Hypocalcemia following thyroid surgery- A prospective study

Abstract

Introduction: This was a prospective observational study of 18-month duration. The purpose of this study is to compare preoperative serum calcium levels with postoperative serum calcium levels and to analyze postthyroid surgery hypocalcemia with regard to prevalence, clinical presentation, and severity and to treat hypocalcemia if it occurs. In addition, we analyzed the correlation of postoperative hypocalcemia with relation to the type of surgery, diagnosis, duration of surgery, and the quantity of blood loss. This study was conducted on consecutive patients who underwent thyroid surgery in the Department of General Surgery of a tertiary hospital in Puducherry for 18 months from November 2014 to April 2016. The median age of the patients was 40 years. The sex ratio was 17:2 in favor of females. Out of 38 patients, 18 patients were diagnosed with multinodular goiter, 8 were follicular carcinoma thyroid, 5 were papillary carcinoma thyroid, 2 were medullary carcinoma thyroid, 4 were adenomatoid nodule, and 1 patient was diagnosed to have thyroid abscess. In addition, 31 patients underwent total thyroidectomy, 6 patients underwent hemithyroidectomy when 1 patient underwent incision and drainage for thyroid abscess. Results: 39% (n = 15) of the patients developed hypocalcemia postoperatively. 87% (n = 11) of the patients were symptomatic and required calcium correction. Two patients had delayed presentation of hypocalcemia on postoperative day 5. One patient who underwent hemithyroidectomy developed hypocalcemia in the postoperative period. Trousseau's sign was the most typical clinical feature seen in hypocalcemia patients. In the present study, no significant association of hypocalcemia with the female gender was noted, and we did not find any association of hypocalcemia with advancing age. We did not find any association between hypocalcemia and prolonged surgery duration or increased blood loss in the present study. In addition, we did not see any increase in the incidence of hypocalcemia in patients who underwent thyroidectomy combined with lymph node clearance. Conclusion: The rate of postoperative hypocalcemia following thyroid surgery in this study was 39%. It coincides with the incidence reported elsewhere in the world. Although the risk of hypocalcemia was associated with increased blood loss, prolonged surgery, and extent of surgery, it was not statistically significant. If a similar study is conducted on a larger scale, including a broader spectrum of the population, important factors that influence postoperative hypocalcemia may be recognized.