Endocrinology (5-10%) Complete Flashcards
In a parathyroid-mediate process, serum calcium and
phosphate go in the __________ direction
In a parathyroid-mediate process, serum calcium and
phosphate go in the opposite direction
In a vitamin D-mediated process, serum calcium and phosphate go in the ____________ direction
In a vitamin D-mediated process, serum calcium and phosphate go in the same direction
When the calcium, phosphate, and PTH are all high, think of __________
When the calcium, phosphate, and PTH are all high, think of kidney (reduced ability to excrete phosphate)
e.g.
Tertiary Hyperparathyroidism (in long-standing renal failure): ↑Ca, ↑PO4
Therefore think of _________ in someone with apparent
hypoparathyroidism (or inappropriately normal PTH).
Therefore think of hypomagnesemia in someone
with apparent hypoparathyroidism (or inappropriately normal PTH).
Magnesium deficiency reduces PTH secretion and causes PTH resistance
Indications for surgery in Primary Hyperparathyroidism (PHPT)
Symptomatic PHPT = Surgery
Asymptomatic PHPT= “Stay The Fudge Away U Stupid Calcium”
AT DIAGNOSIS:
Serum total calcium > 0.25 mmol/L above upper limit
T-score <= -2.5 at L-spine, total hip, femoral neck or distal 1/3 radius
Fractures (Vertebral only; by X-ray, CT, MRI or VFA)
Age < 50
Urine calcium >6.25 mmol/d (>250mg/d) in women or >7.5 mmol/d in men (>300mg/d) NEW cutoffs in 2022
Stones or nephrocalcinosis by x-ray, ultrasound, or CT
Creatinine clearance < 60 mL/min (stage 3 CKD)
JBMR 2022
If patient NOT a candidate for surgery (e.g. per ENT, or too frail for surgery) -> Medical Mgmt*:
• Calcium intake should be consistent with nutritional guidelines (___________ mg/d)
• Correct vitamin D deficiency/insufficiency: target serum 25OH Vit D to _______ nmol/L
• __________ and __________ are effective at increasing BMD
• __________ is effective in reducing serum Ca and should be considered for symptomatic PHPT if surgery is not an option
If patient NOT a candidate for surgery (e.g. per ENT, or too frail for surgery) -> Medical Mgmt*:
• Calcium intake should be consistent with nutritional guidelines (1000-1200 mg/d)
• Correct vitamin D deficiency/insufficiency: target serum 25OH vit D to >75 nmol/L
• Bisphosphonates and denosumab are effective at increasing BMD
• Cinacalcet ($) is effective in reducing serum Ca and should be considered for symptomatic PHPT if surgery is not an option.
- May combine w Bisphosphonates or denosumab in selected pts (to reduce Ca AND increase BMD).
MUST DO A ____________before sending someone
for surgery for primary hyperparathyroidism to rule out ____________
MUST DO A URINE CALCIUM before sending someone
for surgery primary hyperparathyroidism to rule out FHH.
Postop Gastic Surgery (ex. gastric bypass/ bilroth/ whipples surgery where a portion of stomach is removed).
For treating hypocalcemia, USE __________ and Why?
use Calcium Citrate
You CANNOT use Calcium Carbonate as a supplement (there is no acidity to absorb this!)
Hypercalcemia following a renal transplant or ESRD.
Think?
Tertiary hyperparathyroidism
Treatment in tertiary hyperparathyroidism
Cinacalcet (calcimimetics) phosphate binders
MEN 1?
MEN 2A?
MEN 2B?
All are autosomal _________ ?
MEN 1
(PPP) PARATHYROID.
PITUITARY ADENOMA
PANCREATIC (insulin, VIP, gastrin)
MEN 2A
(PMP) PARATHYROID
MEDULLARY THYROID CANCER
PHEOCHROMOCYTOMA
MEN 2B
(MMP)
MARFANOID, MUCOSAL NEUROMAS
MEDULLARY THYROID CANCER
PHEOCHROMOCYTOMA
All Autosomal Dominant
Hyperthyroidism:
High radioactive iodine uptake (RAIU) (usually >25%) = increased endogenous production of thyroid hormone
Causes?
(e.g. Graves disease, toxic multinodular goiter)
Hyperthyroidism:
• Low radioactive iodine uptake = extra
thyroid hormone without increased
endogenous production
Causes?
