Early prediction of hypocalcemia following total thyroidectomy using combined intact parathyroid hormone and serum calcium measurement

Early parathyroid hormone (PTH) level as a predictor of post-surgical hypoparathyroidism

INTRODUCTION

Post-operative hypocalcemia and postoperative persistent hypoparathyroidism remain the most common complications after thyroidectomy. Many approaches have been developed to prevent them, but actually, a common protocol is not yet individuated.

MATERIALS AND METHODS

We retrospectively analyzed the results of a prospectively collected database. We dosed PTH preoperatively and 4 h after surgery (PTH_4); calcium was evaluated preoperatively, on the first (I_POD) and on the second postoperative day (II_POD). Hypocalcemia was defined when calcium <8 mg/dl. PTH_4 and I_POD calcium serum levels are identified to predict postoperative hypocalcemia.

RESULTS

Three hundred and forty-eight patients were enrolled, 37 patients resulted as hypocalcemic on I_POD and 41 on the II_POD. PTH_4 is related to I_POD (p < 0.001, r = 0.45) and II_POD (p < 0.001, r = 0.44) calcemia. PTH_4-cut-off predicting I_POD hypocalcemia was 10.50 pg/ml (sensitivity: 78.7%, specificity: 72.7%). A PTH_4 value of 11.5 pg/ml is able to predict hypocalcemia during II_POD (sensitivity: 76.5%, specificity: 69.2%). We set up a combined test to predict II_POD hypocalcemia, using PTH_4 and I_POD calcium (sensitivity: 77.8%, specificity: 89.9%).

CONCLUSION

This research shows the association between PTH_4 and postoperative hypocalcemia. The PTH_4 cut-off to predict I_POD-hypocalcemia was 10.5 pg/ml. We analyzed the calcemia trend during the postoperative period and we realized a combined test using PTH_4 and I_POD-calcemia. This test improves the accuracy of the previous test. Further studies, in particular multicentric, with a larger sample are necessary to validate the combined model.

Management of Postthyroidectomy Hypoparathyroidism and Its Effect on Hypocalcemia-Related Complications: A Meta-Analysis

OBJECTIVE

The aim of this Meta-analysis is to evaluate the impact of different treatment strategies for early postoperative hypoparathyroidism on hypocalcemia-related complications and long-term hypoparathyroidism.

DATA SOURCES

Embase.com, MEDLINE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and the top 100 references of Google Scholar were searched to September 20, 2022.

REVIEW METHODS

Articles reporting on adult patients who underwent total thyroidectomy which specified a treatment strategy for postthyroidectomy hypoparathyroidism were included. Random effect models were applied to obtain pooled proportions and 95% confidence intervals. Primary outcome was the occurrence of major hypocalcemia-related complications. Secondary outcome was long-term hypoparathyroidism.

RESULTS

Sixty-six studies comprising 67 treatment protocols and 51,096 patients were included in this Meta-analysis. In 8 protocols (3806 patients), routine calcium and/or active vitamin D medication was given to all patients directly after thyroidectomy. In 49 protocols (44,012 patients), calcium and/or active vitamin D medication was only given to patients with biochemically proven postthyroidectomy hypoparathyroidism. In 10 protocols (3278 patients), calcium and/or active vitamin D supplementation was only initiated in case of clinical symptoms of hypocalcemia. No patient had a major complication due to postoperative hypocalcemia. The pooled proportion of long-term hypoparathyroidism was 2.4% (95% confidence interval, 1.9-3.0). There was no significant difference in the incidence of long-term hypoparathyroidism between the 3 supplementation groups.

CONCLUSIONS

All treatment strategies for postoperative hypocalcemia prevent major complications of hypocalcemia. The early postoperative treatment protocol for postthyroidectomy hypoparathyroidism does not seem to influence recovery of parathyroid function in the long term.

