic status is indicated for the patient at risk for SIADH.
Which is the largest endocrine gland?
The thyroid gland.
What 3 hormones does the thyroid gland produce?
thyroxine (T4), triiodothyronine (T3), and calcitonin. Thyroxine and triiodothyronine are needed by all body cells for metabolism.
____________ is essential to the thyroid gland for synthesis of its hormones
Iodine
The secretion of T3 and T4 by the thyroid gland is controlled by ________ .
TSH
What is the main function of Thyroid hormone?
To control cellular metabolic activity.
Is T4 or T3 the most potent hormone?
T4, a relatively weak hormone, maintains body metabolism in a steady state. T3 is about five times as potent as T4 and has a more rapid metabolic action.
Calcitonin is secreted in response to what?
It is secreted in response to high plasma levels of calcium, and it reduces the plasma level of calcium by increasing its deposition in bone.
Congenital hypothyroidism will result in what?
intellectual disability and stunted physical growth because of general depression of metabolic activity
How does hypothyroidism present itself in adulthood?
In adults, hypothyroidism manifests as lethargy, slow mentation, weight gain, constipation, cold intolerance, and generalized slowing of body functions.
How does Hyperthyroidism present itself?
Hyperthyroidism is manifested by a greatly increased metabolic rate. Many of the other characteristics of hyperthyroidism result from the increased response to circulating catecholamines (epinephrine and norepinephrine). Oversecretion of thyroid hormones is usually associated with an enlarged thyroid gland known as a goiter.
Explain what Goiter is.
Goiter is an enlargement of the thyroid gland and is often associated with hyperthyroidism. Goiter can also occur with iodine deficiency.
lack of iodine results in low levels of circulating thyroid hormones, which causes increased release of TSH; the elevated TSH causes overproduction of thyroglobulin (a precursor of T3 and T4) and hypertrophy of the thyroid gland.
What is the primary screening test used to determine thyroid functioning?
Measurement of serum TSH concentration.
Before any Thyroid function testing, why is it important to assess if a patient is allergic to iodine?
Since thyroid tests involve the use of iodine, determining if the patient has any allergies to iodine or is taking medications that contain iodine is essential.
Which medications may alter thyroid test results?
- amiodarone
- aspirin
- cimetidine
- diazepam
- estrogens
- furosemide
- glucocorticoids
- heparin
- lithium
- phenytoin and other anticonvulsants
- propranolol
What is the most common cause of Hypothyroidism in adults?
Autoimmune thyroiditis (Hashimoto disease), in which the immune system attacks the thyroid gland.
Hypothyroidism also commonly occurs in patients with previous hyperthyroidism that has been treated with radioiodine or antithyroid medications or thyroidectomy (surgical removal of all or part of the thyroid gland)
Explain what is meant by central Hypothyroidism.
If the cause of the thyroid dysfunction is failure of the pituitary gland, the hypothalamus, or both, the hypothyroidism is known as central hypothyroidism.
Explain what is meant by pituitary or secondary Hypothyroidism.
If the cause is entirely a pituitary disorder, it may be referred to as pituitary or secondary hypothyroidism.
Explain what is meant by hypothalamic or tertiary hypothyroidism.
If the cause is a disorder of the hypothalamus resulting in inadequate secretion of TSH due to decreased stimulation of TRH, it is referred to as hypothalamic or tertiary hypothyroidism
What is Myxedema?
Myxedema is a severe form of hypothyroidism that occurs when thyroid hormone levels are critically low, leading to widespread tissue swelling and metabolic slowdown.
Name some causes of Hypothyroidism.
- Autoimmune disease (Hashimoto thyroiditis, post-Graves disease) * Atrophy of thyroid gland with aging Infiltrative diseases of the thyroid (amyloidosis, scleroderma, lymphoma)
- Iodine deficiency, iodine excess, and iodine compounds
- Medications (e.g., Lithium) Radioactive iodine (131I)
- Therapy for hyperthyroidism
- Thyroidectomy Radiation to head and neck in treatment for head and neck cancers, lymphoma
What are the clinical manifestations of Hypothyroidism?
