Endocrine/Adrenal/Thyroid Disorders (Deeb) Flashcards
If adrenal insufficiency is present, what do anxiety and stress increase the risk of?
Adrenal Crisis
What should be prescribed for adrenal insufficiency patient during surgical procedures or infection?
Steroid supplementation
What sedative agent is contraindicated in patients with adrenal insufficiency or on steroid treatment for adrenal insufficiency?
No barbiturates
What is an adrenal insufficiency disease?
Addison’s disease
What is a good HbA1c?
6 and below
What is the high limit for systolic BP and treatment?
180 mmHg
What is the high limit for diastolic BP and treatment?
110 mmHg
What is the high limit for blood glucose in diabetes?
400 mg/dL
What is the low limit for blood glucose in diabetic?
80 mg/dL
What is the key every time in a medical emergency
ABC (Airway, Breathing, Circulation)
What is the rule of 2’s for long-term steroid use?
20mg for more than 2 weeks in the past 2 years
If you give an adrenal-suppressed patient steroid coverage to help the body deal with the stress of the procedure, what should be considered post-operatively?
Post-op antibiotic prophylaxis for infection as steroids are immunosuppressive
What is located in the neck near the trachea, having a butterfly shape?
Thyroid
What are 3 thyroid gland hormones?
- Thyroxine T4
- Triiodotyronine T3
- Calcitonin
What is the most abundant thyroid hormone?
Thyroxine T4 (will convert to T3 on uptake)
What is the most potent thyroid hormone?
Triiodotyronine T3
What is the backbone for both T3 and T4 thyroid?
Tyrosine
What is the key component to the tyrosine to make it T3 or T4?
Iodine
How are T3 and T4 released from the thyroid?
Hypothalamus stimulated. Releases Thyroid releasing hormone(TRH) onto anterior pituitary causing anterior pituitary to release Thyroid Stimulating Hormone (TSH) stimulating thyroid to release T3 & T4
How are T3 and T4 inhibited?
Negative feedback loop to hypothalamus and anterior pituitary
What are 3 things that will stimulate the Hypothalamus to secrete Thyroid Releasing Hormone (TRH) onto Anterior Pituitary?
- Stress
- Low temperatures
- Norepinephrine
What is an endogenous substance, beyond T3 and T4, that will inhibit the anterior pituitary from releasing Thyroid Stimulating Hormone (TSH)?
Glucocorticoids (Cortisol) from adrenal glands
What percentage of T4 and T3 is bound to blood carrier protein Thyroxine-Binding Globulin (TBG)?
99%
Where are thyroid hormones produced and stored?
Colloid-containing Thyroid follicles of thyroid gland
The thyroid hormone has to do in general with what facet of homeostasis?
Basal Metabolic Rate (BMR)
What effect does thyroid hormone have on lipid metabolism?
- Stimulates fat metabolism
2. Enhances oxidation of fatty acids
What effect does thyroid hormone have on carbohydrate metabolism?
Enhance insulin-dependent glucose uptake in cells
Increase gluconeogenesis and glycogenolysis to generate free glucose
What effect does the action of thyroid hormone have on the cardiovascular system?
- Increase heart rate
- Increase cardiac output
- Vasodilation
What is hypothyroidism associated with for reproduction?
Infertility
What are 2 thyroid disease states?
- Hypothyroid
2. Hyperthyroid
What is a hypothyroidism that is autoimmune-mediated or via inflammatory response, an example of which is Hashimoto’s thyroiditis in which antibodies are produced against the thyroid gland?
Primary/atrophic hypothyroidism
What is a hypothyroidism that can be caused by impaired hormone synthesis such as an iodine insufficiency, that can result in compensatory gland enlargement?
Goiterous hypothyroidism
Such things as hypothalamic disease, pituitary disease, or TSH (thyroid stimulating hormone) defects can lead to this type of hypothyroidism?
Insufficient stimulation of a normal gland
What type of hpothyroidism in young children results in irreversible growth disruption, mental retardation and physical characteristics of dwarfism, thick lips, protruding tongue and delayed tooth eruption?
Neonatal cretinism
What is an adult-onset hypothroidism with symptoms of fatigue, weakness, cold intolerance, hair loss, reproductive failure, weight gain, dry skin, enlarged tongue, obese, hair loss?
