Inadvertent parathyroidectomy during thyroid surgery: the incidence of a complication of thyroidectomy

Background and aims Incidental parathyroidectomy is a complication of thyroid surgery. The aim of this report is to explore the incidence, risk factors, and clinical relevance of inadvertent parathyroidectomy during thyroidectomy.Materials and methods Patients who underwent thyroidectomy between January 1998 and June 2005 were evaluated. Pathology reports were reviewed for the presence of parathyroid tissue in the thyroidectomy specimens. Information regarding diagnosis, operative details, and postoperative hypocalcemia were collected.Results Three hundred and fifteen thyroid procedures were performed: 163 total thyroidectomies, 124 near-total thyroidectomies, and 28 lobectomies. The findings were benign in 240 and malignant in 75 cases. Incidental parathyroidectomy was found in 68 (21.6%) cases: 58 were benign and 10 were malignant. One and two parathyroids were accidentally removed in 46 and 22 patients, respectively. Parathyroid tissue was found in intrathyroidal (33%) and extracapsular (27%) sites. Total/near-total thyroidectomy was not associated with increased risk of incidental parathyroidectomy (P=0.646), and there was no association of inadvertent parathyroidectomy with postoperative hypocalcemia (P=0.859). Thyroid malignancy was associated with decreased incidence of incidental parathyroidectomy (P=0.047).Conclusion Inadvertent parathyroidectomy, although not uncommon, is not associated with postoperative hypocalcemia. The type of surgical procedure does not increase the risk of incidental parathyroidectomy, while thyroid malignancy may reduce the incidence of inadvertent parathyroidectomy.     

Incidental Parathyroidectomy during Thyroid Surgery: An Underappreciated Complication of Thyroidectomy

The aim of this study was to investigate the incidence, risk factors, and clinical relevance of incidental parathyroidectomy during thyroid surgery. Prospective analysis of data in patients following thyroidectomy, specifically regarding the presence of parathyroid parenchyma in the thyroidectomy specimens, the underlying thyroid pathology, and the presence of postoperative hypocalcemia (biochemical/clinical). The clinical records of 158 patients who underwent thyroid surgery during a 2-year period were reviewed. Pathology reports were carefully reviewed for the nature of the underlying thyroid disease, the presence, number, and size of incidentally resected parathyroid gland(s), their location, and possible parathyroid pathology. Serum calcium levels were measured preoperatively, on the day of surgery, and on postoperative days 1, 2, and 7 or even later as needed. Two groups of patients were studied: a group with incidental parathyroidectomy following thyroidectomy (group A) and a group without incidental parathyroidectomy after thyroidectomy (group B). Total/near-total thyroidectomy was the procedure of choice and was performed in 154 patients; total lobectomy and contralateral subtotal lobectomy was performed in the other 4 patients. Elective central neck lymph node dissection was performed in four patients with neck lymphadenopathy. Inadvertently removed parathyroid tissue was found in 28 cases (17.7 %); in 6 of these patients (21%) the parathyroid tissue was intrathyroidal. The percentage of women in group A was significantly higher than in group B (93% vs. 58.5%, P = 0.0002). There was no statistically significant difference between the two groups (A and B) regarding the preoperative (presumed) diagnosis, the histologic diagnosis of thyroid disease (benign versus malignant), the type/extent of surgery, or the presence of thyroiditis. Biochemical and clinical hypocalcemia was observed in 6 (21%) and 2 (7%) patients in group A, respectively, and in 30 (23%) and 8 (6%) patients of group B, respectively. There was no statistically significant difference regarding the occurrence of postoperative hypocalcemia (clinical/biochemical) between the two groups (P = 0.33). Incidental parathyroidectomy is not uncommon following thyroidectomy and in a significant percentage of cases it may be due to the intrathyroidal location of the parathyroid glands. Incidental parathyroidectomy was not found to be associated with postoperative hypocalcemia (biochemical/clinical). Incidental parathyroidectomy may be considered as a potentially preventable but clinically minor complication of thyroid surgery.     