Clinical manifestations include complaints of fatigue and lethargy that may interfere with activities of daily living, weight gain without an increased intake of calories, cold intolerance, dry skin, and, in some patients, a deepening of the voice.
What will severe hypothyroidism result in?
Severe hypothyroidism results in a subnormal body temperature and pulse rate.
The mental processes become dulled, and the patient appears apathetic. Speech is slow, the tongue enlarges, the hands and feet increase in size, and deafness may occur. The patient frequently reports constipation.
Advanced hypothyroidism may produce personality and cognitive changes characteristic of dementia.
Severe hypothyroidism is associated with an elevated serum cholesterol level, atherosclerosis, coronary artery disease, and poor left ventricular function.
What are patients with advanced hypothyroidism abnormally sensitive to?
The patient with advanced hypothyroidism is hypothermic and abnormally sensitive to sedative, opioid, and anesthetic agents, which must be given with extreme caution. Therefore, patients with unrecognized hypothyroidism who are undergoing surgery are at increased risk for intraoperative hypotension, postoperative heart failure, and altered mental status.
What is the main objective in hypothyroidism treatment?
The objectives in the management of hypothyroidism are to restore a normal metabolic state by replacing the missing hormone, as well as prevention of disease progression and complications.
What is the primary drug of choice in treating hypothyroidism?
Synthetic levothyroxin
How does long-term hypothyroidism affect the cardiovascular system?
✔ Long-term hypothyroidism leads to:
- Elevated cholesterol levels
- Atherosclerosis (narrowing of arteries)
- Coronary artery disease (CAD)
Why don’t patients with hypothyroidism experience immediate heart symptoms despite having CAD?
✔ In hypothyroidism, metabolism is slow, so:
- Oxygen demand is low
- The heart tolerates reduced blood supply without showing CAD symptoms.
Why does thyroid hormone therapy increase the risk of heart complications?
✔ Thyroid hormone increases metabolism, leading to:
- Higher oxygen demand in tissues, including the heart
- Atherosclerosis limits oxygen supply, which does not improve quickly
- Angina or acute coronary syndrome (ACS) may occur if the heart does not receive enough oxygen
Why does thyroid hormone therapy increase the risk of arrhythmias?
✔ Thyroid hormones enhance the effects of catecholamines (e.g., epinephrine & norepinephrine), leading to:
- Increased heart rate
- Higher risk of arrhythmias (irregular heartbeats)
What should we do if arrythmias occur due to levothyroxine treatment?
If angina or arrhythmias occur, thyroid hormone administration must be discontinued immediately. Later, when it can be resumed safely, it should be prescribed cautiously at a lower dosage and with close monitoring by the primary provider and the nurse.
What are some DDI interactions that we need to be aware of with levothyroxine?
Levothyroxine increases the effect of Warfarin.
In addition, the dosage of insulin and oral hypoglycemic medications used to treat diabetes may require adjustment.
Caution is also needed in patients who are concomitantly taking estrogen, which may necessitate an increased dosage of the oral thyroid hormone
How does hypothyroidism affect breathing, and what are key nursing interventions?
✔ Depressed ventilation can lead to impaired breathing.
✔ Assess respiratory rate, depth, oxygen levels, and arterial blood gases.
✔ Encourage deep breathing, coughing, and incentive spirometry.
✔ Use caution with sedatives and hypnotics due to increased risk of respiratory depression.
✔ Maintain airway support if needed
Why is cardiac monitoring essential in hypothyroidism?
✔ Hypothyroidism can cause bradycardia, atherosclerosis, and reduced cardiac output.
✔ Monitor heart rate, rhythm, and blood pressure.
✔ Check serum cholesterol levels and assess for anginal pain.
✔ Monitor ECG, especially after initiating thyroid hormone therapy (risk of arrhythmias)
How do nurses manage cold intolerance in hypothyroid patients?
✔ Provide extra clothing or blankets.
✔ Avoid external heat sources (heating pads, warming blankets) to prevent vascular collapse.
