Several clinical factors were predictive of postoperative hypocalcemia in patients undergoing thyroidectomy, a new study identified. Out of over 126,000 adult patients who underwent total thyroidectomy, nearly 20% had hypocalcemia during the first 30 days following surgery -- defined as a diagnosis of hypocalcemia or hypoparathyroidism -- reported Jonathon Russell, MD, of Johns Hopkins Medicine in Baltimore, and colleagues. However, hypocalcemia resolved in most patients with time, as it was present in only 4.4% of these patients 1 year after the surgery, the team wrote in JAMA Otolaryngology - Head & Neck Surgery. Russell's group pointed out that current recommendations suggest "recognition of devascularized or inadvertently removed parathyroid glands with prompt autotransplantation and the use of routine postoperative calcium supplementation" in order to help reduce the risk of hypocalcemia development after thyroidectomy. At the time of thyroidectomy, a little more than 2% of patients had a magnesium disorder, and the presence of that was the strongest predictor of postoperative hypocalcemia -- both shortly after surgery and in the long-term. Specifically, those with a magnesium disorder had a more than eight-fold higher odds of short-term hypocalcemia after total thyroidectomy (odds ratio 8.40, 95% CI 7.21-9.79). Even more notable, patients with a magnesium disorder at the time of thyroidectomy had more than 25-fold higher odds for long-term hypocalcemia (OR 25.23, 95% CI 19.80-32.17). "We had previously found a strong link between hypomagnesemia and hypocalcemia after thyroidectomy," Russell told MedPage Today. "The big question is if it means anything clinically, or if we are simply demonstrating that some percentage of the population needs more magnesium," he continued, adding that the findings are a reminder to other healthcare professionals "that correcting magnesium levels postoperatively can help some patients after thyroidectomy." "There may be some patients at higher risk who could also benefit from preoperative intervention, but we will need to examine this more first," he concluded. Study Details The retrospective cross-sectional analysis included patient data from large U.S. employment-based database claims. The adult patients underwent a total thyroidectomy for either benign or malignant disease from 2010 to 2012. About half of patients underwent surgery for malignant neoplasm, while the second most common indication was goiter. The development of postoperative hypocalcemia during the initial 30 days after surgery, as well as 1 year out, was also more likely among female patients and among those who were younger than age 40 at the time of surgery. Several other clinical factors and comorbidities were also predictive of developing hypocalcemia after thyroidectomy both in the short and long-term, the researchers found: Thyroiditis -- short-term: OR 1.48 (95% CI 1.16-1.89) and long-term: OR 1.60 (95% CI 1.13-2.26) Cancer -- OR 1.32 (1.05-1.67) and OR 1.17 (0.83-1.63) Vitamin D deficiency -- OR 1.96 (1.74-2.21) and OR 3.72 ( 3.30-4.18) Concurrent lateral neck dissection -- OR 1.51 (1.37-1.66) and OR 1.95 (1.69-2.26) Concurrent central neck dissection -- OR 1.15 (1.07-1.24) and OR 1.25 (1.12-1.40) Intraoperative parathyroid -- OR 1.58 (1.46-1.71) and OR, 2.05 (1.82-2.31) Recurrent laryngeal nerve injury -- OR, 1.49 (1.27-1.74); OR 2.04 (1.64-2.54) Not surprisingly, the presence of comorbidities was also tied to higher costs of care. One year after thyroidectomy, patients with a magnesium disorder incurred an average $14,314 higher overall care costs. Those with a recurrent laryngeal nerve injury saw on average $13,286 in higher costs, while those with hypocalcemia had about $3,392 higher costs. Source