Prevention of hypocalcemia and hypoparathyroidism after total thyroidectomy. Recommendations of the Francophone Association of Endocrine Surgery (AFCE) with the French Society of Endocrinology (SFE) and the French Society of Nuclear Medicine (SFMN)

Postoperative hypoparathyroidism, resulting from removal and/or devascularization of one or more parathyroid glands, is a feared complication of total thyroidectomy. Two forms, which are distinguished by their frequency, their time to onset and their duration as well as by their presentation, must be individualized: early postoperative hypocalcemia, often secondary to early hypoparathyroidism is a frequent and often transient situation occurring within the first days after surgery; permanent hypoparathyroidism, which is rarer, manifests when parathyroid function remains impaired for more than six months after surgery. Because of their severity, these conditions must be known and ideally prevented during total thyroidectomy. The objective of this article is to provide surgeons with practical recommendations for the prevention, diagnosis, and treatment of hypoparathyroidism after total thyroidectomy. These recommendations, which are the fruit of a medico-surgical consensus, were developed by the Francophone Association of Endocrine Surgery (AFCE), the French Society of Endocrinology (SFE) and the French Society of Nuclear Medicine and Molecular Imaging. (SFMN). The content, grade and level of evidence for each recommendation was decided after consultation within a panel of experts, based on an analysis of recent literature.

SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Surgical treatment

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French-speaking Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with the surgical management of thyroid nodules.

Definition and diagnosis of postsurgical hypoparathyroidism after thyroid surgery: meta-analysis

BACKGROUND

Postsurgical hypoparathyroidism (PH) is the most frequent complication after thyroid surgery. The aim of this systematic review and meta-analysis is to summarize a unifying definition of PH and to elucidate the best possible approach for early detection of PH.

METHODS

A systematic review of the literature according to the PICO framework using Embase, PUBMED and the Cochrane library was carried out on 1 December 2021 followed by analysis for risk of bias, data extraction and meta-analysis. All studies addressing the definition of postoperative hypoparathyroidism and/or diagnostic approaches for early detection and diagnosis were included. Case reports, commentaries, non-English articles, book chapters and pilot studies and reviews were excluded.

RESULTS

From 13 704 articles, 188 articles were eligible for inclusion and further analysis. These articles provided heterogeneous definitions of PH. Meta-analysis revealed that postoperative measurements of parathormone (PTH) levels have a higher sensitivity and specificity than intraoperative PTH measurements to predict PH after thyroid surgery. None of the timeframes analysed after surgery within the first postoperative day (POD1) was superior to predict the onset of PH. PTH levels of less than 15 pg/ml and less than 10 pg/ml are both reliable threshold levels to predict the postoperative onset of PH. A relative reduction of mean(s.d.) PTH levels from pre- to postoperative values of 73 (standard deviation 11) per cent may also be predictive for the development of PH. The estimation of calcium levels on POD1 are recommended.

CONCLUSION

PH is best defined as an undetectable or inappropriately low postoperative PTH level in the context of hypocalcaemia with or without hypocalcaemic symptoms. PTH levels should be measured after surgery within 24 h. Both threshold levels below 10 and 15 pg/ml or relative loss of PTH before/after thyroid surgery are reliable to predict the onset of PH.

Predictive value of postoperative day 1 parathyroid hormone levels for early and late hypocalcaemia after thyroidectomy

PURPOSE

Early parathyroid hormone (PTH) levels after total thyroidectomy can predict patients at low risk of hypocalcaemia who can be discharged early without calcium supplementation. For centres without facility to perform early PTH levels, PTH levels sent on the first postoperative day (POD1) may be an alternative. However, there is less data regarding optimal cut-off PTH levels for POD1 discharge.

METHODS

Retrospective review of prospective database of thyroid operations between September 2009 and February 2020 at tertiary referral centre. Main outcome measure was symptomatic hypocalcaemia.

RESULTS

Five hundred seventy patients undergoing total (521) or completion thyroidectomy with POD1 PTH levels available were included. Among patients with POD1 PTH levels ≥ 20 pg/ml and POD1 calcium ≥ 2.0 mmol/l, the incidence of symptomatic hypocalcaemia was 1% (3/300), and need for intravenous calcium 0.3% (1/300). For POD1 PTH levels 15-19 pg/ml and POD1 calcium ≥ 2.0 mmol/l, the incidence of symptomatic hypocalcaemia and need for intravenous calcium was 5.4% (3/55). For PTH levels 10-14 pg/ml and calcium ≥ 2.0 mmol/l, the incidence of symptomatic hypocalcaemia and need for intravenous calcium was 11.7% (7/60). The risk of permanent hypoparathyroidism was < 1% for POD1 PTH levels ≥ 15 pg/ml; 5.4% for levels 10-14 pg/ml; and 19.8% for levels < 10 pg/ml.

CONCLUSIONS

POD1 PTH levels ≥ 15 pg/ml along with calcium ≥ 2.0 mmol/l are associated with low risk of symptomatic hypocalcaemia, and represent a safe criterion for discharge of most patients without calcium supplementation. For certain patient groups, a higher threshold of 20 pg/ml could be considered.