✔ Monitor body temperature and report decreases.
✔ Protect from cold drafts to minimize heat loss.
Why do hypothyroid patients experience confusion, and how is it managed?
✔ Altered cardiovascular and respiratory status can cause confusion.
✔ Orient patient to time, place, and events.
✔ Provide conversation and stimulation within their tolerance level.
✔ Explain that cognitive changes are temporary and improve with treatment.
What are the key nursing interventions for preventing myxedema coma?
✔ Monitor for worsening hypothyroid symptoms:
Decreased consciousness
Low blood pressure, respiratory rate, and temperature
✔ Provide ventilatory support if needed.
✔ Administer thyroid hormone with caution (risk of angina).
✔ Turn and reposition the patient every 2 hours.
✔ Avoid sedatives and opioids to prevent respiratory depression.
The prevalence of hypothyroidism increases with age, most often among ________ .
Women.
Many older people with Hypothyroidism may be asymptomatic, or symptoms may be dismissed as symptoms of the aging process, what are the major initial symptoms of hypothyroidism in older people, that we should be aware of?
Depression, apathy, and decreased mobility or activity may be the major initial symptoms and may be accompanied by significant weight loss. Constipation affects one fourth of older patients.
What are the most common causes of Hyperthyroidism?
The most common causes are Graves disease, toxic multinodular goiter, and toxic adenoma.
Other causes include thyroiditis (inflammation of the thyroid gland) and excessive ingestion of thyroid hormone.
Explain Graves disease.
Graves disease is an autoimmune disorder that results from an excessive output of thyroid hormones caused by abnormal stimulation of the thyroid gland by circulating immunoglobulins. This disease affects women eight times more frequently than men, with onset usually between the second and fourth decades
Graves disease normally presents itself after ____________
an emotional shock, stress, or an infection, but the exact significance of these relationships is not understood
What are the clinical manifestations of Hyperthyroidism?
Clinical manifestations are related to the increase in metabolic rate and increased oxygen consumption. The patient may appear anxious, seem restless and irritable, and exhibit fine tremors of the hands. The patient will be tachycardic and complain of palpitations. Heat intolerance will be noted with increased perspiration. Additional clinical manifestations include an increase in appetite, diarrhea, weight loss, and thin skin. Patients with Graves disease may present with exophthalmos and may exhibit reduced blinking and lid retraction.
What are the physical findings and diagnostic indicators of hyperthyroidism?
✔ Thyroid gland enlargement (goiter) → Soft, may pulsate
✔ Increased blood flow to the thyroid:
Thrill (vibration) on palpation
Bruit (whooshing sound) heard over thyroid arteries
✔ Advanced hyperthyroidism diagnosis based on:
↓ Decreased serum TSH
↑ Increased free T4
↑ Increased radioactive iodine uptake
How do we treat hyperthyroidism?
Appropriate treatment of hyperthyroidism depends on the underlying cause and often consists of a combination of therapies, including antithyroid agents, radioactive iodine, and surgery.
Treatment of hyperthyroidism is directed toward reducing thyroid hyperactivity to relieve symptoms and preventing complications.
What is the most common way to treat Graves disease?
The use of radioactive iodine is the most common form of treatment for Graves disease.
Beta-adrenergic blocking agents (e.g., propranolol, atenolol, metoprolol) are used as adjunctive therapy for symptomatic relief, particularly in transient thyroiditis
What are the risks associated with Hyperthyroidism treatment?
The three treatments (radioactive iodine therapy, antithyroid medications [e.g., thionamides], and surgery) share the same complications: relapse or recurrent hyperthyroidism and permanent hypothyroidism.
What are the treatment of choice for hyperthyroidism?
Radioactive iodine has been used to treat toxic adenomas, toxic multinodular goiter, and most varieties of thyrotoxicosis and is considered the treatment of choice because a single dose is effective in treating 80% to 90% of cases
Radioactive iodine treatment is safe during pregnancy.
