MIssed Endocrine Qs

1. DDAVP after water deprivation can distinguish between central and nephrogenic DI. Pts. w/central DI will have ↑urine osmolality by >50% following AVP or DDAVP. Nephrogenic DI will not have such an increase.
   Tx of choice for central DI is desmopressin (usu intranasally). 1665
2. ↑ serum DHEA-S are specifically seen in pts. w/androgen-producing adrenal tumors. 1531
3. Plasma HbA1c has been added as a screening modality for DM II. Fasting plasma glucose, oral glucose tolerance test, and hyperglycemia in presence of symptoms can also be used. There is still a requirement for repeat testing since the various test may have false positives. It is recommended that repeat testing be performed using the same screening test that was initially abnormal. 1743
4. Untreated milk-alkali syndrome can lead to acute renal failure. Following fluid replacement with normal saline, furosemide should be given for rapid calciuresis. Furosemide works by inhibiting the resorption of sodium and chloride in the thick ascending limb of the loop of Henle.
5. Closed angle glaucoma presents acutely with a unilateral headache, blurry vision and a non-reactive pupil. It can be triggered by anti-cholinergic medications.
6. Primary hyperparathyroidism causes hypercalcemia through the excessive secretion of parathyroid hormone (PTH). The signs and symptoms of primary hyperparathyroidism reflect those of hypercalcemia and can be classically summarized by the mnemonic "stones, bones, abdominal groans and psychic overtones." Patients often have a history of hypophosphatemia, fatigue, peptic ulcer disease, pancreatitis, bone pain, hypercalciuria, and nephrolithiasis from calcium oxalate stones.
7. Adrenal failure presents with hyperkalemia, hyponatremia, hypoglycemia and hypotension. Tuberculosis is a possible cause in the homeless population.
8. A creatinine level above 1.5 is a contraindication for metformin.

MEN I "Wermer Syn" – parathyroid tissue, pancreatic tissue, pituitary tissue (The 3 P's).

MEN II "Sipple Syn" – parathyroid tissue, pheochromocytoma, medullary carcinoma of the thyroid.

MEN III – pheochromocytoma, medullary carcinoma of the thyroid, and oral/intestinal mucosal neuromas.

9. A glucose level above 200mg/dL is one of the Ranson criteria for poor prognosis in acute pancreatitis.

At admission:

1. age in years > 55 years
2. white blood cell count > 16000 cells/mm3
3. blood glucose > 10 mmol/L (> 200 mg/dL)
4. serum AST > 250 IU/L
5. serum LDH > 350 IU/L

At 48 hours:

1. Calcium (serum calcium < 2.0 mmol/L (< 8.0 mg/dL)
2. Hematocrit fall > 10%
3. Oxygen (hypoxemia PO2 < 60 mmHg)
4. BUN increased by 1.8 or more mmol/L (5 or more mg/dL) after IV fluid hydration
5. Base deficit (negative base excess) > 4 mEq/L
6. Sequestration of fluids > 6 L
10. The management of acute pancreatitis is conservative and consists of pancreatic rest (NPO status), IV fluids, and pain control. ERCP can worsen pancreatitis. Abdominal ultrasound may show the gallstone but it is not necessary until after she recovers from her acute illness. The most common cause of death in pancreatitis is hypovolemic shock caused by excess fluid sequestration (third spacing).
11. subacute thyroiditis, which classically presents with a tender diffusely enlarged thyroid gland for several weeks. It commonly occurs following a viral infection. Treatment is supportive with NSAIDs for pain and inflammation. FNA, ultrasound and iodine uptake are unnecessary since this case is not suspicious for cancer. Cancer would present with a painless nodular mass. If time and NSAIDs do not improve her condition an alternative diagnosis may be sought.
12. Adrenal Insufficiency ← CMV is the most likely etiology with a CD4 count between 100 and 200. If the patient’s CD4 count was between 50 and 100, her symptoms would likely be due to cryptococcus. In patients with CD4 counts of less than 50, mycobacterium avium-intracellulare (MAC) would likely be responsible.
13. Autoimmune thyroiditis (Hashimoto thyroiditis) is the most common cause of hypothyroidism in juvenile and adult females and often presents initially as asymptomatic. a/w enlarged thyroid.
14. A) Follicular carcinoma has the highest malignant potential of the thyroid cancers. It spreads hematogenously. Biopsy is needed to distinguish between a benign adenoma and carcinoma by looking for invasion through the capsule.

B) Papillary carcinoma is the most common type of thyroid cancer. It has the best prognosis and spreads through the lymph. It is associated with radiation exposure and biopsy may reveal calcified psammoma bodies.

