Department of Anesthesiology - Residents Section
Anesthesia Knowledge - Hyperparathyroidism
Hyperparathyroidism
Causes:
- adenoma (90%)
- hyperplasia (9%)
- carcinoma (1%)
» High morbidity during pregnancy: placenta allows accumulation of calcium in the fetus with fetal hypercalcemia and hypoparathyroidism
Symptoms:
- nephrolithiasis
- polyuria/polydipsia
- bone demineralization and subperiostal resorption
- peptic ulcers
- weakness, easy fatigability
- depression, memory loss, psychosis
EKG:
- prolongation of PR-interval/widening of QRS progressing to blocks
- bradycardia
Preoperative considerations:
- correction of intravascular volume: NS (rehydration alone can lower Ca by 2mg/dl)
- Lasix (not HCTZ which will lead to an increase in calcium)
- Correction of hypophosphatemia (controversial because of risk of risk of crystallization)
» emergency reduction of Ca is necessary when it exceeds 15mg/dl
- biphosphonates: inhibition of osteaclastic activity
- mithramycin: cytotoxic agent with inhibitory effect on osteoclastic activity (lowers Ca by 2mg/dl within 24-48 hours)
- calcitonin: rapid onset of action (2-4mg/dl) but development of tolerance within 24 hours
- steroids: only in certain malignancies, vitamin D intoxication, NOT useful in primary hyperparathyroidism
- dialysis
Intraoperative considerations:
- unpredictable response to Muscle relaxants, conservative approach recommended
- increased requirement for nondepolarizers