Hipocalcemia posterior a tiroidectomía total: Análisis de dosis para suplemento rutinario profiláctico

Introducción. La hipocalcemia es la complicación más frecuente de la tiroidectomía. La profilaxis con calcio/ calcitriol es una alternativa costo-efectiva, sencilla y expedita para disminuir esta situación, sin alterar la función paratiroidea residual. Lo que no está claro es si hay superioridad de una dosis frente a otra, por lo que el objetivo de este estudio fue evaluar el comportamiento entre diferentes esquemas de profilaxis para hipocalcemia. Métodos. Estudio de cohorte retrospectivo de adultos operados en un hospital de cuarto nivel, entre febrero de 2017 y diciembre de 2020. Se calculó la tasa de síntomas, la hipocalcemia e hipercalcemia bioquímica en el control postquirúrgico durante las siguientes dos semanas. Se hizo análisis bivariado y multivariado entre dosis de calcio/ calcitriol, otros factores asociados y los desenlaces mencionados. Resultados. Se incluyeron 967 pacientes. El 10 % presentaron síntomas. No hubo diferencias significativas en el calcio sérico del control posquirúrgico entre los grupos con distintas dosis de calcio. La dosis de carbonato de calcio >3600 mg/día y el calcio en las primeras 24 horas de cirugía se asociaron a la presencia de síntomas. La dosis de calcitriol  <1 mcg/día y el bocio aumentaron el riesgo de hipocalcemia bioquímica, mientras que la dosis de 1,5 mcg/día lo disminuyó. Ninguna variable evaluada se asoció a hipercalcemia bioquímica. Conclusiones. Teniendo en cuenta los resultados observados con las dosis de calcio y calcitriol, sugerimos iniciar la profilaxis con un esquema de 3600 mg/día de carbonato de calcio y 1,5 mcg/día de calcitriol. Sin embargo, esta dosis debe modificarse en situaciones como bocio o calcio sérico temprano anormal, que fueron las variables asociadas a mayor riesgo en nuestro estudio.

The role of early postoperative parathyroid hormone level after total thyroidectomy in prediction of hypocalcemia

Background

Estimation of parathyroid hormone (PTH) after thyroid surgery helps to predict the development of hypocalcemia and allows early intervention and management with oral calcium and/or vitamin D supplementation in the postoperative period.

Patients and methods

This retrospective study included 57 patients who underwent total or completion thyroidectomy within 4 years. Measurement of serum PTH level was done 3 h after surgery for its change and prediction of hypocalcemia.

Results

The mean age was 42.11 years, females constituted 46 patients (80.7%), the main surgical procedure was total thyroidectomy in 51 patients (89.5%), and the main cause for surgery was multinodular goiter in 33 patients (57.8%). Three hours after surgery 47 patients (82.5%) had serum PTH levels of >10 pg/ml (mean 28.06) and 44 patients (77.2%) had normal serum calcium (mean 8.66). Most of these 47 patients (82.46%) didn't require postoperative supplementation, while from other 10 patients (17.5%) with serum PTH level of <10 pg/ml, 7 patients (12.28%) required both oral calcium and vitamin D, and 3 patients (5.26%) required only oral vitamin D.There was a significant correlation between the 3-h postoperative PTH level and hypocalcemia (P-value 0.000). The type of pathology had no significant association with lowserum PTH level after surgery (P-value 0.166).

Conclusion

PTH measurements at 3 h after total thyroidectomy is an accurate predictor for the development of hypocalcemia and allows starting early calcium and/or vitamin D supplements for the asymptotic patients with PTH level of less than 10 pg/ml, which is considered a high-risk group. Also it facilitates a safe and early (2nd ^t day post operative) discharge of those patients with serum PTH levels greater than 10 pg/ml without any supplements.

Further studies are needed to compare the result of early serum PTH level with the day one serum PTH level after total thyroidectomy to predict hypocalcemia.

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Symptomatic parathyroid dysfunction is a common complication after total or completion thyroidectomy.

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Some studies recommend the routine estimation of parathyroid hormone level after thyroid surgery.

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Routine usage of oral calcium and/or vitamin D reduce hypocalcemia incidence.

Prediction of post-idroidectomy hypocalcemia through rapid PTH determination

INTRODUCTION

Hypocalcemia is the most frequent complication after thyroidectomy. The aim of this work is to identify biochemical risk factors of hypocalcemia using quick perioperative (pre and post-thyroidectomy) intact parathyroid hormone (PTHi) and postoperative calcemias.

