A Practical Protocol: Identifying Thyroidectomy Patients at Low Risk for Significant Hypocalcemia

Fifty of the 135 subjects showed positive slope, and none of those subjects showed significant hypocalcemia at 12 hours.

Of the 85 patients in the non-positive slope group, 70% showed no significant hypocalcemia. Sixty-one had a serum Ca level of at least 8 mg/dl at 12 hours. In this subgroup, eight patients (13%) showed significant hypocalcemia. Seven saw an onset within 24 hours, and one between 24 and 48 hours. There were no readmissions and no necessity of permanent calcium supplements for this subgroup, said Dr. Farrag.

In the 24 non-positive slope patients with a serum Ca level below 8 mg/dl, 18 (75%) showed significant hypocalcemia. Four saw an onset within 24 hours, and 14 between 24 and 48 hours. There were two readmissions and two patients needed permanent calcium supplements.

Dr. Farrag and his colleagues also evaluated patient age, gender, and indication for total thyroidectomy (cases included 81 for cancer, 17 for adenoma, 12 for inflammatory disease, and 25 for goiter) and whether central neck dissection occurred. None of these factors had an impact on the algorithm.

Definitive Results

The results of the research seem clear: Patients who developed significant hypocalcemia had a non-positive slope 100 percent of the time, concluded Dr. Farrag. The researchers concluded that patients with a non-positive slope between 6 and 12 hours postoperatively, with a serum Ca level greater than 8 mg/dl at 12 hours, can be safely discharged from the hospital after 24 hours, as long as they are sent home with patient education and oral calcium supplements. Using the algorithm to identify these patients will eliminate an extra day, possibly longer, in the hospital, thus saving money and making that bed available for the next admission.

The slope of postoperative serum Ca levels is an easy, cost effective, and reliable predictor of who will develop significant hypocalcemia following thyroid surgery, said Dr. Farrag. Our management algorithm safety identifies those patients that can be confidently sent home within a 24-hour period after surgery. It also identifies those who need further hospitalization and are at risk for significant hypocalcemia.

Tarik Y. Farrag, MD

©2006 The Triological Society