Identification of Patients at Low Risk for Thyroidectomy-Related Hypocalcemia by Intraoperative Quick PTH

Background Transient hypoparathyroidism is a frequent and challenging complication following total thyroidectomy. The aim of the study was to identify patients at risk of developing thyroidectomy-related hypocalcemia and symptoms by means of the intraoperative quick parathyroid hormone (PTH) assay. Methods Eighty-one patients undergoing total thyroidectomy were included in the study. Quick PTH levels were measured at induction of anaesthesia and 10 minutes after total thyroidectomy. A sample of 10 patients who underwent unilateral thyroid lobectomy was considered as a control group. The accuracy of intraoperative PTH decline in predicting postoperative hypoparathyroidism was analysed. Results After total thyroidectomy, 27 patients (33.3%) developed postoperative hypocalcemia. Symptoms were reported by 21 patients (25.9%). The mean percentage decline of intraoperative quick PTH was 81% in hypocalcemic compared with 39% in normocalcemic patients (P < 0.001), and it was 83% in symptomatic compared with 42% in asymptomatic patients (P < 0.001). Mean proportion decline of quick PTH after unilateral lobectomy was 20%, significantly lower than the 53% registered after total thyroidectomy (P = 0.005). Analysis of variation of intraoperative quick PTH with the receiver operator characteristics (ROC) curve showed a 75.7% decline as the cut-off value predicting postoperative hypocalcemia with the highest accuracy (91.4%) (sensitivity: 81.5% specificity: 96.3% positive likelihood ratio: 22; negative likelihood ratio: 0.2). Regarding the prediction of postoperative symptoms, a 79.5% decline was the most accurate (92.6%) cut-off point (sensitivity: 76.2% specificity: 98.3% positive likelihood ratio: 46; negative likelihood ratio: 0.2). Conclusions Quick PTH monitoring during total thyroidectomy is a useful means for identifying low-risk patients for postoperative hypoparathyroidism and candidates for early, safe discharge. Furthermore, it is an objective method complementary to the surgeon’s judgement of the intraoperative function of parathyroid glands, which should be implanted in the event of a 75%–80% decline.     

Persistently elevated parathyroid hormone levels after parathyroid surgery

BACKGROUND: Persistent elevation of serum parathyroid hormone (PTH), despite normocalcemia, occurs in 8% to 40% of patients after parathyroidectomy. Explanations have included hypocalcemia owing to vitamin D deficiency or bone remineralization, and persistent hyperparathyroidism. METHODS: A retrospective chart review of 816 consecutive patients who underwent surgery for primary hyperparathyroidism was conducted. RESULTS: One hundred fourteen patients (15%) had persistently elevated PTH levels (PPTH). Patients with PPTH had higher preoperative PTH levels than those with normal PTH levels postoperatively. They also had lower postoperative Ca(++) and vitamin D levels. Multiple gland enlargement was identified in fewer patients with PPTH than in those with normal postoperative PTH levels. In patients with PPTH and a postoperative Ca(++) less than 9.6 mg/dL (group I), there was a greater decrease in IOPTH, a higher initial postoperative PTH level, and a lower postoperative vitamin D level than in PPTH patients whose postoperative Ca(++) was > or =9.6 mg/dL (group II). Postoperative Ca(++) and vitamin D levels were also lower in patients whose PPTH did not ultimately resolve. Three patients in group II had recurrent disease. CONCLUSIONS: Persistent elevation of postoperative serum PTH levels in normocalcemic patients is associated with mild hypocalcemia, probably owing to vitamin D deficiency. In some patients it may also be indicative of mild persistent hyperparathyroidism.     

Applicability of Intraoperative Parathyroid Hormone Assay During Total Thyroidectomy as a Guide for the Surgeon to Selective Parathyroid Tissue Autotransplantation

