Hypercalcemia: Tweetorial
Calcium regulated to levels between 9-10.5 mg/dL
↑PTH = ↑calcium
↑Calcitonin = ↓calcium
PTH produced by the chief cells in parathyroid glands Calcitonin produced by thyroid parafollicular cells
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Calcium regulated to levels between 9-10.5 mg/dL
↑PTH = ↑calcium
↑Calcitonin = ↓calcium
PTH produced by the chief cells in parathyroid glands Calcitonin produced by thyroid parafollicular cells
End MOC sign the petition!
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PTH = ⬆️Ca⬇️Phos
↑renal reabsorption Ca in distal tubule
↑urinary Phos excretion
↑release Ca from bones Binds osteoblasts
↑ RANKL -> activates osteoclasts
↑25-OH D3 1-α hydroxylase -> vit D to active form (1,25-dihydroxy) Active vit D ↑absorption of intestinal Ca
↑renal reabsorption Ca in distal tubule
↑urinary Phos excretion
↑release Ca from bones Binds osteoblasts
↑ RANKL -> activates osteoclasts
↑25-OH D3 1-α hydroxylase -> vit D to active form (1,25-dihydroxy) Active vit D ↑absorption of intestinal Ca
Causes of Hypercalcemia
Primary hyperparathyroidism
Malignancy (3 mechanisms):
Osteolytic mets
PTHrP (squamous cell lung cancer)
↑production of active vitamin D (NHL)
Meds:
Lithium
Thiazides diuretics
Thyrotoxicosis
Milk alkali syndrome
Familial hypocalciuric hypercalcemia
Primary hyperparathyroidism
Malignancy (3 mechanisms):
Osteolytic mets
PTHrP (squamous cell lung cancer)
↑production of active vitamin D (NHL)
Meds:
Lithium
Thiazides diuretics
Thyrotoxicosis
Milk alkali syndrome
Familial hypocalciuric hypercalcemia
Clinical Manifestations
"stones, bones, abdominal groans, thrones and psychiatric overtones"
Renal:
Polyuria
Polydipsia
GI:
Anorexia
N/V
Pancreatitis
MSK:
Weakness
Bone pain
Neurologic:
Confusion
Stupor/coma
Cardiovascular:
Shortened QT
Bradycardia
Hypertension
"stones, bones, abdominal groans, thrones and psychiatric overtones"
Renal:
Polyuria
Polydipsia
GI:
Anorexia
N/V
Pancreatitis
MSK:
Weakness
Bone pain
Neurologic:
Confusion
Stupor/coma
Cardiovascular:
Shortened QT
Bradycardia
Hypertension
Check ionized Calcium to make sure calcium is truly elevated!
Changes in albumin will affect total serum calcium without changing the level of free calcium.
[decreased albumin --> decreased total Ca--> constant free Ca]
Corrected Ca = [Measured Ca] + 0.8 x [4.0-Albumin]
Changes in albumin will affect total serum calcium without changing the level of free calcium.
[decreased albumin --> decreased total Ca--> constant free Ca]
Corrected Ca = [Measured Ca] + 0.8 x [4.0-Albumin]
Diagnostic workup
First check PTH
If ⬆️ PTH
Measure urine 24 hour calcium
If ⬇️24 hr urine Ca->Familial hypocalciuric hypercalcemia
If ⬆️ 24 hr urine Ca perform parathyroid scan (Sestamibi)
Likely primary hyperparathyroidism
If ⬇️PTH Check meds Start worrying about cancer!
First check PTH
If ⬆️ PTH
Measure urine 24 hour calcium
If ⬇️24 hr urine Ca->Familial hypocalciuric hypercalcemia
If ⬆️ 24 hr urine Ca perform parathyroid scan (Sestamibi)
Likely primary hyperparathyroidism
If ⬇️PTH Check meds Start worrying about cancer!
Treatment of Hypercalcemic crisis
Replace IV fluids first!
At least 20-30 ml/kg (2L) IV NS
Avoid lasix unless volume overload!
Bisphosphonate
Zoledronic acid 4 mg IV over 15 minutes
Caution with kidney failure
Calcitonin SC
Tachyphylaxis occurs (stops working after few doses)
Replace IV fluids first!
At least 20-30 ml/kg (2L) IV NS
Avoid lasix unless volume overload!
Bisphosphonate
Zoledronic acid 4 mg IV over 15 minutes
Caution with kidney failure
Calcitonin SC
Tachyphylaxis occurs (stops working after few doses)
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