Effectiveness of Routine Supplement of Oral Calcium and Vitamin D to Prevent Postoperative Hypocalcemia after Total or Completion Thyroidectomy
Eakarach Lewthanamongkol MD, FRCST*, Waraporn Imruetaicharoenchoke MD, FRCST*, Pornchai O-charoenrat MD, FRCST, MSc, PhD*
Affiliation : * Division of Head and Neck Surgery, Department of Surgery, Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : The incidence of hypocalcemia after total/completion thyroidectomy was 30 to 40% in recent studies. There is
no consensus regarding the role of routine supplement of calcium and vitamin D.
Objective : To study the efficacy of routine oral calcium and vitamin D supplement to prevent postoperative hypocalcemia.
Material and Method: Sixty-eight patients who underwent total/completion thyroidectomy at the Division of Head Neck and
Breast Surgery, Siriraj Hospital were included and randomized into two groups: Supplement and Control. Serum ionized
calcium and total calcium were measured at 6 hour, and Days 1, 2, 3, 7 and 30 postoperatively. Clinical signs and symptoms
of hypocalcemic state were recorded.
Results : The incidences of biochemical hypocalcemia were 74.3% and 96.9%, and of symptomatic hypocalcemia were 28.6%
and 33.3%, in Supplement and Control groups, respectively. Most patients had hypocalcemia within the first postoperative
days. Symptomatic hypocalcemia was related to ionized calcium less than 4.2 mg/dL or total calcium less than 7.9 mg/dL.
Conclusion : The incidence of post-thyroidectomy hypocalcemia was high. Most occurred within 24 hours but only 30% of
these patients became symptomatic. The immediate postoperative calcium supplement may prevent this condition.
Keywords : Calcium, Hypocalcemia, Hypoparathyroidism, Thyroidectomy, Vitamin D
