Hypocalcemia

Background

• Low <8.5 (<2.0 ionized)
• Low! <6.5 (<1.5 ionized)

• Correct for hypoalbumimia
  • Corrected Ca = (0.8 * (Normal Alb - Pt's Alb)) + Serum Ca

Diagnosis

1. Paresthesias (mouth, fingertips)
2. Incr DTRs
3. Cramps
4. Weakness
5. Confusion
6. Sz
7. Chvostek/Trousseau
8. ECG
   1. QT prolongation

DDX

1. Misc
   1. Shock
   2. Sepsis
   3. Pancreatitis
   4. Hypomag
   5. Rhabdo (phosphate overload)
2. Decreased absorption
   1. Vit D def
3. Increased excretion
   1. Alcoholism
   2. Renal failure
   3. Diuretics
4. Endocrine
   1. Hypoparathyroidism
5. Drugs
   1. Cimetidine
   2. Phenytoin
   3. Lasix

Treatment

• Be careful in dig pts

1. Asymptomatic
   1. Calcium gluconate 1 gm PO Q6hrs
   2. Vitamin D (calcitriol) 0.2 mcg BID
2. Symptomatic
   1. Calcium gluconate/chloride 10mL of 10% soln IV over 10min

• Correct hypomag at same time (otherwise PTH is inhibited)

Source

2/12/06 DONALDSON (adapted from Tintinalli)