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
Most common therapy to treat graves disease (toxic diffuse goiter)
Radioactive iodine to ablate thyroid
Purpose of methimazole or propylthiouracil in graves disease***
May be used prior to more definitive treatment like thyroidectomy or radioactive iodine, methimazole preferred unless PREGNANT OR THYROID STORM*** then propylthiouracil preferred
Toxic adenoma definition
Multiple functioning autonomous nodules of the thyroid that can cause signs of hyperthyroidism and can be diagnosed with a radioactive iodine uptake scan demonstrating hot nodules, managed definitively with radioactive iodine ablation
Suppurative thyroiditis definition
Bacterial infection of the thyroid gland, very rare and usually occurs in children and demonstrates thyroid pain and tenderness, fever, chills, pharyngitis, overlying erythema of skin, leukocytosis on labs and FNA yielding gram stain findings, managed wih antibiotics or surgical drainage
Thyroid storm management
Propranolol, propylthiouracil, IV glucocorticoids
Most common type of thyroid cancer and how is it treated?
Papillary thyroid carcinoma, treated with thyroidectomy followed by post op levothyroxine replacement
Medullary thyroid carcinoma definition
Thyroid tumor derived from calcitonin synthesizing parafollicular C cells, sees increased calcitonin and decreased blood Ca2+ level, managed with total thyroidectomy
If TSH is normal or high in a patient with a thyroid nodule, what is indicated? What if TSH is low?
FNA with biopsy, radioactive iodine uptake scan with cold nodules being biopsied to rule out malignancy
Most common presentation of type I diabetes
Hyperglycemia without acidosis (polyuria, polydypsia, polyphagia)
Second most common presentation of type I diabetes
Diabetic ketoacidosis
Greatest risk factor for type II DM
Obesity
Gold standard for diagnosing DM
Fasting plasma glucose > or = 126 blood sugar fasting at least 8 hours on 2 occasions
Normal HbA1c vs prediabetic vs diabetic
5.6 or or = 6.5
Screening for diabetes
All adults >45 years every 3 years or any adult with BMI >25 and one additional risk factor every 3 years
Name a biguanide
Metformin
Metformin side effects
- Diarrhea and GI upset
- Lactic acidosis
Sulfonyureas mechanism of action and name
Stimulate insulin release from pancreatic beta cells, Gly- or Gli-
Meglitinide mechanism of action and name
Stimulate insulin release from pacnreatic beta cells, -glinide
What blood sugar agent is safest in patients with chronic renal disease
Repaglinide (metformin is metabolized by liver and kidneys so contraindicated in severe disease of either)
Thiazolidinediones mechanism of action and name
Increase insulin sensitivity at peripheral receptor sites leading to increased glucose absorption and utilization, no impact on pancreatic beta cells, -glitazone
GLP-1 receptor agonist mechanism of action and name
Mimics incretin effect leading to increased glucose dependent insulin secretion from beta pacnreas cells, administered via injection except semaglutide (rybelsus), associated with weight loss, -tide
DPP4 inhibitors mechanism of action and name
Increase GLP-1 levels which therefore mimic incretin effect leading to increased glucose dependent insulin secretion from beta pancreas cells, -gliptin
Somogyi phenomenon definition
Nocturnal hypoglycemia followed by rebound hyperglycemia in the morning, see night sweats and nightmares and such
Dawn phenomenon
Rise in serum glucose levels between 2am and 8am requiring reduction of early morning hyperglycemia to control levels consistently
Hypoglycemia blood glucose level
<70 mg/dL
Way to differentiate between endogenous insulin overproduction causing hypoglycemia vs exogenous insulin over administration?
C peptide levels which only are elevated with endogenous insulin production
Kussmaul respirations
Deep rapid continuous respirations
Management of DKA and HHS
Saline, insulin, K+ repletion, when glucose <250 add D5 saline to prevent hypoglycemia
DKA serum glucose vs HHS
DKA is between 250-600, HHS will be greater than 600
Most common type of diabetic neurpathy
Symmetric polyneurpathy involving progressive distal sensory loss in a stocking glove pattern involving distal lower extremities first
Most common cause of end stage renal disease
Diabetic nephropathy
First sign of diabetic nephropathy
Microalbuminuria
Management of mild vs severe SIADH
Mild water restriction, severe IV hypertonic saline plus furoseminde
Rapid correction of SIADH can lead to what condition
Central pontine myelinolysis
SIADH leads to ___natremia while Diabetes insipidus leads to ___natremia
Hypo, hyper
Lab to diagnose diabetes insipidus
Fluid deprivation test, desmopressin stimulation test distinguishes central from nephrogenic
Management of central DI vs nephrogenic DI
Desmopressin DDAVP first line vs HCTZ
Management of moderate hypercalcemia (most often caused by hyperparathyroidism)
IV fluids initially, IV loop diuretics can be added to promote calcium excretion, bisphosphonates
Chvostek and trousseau’s sign indicate….
hypocalcemia
Management of severe or symptomatic hypocalcemia
IV calcium gluconate
Most common type of pituitary adenoma and what are the manifestations and what is the management
Prolactinoma, manifests in women with oligomenorrhea, amenorrhea, infertility, galactorrhea rarely, and hypogonadism in med, inferitlity, decreased libido, erectile dysfunction, dopamine agonists like cabergoline or bromocriptine, watchful waiting employed if asymptomatic, transphenoidal surgery possibly
Metabolic syndrome 3 of 5 diagnostic criteria
- Decrease HDL
- Increased blood pressure
- Elevated fasting triglyceride levels
- Elevated fasting blood sugar
- Abdominal obesity