True/False
Women of childbearing age should be given a pregnancy test 48 hours before administration of radioactive iodine. They should also be instructed to not conceive for at least 6 months following treatment. In addition, breast-feeding for up to 6 weeks prior to radioactive iodine treatment is contraindicated.
How does radioactive iodine treatment work ?
Almost all of the iodine that enters and is retained in the body becomes concentrated in the thyroid gland. Therefore, the radioactive isotope of iodine is concentrated in the thyroid gland, where it destroys thyroid cells without jeopardizing other radiosensitive tissues. Over a period of several weeks, thyroid cells exposed to the radioactive iodine are destroyed, resulting in reduction of the hyperthyroid state and inevitably hypothyroidism.
Explain what is meant by the term ‘Thyroid Storm’.
A life-threatening condition manifested by cardiac arrhythmias, fever, and neurologic impairment which may lead to heart failure, circulatory collapse and dangerous elevation of body temperature, all related to the increase in metabolism.
How do we treat Thyroid Storm medically?
With Beta-blockers
After antithyroid medications/measures have been put in place, at what point does the patient start to take thyroid hormone replacements?
4-18 weeks.
Why do we wait 4-18 weeks before starting thyroid replacement therapy after antithyroid treatment?
TSH measurements can be misleading in the early months following treatment with radioactive iodine. Therefore, serum free T4 is the principal test measured at 3 to 6 weeks following administration of radioactive iodine and then every 1 to 2 months until normal thyroid function is established.
Once a normal thyroid state has been established, TSH should be measured every ____________ months for life
6 to 12
What are the clinical manifestations of ‘Thyroid Storm’.
*Hyperpyrexia (high fever), >38.5°C (>101.3°F)
*Extreme tachycardia (>130 bpm)
*Exaggerated symptoms of hyperthyroidism with disturbances of a major system—for example, gastrointestinal (weight loss, diarrhea, abdominal pain) or cardiovascular (edema, chest pain, dyspnea, palpitations)
*Altered neurologic or mental state, which frequently appears as delirium psychosis, somnolence, or coma
Life-threatening thyroid storm is usually precipitated by what factors?
Stress, such as injury, infection, thyroid and non-thyroid surgery, tooth extraction, insulin reaction, diabetic ketoacidosis, pregnancy, digitalis intoxication, abrupt withdrawal of antithyroid medications, extreme emotional stress, or vigorous palpation of the thyroid.
What is another name for anti-thyroid medications?
Thionamides
How does Thionamides work?
Antithyroid agents block the utilization of iodine by interfering with the iodination of tyrosine and the coupling of iodotyrosines in the synthesis of thyroid hormones. This prevents the synthesis of thyroid hormone.
What are the commonly used antithyroid drugs in the United States? How do they work?
Methimazole or Propylthiouracil.
These medications block extrathyroidal conversion of T4 to T3
How should the patient be educated on when to take Methimazole or Propylthiouracil ?
The patient should be instructed to take the medication in the morning on an empty stomach 30 minutes before eating to avoid decrease in absorption associated with some foods such as walnuts, soybean flour, cottonseed meal, and dietary fiber.
How should these medications be taken in pregnancy? (Methimazole or Propylthiouracil.)
Propylthiouracil is recommended during the first trimester of pregnancy rather than methimazole due to the teratogenic effects of methimazole. Due to risk of hepatotoxicity, propylthiouracil should be discontinued after the first trimester and the patient should be switched to methimazole for the remainder of the pregnancy and when breast-feeding.
For patients diagnosed with Hyperthyroidism, when would we do a surgery to remove thyroid tissue?
Surgery to remove thyroid tissue is reserved for special circumstances, for example, in pregnant women who are allergic to antithyroid medications, in patients with large goiters, or in patients who are unable to take antithyroid agents.
How are Thyroid tumors classified?
Tumors of the thyroid gland are classified on the basis of being benign or malignant, the presence or absence of associated thyrotoxicosis, and the diffuse or irregular quality of the glandular enlargement. If the enlargement is sufficient to cause a visible swelling in the neck, the tumor is referred to as a goiter.
What has been the single most effective means of preventing goiter in at-risk populations?
