Endocrine #1 Flashcards
Chronic Adrenocortical Insufficiency is due to _________
Pituitary failure of ACTH secretion
Causes of adrenocortical insufficiency
-History of exogenous glucocorticoid use
Symptoms of Primary Adrenocortical Insuffiency (Addison’s Disease)
-Due to lack of sex hormone and aldosterone
- Hyperpigmentation, orthostatic hypotension
- Amenorrhea, loss of libido, loss of pubic/axillary hair
Baseline labs for adrenocortical insufficiency
- Elevated ACTH (Primary), Decreased ACTH (Secondary)
- Hypoglycemia
- Hyperkalemia
Explain the high-dose ACTH Cosyntropin Stimulation Test
Adrenal insufficiency if insufficient or absent rise in serum cortisol (< 18) after ACTH administration
Treatment for adrenocortical insufficiency
- Glucocorticoid Replacement: Hydrocortisone
- Mineralocorticoid Replacement: Fludricortisone (In Addison’s, may be added)
Treatment for Addison’s Disease
- Isotonic fluids (normal saline or D5N5) + IV Hydrocortisone or Dexamethasone
- Fludricortisone to reverse electrolyte disorders
What is Cushing’s Syndrome?
Signs and symptoms related to Cortisol excess
4 main causes of Cushing’s
- Long-term high-dose glucocorticoid therapy (MC)
- Pituitary gland ACTH overproduction (MC endogenous cause)
- Ectopic ACTH-producing tumor (small cell lung cancer)
- Adrenal Tumor/Adenoma
Symptoms of Cushing’s
- Weight gain, obesity
- Moon facies
- Buffalo Hump
- Supraclavicular Fat Pads
- Thin Extremities
- Striae
- Acanthosis Nigricans
- Hypertension
- Hirsuitism oily skin
Screening tests for Cushing’s
- 24 hour urinary free cortisol (most specific)
- Nighttime salivary cortisol
- Low-dose overnight Dexamethasone suppression test
What is the test that helps differentiate Cushing’s from other causes of cortisol excess?
- Baseline ACTH + Dexamethasone suppression test
- –Increased ACTH + suppression of cortisol on high dose = Cushing’s
Treatment of Cushing’s Disease
- Corticosteroid use: Gradual taper
- Transsphenoidal Resection
Primary hyperaldosteronism is a cause of _______
Secondary hypertension
Triad of symptoms for primary hyperaldosteronism
-Hypertension, Metabolic Alkalosis, Hypokalemia
Labs for hyperaldosteronism
- Plasma renin and aldosterone levels: aldosterone to renin ratio: ARR > 20:1
- Hypokalemia
- Metabolic Alkalosis
What is a confirmatory test for primary hyperaldosteronism?
oral sodium loading test: high urine aldosterone
what are some symptoms of hypokalemia?
Proximal muscle weakness, polyuria, fatigue, constipation, decreased DTRs
Treatment for primary aldosteronism
-Spironolactone, ACE inhibitors
A Pheochromocytoma is a ______ secreting tumor
Catecholamine
Pathophysiology of a Pheochromocytoma
-Secretes norepinephrine, epinephrine, and dopamine autonomously and intermittently
Symptoms of a Pheochromocytoma
-Hypertension
PHE
- Palpitations
- Headache
- Excessive Sweating
Confirmatory test for Pheochromocytoma
-24 hour urinary fractionated catecholamines including metabolites (increased metanephrines and vanillylmandelic acid)
Treatment for Pheochromocytoma
- Nonselective alpha blockade: Phenoxybenzamine or Phentolamine 1-2 weeks followed by BB
- Complete adrenalectomy after 1-2 weeks of medications
Regarding Levothyroxine for Hypothyroidism, what are the rules if TSH is low or TSH is high?
TSH Low: decrease dose of Levothyroxine
TSH high: increase dose of Levothyroxine
When using Levothyroxine, when should labs be taken?