C) Medullary carcinoma is the least common type of thyroid cancer. It is caused by neoplasm of the parafollicular cells which secrete calcitonin. It is commonly associated with MEN-2a (medullary carcinoma of the thyroid, pheochromocytoma and parathyroid adenoma). Despite the fact that calcitonin functions to lower calcium levels, patients with MEN-2a present with hypercalcemia due to elevated PTH.

D) Riedel thyroiditis is caused by the replacement of thyroid tissue with fibrosis. The gland becomes a rock-hard painless mass. It is completely benign.

E) Metastasis to the thyroid gland is rare.

15. Excessive corticosteroid administration is a common cause of hypercortisolism (Cushing's syndrome) and should be monitored in patients receiving treatment for asthma and COPD.
    Cushing’s syndrome has also been associated with ACTH-secreting pituitary adenomas, in which case you would diagnose Cushing's disease.
16. Other causes of Cushing’s syndrome are less common and include
1. ectopic ACTH production such as in small cell lung cancer
2. primary adrenal hyperplasia
3. adrenal cancer
17. The most common cause of hypercalcemia in an otherwise healthy, ambulatory patient is hyperparathyroidism.
1. Metastasis can also present as hypercalcemia but there is no reason to suspect it in this case. DCIS does not metastasize.
2. Elevated albumin could cause an increase in total calcium levels (although free calcium would be normal) but this is less likely than hyperparathyroidism.
3. Peptic ulcer disease and hypercalcemia can occur together in MEN-1 syndrome but even in this case the elevated calcium is due to excess parathyroid hormone.
18. Meconium Ileus=Cystic Fibrosis, usu deletion of three base pair encoding for phenylalanine in CFTR gene on chromosome 7.
19. Any pt w/acute, severe illness may have abn thyroid fxn tests "Euthyroid Syn" usu ↓T3 (free and total) with N T4 and TSH.
20. Hypercalcemia can occur following immobilization in pts w/preexisting high bone turnover (young children and adults, Paget's dz) d/t osteoclastic activation. Bisphosphonate therapy helps reduce hypercalcemia and prevents osteopenia.
    Acute renal failure d/t rhabdomyolysis → hypocalcemia d/t ↑binding of Ca²⁺ to phosphorus released by muscles.
    40% of circulating serum Ca²⁺ is protein bound (90% albumin) any change in albumin will affect total serum calcium levels Ø affecting ionized fraction.
21. Asymptomatic pts w/Paget's dz generally do not require any treatment. Symptomatic pts are best Tx w/IV bisphosphonates.
    Indications for Tx:
1. Bone pain
2. Hypercalcemia of immobilization
3. Neurological deficit
4. High output cardiac failure
5. Preparation for orthopedic surgery
6. Involvement of weight-bearing bones (to prevent deformities)
22. Chronic supraphysiological doses of glucocorticoids suppress CRH from the hypothalamus → central adrenal insufficiency. Aldosterone secretion is relatively preserved. (↓ACTH, ↓cortisol).
23. Most pts w/DM eventually require addition of more antidiabetic drugs to achieve optimal glycemic control. Combining antidiabetic agents w/different MOAs to achieve better glycemic control.
    Metformin is the only antidiabetic drug that → weight loss.
24. Fever and sore throat in any patient taking antithyroid drugs suggests agranulocytosis. Antithyroid drugs should be stopped and WBC count checked.
1. Routine WBC check is not recommended.
25. Acromegaly Dx: GH glucose suppression test, usu after IGF1 screening.
26. Factitious thyrotoxicosis ← ingestion of exogenous thyroid hormone. Pts present w symptoms of hyperthyroidism, but NO goiter or exophthalmos. ↓TSH and ↑T3, ↑T4, confirmed by 24 hr radioiodine uptake test(↓iodine uptake by thyroid) → follicular atrophy.
27. β-blocker overdose → AV block, bradycardia, hypotension, wheezing, cardiogenic shock.
1. Tx: Atropine, IVFs, glucagon.(↑cAMP and ↑intracellular Ca²⁺→ ↑cardiac contractility)
28. DKA Tx:
1. Restore intravascular volume w/NS
2. Correct hyperglycemia w/regular insulin
3. Correct electrolyte abn, esp K⁺
4. Treat precipitating factors (infections w/abx)
29. Majority of thyroid nodules are benign. 1st Step measure TSH.
1. ↑TSH or cold nodules
1. US
2. FNA
2. ↓TSH
1. Radioisotope scan
30. SIADH is hypotonic hyponatremia w/euvolemia.
1. ↓plasma osmolality (<280)
2. ↑urine osmolality (>100-150)
3. One of the causes of SIADH is NSAID tx - potentiate ADH action.
4. Advanced renal failure and nephrotic syn both produce hypotonic hyponatremia but usu w/hypervolemia.