29. Hypocalcemia Flashcards
(12 cards)
What is hypocalcemia?
Hypocalcemia is a condition characterized by low levels of calcium in the blood.
What are the clinical manifestations of hypocalcemia?
- Cardiac arrhythmias
- Rickets and osteomalacia
- Increased neuromuscular irritability
- Basal ganglia calcifications
- Prolonged QT interval on ECG
- Cataracts
What are the symptoms of increased neuromuscular irritability due to hypocalcemia?
a) Numbness/tingling in mouth, fingers, and toes.
b) Tetany: Muscle spasms and cramps with hyperactive reflexes, Chvostek sign, and Trousseau sign.
What is the Chvostek sign?
Facial twitching that occurs when tapping on the facial nerve.
What is the Trousseau sign?
Carpal spasms that occur with cuff inflation above systolic pressure for 3 minutes.
What are the causes of hypocalcemia?
- Absent Parathyroid Hormone (PTH)
- Ineffective PTH
- Overwhelmed PTH
What is transient hypocalcemia?
Occurs in critically ill patients with burns, sepsis, acute renal failure, after transfusion with citrated blood, or due to medications like protamine and heparin.
How is hypocalcemia diagnosed?
Blood tests show low serum calcium and low ionized calcium. Check PTH, magnesium, and vitamin D levels. ECG may show prolonged QT interval.
What is the treatment for severe hypocalcemia?
IV calcium gluconate: Bolus 1–2 g IV over 10–20 min, followed by infusion of 10 amp. 10% calcium gluconate diluted in 1L D5W at 100 mL/h.
What is the treatment for mild to moderate hypocalcemia?
Oral calcium (1–3 g/d) and vitamin D supplementation (calcitriol) at a dose of 0.25–1 μg/d.
What should be monitored when treating hypocalcemia?
Aim for serum calcium of 8.0 to 8.5 mg/dL. Vitamin D and calcium supplements may raise urinary calcium, increasing kidney stone risk.
What is the role of magnesium supplementation in hypocalcemia?
Magnesium supplementation is indicated if hypomagnesemia is present.
