Endocrine Prt 1

Adrenal Glands Make Up

Capsule (Outer)
Cortex (Middle)
Medulla (Inner)

Hormones from Adrenal Cortex

Glucocorticoids
Mineralocorticoids
Androgens

What does the Glucocorticoids produce?

Hydrocortisol (cortisol)
Corticosterone

Hydrocortisol (Cortisol)

Breaks down fats, proteins, and carbs for energy (helps in homeostasis)

Corticosterone

Related to the immune response and suppression of inflammation

What does the Mineralcorticoids produce

Aldosterone

Aldosterone

Stimulated by renin-angiotensin system
Acts on kidneys to conserve water and sodium to increase BP

Renin-angiotensin system

Drop in BP or volume stimulates → angiotensin to be released from the liver which stimulates → renin to be released from the kidney (adrenal cortex)

What does the Androgens (male sex hormone) produce

Testosterone

Hormone from Hypothalamus

CRH: Cortico-Releasing Hormone
Triggered by stress
Stimulates the ACTH

Hormone from Anterior pituitary gland (from handout)

ACTH: Adrenocorticotropic hormone
Stimulates the adrenal glands to produce cortisol

Hormones from Adrenal Medulla

Catecholamines

What does Catecholamines produce

Epinephrine
Norepinephrine

Epinephrine

Increases HR, rushes blood to brain and muscles
Converts glycogen to glucose in liver for quick energy (works on alpha and beta receptors)

Norepinephrine

Same functions as Epinephrine, but causes vasoconstriction too
(Only works on the alpha receptors)

What is Epinephrine stimulated by from the sympathetic nervous system

Stress
Surprise
Emergency
Perceived harm

Where are the Alpha receptors located

Only in the Arteries

Where are the Beta receptors located

In the heart, lungs, and arteries of the skeletal muscles

ATCH Stimulation Test

Used to diagnose adrenal insufficiency (Addison’s disease).
Also used to determine if the pituitary gland is not working properly due to hypopituitarism

ATCH Suppression Test

To see if ATCH can be suppressed or not
During test, pt is given dexamethasone (synthetic glucocorticoid medicine, then a cortisol is drawn

Cortisol Test

Blood drawn test done twice in same day (one in morning, second in afternoon or 4 pm)
Reason why is because cortisol levels change a lot throughout the day

Late Night Salivary Cortisol Test

One of the most sensitive diagnostic tests for Cushing’s syndrome
Elevated cortisol levels between 11 PM and Midnight are earliest signs of the disorder

17 ketosteroids Urine Test

17 ketosteroids are substances formed when the body breaks down androgens (male steroid sex hormones) and other hormones released by the adrenal gland (from men and women) and testes (from males)

A clean catch urine sample is performed by collecting the urine in midstream

MIBG scan

A nuclear medicine scan that uses iodine-123 meta-idoboenzylguanidine (MIBG)

Used to detect neuroendocrine tumors, such as neuroblastoma and phaeochromocytoma. Also helps detect for carcinoid and medullary thyroid carcinoma

Growth Hormone Test

Measures the body’s ability to produce GH
Blood is drawn several times, and the samples are taken through an IV line instead of reinserting a needle each time. Takes between 2 and 5 hours

Human Growth Hormone (hGH)

A peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. Important in human development

Human Growth Hormone Test

A blood test used to measure the amount of Human Growth Hormone in a patient

Somatomedin C

A insulin-like growth factor-1 or IGF-1 produced by the liver, following the GH production from pituitary gland

Somatomedin C function

Somatomedins can belong to any of several endogenous (made by the body) peptides produced especially in the liver that are dependent on and likely mediate growth hormone activity.

Water Deprivation Test

A test used as an aid in diagnosing polyureic disorders. Used for pts with diabetes insipidus (DI), due to either hypothalamic (HDI) or nephrogenic disease (NDI), cannot conserve free water.

Why use a Water deprivation test?

When these patients are deprived of water for extended periods, they will lose weight due to dehydration to a greater extent than healthy controls. This water loss is accompanied by hypernatremia and an increase in plasma osmolality.

How do normal/polydipsia patients do on the water deprivation test?

Normal people and patients w/ psychogenic polydipsia won’t lose >3% of their body weight during the water deprivation test and will maintain serum sodium and osmolality levels within normal limits

How do patients with DI do on the water deprivation test?

The urine osmolality of patients with DI remains low, often less than that of plasma whereas subjects that do not have DI will produce concentrated urine (osmolality typically between 300 and 400 mOsm/kg).

How do some patients w/psychogenic polydipsia do on the water deprivation test?

They fail to produce concentrated urine unless the deprivation is prolonged

How do people with NDI or HDI do on the water deprivation test?

Show high ADH levels as the plasma osmolality exceeds 300 mOsm/kg while patients with HDI have low or normal levels.

