Hypoparathyroidism is under-production of parathyroid hormone. It most commonly occurs after operations on the neck for disorders of the thyroid or larynx. Symptoms result from the low blood calcium level such as muscle spasms; pins and needles over face, or extremities
Medications:
Non- life-threatening hypocalcaemia – ionised calcium > 4mg/dl
- Tab. Supracal (Calcium Citrate 1000 mg) 1 tablet thrice a day
- Cap. Laretol (Calcitriol 0.25 mcg) 1 – 2 capsules per day.
- Correct serum Magnesium if abnormal (low magnesium can cause hypoparathyroidism)
- Dietary advice – diet rich in calcium (milk, cheese, soya beans, tofu, nuts, cabbage, broccoli)
- Repeat serum calcium after 4 weeks (aim for serum calcium levels of 8-8.5 mg/dl).
Severe hypocalcaemia – ionised calcium < 4mg/dl or tetany and seizures due to hypocalcaemia (urgent correction is needed).
- Give inj. Calcium gluconate 10% – 10 ml diluted in 100 ml of 0.9% normal saline over 10-20 minutes intravenously with ECG monitoring.
- If serum calcium is low after 2 hours – repeat above dose of calcium gluconate, followed by continuous i.v. infusion – 100 ml of Calcium gluconate 10% in 1litre of normal saline at 50 ml/hour.
- Monitor serum calcium every 4 – 6 hrs to maintain serum calcium levels.
- Switch to oral calcium as above for maintenance.
Investigations:
- Serum calcium level – to look for low calcium levels (less than 7.2 mg/dl).
- Serum parathyroid levels – to monitor parathyroid hormone levels (normal range 10-65 pg/mL or 10-65 ng/L).
- Serum phosphorus levels – PTH is responsible for phosphate excretion in urine. In its absence, phosphorus levels in the blood increase.
- Serum electrolytes, serum magnesium, serum creatinine.
- Vitamin D (25-Hydroxyvitamin D, 1,25-Dihydroxyvitamin D) level – to exclude vitamin D deficiency as a cause of hypocalcaemia.
- Serum magnesium – hypomagnesemia may cause parathyroid hormone deficiency and subsequent hypocalcaemia. Exclude it in any patient with primary hypoparathyroidism.
Referrals:
Consider referral to endocrinologist or secondary care in severe cases or if patient fails to respond.