Association of Preoperative Calcium and Calcitriol Therapy With Postoperative Hypocalcemia After Total Thyroidectomy.

Importance: Hypocalcemia is the most common complication after total thyroidectomy and can result in prolonged hospital admissions and increased hospital charges. Objective: To determine the effectiveness of preoperative calcium and calcitriol supplementation in reducing hypocalcemia following total thyroidectomy. Design, Setting, and Participants: A retrospective cohort study was conducted at a tertiary care center in 65 patients undergoing total thyroidectomy by a single surgeon. Patients were divided into 2 groups: those receiving preoperative as well as postoperative supplementation with calcium carbonate, 1000 to 1500 mg, 3 times daily and calcitriol, 0.25 to 0.5 µg, twice daily, and those receiving only postoperative supplementation with those agents at the same dosages. Data on patients who underwent surgery between January 1, 2008, and December 31, 2011, were acquired, and data analyses were conducted from March through June 2012, and from October through December 2016. Interventions: Calcium and calcitriol therapy. Main Outcomes and Measures: Postoperative serum calcium levels and development of postoperative hypocalcemia.
Results: Of the 65 patients who underwent total thyroidectomy 27 (42%) were men; mean (SD) age was 49.7 (16.7) years. Thirty-three patients received preoperative calcium and calcitriol supplementation, and 32 patients received only postoperative therapy. In the preoperative supplementation group, 15 of 33 (45%) patients underwent complete central compartment neck dissection and 11 of 33 (33%) had lateral neck dissection, compared with 16 of 32 (50%) and 12 of 32 (38%), respectively, patients without preoperative supplementation. The mean measured serum calcium level in those without preoperative supplementation vs those with supplementation are as follows: preoperative, 9.6 vs 9.4 mg/dL (absolute difference, 0.16; 95% CI, -0.12 to 0.49 mg/dL); 12 hours postoperative, 8.3 vs 8.6 mg/dL (absolute difference, -0.30; 95% CI,  -0.63 to 0.02 mg/dL); and 24 hours postoperative, 8.4 vs 8.5 mg/dL (absolute difference, -0.13; 95% CI, -0.43 to 0.16 mg/dL). In patients not receiving preoperative supplementation, 5 of 32 (16%) individuals became symptomatically hypocalcemic vs 2 of 33 (6%) in the preoperative supplementation group; an absolute difference of 10% (95% CI, -6.6% to 26.3%). Compared with the group not receiving preoperative supplementation, the mean [SD] length of stay was significantly shorter in the preoperative supplementation group (3.8 [1.8] vs 2.9 [1.4] days; absolute difference, -0.9; 95% CI, -1.70 to -0.105 days). Preoperative supplementation resulted in an estimated $2819 savings in charges per patient undergoing total thyroidectomy. Conclusions and Relevance: Preoperative calcium and calcitriol supplementation, in addition to routine postoperative supplementation, was associated with a reduced incidence of symptomatic hypocalcemia, length of hospital stay, and overall charges following total thyroidectomy.