METHODS

In a consecutive series of 310 total thyroidectomies, samples of quick PTHi at the anaesthetic induction and 10 minutes after surgery, together with serum calcemias every 12 hours were obtained. The sensitivity, specificity, positive and negative predictive value are analyzed and related to hypocalcemia. A control group of hemithyroidectomies is also analyzed to compare the effects of surgery on PTH secretion.

RESULTS

Of the 310 patients, 202 (65.1%) remained normocalcemic and asymptomatic (group A), 108 (34.9%) presented hypocalcemia (Group B), requiring oral calcium (79 symptomatic). After analysis of several cut-off points, combining a PTHr drop gradient of 60% or calcemia inferior to 7.4 mg/dl at 24 hours, a sensitivity of 100% is achieved without leaving false negatives. Compared to the control group, there is a significant difference with respect to the post-operative calcemias and PTHr, p < 0.001.

CONCLUSIONS

Total thyroidectomy affects parathyroid function with evident decrease in rPTH and risk of hypocalcemia. The combination of PTHr decrease of 60% or less than 7.4 mg/dl calcemia at 24 hours gives a 100% sensitivity for predicting patients at risk of hypocalcemia.

Predictors of post-thyroidectomy hypocalcaemia: a systematic and narrative review

OBJECTIVE

Hypocalcaemia is the most common complication after total or completion thyroidectomy. This study assesses recent evidence on predictive factors for post-thyroidectomy hypocalcaemia in order to identify the patients affected and aid prevention.

METHOD

Two authors independently assessed articles and extracted data to provide a narrative synthesis. This study was an updated systematic search and narrative review regarding predictors of post-thyroidectomy hypocalcaemia using the Ovid Medline, Embase, Cochrane and Cinahl databases. Results were limited to papers published from January 2012 to August 2019.

RESULTS

Sixty-three observational studies with a total of 210 401 patients met the inclusion criteria. The median incidence was 27.5 per cent for transient biochemical hypocalcaemia, 12.5 per cent for symptomatic hypocalcaemia and 2.2 per cent for permanent hypocalcaemia. The most frequent statistically significant predictor of hypocalcaemia was peri-operative parathyroid hormone level. Symptomatic hypocalcaemia and permanent hypocalcaemia were seen more frequently in patients undergoing concomitant neck dissection.

CONCLUSION

Many factors have been studied for their link to post-thyroidectomy hypocalcaemia, and this study assesses the recent evidence presented in each case.

Risk factors and effects of hypocalcemia prior to discharge following thyroidectomy

PURPOSE

To find patient and surgical characteristics associated with hypocalcemia prior to discharge (HPTD) in thyroidectomy patients.

MATERIALS AND METHODS

In a retrospective analysis of the 2016-2017 National Surgical Quality Improvement Program, eligible total thyroidectomy patients were stratified into cohorts based on development of HPTD. We identified demographic and surgical risk factors for the development of hypocalcemia via binary logistic regression and identified the negative sequelae of HPTD utilizing univariate and multivariate methods.

RESULTS

We identified a total of 6519 patients who underwent total thyroidectomy, of which 450 (6.9%) had HPTD. Predictors associated with an increased incidence of HPTD included female sex (OR: 1.737 [95% CI: 1.319-2.288]; p < .001), increased operative time (OR: 1.003 [1.002-1.004]; p < .001), and central neck dissection (OR: 1.484 [1.190-1.850]; p < .001). However, factors that decreased incidence of HPTD included increased age, obesity (OR: 0.648 [0.501-0.837]; p = .001), and the use of vessel sealant devices (VSD) (OR: 0.650 [0.527-0.803]; p < .001). Multivariate analysis further revealed that HPTD independently led to an increased hospitalization length after surgery (B: 0.708 [0.607-0.809]; p < .001) and an increased 30-day readmission rate (OR: 2.429 [1.594-3.704]; p < .001).

CONCLUSION

Obesity, increased age, and intra-operative VSD use were significantly associated with decreased rates of HPTD after total thyroidectomy. Female sex, longer operations, and central neck dissections were associated with HPTD. Delineating risk factors and protective factors for HPTD in total thyroidectomy patients is important as patients with HPTD were found to be at a significantly higher risk for longer post-operative stays, increased odds of 30-day readmission, and increased hypocalcemia-related event.