Background Intraoperative parathyroid hormone assay (IOPTH) has been suggested to have value in predicting the development of postoperative hypoparathyroidism after thyroid surgery. IOPTH has been validated in identification of patients at risk of postoperative hypocalcemia requiring early onset of calcium supplementation therapy and in improving selection of patients eligible for a safe early discharge. However, the value of IOPTH has not been assessed in a randomized study as a guide for the surgeon to parathyroid tissue autotransplantation (PA). The objective of this study was to evaluate the applicability of IOPTH in guiding the surgeon to selective parathyroid tissue autotransplantation during total thyroidectomy (TT). Methods Between January 2005 and December 2005, 340 patients qualified for total thyroidectomy (TT) who met the inclusion criteria were randomized to two equal-sized groups (n = 170): group A, in which elective PA of at least one parathyroid gland was performed in all cases without IOPTH as a guide; and group B, in which selective IOPTH-guided PA was performed, if only the iPTH plasma level was <10 ng/L at 10–20 min after TT (before skin closure). The standard technique of PA consisting of implanting the parathyroid tissue into 10–20 sternocleidomastoid muscle pockets was used in both groups. IOPTH measurements were performed by the STAT-Intraoperative-iPTH-Assay. Serum calcium was routinely monitored at 4, 12, 24, 48, and 72 hr postoperatively. The incidence and severity of hypocalcemia and related symptoms were matched with the IOPTH results. On follow-up, serum calcium and plasma iPTH values were measured at 1, 3, and 6 months postoperatively. The primary end point was the success rate in preventing permanent postoperative hypoparathyroidism. The secondary end point was the use of postoperative medication for transient hypocalcemic symptoms. Results Twenty-one group B patients (12.3%) had plasma iPTH levels <10 ng/L at 10–20 min after TT (before skin closure) and they underwent selective IOPTH-guided PA. None of the patients from both groups experienced permanent postoperative hypoparathyroidism. Transient postoperative hypocalcemia occurred in 22.3% vs. 11.2% of patients (group A vs. B, respectively; p < 0.05). The mean cumulated serum calcium values were significantly lower for group A vs. group B patients within the entire 3-month period after TT (2.12 ± 0.09 mmol/L vs. 2.27 ± 0.05 mmol/L, respectively; p < 0.001). The mean oral calcium supplementation was significantly higher for group A vs. group B patients during the 3 months after TT (2.7 ± 0.9 g/day vs. 0.9 ± 0.4 g/day, respectively; p < 0.001). Conclusions IOPTH offers valuable information during TT, correctly identifying patients at risk of postoperative hypocalcemia. Selective IOPTH-guided PA in patients with plasma iPTH levels <10 ng/L at 10–20 min after TT reduces the risk of permanent postoperative hypoparathyroidism to zero, and this approach seems to be as effective as elective PA of at least one parathyroid gland without IOPTH guidance. Moreover, selective IOPTH-guided PA significantly decreases the incidence of transient postoperative hypoparathyroidism and the need for calcium supplementation therapy compared with elective PA without IOPTH. Presented at the 42^nd World Congress of Surgery, Montreal, Canada, August 26 to 30, 2007.     

Applicability of intraoperative parathyroid hormone assay during thyroidectomy

OBJECTIVE: To evaluate the applicability of intraoperative parathyroid hormone (quick PTH) assay to monitor parathyroid function and to identify clinically significant hypocalcemia compared with postoperative serum calcium monitoring. SUMMARY BACKGROUND DATA: Close monitoring of serum calcium levels is a standard of care to identify post-thyroidectomy hypocalcemia due to parathyroid insufficiency. METHODS: Quick PTH assay was performed before and after thyroidectomy for 100 patients at risk of postoperative hypocalcemia and 20 control patients who underwent unilateral lobectomy. Postoperative serum calcium levels were closely monitored. RESULTS: Control patients had a normal but 38.9 +/- 5.9% (mean +/- SEM) decline in quick PTH after thyroidectomy. Eleven of 100 at-risk patients (11%) developed postoperative hypocalcemia. Hypocalcemic patients had significantly lower quick PTH values after thyroidectomy compared with that of normocalcemic patients. Serum calcium was significantly lower in hypocalcemic patients the morning after operation but not early after the operation (within 6 hours). A normal or less than 75% decline in quick PTH after thyroidectomy can accurately identify normocalcemic patients during surgery as compared to more than 24 hours by serum calcium monitoring. CONCLUSIONS: The quick PTH assay can monitor parathyroid function during thyroidectomy and identify patients at risk of clinically significant hypocalcemia much earlier than serum calcium monitoring. It may facilitate early discharge and the use of parathyroid autotransplantation during thyroidectomy.     