Exogenous ingestion or inflammatory leak (e.g. acute, sub-acute, post-partum, or amiodarone-induced thyroiditis)*
RAIU may be falsely low if _________?
There is an interfering factor (e.g. recent iodine load via IV contrast or amiodarone, use of thionamide medications
A big gland (goiter) usually means ________
Think?
The thyroid is being stimulated and think about what is stimulating it
Ø TSH (Hashimoto’s)
Ø Thyroid receptor antibodies (Graves’)
Ø B-hCG (pregnancy)
A painful thyroid gland usually means _______?
A painful gland usually means the thyroid is inflamed
Ø Thyroiditis
Hyperthyroidism treatment:
Use _________ for symptomatic patients (“especially elderly, those with ________)
Use beta-blockers (e.g. propranolol) for symptomatic patients (“especially elderly, those with resting HR > 90 or CVD”)
Hyperthyroidism treatment Medical Management:
Use MMZ instead of PTU because less hepatotoxic EXCEPT in the following situations?
Use MMZ instead of PTU because less hepatotoxic EXCEPT in the following situations:
Ø First trimester of pregnancy (risk of aplasia cutis & cleft palate)
Ø Thyroid storm (PTU Is shorter acting)
Ø Minor MMZ reactions (if severe, then shouldn’t use anti-thyroid drugs at all)
Treatment in GRAVES:
• RAI
– _______ dose of ablative radioactive iodine.
– Contraindications: _______, _______, _______, _______
– Adverse effects: Worsened _______, Thyroiditis
– Delay _________ for 6 months after tx
– If giving RAI with orbitopathy, should give _______
– Should be off _______ for at least 2-3 days before radioactive iodine ablation
• Surgery
- Patient should be _______ prior to surgery
• RAI
– Single dose of ablative radioactive iodine.
– Contraindications: Pregnancy, breastfeeding, moderate-severe
orbitopathy, thyroid cancer
– Adverse effects: Worsened Orbitopathy, Thyroiditis
– Delay pregnancy for 6 months after tx
– If giving RAI with orbitopathy, should give steroids
– Should be off methimazole for at least 2-3 days before radioactive iodine ablation
• Surgery
- Patient should be euthyroid prior to surgery
Moderate to severe Graves ophthalmopathy treatment?
IV Steroids + mycophenolate is the EUGOGO first-line treatment for those with ACTIVE GO if no contraindications (ie CHF, severe hyperglycemia).
Surgery is Graves ophthalmopathy?
Surgery only offered for __________
Surgery only offered for stable INACTIVE GO (must be inactive >6 months)
Thyroid Storm?
Think of this with a very sick patient with thyrotoxicosis (tachycardia, confusion, hyperthermia)
Thyroid Storm Treatment?
Order of meds?
Thyroid Storm Treatment
• ABCs – get ICU involved early!
• Supportive care
IN THIS ORDER:
• Beta-blockers (careful with hemodynamic status!!) E.g. Propranolol 60-80mg PO q4-6h, if unsure, start at lower Propranolol dose 20-40mg po q4-6hr [the intention is to reduce adrenergic drive]
• PTU (usually 200 mg PO q4h) THEN
• Iodine: Lugol’s iodine 10 drops q8h. Should be given 1 hour after the loading dose of PTU
• Glucocorticoids (often AI co-exists, also help to reduce fT4 -> fT3 conversion)
Myxedema Coma?
Life-threatening SLOWING of function in multiple organs
Severe hypothyroidism leading to:
– Altered LOC / lethargy
– Hypothermia
– Hypotension
– Bradycardia
– Hyponatremia
– Hypoventilation
Myxedema Coma Treatment
• IV levothyroxine load 200-400mcg x1 followed by
1.6mcg/kg/d (this is the PO dose, multiple by 75% if given IV)
• IV glucocorticoids (HC 100mg IV Q8H) until AI ruled out
• IV liothyronine load 5-20mcg x1 followed by 2.5-10mcg Q8H
• Supportive measures (ICU monitoring, mechanical
ventilation, fluids, warming)
Subclinical Hypothyroidism in Already Pregnancy?
Different scenarios explain?
Levothyroxine prepregnancy – preconception guidelines?
Do not treat if TSH is less than 4 regardless of the TPO antibody titers