Myxedema
What is the easiest way to treat hypothyroidism?
Give thyroid hormone substitute = Synthroid
What is a key component of synthroid medication?
Dosing must be adjusted once the drug has evened out the thyroid to get patient onto maintenance
What is a subsequent problem with synthroid therapy for hypothyroidism?
If the patient goes through a stressful event, they will need to change dosage
What is the most common hyperthyroid disease that is a diffuse toxic goiter?
Grave’s disease
What is an autoimmune disease in which antibodies bind to and activate TSH (thyroid stimulating hormone) receptors leading to continual thyroid stimulation and secretion of T4 and T3?
Grave’s disease
How will the thyroid feel in Grave’s disease?
Firm
What are three thyrotoxicoses causing hyperthyroidism?
- Grave’s disease
- Plummer’s disease (toxic multinodular goiter)
- Toxic Adenoma
What are 6 signs of hyperthyroidism?
- Tachycardia
- Atrial fibrillation
- Goiter
- Tremor
- Opthalmopathy (exophthalmos, retracted eyelids)
- Melanin-pigmented oral mucosa
What are 5 symptoms of hyperthyroidism?
- Palpitations/Tachycardia
- Nervousness/anxiety
- Heat intolerance
- Weight loss
- Insomnia
If an elderly person has atrial fibrillation with no history of atrial fibrillation, what should be the main cause?
Subclinical hyperthyroidism
If a person has atrial fibrillation, what medication will they most likely be on?
Blood thinners
If a patient has atrial fibrillation what are they at risk for?
Hyperthyroidism
When a person tells you they have atrial fibrillation, what should be the next question?
“Are you on blood thinners?”
What is the most popular treatment for hyperthyroidism?
Remove thyroid (thyroidectomy)
What is one method to destroy the thyroid in hyperthyroid patient?
Give radioactive iodine
What hyperthyroid patient population is radioactive iodine contraindicated in and what is the alternative?
- Pregnant women
2. Give propylthiouracil or methimazole
What treatment is indicated if nature of thyroid nodule is unclear in hyperthyroid patient?
Subtotal thyroidectomy
Why can a beta blocker (Propranolol) be given to a hyperthyroid patient?
It treats the Tachycardia symptom of hyperthyroidism
What are some signs/symptoms of Thyrotoxic Crisis/Thyroid Storm?
- Goiter
- Wide pulse pressure
- Eye signs
- Nausea/vomiting
- Fever/sweating
- Tachycardia
- Arrhythmia
- Congestive Heart Failure
What is the treatment for Thyrotoxic Crisis/Thyroid Storm?
- Popylthiouracil
- Potassium iodide
- Propranolol
- Hydrocortisone/Dexamethasone
- IV Glucose
What is increased in Thyroid function test indicating hyperthyroidism?
Hormones T3 and T4
What is decreased in thyroid function test indicating hyperthyroidism?
TSH and TRH due to negative feedback inhibition from the release of T3 and T4
What is increased in thyroid function test indicating hypothyroidism?
TSH and TRH
What is decreased in thyroid function test indicating hyperthyroidism?
T3 and T4
What are 3 other tests beyond thyroid function test for testing the function of the thyroid?
- Radioactive Iodine Uptake Test (RAIU)
- Thyroid binding globulin test
- Thyroid scan
When should a hypothyroid patient receive dental treatment?
When controlled with synthroid to a euthyroid state
Should oral narcotics be prescribed to hypothyroid patient for dental treatment?
Should be limited
Would IV sedation be indicated for dental treatment of a hypothyroid patient?
No, they will have increased sensitivity
What is contraindicated for a hyperthyroid patient receiving dental treatment?
No epinephrine
When should dental treatment of a hyperthyroid patient be rendered?
Limit until controlled with Synthroid to euthyroid state
How long does propylthiouracil take to be effective for hyperthyroid treatment?
4-6 weeks
If a patient has hypocalcemia, what will they have a problem with?
Blood clotting
Do we absorb a lot of calcium or do we depend more on the Ca stores in our bones?
No much absorption. Dependent on Calcium in the body.
99% of the calcium in the body is found where?
In the bone, mostly in hydroxyapatite crystals
What are 3 hormones that regulate calcium homeostasis?
- Parathyroid hormone
- 1,25 dihydroxy Vit D3
- Calcitonin
When is parathyroid hormone released?