Intraoperative parathyroid hormone assay for management of patients undergoing total thyroidectomy

BACKGROUND: Rapid parathyroid hormone (PTH) assay has been applied to predict hypocalcemia after thyroidectomy compared with conventional close monitoring of serum calcium levels. We evaluated the reliability of intraoperative intact PTH (ioPTH) assay to predict hypocalcemia after total thyroidectomy and sought to develop an algorithm for the management of postthyroidectomy patients. METHODS: Rapid PTH assays were performed before and after thyroidectomy for 92 new patients receiving total thyroidectomy. Preoperative and postoperative serum calcium and standard PTH levels were serially obtained to 6 months after surgery RESULTS: Postoperative hypocalcemia developed in 34 of 92 patients (37%), who showed significantly lower ioPTH values compared with those of normocalcemic patients (mean 9.2 pg/mL vs 31.3 pg/mL). The ioPTH levels were significantly correlated with standard PTH levels (p < .001, r > 0.62), but not with early serum calcium levels within 8 hours after the operation. Sensitivity and specificity of ioPTH levels of <15.0 pg/mL for the prediction of postoperative hypocalcemia were 85% and 84%, respectively. A value of >15.0 pg/mL and <70% decline in ioPTH after thyroidectomy can reliably identify normocalcemic patients during thyroidectomy or patients requiring close monitoring and early calcium supplement CONCLUSIONS: Rapid ioPTH assay can reliably monitor parathyroid function after thyroidectomy and predict postoperative hypocalcemia. The proposed algorithm based on rapid PTH levels will lead to improved prediction of normocalcemic patients.     

Low parathyroid hormone levels after thyroid surgery: a feasible predictor of hypocalcemia

BACKGROUND: Selecting patients with a low risk of hypocalcemia is mandatory if patients are to be discharged on the first day after bilateral thyroidectomy. This study investigated the predictive value of intraoperative parathyroid hormone (PTH). METHODS: Thirty-eight patients underwent total or near-total thyroidectomy. Patients with or without biochemical and symptomatic hypocalcemia were compared regarding intraoperative PTH levels and previously suggested risk factors. The accuracy of intraoperative PTH to predict patients at risk for postoperative hypocalcemia was compared with a calcium concentration of less than 2.00 mmol/L (8.0 mg/dL) on the first postoperative day. RESULTS: PTH levels after resection of the second lobe, age, and number of parathyroid glands identified intraoperatively were independently associated with the reduction in serum calcium concentration measured at nadir on the first or second postoperative day. PTH levels after resection of the second lobe were lower among patients who developed biochemical (P <.001) and symptomatic hypocalcemia (P <.01) compared with those who did not. Low levels of intraoperative PTH identified the 3 patients who required intravenous calcium during the first 24 postoperative hours. An intraoperative PTH level below reference range and a calcium concentration of less than 2.00 mmol/L measured 1 day postoperatively both predicted biochemical hypocalcemia with a similar sensitivity (90% vs 90%) and specificity (75% vs 82%). Intraoperative PTH was slightly better than a serum calcium concentration of less than 2.00 mmol/L on postoperative day 1 to predict symptomatic hypocalcemia, with a sensitivity of 71% vs 52% and a specificity of 81% vs 76%, respectively. CONCLUSIONS: Parathyroid gland insufficiency is the main determinant of transient hypocalcemia after bilateral thyroid surgery. Low intraoperative PTH levels during thyroid surgery are therefore a feasible predictor of postoperative hypocalcemia.     

A Prophylactic Infusion of Calcium Solution Reduces the Risk of Symptomatic Hypocalcemia in Patients after Total Thyroidectomy

Background Several risk factors have been associated with post-operative transient hypocalcemia after thyroid surgery. However, there are no studies evaluating preventive measures to avoid symptomatic postoperative hypocalcemia. Although intravenous infusion of calcium improves hypocalcemic symptoms, it is unknown whether prophylactic infusion prevents symptoms of postoperative hypocalcemia. Patients and Methods Five hundred and forty-seven patients underwent total thyroidectomy. Two groups were identified: group A (n = 243) received prophylactic intravenous drip infusion of 78–156 mg of calcium solution at 3–8hours after operation, and group B (n = 304) received no prophylactic treatment. Prophylactic infusion was used only once if the patients did not have symptoms of hypocalcemia. Serum calcium (Ca) levels, intact parathyroid hormone (i-PTH) levels on the first postoperative day (1st POD), and the prevalence of symptoms of hypocalcemia were prospectively analyzed. Results The serum Ca levels at the 1st POD in group A patients (7.91 ± 0.49 mg/dl, mean ± SD) was significantly higher than group B patients (7.65 ± 0.54, P < 0.0001), while the serum i-PTH levels were not significantly different between the two groups. The prevalence of numbness and / or tetany before noon on the 1st POD was significantly lower in group A patients. Prophylactic infusion of calcium solution reduced the prevalence of tetany from 8.6% to 2.1%. Conclusion A prophylactic infusion of calcium solution after total thyroidectomy may be useful in reducing the development of symptomatic hypocalcemia and reduces the patients’ risk of having discomfort and anxiety due to hypocalcemia.     

