Difference between revisions of "Endocrinology"
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=Missed Concepts= | =Missed Concepts= | ||
+ | *During vitamin B12 repletion, you should monitor '''serum potassium, which can drop as new RBCs are formed.''' | ||
+ | *'''Prolactin-secreting''' pituitary adenomas, including large ones, are first treated with '''oral dopamine antagonists''', whereas other pituitary adenomas are treated with surgery if large enough. | ||
+ | *Congenital Adrenal Hyperplasia is most commonly '''21-hydroxylase deficiency''' (hypotension, low Na, high K, hypoglycemia, ambiguous genitalia in girls), but can also be '''11β-hydroxylase deficiency''' (hypertension, low K, hypoglycemia, ambiguous genitalia in girls) or '''17α-hydroxylase deficiency''' (hypertension, low K, euglycemia, ambiguous genitalia in boys). | ||
+ | *Discontinue metformin prior to surgeries with a high contrast load (e.g. cardiac cath) | ||
+ | |||
+ | =Thyroid= | ||
*Workup of thyroid nodule almost always ends with FNA, the one exception is '''a patient without suspicious US findings or cancer risk factors, a low TSH, and a hot nodule on 123-Iodine scan (toxic adenoma).''' For these patients '''go straight to treatment (Methimazole pretreatment to achieve euthyroid > RF ablation vs. surgery)''' | *Workup of thyroid nodule almost always ends with FNA, the one exception is '''a patient without suspicious US findings or cancer risk factors, a low TSH, and a hot nodule on 123-Iodine scan (toxic adenoma).''' For these patients '''go straight to treatment (Methimazole pretreatment to achieve euthyroid > RF ablation vs. surgery)''' | ||
*Hashimoto thyroiditis can be associated with other autoimmune conditions such as atrophic gastritis (pernicious anemia). | *Hashimoto thyroiditis can be associated with other autoimmune conditions such as atrophic gastritis (pernicious anemia). | ||
− | |||
− | |||
*Total T3 and T4 in pregnancy can be 1.5x normal range and still be physiologic. TSH is suppressed. '''There is no role for measuring free T4 in pregnancy''' | *Total T3 and T4 in pregnancy can be 1.5x normal range and still be physiologic. TSH is suppressed. '''There is no role for measuring free T4 in pregnancy''' | ||
+ | *Amiodarone decreases peripheral conversion of T4 to T3, but generally this self resolves in 6-9 months after treatment initiation. Amiodarone has a half-life of 100 days. | ||
+ | *Low T4 and low TSH suggests central hypothyroidism. Measure ACTH levels and get an ACTH stim test as well as AM serum cortisol. | ||
+ | |||
+ | =Glucose Homeostasis= | ||
+ | *One complication of SGLT2 inhibitors is '''euglycemic DKA with BG < 250, but still with an elevated AG and low pH.''' | ||
*Hyperglycemia and catabolic symptoms (weight loss, urinary frequency) are indications for insulin. | *Hyperglycemia and catabolic symptoms (weight loss, urinary frequency) are indications for insulin. | ||
− | * | + | *Young, normal weight patient, without family history of diabetes presents with symptomatic DKA? '''T1DM''' |
− | + | ||
− | =Hyponatremia= | + | =Electrolyte Imbalanaces= |
− | *Moderate to severe hypothyroidism can cause cause mild euvolemic hyponatremia. | + | {| class="wikitable" |
+ | |+ Symptoms of Electrolyte Disturbances | ||
+ | |- | ||
+ | ! Electrolyte !! High !! Low | ||
+ | |- | ||
+ | | Sodium || Example || Example | ||
+ | |- | ||
+ | | Potassium || Nausea, vomiting, ECG changes, asystole || Example | ||
+ | |- | ||
+ | | Calcium || Example || Usually asymptomatic, but can cause increased DTRs, muscle cramps, convulsions | ||
+ | |- | ||
+ | | Magnesium || Low-absent DTRs, flaccid paralysis, apnea || Example | ||
+ | |- | ||
+ | | Phosphorus || Example || Example | ||
+ | |} | ||
+ | |||
+ | ==Hyponatremia== | ||
+ | *Dx: Correct for Glucose. '''Moderate to severe hypothyroidism''' can cause cause mild euvolemic hyponatremia. | ||
− | =Hypercalcemia= | + | ==Hypercalcemia== |
*H&P: | *H&P: | ||
*Dx: Best initial test is '''PTH''' | *Dx: Best initial test is '''PTH''' | ||
*Tx: | *Tx: | ||
+ | |||
+ | ==Hypocalcemia== | ||
+ | *Dx: correct for albumin (Ca + 0.8*[4 - albumin]) |
Latest revision as of 16:31, 16 January 2023
Missed Concepts
- During vitamin B12 repletion, you should monitor serum potassium, which can drop as new RBCs are formed.
- Prolactin-secreting pituitary adenomas, including large ones, are first treated with oral dopamine antagonists, whereas other pituitary adenomas are treated with surgery if large enough.
- Congenital Adrenal Hyperplasia is most commonly 21-hydroxylase deficiency (hypotension, low Na, high K, hypoglycemia, ambiguous genitalia in girls), but can also be 11β-hydroxylase deficiency (hypertension, low K, hypoglycemia, ambiguous genitalia in girls) or 17α-hydroxylase deficiency (hypertension, low K, euglycemia, ambiguous genitalia in boys).
- Discontinue metformin prior to surgeries with a high contrast load (e.g. cardiac cath)
Thyroid
- Workup of thyroid nodule almost always ends with FNA, the one exception is a patient without suspicious US findings or cancer risk factors, a low TSH, and a hot nodule on 123-Iodine scan (toxic adenoma). For these patients go straight to treatment (Methimazole pretreatment to achieve euthyroid > RF ablation vs. surgery)
- Hashimoto thyroiditis can be associated with other autoimmune conditions such as atrophic gastritis (pernicious anemia).
- Total T3 and T4 in pregnancy can be 1.5x normal range and still be physiologic. TSH is suppressed. There is no role for measuring free T4 in pregnancy
- Amiodarone decreases peripheral conversion of T4 to T3, but generally this self resolves in 6-9 months after treatment initiation. Amiodarone has a half-life of 100 days.
- Low T4 and low TSH suggests central hypothyroidism. Measure ACTH levels and get an ACTH stim test as well as AM serum cortisol.
Glucose Homeostasis
- One complication of SGLT2 inhibitors is euglycemic DKA with BG < 250, but still with an elevated AG and low pH.
- Hyperglycemia and catabolic symptoms (weight loss, urinary frequency) are indications for insulin.
- Young, normal weight patient, without family history of diabetes presents with symptomatic DKA? T1DM
Electrolyte Imbalanaces
Electrolyte | High | Low |
---|---|---|
Sodium | Example | Example |
Potassium | Nausea, vomiting, ECG changes, asystole | Example |
Calcium | Example | Usually asymptomatic, but can cause increased DTRs, muscle cramps, convulsions |
Magnesium | Low-absent DTRs, flaccid paralysis, apnea | Example |
Phosphorus | Example | Example |
Hyponatremia
- Dx: Correct for Glucose. Moderate to severe hypothyroidism can cause cause mild euvolemic hyponatremia.
Hypercalcemia
- H&P:
- Dx: Best initial test is PTH
- Tx:
Hypocalcemia
- Dx: correct for albumin (Ca + 0.8*[4 - albumin])