The introduction of iodized salt .
What lesions are associated with malignancy?
Lesions that are single, hard, and fixed on palpation or associated with cervical lymphadenopathy suggest malignancy.
Where do we find the parathyroid glands?
The parathyroid glands (normally four) are situated in the neck and embedded in the posterior aspect of the thyroid gland.
What hormone is secreted by the parathyroid glands, what is the action of this hormone?
Parathormone (parathyroid hormone)—the protein hormone produced by the parathyroid glands—regulates calcium and phosphorus metabolism.
Increased secretion of parathormone results in increased calcium absorption from the kidney, intestine, and bones, which raises the serum calcium level.
Some actions of the parathyroid hormone are increased by the presence of ___________ ____ .
Vitamin D
Parathormone also tend to lower serum ____________ .
Phosphorus.
Increased serum calcium result in ___________ parathormone secretion.
Decreased
Explain hyperparathyroidism.
Hyperparathyroidism is caused by overproduction of parathormone by the parathyroid glands and is characterized by bone decalcification and the development of renal calculi (kidney stones) containing calcium.
what are some reasons for secondary hyperparathyroidism?
Secondary hyperparathyroidism, with manifestations similar to those of primary hyperparathyroidism, occurs in patients who have chronic kidney failure and the so-called renal rickets as a result of phosphorus retention, increased stimulation of the parathyroid glands, and increased parathormone secretion.
How is primary hyperparathyroidism diagnosed?
Primary hyperparathyroidism is diagnosed by persistent elevation of serum calcium levels and an elevated concentration of parathormone.
What is the recommended primary treatment of hyperparathyroidism?
The recommended treatment for primary hyperparathyroidism is parathyroidectomy, the surgical removal of abnormal parathyroid tissue.
For surgery r/t hyperparathyroidism, what criteria’s should be met in patients who are asymptomatic?
Younger than 50 years;
unable or unlikely to participate in follow-up care;
serum calcium level more than 1 mg/dL (0.25 mmol/L) above normal reference range;
GFR less than 60 mL/min;
urinary calcium level greater than 400 mg per day (10 mmol per day); bone density at hip, lumbar spine, or distal radius with T score less than –2.5 or previous fracture at any site; or nephrolithiasis or nephrocalcinosis
Patients with hyperparathyroidism are at risk for __________ _________ .
renal calculi.
Due to the risk of renal calculi in patients with hyperparathyroidism, what it is suggested that they drink how many ml of fluids per day?
a daily fluid intake of 2000 mL or more is encouraged to help prevent calculus formation.
Why are thiazide diuretics avoided in patients with hyperparathyroidism?
Thiazide diuretics are avoided, because they decrease the renal excretion of calcium and further elevate serum calcium levels.
A hypercalcemic crisis is likely to occur when serum calcium levels reach __________ .
Serum calcium levels greater than 13 mg/dL (3.25 mmol/L) result in neurologic, cardiovascular, and kidney symptoms that can be life-threatening
How do we treat a hypercalcemic crisis?
Rapid rehydration with large volumes of IV isotonic saline fluids to maintain urine output of 100 to 150 mL per hour is combined with administration of calcitonin. Calcitonin promotes renal excretion of excess calcium and reduces bone resorption.
Bisphosphonates are added to promote a sustained decrease in serum calcium levels by promoting calcium deposition in bone and reducing the GI absorption of calcium.
When there is an emergency situation of hypercalcemic crisis, what medications do we give?
A combination of calcitonin and corticosteroids is given in emergencies to reduce the serum calcium level by increasing calcium deposition in bone
What causes hypoparathyroidism?
abnormal parathyroid development, destruction of the parathyroid glands (surgical removal or autoimmune response), and vitamin D deficiency.
What is the most common cause for hypoparathyroidism?
The most common cause is the near-total removal of the thyroid gland.
Deficiency of parathormone results in __________ & __________ .
Hyperphosphatemia and Hypocalcemia.
What is the chief symptom of hypoparathyroidism?
Tetany.
Explain what Tetany is.