How/Why is ADH administered in the second phase of the Water deprivation test?

Used to find the cause of diabetes insipidus

ADH administrations in pts w/ HDI will increase urine osmolality >10% and will fail to produce this level of concentration in pts w/ NDI 1

Protocol phase 1 (10 PM)

Test done at 10 PM at which the test serum and urine specimen are collected for determination of sodium and osmolatility. Patients should also be weighted and prevent any oral intake till test is done

Protocol phase 1 (6 AM)

Patient is weighed again and urine collected hourly for volume measurement and determination of osmolality

Once urine osmolality is stable (changing to < 30 mOsm/kg for 2 hrs), specimens are collected for serum sodium, osmolality, and ADH levels

Protocol Phase 2

Five units of aqueous vasopressin (ADH) is given subcutaneously, and urine osmolality is measured one hour later.

The test can then be terminated

Thyroid Test: STATS

More than 12% of Americans will develop some form of thyroid condition in their lifetime, and more than 20 million are currently living with some variation of thyroid disease

Radioactive Iodine Uptake Test

Patient is given a pill/liquid containing radioactive iodine with retest in 6 and 24 hr intervals. Technician will place a gamma probe over thyroid gland, and it measures how much radioactive iodine is absorbed

Patient will later excrete the radioactive iodine in their urine for 24 to 48 hrs afterward. Small amount of iodine is used and no special precautions are needed

Thyroid Antibodies (TA)

A test that usually measures one or more of the following types of antibodies: Thyroid peroxidase antibodies (TPO) which can be a sign of Hashimoto’s thyroiditis.

Thyroid Scan

Client drinks/swallows a pill that contains iodine. It’s absorbed by the thyroid after 4 hrs.

A scintigraphy camera is used to take pictures that determine the amount of iodine absorbed using gamma rays emitted by the radioactive iodine

Thyroid Suppression Test

Can be tested with a single dose of L-Thyroxine

Three milligrams of thyroxine is administered orally after a baseline of 24-hr radioactive iodine uptake test

24 hr uptake 7 days later may be taken as a post suppression value

Triiodothyronine resin uptake (T3RU) test

Measures blood T4 (thyroxine) levels

Lab analysis of the test takes several days, and it’s used less often than other tests that get results quicker

Long Acting Thyroid Stimulator (LATS)

A test that shows whether blood contains long-acting thyroid stimulator

What do you always check for?

Kidney function!

Why do we check for kidney function

Because the tests can detect and influence functions.

Also used to assess the endocrine system and detect any issues before symptoms can occur

Acromegaly

Too much GH

When epiphyseal plate (in the bone) is not closed and there is an influx of GH, growth will occur

Acromegaly Presentation

Bone and soft tissue deformities

Enlargement of viscera

Increase in height

Gigantism

Acromegaly Assessment

IGF-1 measurement

Growth hormone suppression test

Imaging tests

Acromegaly Treatment

Surgery

Medication

Radiotherapy

Diabeteus Insipidus (DI)

Too little ADH

Kidneys lost too much water (dry inside!)

High sodium levels

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

Too much ADH

Kidneys retained too much water (soaked inside!)

Low sodium levels

Corticosteroids

Medication used to reduce inflammation and suppress the immune system

What can hypothyroidism lead to?

- Hashimoto's
- Myxedema coma

Hashimoto

- From hypothyroidism
- Autoimmune
- Most common cause

Myxedma coma

- Worst case of Hypothyroidism
- Rare life-threatening condition
- Leads to stupor, coma and death
- High mortality rate

What might myxedema coma pt be sensitive to?

Extremely sensitive to opioids which can keep the problem

What can hyperthyroidism lead to?

- Graves disease
- Thyroid storm

Graves disease

- Autoimmune
- Excessive output of thyroid hormone (hyperthyroidism)

Thyroid storm

Worst case of hyperthyroidism
- Develops abruptly and affects all systems of the body
- As soon as thyroid storm is suspected (usually even before lab results are ready) then you need to make sure you know what the tx is going to be

Cardiac sign of thyroid storm and what to do

- HR >130
- Treatment (meds): Propranolol & digoxin
- Nursing Considerations: Pulse ox, humidified O2, ABG's

Fever sign of thyroid storm and what to do

- >101.3 F
- Nursing considerations: Hypothermia blanket, cool environment
- Treatment: Hydrocortisone, acetaminophen

Neuro sign of thyroid storm and what to do

- Symptoms: Delirium, psychosis (hallucination), coma
- Treatment: IV fluids (D5 bc they need glucose), Propylthyroid uracil (PTU)
- Meds: Hydrocortisone, iodine

Thyroid storm Risk factors

- Stress
- Injury
- Dig toxicity
- Infection
- Diabetic ketoacidosis (DKA)
- Insulin reaction
- Surgery
- Pregnancy