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??Analysis of the risk factors of hypoparathyroidism following total thyroidectomy ZHU Li-zhang, LI Peng, HAN Bin, et al. Department of Thyroid Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
Corresponding author??WEI Wei, E-mail??rxwei1123@163.com
Abstract Objective To investigate the risk factors of transient hypoparathyroidism after total thyroidectomy and the clinical value of routine postoperative calcium supplementation. Methods The data of 237 patients performed total thyroidectomy in Peking University Shenzhen Hospital from January 2017 to October 2017 were analyzed retrospectively. All the patients were given calcium supplementation on the day of operation prophylactically. Meanwhile, PTH and Ca2+ were reexamined on the first day after operation. The clinical data of all the patients were collected and analyzed. Results (1) Among the patients, hypoparathyroidism was occurred in 139 cases (58.6%). Three cases (1.3%) were permanent hypoparathyroidism and 136 cases (57.3%) were transient hypoparathyroidism. (2) There was no significant difference in the incidence of transient hypoparathyroidism among different age, sex, and surgical pathway (P>0.05). (3) The scope of lymph node dissection, reoperation and whether the parathyroid glands were misdissection had statistical significance in the incidence of postoperative hypoparathyroidism (P<0.05). Conclusion (1) Wider lymphadenectomy, complicated surgery and incidental parathyroidectomy are the risk factors of transient hypoparathyroidism.(2) The detection of PTH on the first day after operation can predict postoperative hypoparathyroidism better than serum calcium. (3) Regular supplement of calcium and calctriol can avoid hypocalcemia effectively.     

Prospective study of early predictive factors of permanent hypocalcemia after bilateral thyroidectomy

AIM OF THE STUDY: The aim of this prospective cohort study was to identify the early criteria potentially predictive for outcome of permanent hypocalcemia after thyroidectomy. PATIENTS ET METHODS: Serum calcium (Ca) et phosphorus (Ph) were measured daily until discharge in 2035 consecutive patients undergoing bilateral thyroidectomy. In all patients experiencing postoperative hypocalcemia, defined as a Ca < 8.0 mg/dl on two consecutive days, parathyroid hormone was measured prior initiation of calcium therapy et discharge (early PTH), et blood sample was also obtained 7 to 14 days after discharge for Ca et Ph measurements (delayed Ca et Ph). These patients were then followed up until complete resolution of hypocalcemia or at least one year. Those still needing substitutive therapy to maintain normocalcemia one year after surgery were considered to have permanent hypocalcemia. Correlation of outcome with clinical characteristics, postoperative Ca et Ph levels, early PTH, et delayed Ca et Ph were examined with univariate analysis et multivariate logistic regression. RESULTS: Postoperative hypocalcemia occurred in 153 patients (7.5%) and spontaneously recovered in all but 7 patients (0.3%). Delayed Ca, and delayed Ph were found to be predictive for outcome of hypocalcemia by univariate analysis (p < 0.01). Relative risk to develop permanent hypocalcemia was 15 for patients with early PTH < 12 pg/ml, 52 when delayed Ph was > 4.0 mg/dl, and 121 when delayed Ca was < 8.0 mg/dl. None of the 113 patients with delayed Ca > or = 8.0 mg/dl and delayed Ph < or = 4.0 mg/dl developed permanent hypocalcemia, in contrast to 1 out of 31 patients (3%) with delayed Ca > 8.0 mg/dl or delayed Ph > 4.0 mg/dl, and 6 out of 9 patients (66%) with delayed Ca < 8.0 mg/dl and delayed Ph > 4.0 mg/dl. Both delayed Ca and delayed Ph appeared as independent factors predicting outcome of hypocalcemia at one year with multivariate logistic regression analysis. CONCLUSION: Delayed serum calcium and phosphorus levels, when measured one week after starting calcium therapy but prior to administration of any vitamin D analogs, accurately predict outcome of hypocalcemia after thyroidectomy. Patients with delayed Ca under 8.0 mg/dl and/or delayed Ph above 4.0 mg/dl are at high risk to develop permanent hypocalcemia.     