Correlation between iPTH Levels on the First Postoperative Day After Total Thyroidectomy and Permanent Hypoparathyroidism: Our Experience

Permanent hypoparathyroidism is the most common long-term complication after thyroidectomy. We evaluated whether iPTH concentrations on the first postoperative day may be a good predictor of this complication.

Patients undergoing thyroidectomy in our Unit between January 2017 and February 2018 who developed postsurgical hypoparathyroidism were analysed. According to iPTH values on the first postoperative day and on the basis of the detection threshold of the iPTH test used, patients were divided into 2 groups: Group A (iPTH < 6.3 pg/mL, undetectable), Group B (iPTH ≥ 6.3 pg/mL).

Seventy-five patients were included in this study: 64 in Group A and 11 in Group B. Permanent hypoparathyroidism occurred in 14 (21.88%) patients in Group A, while none developed this complication in Group B. When iPTH was < 6.3 pg/mL, the sensitivity for the prediction of permanent hypoparathyroidism was 100%, the specificity was 18.03%, the positive predictive value was 21.88% and the negative predictive value was 100%.

No patient with iPTH ≥ 6.3 pg/mL on the first postoperative day developed permanent hypoparathyroidism. On the other hand, iPTH concentrations < 6.3 pg/mL have not proved to be a strong predictor of this condition. However, this cut-off value can be useful to identify patients at risk of developing this complication.

Huge variations in definition and reported incidence of postsurgical hypoparathyroidism: a systematic review

PURPOSE

The reported incidence of post surgical hypoparathyroidism (HypoPT) varies greatly. Previous research suggests that the definition of HypoPT is not consistent in the literature. We therefore conducted a systematic review to investigate how HypoPT is defined and whether this definition, as well as the selected threshold for hypocalcemia affects the incidence.

METHODS

Using a predefined search string we identified all articles in PubMed reporting on the incidence of postsurgical HypoPT from 1st January 2010 to January 2017.

RESULTS

We identified 89 articles that employed 20 different definition of HypoPT. The incidence of HypoPT varied from 0.0% to 20.2%. The definitions were not associated with incidence of HypoPT. Use of prophylactic post-operative calcium supplements, however decreased the risk of HypoPT (p = 0.03), and there was a trend towards a lower risk of HypoPT when using a definition of hypocalcemia below lower limit of the reference range (p = 0.09).

CONCLUSION

The large number of definitions of HypoPT, as well as the huge variation in incidence point to a problem suggests that the awareness of HypoPT should be raised. Use of prophylactic post-operative calcium supplements may decrease risk of HypoPT. This, however, may be due to reverse causality as awareness of the risk of HypoPT may promote the use of calcium supplementation.

The Impact of Postoperative Percent Change of Parathormone Level From Baseline Value on the Rate of Hypocalcemia After Total Thyroidectomy

Background

The purpose of this study was to investigate the impact of the percent change of postoperative parathormone (PoPTH) level from baseline value (ΔPTH) on the rate of hypocalcemia after total thyroidectomy.

Methods

Assays of serum PTH and calcium (Ca) were performed preoperatively and at 24 hours postoperatively in 222 consecutive patients who underwent total thyroidectomy. Postoperative hypocalcemia was defined as serum calcium level corrected for albumin concentration (cCa) &lt;8.5 mg/dL. Patients with postoperative hypocalcemia were classified as group 1 (n = 100) and those with normal Ca levels as group 2 (n = 122). The PoPTH levels and ΔPTH were compared between the 2 groups. Receiver operating characteristic analysis was performed to determine the cutoff values for PoPTH and ΔPTH.

Results

The mean PoPTH level was significantly lower in group 1 compared with group 2 (18.6 ± 15.3 versus 32.3 ± 15.6 pg/mL, respectively; P &lt; 0.0001). PoPTH values were within the normal range in 54% of the patients with hypocalcemia and 35% of those with symptomatic hypocalcemia. PoPTH &lt;28 pg/mL or ΔPTH &gt;45 were significantly associated with increased risk of post-thyroidectomy hypocalcemia (P = 0.0001). A ΔPTH &gt;70%, PoPTH ≤15.5 pg/mL, and postoperative serum cCa concentrations&lt;8.0 mg/dL significantly predicted symptomatic hypocalcemia (P = 0.009, P = 0.006, and P = 0.0001, respectively). The sensitivities of ΔPTH, PoPTH level, and postoperative serum cCa concentration to predict symptomatic hypocalcemia were 67%, 64%, and 100%, respectively.