Meds that are risk factor for hypothyroidism

- Hyperthyroid meds
- Amiodarone
- Lithium
- Thaldomides
- Oncology meds

Med for Hypothyroidism

Synthetic levothyroxine-replacement therapy (synthroid)

Synthetic levothyroxine (Synthroid)

- Replacement therapy of thyroid hormone (not to cure just manage)
- Potential med interactions
- PO or IV

Contraindications with taking Synthetic levothyroxine (synthroid)

- Hyperthyroidism
- Untreated adrenal insufficiency
- Untreated cardiac arrhythmia
- MI/Inflammatory cardiac process

Client education with taking Synthetic levothyroxine (Synthroid)

Monitor for side effects (HA, vomiting, diarrhea, appetite changes, leg cramps, palpitations, sweating, etc.)

Pt education with taking Synthetic levothyroxine (synthroid)

- Continue meds even if symptoms resolve
- LIFELONG therapy
- 1/day at same time in the morning
- 30 mins before breakfast (empty stomach)
- Prego safe
- May take 8 weeks for full effect

What may increase with taking Synthetic levothyroxine (synthroid)?

- Blood glucose
- Oral antidiabetics
- Digitalis
- Anticoagulants
- Indocin
- Dilantin
- Antidepressants

Post Thyroidectomy Care

• Always check for bleeding

• Have the patient in semi-flower position

• Treat for emergent hypocalcemia (low calcium)

• Monitor for S/S of hypocalcemia

• Monitor for Chvostek/Trousseau

What does parathormone (parathyroid hormone) do?

It senses when there’s low Ca or phosphorus in the blood and supplies if needed

Calcium/phosphorus inverse relationship

- If Ca is low, the parathormone from the parathyroid gland pulls Ca from the bones and other parts of the body to get it into the blood.
- If the parathyroid gland is injured, the calcium balance could be offset

Hypocalcemia is a medical emergency so what should we do?

Its a medical emergency so know where the IV calcium gluconate is bc that's going to be IV not PO and report immediately

S/S of hypocalcemia

- <9 mEq/L
- Dysrhythmias
- Chvostek sign
- Trousseau sign
- Seizures
- Muscle spasms
- Circumoral numbness
- Increased DTRs
- Tetany (spasms)

Chvostek signs

Abnormal spasm of the facial muscles triggered by light taps on the facial nerve

Trousseau signs

- Carpopedal spasm induced by pressure applied to the arm
- Wrist and thumb are flexed

Parathyroid gland purpose

Regulate the calcium levels in the blood

Hormones in the anterior pituitary gland (ones tested in this class)

- Growth hormone (GH) aka somatotropin

- Thyroid-stimulating hormone (TSH)

- Adrenocorticotropic hormone (ACTH)

What is Growth hormone (GH) also known as?

Somatotropin

Thyroid-stimulating hormone (TSH)

Controls release of thyroid hormone

Parathyroid gland

We have 4 dots in the back of the thyroid (parathyroid gland) and their role is to balance Ca and phosphorus

Adrenocorticotropic hormone (ACTH)

Stimulates secretion from adrenal glands (cortex or medulla)

Hormones in the posterior pituitary gland

- Vasopressin (aka antidiuretic hormone "ADH")
- Oxytocin

What is vasopressin also known as?

Antidiuretic hormone "ADH"

Vasopressin (ADH) Purpose

- Maintains water balance
- Regulated by need
- Increased at night (to not pee)
- Decreases urine production & sweat
- Increases BP

What is essential with Thyroid-stimulating hormone (TSH)?

Iodine (salt)

What proper thyroid hormones?

T3 & T4 (they're powerhouses)

Adrenocorticotropic hormone (ACTH) pathway

1. Hypothalamus releases corticotropin-releasing hormone (CRH) to anterior pituitary
2. Anterior pituitary releases ACTH
3. Message goes to the adrenal gland (cortex or medulla)

Vasopressin (ADH) actions

- Low BP (dehydrated) → ADH released
- High BP (over hydrated) → ADH inhibited

Feedback system of the pituitary gland

When the level of thyroid hormone of the bloodstream determines that it’s not needed anymore, then a message is sent to the hypothalamus to stop production

Is the feedback system only triggered when there’s an overreaction?

It’s not always when there’s an overreaction (either not enough or too much) it’s not always going to be the hypothalamus that's not releasing TRH.

It might be the anterior pituitary that's not releasing thyroid stimulating hormone or it could be the thyroid itself so that's why the various test that we do will isolate which problem it might be so we can have proper tx

Pathway of a functioning thyroid

1. TRH is released from the hypothalamus
2. Goes to the anterior pituitary
3. TSH is released
4. TSH goes to the thyroid gland
5. T3 & T4 is released