Identifying Predictors of Prolonged Levothyroxine Dose Adjustment After Thyroidectomy.

BACKGROUND: Levothyroxine (LT4) is one of the most prescribed drugs in the United States; however, many patients started on LT4 after thyroidectomy suffer from symptoms of hyper- or hypo-thyroidism before achieving euthyroidism. This study aims to describe the time required for dose adjustment before achieving euthyroidism and identify predictors of prolonged dose adjustment (PDA+) after thyroidectomy. METHODS: This is a single institution retrospective cohort study of patients who achieved euthyroidism with LT4 therapy between 2008 and 2017 after total or completion thyroidectomy for benign disease. Patients who needed at least three dose adjustments (top quartile) were considered PDA+. Binomial logistic regression was used to identify predictors of PDA+. RESULTS: The 605 patients in this study achieved euthyroidism in a median of 116 d (standard deviation 124.9) and one dose adjustment (standard deviation 1.3). The 508 PDA- patients achieved euthyroidism in a median of 101 d and one dose adjustment. The 97 PDA+ patients achieved euthyroidism in a median of 271 d and three dose adjustments. Iron supplementation (odds ratio = 4.4, 95% confidence interval = 1.4-13.5, P = 0.010) and multivitamin with mineral supplementation (odds ratio = 2.4, 95% confidence interval = 1.3-4.3, P = 0.004) were independently associated with PDA+. Age, gender, preoperative thyroid disease, and comorbidities did not independently predict PDA+. CONCLUSIONS: After thyroidectomy, achieving euthyroidism can take nearly 4 mo. Iron and mineral supplementation are associated with PDA+. This information can inform the preoperative counseling of patients and suggests that this may expedite achieving euthyroidism.

Failure to Diagnose and Treat Hyperparathyroidism Among Patients with Hypercalcemia: Opportunities for Intervention at the Patient and Physician Level to Increase Surgical Referral.

BACKGROUND: Hyperparathyroidism is both underdiagnosed and undertreated, but the reasons for these deficiencies have not been described. The purpose of this study was to identify reasons for underdiagnosis and undertreatment of hyperparathyroidism that could be addressed by targeted interventions. MATERIALS AND METHODS: We identified 3,200 patients with hypercalcemia (serum calcium >10.5 mg/dL) who had parathyroid hormone (PTH) levels evaluated at our institution from 2011 to 2016. We randomly sampled 60 patients and divided them into three groups based on their PTH levels. Two independent reviewers examined clinical notes and diagnostic data to identify reasons for delayed diagnosis or referral for treatment. RESULTS: The mean age of the patients was 61 ± 16.5 years, 68% were women, and 55% were white. Fifty percent of patients had ≥1 elevated calcium that was missed by their primary care provider. Hypercalcemia was frequently attributed to causes other than hyperparathyroidism, including diuretics (12%), calcium supplements (12%), dehydration (5%), and renal dysfunction (3%). Even when calcium and PTH were both elevated, the diagnosis was missed or delayed in 40% of patients. For 7% of patients, a nonsurgeon stated that surgery offered no benefit; 22% of patients were offered medical treatment or observation, and 8% opted not to see a surgeon. Only 20% of patients were referred for surgical evaluation, and they waited a median of 16 months before seeing a surgeon. CONCLUSION: To address common causes for delayed diagnosis and treatment of hyperparathyroidism, we must improve systems for recognizing hypercalcemia and better educate patients and providers about the consequences of untreated disease. IMPLICATIONS FOR PRACTICE: This study identified reasons why patients experience delays in workup, diagnosis, and treatment of primary hyperparathyroidism. These data provide valuable information for developing interventions that increase rates of diagnosis and referral.

Hypoparathyroidism after total thyroidectomy: incidence and resolution.

BACKGROUND: Parathyroid hormone (PTH) levels are often measured after thyroid surgery and are used to detect patients at risk for postoperative hypoparathyroidism. However, there is a lack of consensus in the literature about how to define the recovery of parathyroid gland function and when to classify hypoparathyroidism as permanent. The goals of this study were to determine the incidence of low postoperative PTH in total thyroidectomy patients and to monitor their time course to recovery of parathyroid gland function. METHODS: We identified 1054 consecutive patients who underwent a total or completion thyroidectomy from January, 2006-December, 2013. Low PTH was defined as a PTH measurement <10 pg/mL immediately after surgery. Patients were considered to be permanently hypoparathyroid if they had not recovered within 1 y. Recovery of parathyroid gland function was defined as PTH ≥10 pg/mL and no need for therapeutic calcium or activated vitamin D (calcitriol) supplementation to prevent hypocalcemic symptoms. RESULTS: Of 1054 total thyroidectomy patients, 189 (18%) had a postoperative PTH <10 pg/mL. Of those 189 patients, 132 (70%) showed resolution within 2 mo of surgery. Notably, 9 (5%) resolved between 6 and 12 mo. At 1 y, 20 (1.9%) were considered to have permanent hypoparathyroidism. Surprisingly, 50% of those patients had recovery of PTH levels yet still required supplementation to avoid symptoms. CONCLUSIONS: Most patients with a low postoperative PTH recover function quickly, but it can take up to 1 y for full resolution. Hypoparathyroidism needs to be defined not only by PTH levels but also by medication requirements.

Preventing postoperative hypocalcemia in patients with Graves disease: a prospective study.

BACKGROUND: Hypocalcemia occurs after total thyroidectomy (TT) for Graves disease via parathyroid injury and/or from increased bone turnover. Current management is to supplement calcium after surgery. This study evaluates the impact of preoperative calcium supplementation on hypocalcemia after Graves TT. METHODS: A prospective study of patients with Graves disease undergoing TT was performed. Patients with Graves disease managed over a 9-month period took 1 g of calcium carbonate (CC) three times a day for 2 weeks before TT. Those managed the previous year without supplementation served as historic controls. Age-, gender-, and thyroid weight-matched, non-Graves TT patients were procedure controls. Patient demographics, postoperative laboratory values, complaints, and medications were reviewed. Parathyroid hormone (PTH)-based postoperative protocols dictated postoperative CC and calcitriol use. RESULTS: Forty-five patients with Graves disease were treated with CC before TT, and 38 patients with Graves disease were not. Forty control subjects without Graves disease were identified. Age, gender, and thyroid weight were comparable. Preoperative calcium and PTH levels were equivalent. PTH values immediately after surgery, at postoperative day 1, and at 2-week follow-up were equivalent. Postoperative use of scheduled CC (p = 0.10) and calcitriol (p = 0.60) was similar. Postoperatively, patients with untreated Graves disease had lower serum calcium levels than pretreated patients with Graves disease or control subjects without Graves disease (8.3 mg/dL vs. 8.6 vs. 8.6, p = 0.05). Complaints of numbness and tingling were more common in nontreated Graves disease (26%) than in pretreated Graves disease (9%) or in control subjects without Graves disease (10%, p < 0.05). CONCLUSIONS: Calcium supplementation before TT for Graves disease significantly reduced biochemical and symptomatic postoperative hypocalcemia. Preoperative calcium supplementation is a simple treatment that can reduce symptoms of hypocalcemia after Graves TT.