Hypocalcemia

Key Images

Introduction

Causes of hypocalcemia include decreased PTH that can be caused by hypoparathyrodism  pseudohypoparathyroidism  renal osteodystrophy  decreased vitamin D3

Presentation

Symptom symptoms of hypocalcemia paresthesia  fingertip, toes, perioral abdominal pain, biliary colic muscle cramps, tetany dyspnea (laryngospasm, bronchospasm) convulsions mental status changes  anxiety, fatigue, mood swings Physical exam findings of tetany Trousseau's Sign  carpopedal spasm after blood pressure readings inflate BP cuff 20mmHg above systolic BP x 3-5min hand adopts a MCP flexed, DIP and PIP extended position more sensitive than Chvostek's sign  Chvostek's Sign  facial muscle contractions after tapping on the facial nerve dermatologic  fungal nail infections hair loss blotchy skin pigment loss, vitiligo

Radiographs

Basal ganglia calcification   comprises striatum, globus pallidus, substantia nigra, subthalamic nucleus

Evaluation

Serum calcium, phosphate, vit D, PTH Serum albumin low serum albumin (low protein) leads to low total calcium but ionized calcium levels will be normal pH alkalosis increases albumin binding to ionized calcium leads to hypocalcemia EKG prolonged QT interval

Serum Ca Serum Phos PTH Common Cause Hyperparathyroidism ↑ ↓ ↑ adenoma Hypoparathyroidism ↓ ↑ ↓ parathyroidectomy Ectopic PTH ↑ ↓ ↓ malignancy Vit D malabsorption ↓ ↓ ↑ celiac disease, other GI isease Hypo vit D with no phosphate excretion from the kidney. ↓ ↑ ↑ renal failure, pseudo hypoparathyroidism

Treatment

Nonoperative calcium gluconate infusion with cardiac monitoring to prevent hypercalcemia) activated vitamin D (calcitriol)