Hypocalcemia after Total and Completion Thyroidectomy: Analysis of 100 Consecutive Patients

Abstract

Objectives:

Evaluate incidence of hypocalcemia (time-course) after thyroid surgery in 100 consecutive cases who underwent total/completion thyroidectomy.

Methods:

Retrospective case note analysis of 100 cases from 2009 -2012. We assessed ionic calcium preoperatively and postoperatively at 6-24-48 hours, 1 week, 6 weeks and 6 months. Serum parathormone level 24 hours post-surgery (and later if persistent hypocalcaemia), patient demographics, details of surgery, duration of stay, histopathological diagnosis were also analyzed.

Results:

79/100 patients were female, 21 male. Mean age was 55 (range 14-87). 74/100 had total thyroidectomy and 26 had completion. Preoperative mean calcium was 2.39 (range 2.1-3.86) and at 6 hours post-operatively dropped to 2.1 (1.84-2.53), 24 hours 2.16 (1.6-2.5), 48 hours 2.24 (1.7-2.7) and 1 week 2.3 (1.74-2.67) and stabilized at 6 weeks and 6 months 2.3 (1.9-2.66). 18/100 patients had hypocalcemia (below 1.99) and parathormone at 24 hours post-operation measured below 5. Delayed hypocalcemia was seen in 4 of 18 patients (after 24-48 hours) and 2 of them had parathyroid adenoma with pre-op high calcium. Persistent hypocalcemia at 6 weeks was seen in 7/18 patients and at 6 months in 5/18 patients (necessitating long term calcium/Vitamin D supplement) despite parathormone levels measuring above 5 (mean:7 range:2-20). Of 18 patients who had hypocalcemia, 10 had surgery for malignancy (with level-6 neck dissection), 2 had Graves disease, and 2 had Hashimoto’s thyroiditis.

Conclusions:

Extensive surgery with neck dissection, elderly patients and peri-glandular fibrosis predict high risk for post-operative hypocalcemia. Patients should be warned about risk of delayed hypocalcemia occurring late (after 48 hrs) and seek immediate medical attention.