The impact of age, vitamin D3 level, and incidental parathyroidectomy on postoperative hypocalcemia after total or near total thyroidectomy

Background

Hypocalcemia caused by transient or definitive hypoparathyroidism is the most frequent complication after thyroidectomy. We aimed to compare the impact of incidental parathyroidectomy and serum vitamin D₃ level on postoperative hypocalcemia after total thyroidectomy (TT) or near total thyroidectomy (NTT).

Patients

Two hundred consecutive patients with nontoxic multinodular goiter treated by TT and NTT were included prospectively in the present study. Group 1 (n = 49) consisted of patients with a postoperative serum calcium level ≤8 mg/dL, and group 2 (n = 151) had a postoperative serum calcium level greater than 8 mg/dL. Patients were evaluated according to age, preoperative serum 25-hydroxy vitamin D (25-OHD) levels, postoperative serum calcium levels, incidental parathyroidectomy, and the type of thyroidectomy.

Results

Patients in group 1 (n = 49) were hypocalcemic, whereas patients in group 2 (n = 151) were normocalcemic. Preoperative serum 25-OHD levels in group 1 were significantly lower than in group 2 (P < .001). The incidence of hypoparathyroidism was significantly higher following TT (13.5%) than following NTT (2.5%) (P < .05). The risk for postoperative hypocalcemia was increased 25-fold for patients older than 50 years, 28-fold for patients with a preoperative serum 25-OHD level less than 15 ng/mL, and 71-fold for patients who underwent TT. Incidental parathyroidectomy did not have an impact on postoperative hypocalcemia. The highest risk of postoperative hypocalcemia was found in the patients with all of the above variables.

Conclusions

Age, preoperative low serum 25-OHD, and TT are significantly associated with postoperative hypocalcemia. Patients with advanced age and low preoperative serum 25-OHD levels should be placed on calcium or vitamin D supplementation after TT to avoid postoperative hypocalcemia and decrease hospital stay.     

Intraoperative Secretion of Intact Parathyroid Hormone and Amino-Terminal Parathyroid Hormone Fragments from Normal Parathyroid Glands Associated with Solitary Parathyroid Adenoma

p < 0.05 for both). Because the reduction was more pronounced for i-PTH than for N-PTH, the N/i ratio increased from 0.54 ± 0.33 to 3.76 ± 1.62 ( p < 0.05). Furthermore, the levels of i-PTH and N-PTH were higher centrally than peripherally both before and after adenoma excision ( p < 0.05). The results therefore suggest that the secretion of i-PTH and N-PTH in the remaining normal-size parathyroid glands is not completely suppressed. Furthermore, in these parathyroid glands the secretion of amino-terminal PTH fragments is relatively predominant when compared to the release of the intact PTH. The findings underscore the importance of the N-terminal PTH fragment for maintaining calcium homeostasis during the early postoperative period after surgery for pHPT and may explain the rarity of prolonged hypocalcemia after parathyroidectomy.     

Does Preoperative 25-Hydroxyvitamin D Status Significantly Affect the Calcium Kinetics after Total Thyroidectomy?

Background

Although previous studies have suggested that low preoperative 25-hydroxyvitamin D (25-OHD) is a risk factor for hypocalcemia after total thyroidectomy, the impact of preoperative 25-OHD on calcium (Ca)/parathyroid hormone (PTH) kinetics in the immediate postoperative period remains unclear. The study compared the postoperative Ca/PTH kinetics between different preoperative 25-OHD levels.

Patients

A total of 281 patients who underwent a total thyroidectomy were analyzed. Serum Ca was measured preoperatively within 1 h after surgery (Ca-D0) and on the following morning (Ca-D1). Preoperative 25-OHD was also measured after overnight fasting while postoperative PTH was checked at skin closure on day 0 (PTH-D0) and on the following morning on day 1 (PTH-D1). The Ca/PTH kinetics were compared between three groups (group I: preoperative 25-OHD < 10 ng/mL; group II: 25-OHD = 10–20 ng/mL; group III: 25-OHD > 20 ng/mL).

