Poster Presentation 33rd ASM of the Australian & New Zealand Bone & Mineral Society 2023

Severe hypocalcaemia postoperatively from a laryngectomy, total thyroidectomy and total parathyroidectomy requiring Teriparatide (#248)

Liam Clifford 1 , Flavian Joseph 1 , Tripti Joshi 1
  1. Endocrine, Gosford Hospital, Gosford, NSW, Australia

Summary

A 71-year-old gentleman underwent a salvage total laryngectomy and bilateral selective neck dissection for recurrent glottic squamous cell carcinoma that included a total thyroidectomy and total parathyroidectomy. Post-operatively complicated by severe hypoparathyroidism and hypocalcaemia, which required intravenous and oral calcium replacement and Teriparatide on a short-term basis to maintain normocalcaemia. Pre-operatively, his corrected calcium level was 2.55mmol/L (RR 2.10-2.60), ionised calcium level 1.21mmol/L (RR 1.15-1.30), and an intact PTH level 5.2pmol/L (RR 1.6-7.2). Renal function and other electrolytes were normal. Post-operatively, the corrected calcium level remained intact at 2.45mmol/L, however the PTH level was undetectable at <0.4pmol/L with an ionised calcium level of 0.91mmol/L but no symptoms of hypocalcaemia. He required 4.4mmol/L of calcium gluconate TDS a day intravenously as well as oral calcium carbonate 1200mg TDS, and 0.25mcg calcitriol for replacement of calcium for a total of 19 days whilst an inpatient, and oral replacement was continued on discharge. Due to the persistently low hypocalcaemia Teriparatide 20mcg BD SC was commenced and then weaned on discharge.

Brief Outline of Literature

Acute hypocalcaemia is considered a medical emergency and requires rapid treatment with a combination of calcium and vitamin D supplementation, with severe cases requiring intravenous calcium supplementation.1,-3 A novel approach to the treatment of severe hypocalcaemia and hypoparathyroidism not responsive to conventional therapy is the use of Teriparatide. The studies, although small and limited, have shown that it is efficacious in improving hypocalcaemia and reducing the supplementation required to maintain normocalcaemia post-operatively.4-7

Long-term management of hypoparathyroidism involves aiming for a serum calcium level towards the low normal reference range to avoid symptoms, associated complications, and to preserve bone health. Part of therapy is to prevent hypercalciuria, and to reduce the total amount of calcium supplementation required, hydrochlorothiazide can be added to the daily regimen.1,3 A long-term risk with oral calcium supplementation is the potential for renal calculi, and there is also the added component of pill burden. For patients with difficult to control or recalcitrant hypocalcaemia/hypoparathyroidism, teriparatide is an option for long-term management beyond a few weeks.8-9

  1. Lechner, M., Moghul, G., Chandrasekharan, D., Ashraf, S., Emanuel, O., Magos, T., et al. (2023). Preoperative and postoperative optimisation of patients undergoing thyroid surgery: a multicentre qualify improvement project at Barts Health NHS Trust. BMJ Open Quality 12; 1-7.
  2. Chen, Z., Zhao, Q., Du, J., Wang, Y., Han, R., Xu, C., et al. (2021). Risk factors for postoperative hypocalcaemia after thyroidectomy: A systematic review and meta-analysis. J Int Med Res 49(3); 1-21.
  3. Orloff, LA., Wiseman, SM., Bernet, VJ., Faheylll, TJ., Shaha, AR., Shindo, ML., et al. (2018). American Thyroid Association Statement on Postoperative Hypoparathyroidism: Diagnosis, Prevention, and Management in Adults. Thyroid 28(7); 830-841.
  4. Shah, M., Bancos, I., & Thompson, GB. (2015). Teriparatide Therapy and Reduced Postoperative Hospitilization for Postsurgical Hypoparathyroidism. JAMA Otolaryngol Head Neck Surg 141(9); 822-829.
  5. Cheng, ML., & Gupta, V. (2012). Teriparatide – Indications beyond osteoporosis. Indian J Endocrinol Metab 16(3); 343-348.
  6. Andrysiak-Mamos, Elzbieta, Zochowska, E., Kazmierczyk-Puchalska, A., Popow, M., Kaczmarska-Turek, D., Pachucki, J., et al. (2016). Treatment of severe life-threatening hypocalcaemia with recombinant human teriparatide in patients with postoperative hypoparathyroidism – a case series. Endokrynol Polska 67(4); 403-412.
  7. Marcucci, G., Masi, L., Cianferotti, L., Giusti, F., Fossi, C., Parri, S., et al. (2021). Chronic hypoparathyroidism and treatment with teriparatide. Endocrine 72(1); 249-259.
  8. Cusano, NE., Rubin, MR., McMahon, DJ., Zhang, C., Ives, R., Tulley, A., (2013). Therapy of Hypoparathyroidism with PTH(1-84): A Prospective Four-Year Investigation of Efficacy and Safety. JCEM 98; 137-144.
  9. Upreti, V., Somani, S., & Kotwal, N. (2017). Efficacy of Teriparatide in Patients with Hypoparathyroidism: A Prospective, Open-label Study. Indian J Endocrinol Metab 21(3); 415-418.