- Monitor TSH levels at 6-week intervals, when initiating or changing the dose
- During pregnancy, the dose needs to be increased
Overshoot of Levothyroxine can cause two things. Name them.
- Cardiovascular effects
- Osteoporosis
MCC of hypothyroidism in the US in women 30-50
Hashimoto Thyroiditis
Exam findings of Hashimoto Thyroiditis
- Bradycardia
- Loss of outer 1/3 of eyebrows
- Myxedema (non pitting edema)
- Fatigue, cold intolerance, dry thickened skin, weight gain, menorrhagia, weakness, lethargy
Diagnostics for Hashimoto Thyroiditis
- Increased TSH and Decreased free T4 and T3
- Positive Antithyroid Peroxidase and/or anti-thyroglobulin antibodies
- Radioactive iodine scan: diffuse decreased iodine uptake
- Biopsy: rarely done, Hurthle cells, lymphocytic infiltration
Treatment for Hashimoto Thyroiditis
Levothyroxine
Myxedema Coma is MC seen in
Elderly women with long standing hypothyroidism during the winter
Subacute Thyroiditis often follows
Antecedent Viral respiratory tract infection or post-viral inflammation
Symptoms of Subacute Thyroiditis
- Hyperthyroidism
- Painful thyroid gland aggravated with head movements and swallowing
- URI symptoms
Diagnostics for Subacute Thyroiditis
- High ESR + negative thyroid antibodies
- Hyperthyroid profile early in the disease
- Biopsy: multinucleate giant cells
Treatment for Subacute Thyroiditis
- Supportive
- NSAIDs or Aspirin for pain and inflammation
MCC of hyperthyroidism in the US
-Graves Disease
Pathophysiology of Graves Disease
-Autoimmune disease: TSH receptor autoantibodies target and stimulate the TSH receptor
Symptoms of Graves Disease
- Atrial Fibrillation, heat intolerance, tremors, palpitations, weight loss
- Ophthalmopathy: proptosis, exophthalmos, lid lag
- Pretibial Myxedema: Swollen red patches on leg with non-pitting edema
- Thyroid Bruit
Diagnostics for Graves Disease
- Primary hyperthyroid profile: decreased TSH and high T3 or T4
- Positive Thyroid-stimulating immunoglobulins (TSH receptor antibodies)
Treatment for Graves Disease
- Radioactive iodine
- Methimazole or PTU
- BB for palpitations
- Glucocorticoids for eye symptoms
For a TSH-secreting pituitary adenoma, what are the symptoms
- Diffuse goiter
- Signs of hyperthyroidism
- Bitemporal Hemianopsia: compression of optic chiasm
- Headache
- Mental disturbances
Diagnostics for TSH Secreting Adenoma
- Secondary Hyperthyroidism Profile: High TSH and High T3/T4
- Diffuse increased uptake with radioactive iodine
- Pituitary MRI to detect adenoma
treatment for TSH secreting pituitary adenoma
-Transsphenoidal surgery
What is a Thyrotoxic Crisis (Thyroid Storm)
-Potentially fatal thyrotoxicosis usually after a precipitating event (surgery, trauma, infection, pregnancy)
Symptoms of Thyroid Storm
- Hyperthyroid Symptoms
- Cardiovascular Dysfunction (palpitations, A-fib, tachycardia, CHF)
- High fever
- Tremors
- CNS dysfunction (agitation, delirium, stupor, coma)
Treatment for Thyroid Storm
- IVF + Propanolol + Antithyroid Medication (PTU) + Glucocorticoids
- Then, oral or IV sodium iodide
- Avoid Aspirin
MC type of thyroid cancer
-Papillary thyroid carcinoma
What diagnostic is done for papillary thyroid cancer?
-Fine Needle Aspiration
Treatment for papillary thyroid cancer
-Thyroidectomy followed by post-op Levothyroxine
Papillary Thyroid Cancer is MC after
Radiation exposure of the neck