Tetany is general muscle hypertonia, with tremor or uncoordinated contractions occurring with/without efforts to make voluntary movements.
Symptoms of latent tetany are numbness, tingling, and cramps in the extremities, and patient complains of stiffness in the hands & feet. In overt tetany, signs incl. bronchospasm, laryngeal spasm, carpopedal spasm (flexion of the elbows and wrists and extension of the carpophalangeal joints and dorsiflexion of the feet), dysphagia, photophobia, cardiac arrhythmias, and seizures.
What is the goal of treatment for hypoparathyroidism?
The goal of therapy is to increase the serum calcium level to 9 to 10 mg/dL (2.2 to 2.5 mmol/L) and to eliminate the symptoms of hypoparathyroidism and hypocalcemia.
Which medication is preferred in treating hypoparathyroidism?
Calcitriol
What is the most common cause of Cushing’s Syndrome?
The use of corticosteroid medications, but the syndrome can also be due to excessive glucocorticoid production secondary to hyperplasia of the adrenal cortex
The S&S of Cushing’s syndrome are primarily a result of over secretion of _____________ &____________ .
glucocorticoids and androgens
What are the 3 tests used to diagnose Cushing’s syndrome?
serum cortisol, urinary cortisol, and low-dose dexamethasone suppression tests - Two of these three tests need to be unequivocally abnormal to diagnose Cushing’s syndrome.
Explain how the serum cortisol test may indicate Cushing’s disorder.
Serum cortisol levels are usually higher in the early morning (6 to 8 am) and lower in the evening (4 to 6 pm). This variation is lost in patients with Cushing’s syndrome.
Explain how the urinary cortisol test may indicate Cushing’s disorder.
A urinary cortisol test requires a 24-hour urine collection. The nurse instructs the patient how to collect and store the specimen. If the results of the urinary cortisol test are three times the upper limit of the normal range and one other test is abnormal, Cushing’s syndrome can be assumed.
Explain how the overnight dexamethasone suppression may indicate Cushing’s disorder.
An overnight dexamethasone suppression test is used to diagnosis pituitary and adrenal causes of Cushing’s syndrome. It can be performed on an outpatient basis. Dexamethasone (1 or 8 mg) is given orally late in the evening or at bedtime, and a plasma cortisol level is obtained at 8 am the next morning. Suppression of cortisol to less than 5 mg/dL indicates that the hypothalamic–pituitary–adrenal axis is functioning properly.
What factors/conditions can falsely elevate cortisol levels?
Stress, obesity, depression, and medications such as anticonvulsant agents, estrogen (during pregnancy or as oral medications), and rifampin can falsely elevate cortisol levels.
What is primary Aldosteronism characterized by?
Primary Aldosteronism is characterized by excessive production of aldosterone, leading to sodium retention, potassium excretion, and hydrogen ion loss.
What are 3 causes of Aldosteronism?
Adrenal gland tumors (most common)
Ovarian tumors secreting aldosterone
Family history of hyperaldosteronism
What is the most common clinical manifestation of Primary Aldosteronism?
Hypertension (high blood pressure) – Often resistant to treatment.
How does hypokalemia present in Primary Aldosteronism?
✔ Muscle weakness, cramping, fatigue.
✔ Polyuria (excess urine output).
✔ Polydipsia (excess thirst).
What metabolic imbalance occurs in Primary Aldosteronism?
✔ Hypokalemic alkalosis → May cause: Tetany & paresthesias &
Chvostek’s & Trousseau’s signs
✔ Glucose intolerance → Due to hypokalemia interfering with insulin secretion.
What tests confirm Primary Aldosteronism?
✔ PAC/PRA (Plasma Aldosterone Concentration/Plasma Renin Activity) test.
✔ Aldosterone-Renin Ratio (ARR).
What is the preferred surgical treatment for unilateral Primary Aldosteronism?
✔ Laparoscopic adrenalectomy (less invasive, shorter recovery).
✔ Pre-op: Monitor BP & potassium.
✔ Post-op: Discontinue spironolactone & potassium supplements.
