DR Medhat MRCP

Hypocalcemia
- Decrease plasma Ca level below 2.25 mmol/L.
Causes :
1. Vit D deficiency (osteomalacia).
2. Hypoparathyroidism(e.g post thyroidectomy,parathyroidectomy).
3. Pseudohypoparathyroidism (target cells are insensitive to PTH).
4. Rhabdomyolysis (initial stages)(hyperphosphatemia)
5. Chronic renal failure.
6. Magnesium deficiency (due to end organ PTH resistance)e.g
‣ GI loss (vomiting &diarrhea)
‣ Alcoholism .
‣ Cisplatin (used in ttt of lung non-small cell cancer)
■ Without correcting hypomagnesemia, it`s very difficult to
هام جدا correct hypocalcemia
7. Hyperphosphatemia
8. Others Acute pancreatitis
Contamination of blood samples with EDTA false hypocalcemia.
Clinical picture :
هام parathesia. ■ Acute hypocalcemia : Tetany , peri-oral
■ Chronic hypocalcemia :
o Lethargy, personality changes
o Psychic depression.
o Cataract .
o ECG : prolonged Q-T .
■ C/P of the cause.
Tetany :
سؤال Post thyroidectomy acute hypocalcemia
10% : transient hypocalcemia→TTT : I.V cagluconate
(or cacl) slowly I.V.
1% : permanent hypoparathyroidism →TTT:
long term α calcidol
- Clinical syndrome chracterised by increased neuromuscular excitability due to
either Acute hypocalcemia
Alkalosis ( which → ionization of calcium)
Hypomagnesemia
- It`s either latent tetany or manifest tetany.
Latent tetany
Ca level > 1.9 & < 2.25 (>7mg/dl).
No manifestations of tetany.
Provocative tests are positive.
Manifest tetany
Ca level < 1.9 mmol/L (< 7 mg/dl)
Manifestations of tetany.
No Ca in urine (renal threshold for
Ca 1.9 mmo/L)