Endocrinology Flashcards
Most common cause of secondary adrenocortical insuffiency (pituitary failure of ACTH secretion)
Sudden exogenous glucocorticoid use cessation without a taper
Addison Disease definition
Primary chronic adrenocortical insufficiency, due to adrenal gland destruction causing lack of cortisol and aldosterone, most commonly autoimmune in origin, will see hyponatremia, hyperkalemia, appetite loss, weight loss, nausea, vomiting, hypotension, salt craving, diarrhea
What causes hyperpigmentation in addison’s disease?
Excess ACTH release trying to stimulate non responsive adrenal glands
Screening for addison disease
High dose ACTH Cosyntropin stimulation test demonstrating an insufficient or absent rise in serum cortisol in response to administration
Most common cause of addisonian crisis
Abrupt withdrawal of glucocorticoids without taperring
Cortisol levels should increase to what levels in response to stress?
3x basal limits
cushing’s syndrome definition
Signs and symptoms related to cortisol excess due to 1 of 4 main causes
1) long term high dose glucocorticoid therapy (most common cause overall)
2) cushing’s disease (most common endogenous cause, pituitary gland ACTH overproduction)
3) Ectopic ACTH producing tumor like small cell lung cancer or medullary thyroid cancer
4) Adrenal tumor
Most specific screening test for cushing’s syndrome
24 hr urinary free cortisol
Screening test to differentiate cushing’s syndrome from cushing’s disease?
Overnight Dexamethasone suppression test demonstrating suppression of cortisol defines cushing’s disease
Cushing disease definitive management
Transsphenooidal surgical resection
Primary hyperaldosteronism as a secondary cause of hypertension
Suspected in patients who develop hypertension at extremes of age (<30 or >60 year) or are not controlled on 3 blood pressure meds, may see triad of hypertension plus hypokalemia plus metabolic alkalosis (H+ ions and K+ ions being lost while retaining Na+)
Screening test for primary hyperaldosteronism
Plasma renin and aldosterone levels
Drugs to manage primary hyperaldosteronism (2)
Spirinolactone, ACE inhibitors
Most common clinical manifestation of a pheochromocytoma
Hypertension, may also see headache (most common symptom)
Lab testing for pheochromocytoma
Plasma fractionated metanephrines confirmed by 24 hour urinary fractinated catecholamines
Preop management for a pheochromocytoma
Non selective alpha blockade PHEnoxybezamine or PHEntolamine 1-2 weeks followed by B blockers or Ca2+ channel blockers to control blood pressure prior to surgery
Hypertensive crisis due to pheochromocytoma immediate management
Phentolamine, nitroprusside, or nicardipine
Definitive management of pheochromocytoma
Complete adrenalectomy after 1-2 weeks of medical pre op management
TSH receptor Ab vs anti thyroid peroxidase Ab
Speciic for graves vs specific for hashimoto’s thyroiditis
2 thyrotoxic medications
Lithium and amiodarone
Menstrual flow and thyroid disorders
Menstrual flow is decreased in hyperthyroidism (contrary to what you might think), and increased in hypothyroidism
Cretinism definition
Untreated congenital hypothyroidism, often due to lack of maternal iodine intake in developing countries or dysgensis of thyroid gland in developed countries, see mental developmental delays, symptoms of hypothyroidism, goiter symptoms, macroglossia, congenital malformations, managed with levothyroxine replacement
Subclinical hypothyroidism definition
Isolated increased TSH with normal T4/T3 in patients with few or no symptoms of hypothyroidism, managed conservatively with observation or low dose levothyroxine
Euthyroid sick syndrome definition
Abnormal thyroid funciton tests in patients with normal thyroid function, most commonly seen in severe non thyroidal illness, management focused on treating the underlying illness, thyroid hormone replacement usually not indicated
Myxedema coma management
IV thyroid hormone replacement plus supportive care and ICU admission, IV glucocorticoids often given
Manifestations of subacute thyroiditis
Viral illness followed by hyperthyroidism symptoms initial presesntation, followed by euthyroidism, followed by hypothyroidism, followed by return to baseline, painful thyroid gland aggravated with movements or swallowing (acute neck pain)
Diagnosis of subacute thyroiditis, what about the management?
High ESR with negative thyroid antibodies, managed with supportive care as self limiting