Results

Group I had significantly lower preoperative Ca (p = 0.016) and Ca-D0 (p = 0.036) but higher PTH-D1 (p = 0.015) than groups II and III. PTH-D0, Ca-D1, and the rate of clinically significant hypocalcemia were similar in the three groups. Group I had a significantly smaller Ca drop (?0.02 vs. 0.01 and 0.02 mmol/L, p = 0.011) and a tendency for a significantly smaller PTH drop (0.4 vs. 0.5 and 1.0 pmol/L, p = 0.073) than groups II and III. PTH-D1 (OR = 1.550) and 25-OHD (OR = 0.958) were independent factors for Ca drop from day 0 to day 1.

Conclusions

Although group I began with lower serum Ca, those patients tended to have a greater PTH response to Ca drop and so preoperative 25-OHD did not significantly affect the overall Ca kinetics from preoperative to day 1.     

An Algorithm Informed by the Parathyroid Hormone Level Reduces Hypocalcemic Complications of Thyroidectomy

Background  

Measurement of the parathyroid hormone (PTH) level following total thyroidectomy (TTx) may allow prediction of postoperative hypocalcemia. We present an algorithmic method of managing hypocalcemia pre-emptively, based on the PTH level 1 h after operation.     

Parathyroid hormone: A sensitive predictor of hypocalcemia following total thyroidectomy

OBJECTIVE: To investigate whether monitoring parathyroid hormone (PTH) could predict hypocalcemia following total thyroidectomy or other bilateral thyroid manipulations. STUDY DESIGN AND SETTING: Forty patients undergoing total thyroidectomy as well as other bilateral thyroid procedures were prospectively enrolled. PTH levels were measured preoperatively and 30 minutes postoperatively. Calcium levels were measured preoperatively and every 8-12 hours for the first 72 postoperative hours. Changes in PTH levels as well as symptoms of hypocalcemia were correlated with postoperative hypocalcemia. RESULTS: Hypocalcemia developed in 13/40 patients (32.5%), mainly those patients undergoing total thyroidectomy in conjunction with paratracheal neck dissections. The respective sensitivity and specificity of a drop in PTH for detecting hypocalcemia was 92% and 66% (50% drop), 23% and 75% (75% drop), and 46% and 100% (drop below normal range). CONCLUSIONS: A 50% drop in PTH levels 30 minutes following bilateral thyroid procedures is a sensitive predictor of hypocalcemia. A drop of 75% is a highly specific indicator of postoperative hypocalcemia, though not highly sensitive. EBM RATING: C-4.     

Same-day discharge after total thyroidectomy: the value of 6-hour serum parathyroid hormone and calcium levels

BACKGROUND: The purpose of this study was to determine whether patients who undergo total thyroidectomy will have postoperative hypocalcemia develop when they reach the critical 6-hour serum levels defined as parathyroid hormone (PTH) > or =28 ng/L and simultaneous corrected calcium > or =2.14 mmol/L. METHODS: This was a prospective study involving 70 consecutive total thyroidectomy patients. There were 51 women and 19 men involved in the study. The mean age was 49.3 years (range, 21-76 years). Patients who had completion thyroidectomy or neck dissections were excluded. Patients undergoing parathyroidectomy at the time of thyroidectomy were also excluded. PTH and corrected calcium levels were measured postoperatively at 6, 12, and 20 hours. RESULTS: Hypocalcemia developed in 24% (17 of 70) of the patients. Of the 53 patients who remained normocalcemic, 68% (36 of 53) reached the 6-hour critical level. None of the hypocalcemic patients (0 of 17) attained the 6-hour critical level (chi-square test p < .0001). This translates into a specificity of 100% (95% confidence interval [CI], 80.5% to 100%) and a positive predictive value of 100% (95% CI, 90.1% to 100%). CONCLUSIONS: The simultaneous evaluation of PTH and corrected calcium levels 6 hours after thyroidectomy allows for an accurate prediction of the trend of serum calcium. This study enables us to confidently consider same-day discharge for most of our thyroidectomy patients.     

The utility of serum PTH assessment 24 hours after total thyroidectomy.