When there are decreased plasma calcium levels
What does parathyroid hormone do?
Increase plasma calcium level
What does parathyroid hormone do?
- Increase blood calcium by increasing bone resorption
2. Increase calcium absorption
What is required to convert Vit D to 1,25 dihydroxy Vit D3?
PTH
What is a hormone that regulates calcium and phosphorus metabolism by suppressing the resorption of bone by inhibiting osteoclast activity as well as inhibiting renal tubular resorption of Calcium and phosphorus, leading to increased rates of Calcium and phosphorus in the urine?
Calcitonin
Where does calcitonin originate?
Parafollicular Cells/C-cells in thyroid
What is a major stimulation of calcitonin secretion from Parafollicular cells of the thyroid?
Rise in plasma calcium levels
What is the calcitonin target cell?
Osteoclast. By increasing cAMP to inhibit motility and cell shape thereby inactivating them.
What is a major effect of calcitonin administration?
A rapid fall in calcium caused by inhibition of bone resorption
Primary hyperthyroidism will lead to what?
Excess PTH causing increased osteoclast activity, intestinal calcium absorption, and renal tubular reabsorption
What is the most common cause of hyperparathyroidism?
Benign tumor of parathyroid
What is the second most common cause of hyperparathyroidism?
Lung cancer
What else can cause a hypercalcemia?
- Malignancy (multiple myeloma)
- 1,25-(OH)2-D synthesis by lymphoma
- Local osteoclastic hypercalcemia
What are the symptoms of hyperparathyroidism (leading to hypercalcemia)?
- Groans
- Moans
- Bones
- Stones
- EKG changes (short QT interval or long(?) P wave)
What are some manifestations of hypocalcemia? (Dr Deeb said to know this)
- Perioral parathesia
- Generalized tetany
- Hyperactive tendon reflex
- Trousseau sign
- Chvostek’s Sign
- EKG: QT prolongation
What will be the characteristic EKG of a hyperparathyroid patient?
- Short QT interval
2. Widening T wave
What are 2 ways to decrease calcium in the blood stream?
- Diuretic to urinate out calcium
2. IV bisphoshponates to slow down bone resorption
What will the patient have and what is the sign called if the patient has carpal spasm when inflating the BP cuff above systolic BP?
Hypocalcemia = Trousseau sign
If a patient has hypocalcemia, what is the sign called when tapping of the face produces a facial spasm?
Chvostek’s sign
What is the character of the EKG in a hypocalcemic patient?
QT prolonged
Why are there spasms (Trousseau’s and Chvostek’s sign) in a hypocalcemic patient?
They lack calcium which is required for sustained muscle contraction
If the patient has more than 15-16mg/dL of calcium, what will they show and what should the dentist do?
Have acute myocardial infarction, activate ems
How is chronic hypercalcemia treated?
IV bisphoshponates
What is produced in the adrenal gland capsule?
- Mineralocorticoids (aldosterone)
2. Glucocorticoids (Cortisol)
What is produced in the Adrenal gland cortex?
Androgens (testosterone, DHEA (estrogen))
What is produced in the adrenal gland medulla?
Catecholamines (Epi, norepi)
What is the principle cell type of the adrenal medulla and its innervation?
Chromaffin cell, preganglionic sympathetic fibers
What is the amino acid precursor to the Catecholamines (Epi, Norepi, Dopamine)?
Tyrosine
What are catecholamine percentages in the adrenal medulla?
- 20% Norepi
2. 80% Epi
Epi and NE bind what receptors on their target cells?
Adrenergic receptors
What are 3 stresses that cause release of catecholamines, NE and EPI, from the adrenal medulla?
- Exercise
- Hypoglycemia
- Trauma
Epinephrine has what effect through the beta receptors on the heart muscle?
- Increased rate
2. Increased force of contraction
Norepi has what effect on blood vessels?
Widespread vasoconstriction causing increased arterial blood pressure
Norepi and Epi have what effect on bronchioles?
Dilation
Norepi and Epi have what effect on fat?
Increased lipolysis in fat cells
What does Norepi and Epi do to the metabolic rate?
- Increases
- Increased oxygen consumption
- Increased heat production throughout body
Increased heat production throughout the body is due to what Catecholamine in particular?
Epi
Will Epi/Norepi cause pupil dilation (mydriasis) or pupil constriction (miosis)?
