Introduction: In young patients with Primary hyperparathyroidism, parathyroidectomy is the treatment of choice. Transient hypocalcaemia is common complication of parathyroidectomy but rarely potentially life threatening hungry bone syndrome (HBS) can develop. HBS is a state of hypocalcaemia, hypophosphataemia and tetany without concomitant hypoparathyroidism, and is caused by massive calcium deposition to the bone. Resulting hypocalcaemia can be severe and prolonged, requiring massive amounts of calcium to prevent symptoms of neuromuscular irritability, tetany.
Method: We present a 45 year old female who had long standing knee pain affecting her mobility. On examination she had pseudoclubbing, palpable neck mass and tenderness in left loin.
Adjusted calcium 3.01 mmol/L, Serum parathyroid hormone 200 pmol/L, X ray Hands showed extensive subperiosteal bone resorption involving phalanges, X-ray Ankle revealed brown tumours. USG abdomen showed bilateral kidney stones. Diagnosis of primary hyperparathyroidism with significant bone and kidney involvement was made and she was referred for parathyroidectomy.
Result: Postoperatively she developed symptoms of neuromuscular irritability and profound hypocalcaemia, Adjusted Calcium 1.53 mmol/L, markedly raised serum alkaline phosphatase peak 2300 IU/L. She required daily intravenous elemental calcium supplementation of 22.5 gram along with 68 gram oral calcium and 23 microgram oral 1,25-Dihydroxycholecalciferol. After about 4 weeks, serum ALP started decreasing and intravenous calcium supplement was stopped. She was discharged on oral calcium and 1, 25-Dihydroxycholecalciferol. Histology was consistent with parathyroid carcinoma.
Conclusion: Hungry bone syndrome should be considered in differential diagnosis of postoperative hypocalcaemia following parathyroidectomy, particularly in severe cases. Close monitoring of serum calcium with aggressive calcium replacement in early postoperative period is essential to prevent neuromuscular complications and seizures.
Earlier detection of risk factors for HBS and preoperative treatment with Calcitriol / bisphosphonates may reduce development of potentially life threatening hypocalcaemia in such patients.