BACKGROUND: Hypocalcemia is the most frequent complication following total thyroidectomy. This prospective study examines the predictive value of parathyroid hormone (PTH) levels measured 24 hours after surgery. MATERIAL AND METHODS: A total of 1006 consecutive patients (mean age, 54.8 years; female/male ratio, 4/1) underwent total thyroidectomy for benign or malignant thyroid from January 1995 to November 2003. Serum calcium, phosphorus, and PTH were measured preoperatively and at 24 hours after surgery. All patients underwent preoperative examination to assess cord motility. RESULTS: A total of 253 (25.1%) patients presented with hypocalcemia demonstrated by clinical and laboratory findings. In 101 cases the hypocalcemic syndrome manifested after 24 to 36 hours whereas in 5 of 101 cases, symptom onset was between 48 and 72 hours. Serum calcium levels lower than 7.5 mg/dL were recorded in all the 101 cases. In 239 of 253 cases serum calcium returned to normal values within 7 days following surgery. PTH at 24 hours was below normal levels in 49 of the 101 patients but was within normal limits in 52 cases. The incidence of hypocalcemia was higher in patients undergoing surgery for malignant thyroid ( P < 0.05). CONCLUSIONS: We do not consider PTH levels at 24 hours postoperatively as predictive of hypocalcemia.     

甲状腺全切除术后暂时性甲状旁腺功能减退危险因素分析

目的 探讨甲状腺全切除术后暂时性甲状旁腺功能减退发生的危险因素及术后常规补钙的临床价值。方法 回顾性分析2017年1-10月于北京大学深圳医院行甲状腺全切除术的237例病人资料,所有病人术后当天给予预防性补钙,且于术后第1天均复查甲状腺素（PTH）、血钙,术后1、3、6个月随访PTH及血钙水平。统计所有病人的临床数据并进行数据分析。结果 （1）237例中出现术后甲状旁腺功能减退的病人139例（58.6%）,其中暂时性甲状旁腺功能减退的病人136例（57.3%）,永久性甲状旁腺功能减退3例（1.3%）。（2）不同年龄、性别、手术路径与术后暂时性甲状旁腺功能减退发生率差异无统计学意义（P＞0.05）。（3）淋巴结清扫范围、是否再次手术及是否误切甲状旁腺与术后暂时性甲状旁腺功能减退发生率差异有统计学意义（P＜0.05）。结论 （1）术后暂时性甲状旁腺功能减退与年龄、性别、手术路径无关,淋巴结清扫范围大、再次手术及甲状旁腺误切更容易导致甲状旁腺功能减退。（2）术后第1天检测PTH能较血钙更好地预测术后甲状旁腺功能减退的发生情况。（3）术后预防性使用钙剂及维生素D3可有效预防低钙血症的发生。     

Excessive Decrease in Serum Magnesium After Total Thyroidectomy for Graves’ Disease Is Related to Development of Permanent Hypocalcemia

Background

Transient postoperative hypocalcemia is one of the most common complications after thyroidectomy. Permanent hypocalcemia, however, is rare, but usually requires life-long treatment and follow-up. The risk of permanent hypocalcemia has been shown to be significantly higher in patients with Graves’ disease. In the present study we evaluated short-term and long-term changes in serum calcium, phosphate, magnesium, and parathyroid hormone (PTH) levels in order to characterize subjects at risk of postoperative hypoparathyroidism.

Methods

Forty patients who underwent total thyroidectomy for Graves’ disease were included in the study. Calcium, phosphate, magnesium, and PTH were measured before surgery and regularly during the year that followed.

Results

Postoperative hypocalcemia was seen in 21/40 (53 %) patients. Undetectable PTH (<0.6 pmol/L) was registered in 11/40 (27 %) patients. All patients with measurable PTH 6–48 h after operation regained normal calcium. Of those with undetectable PTH after 6–48 h, four developed permanent hypocalcemia. We found a significantly lower serum calcium level before operation in patients who developed permanent hypocalcemia compared to those who did not (p < 0.001). We also found a significant correlation between the decrease in serum magnesium from time 0 to 48 h after operation and permanent hypocalcemia (p = 0.015).

Conclusions

Serum calcium prior to operation, serum PTH, and degree of decrease in magnesium levels in serum 48 h after operation may predict development of permanent hypocalcemia. Magnesium plays an important role in calcium homeostasis via stimulation of PTH secretion and modulation of PTH receptor sensitivity. Both mechanisms may have played a role for the findings reported in this article.