Dilation (mydriasis)
What is the effect of Epi/Norepi on the gut?
Inhibit gastric secretions and motility
Adrenal cortex is a factory for what type of hormones and from what are they sunthesized?
- Steroid hormones
2. Synthesized from cholesterol
What is the pathway for the release of the Adrenal cortex hormones Cortisol (a glucocorticoid) and Aldosterone (a mineralcorticoid)?
Hypothalamus releases Corticotropin Releasing Hormone (CRH) onto Anterior pituitary causing release of Adrenocorticotropic Hormone (ACTH) release leading to Aldosterone and cortisol release from adrenal cortex
How is the release of Cortisol and aldosterone stopped?
Negative feedback of cortisol and aldosterone on hypothalamus and anterior pituitary
Where does aldosterone work and what 3 things does it affect?
Distal tubule of kidney to increase resorption of sodium causing resorption of water and excretion of postassium
With aldosterone acting on the distal tubule of kidney to take up sodium and thereby take up water, what should be increased systematically?
Increased blood pressure due to increased blood volume
What are 4 things that can stimulate Aldosterone secretion?
- Increase in potassium ion in extracellular fluid
- Angiotensin II release due to decreased vascular volume
- Adrenocorticotropic hormone (ACTH) release from anterior pituitary
- Sodium deficiency
What 2 things will suppress aldosterone secretion?
- High sodium concentration
2. Potassium deficiency
Can the adrenal glands be removed?
No, will cause death due to increased potassium, decreased sodium and thereby decreased water resorption, leading to less blood volume, decreased cardiac output, and eventual shock
The majority of glucocorticoid cortisol is bound or unbound in circulation?
Bound (90%)
What does Cortisol affect for Metabolism?
- Increased gluconeogenesis from amino acids to get glucose into blood
- Inhibits glucose uptake by muscles and adipose tissue
- Stimulates lipolysis in adipose cells
What effects does Cortisol have on the immune system?
- Potent anti-iinflammatory
2. Immunosuppressive
What effect does glucocorticoid have on the development of the lung?
Aides maturation and pulmonary surfactant production
Excessive glucocorticoid will have what three effects?
- Inhibit bone formation
- Suppress calcium absorption
- Delay wound healing
Excessive glucocorticoid can lead to what disease?
Secondary diabetes
What is a disease caused by excessive production of Cortisol either due to an adrenal tumor or pituitary gland tumor causing excessive secretion of ACTH, or due to excessive administration of Glucocorticoids for therapy?
Cushing’s Disease (Hyperadrenocoriticism)
What are the signs/symptoms of Cushing’s Disease?
- HTN
- Obesity
- Muscle wasting
- Thin skin
- Metabolic aberrations (diabetes)
What is a disease caused by deficiency in aldosterone either by autoimmune destruction of the adrenal cortex by an infectious disease (e.g. Tuberculosis)?
Addison’s disease (Hypoadrenocorticism)
Characteristics of Addisonian Crisis (Acute adrenal insufficiency)
- Abdominal pain
- Nausea.vomiting
- Electrolyte imbalance
- Hypotension
- Cardiac failure
If the patient is adrenally suppressed, should a dental procedure be performed with the aide of a barbiturate and why?
No. Barbiturate decreases cortisol production
If the patient has taken 20mg of steroids for 2 weeks within the last 2 years, what is indicated before dental treatment so their body will be able to deal with the stress (e.g. what must be done to give the patient a predictable Cortisol reserve)?
100mg hydrocortisone IV/IM within 2 hrs of surgery
What is indicated for a patient receiving a current steroid (Predisone) for adrenal insufficiency on the morning of an extraction or stressful dental procedure?
2 times the normal oral dose
What is indicated for a patient receiving a current steroid (Predisone) for adrenal insufficiency if post-operative pain is expected?
3 times the normal oral dose
When is antibiotic prophylaxis indicated for adrenally suppressed patient taking steroids or having taken 20mg of steroid for 2 weeks within the last 2 years?
- Maxillofacial surgical procedures
2. Extractions
What patient care should be followed for adrenally suppressed patient taking steroids or having taken 20mg of steroid for 2 weeks within the last 2 years?
- Keep well-hydrated
- Monitor BP
- Give post-operative pain control
- Check with patient 4 hrs post op
