An intact parathyroid hormone–based protocol for the prevention and treatment of symptomatic hypocalcemia after thyroidectomy

Abstract

Background Symptomatic hypocalcemia after thyroidectomy is a barrier to same day surgery, and the cause of ER visits. A standard protocol of calcium and vitamin D supplementation, dependent on intact parathyroid hormone (iPTH) levels, can address this issue. How effective is it? When does it fail? Methods We performed a retrospective review of the prospective Thyroid Database from January 2006 to December 2010. 620 patients underwent completion (CT) or total thyroidectomy (TT), and followed our post-operative protocol of calcium carbonate administration for iPTH levels ≥10pg/ml and calcium carbonate and 0.25μg calcitriol BID for iPTH <10pg/ml. Calcium and iPTH values, pathology and medication, were compared to evaluate protocol efficacy. A p value <0.05 was considered statistically significant. Results Using the protocol, sixty-one (10.2%) patients were chemically hypocalcemic but never developed symptoms and twenty-four (3.9%) patients developed breakthrough symptomatic hypocalcemia. The symptomatic (SX) and asymptomatic (ASX) groups were similar with regard to gender, cancer diagnosis, and pre-operative calcium and iPTH. The symptomatic group was significantly younger (39.6 ± 2.8 vs. 49 ± 0.6 years, p=0.01), with lower post-operative iPTH levels. 33% (n=8) of SX patients had an iPTH ≤5 pg/ml vs. only 6% (n=37) of ASX patients. While the majority of patients with a PTH <5 pg/ml were asymptomatic, 62.5% (n=5) of SX patients with iPTH levels ≤5 pg/ml, required an increased in calcitriol dose to achieve both biochemical correction and symptom relief. Conclusion Prophylactic calcium and vitamin D supplementation based on post-operative iPTH levels can minimize symptomatic hypocalcemia after thyroidectomy. An iPTH ≤ 5pg/ml may warrant higher initial doses of calcitriol in order to prevent symptoms.

When patients call their surgeon's office: an opportunity to improve the quality of surgical care and prevent readmissions

“…These were managed according to established protocols. [3] Additionally, 23% of patients initiated or received a phone call to discuss results of laboratory tests or pathology while a similar number needed to discuss medications (changes in dosing, starting or stopping pills). Other reasons for postoperative calls are shown in Table 2.…”

Selective Prophylactic Calcium Supplementation reduces Length of Stay after Total Thyroidectomy

“…Predicting postoperative hypocalcemia using PTH has been extensively studied in recent years 8,[12][13][14]17,20 and various authors have attempted to ascertain the optimal time point at which to measure the PTH level. Noordzij et al 13 analyzed the pooled data from nine studies, finding that the PTH level 6 hours after surgery had the highest accuracy for predicting hypocalcemia.…”

“…11 Prior to 2008, most patients at our institution remained in hospital for at least 2 days postoperatively to monitor for hypocalcemia, and supplementation was initiated, if required. In recent years, multiple studies have demonstrated that a low postoperative PTH can predict hypocalcemia; [12][13][14][15][16] however, its accuracy may be as low as 80%. 17 The halflife of PTH is approximately 2 to 3 minutes; 18 therefore, specimens sent from the recovery room should predict postoperative parathyroid status.…”

Identifying Predictors of a Difficult Thyroidectomy

“…Many of the traditional markers of morbidity and mortality do not necessarily apply to thyroidectomy where the mortality rate approaches zero, but the morbidity can be significant (27)(28)(29)(30). The American College of Surgeons (ACS) developed a surgical risk calculator that can be used to estimate the risks of most operations and will allow clinicians and patients to make decisions using empirically derived, patient-specific postoperative risks (31).…”