Conclusion

Although PTH decline significantly correlates with symptomatic hypocalcemia, a considerable number of patients may experience hypocalcemic symptoms despite normal PoPTH levels. Analysis of serum Ca concentrations at 24 hours postoperatively help to achieve a more precise prediction of patients who bear a high risk for developing hypocalcemic symptoms.

Risk factors for hypocalcemia and hypoparathyroidism following thyroidectomy: a retrospective Chinese population study

Background

Hypocalcemia is one of the most common postoperative complications following thyroid surgery in clinical practice. The occurrence of hypocalcemia is mainly attributed to hypoparathyroidism when parathyroid glands are devascularized, injured, or dissected during the surgery. The aim of this study was to analyze the risk factors for hypocalcemia and hypoparathyroidism following thyroidectomy.

Patients and methods

A total of 278 patients who underwent thyroid surgery were analyzed retrospectively. Univariate analysis and multivariable logistic regression were performed to discover the risk factors for hypocalcemia and hypoparathyroidism.

Results

Postoperative hypocalcemia occurred in 76 (27.3%) patients and hypoparathyroidism occurred in 42 (15.1%) patients. Seven factors were significantly related to the presence of postoperative hypocalcemia, namely, age (P=0.049), gender (P=0.015), lateral lymph node dissection (P=0.017), operation type (P<0.001), preoperative parathyroid hormone (PTH) level (P=0.035), operation time (P=0.001), and applying carbon nanoparticles (CNs; P=0.007). Our result revealed that gender (P=0.014), lateral lymph node dissection (P=0.038), operation type (P<0.001), operative time (P<0.001), and applying CNs (P=0.001) had a significant correlation with postoperative hypoparathyroidism.

Conclusion

These findings were crucial for guiding surgeons to prevent the occurrence of hypocalcemia and hypoparathyroidism.

[Intraoperative parathyroid hormone measurement is the best predictor of postoperative symptomatic hypocalcemia]

BACKGROUND

The goal of this study is to evaluate risk factors for transient postoperative hypocalcemia (HC) and to define cutoff values for perioperative parathyroid hormone (PTH) and calcium parameters (Ca) to reduce the morbidity of symptomatic HC.

MATERIALS AND METHODS

At our tertiary referral hospital (Luzerner Kantonsspital, Switzerland), a total of 353 patients underwent total thyroidectomy between 2006 and 2013 and were analyzed retrospectively in terms of HC risk. The serum values of calcium and PTH were measured at strictly defined time intervals, and patients' symptoms and the necessity of treatments were determined from patients' charts.

RESULTS

The prevalence of transient postoperative HC was 43%; however, only 10% of patients were symptomatic. Significant risk factors for serum and symptomatic HC were calcium values (pre-, intra-, 4 h and 1 d postoperative), PTH values (intraoperative, 4 h and 1 d postoperative), and PTH decline. Interestingly, preoperative PTH values, patient age, weight of the thyroid gland, diagnosis, and sex were not significant risk factors. In the ROC analysis ('receiver operating characteristics'), calcium measurement 4 h postoperatively showed the best predictive ability for detecting serum HC, whereas intraoperative PTH measurements were predictive for symptomatic HC.

CONCLUSION

Calcium and PTH values as well as PTH decline are significant risk factors for postoperative HC. Preoperatively, only calcium measurement is prognostically significant. Intraoperative PTH measurement is the most reasonable and sensitive factor for early recognition of temporary postoperative HC in the clinical setting.

Early prediction of hypocalcemia following thyroid surgery. A prospective randomized clinical trial

PURPOSE

The aim of this randomized-controlled trial was to validate the results of a previous prospective single-cohort observational study conducted in the same surgical unit regarding the use of concomitant intact parathyroid hormone (iPTH) and serum calcium measurement in predicting hypocalcemia after total thyroidectomy.

METHODS

From January 2014 to January 2015, 150 patients underwent total thyroidectomy in our department and were randomized into two groups. The experimental group was submitted to iPTH assay 6 h after surgery while the control group was submitted to a daily assay of serum calcium and phosphorus. Sensitivity and specificity of different serum measurements have been calculated using the receiver-operator characteristics (ROC) curve.

RESULTS

The prevalence of hypocalcemia was 14.25% in both groups. The assay of iPTH 6 h after surgery combined with the serum calcium assay 24 h after surgery yielded the highest diagnostic accuracy in predicting hypocalcemia using ROC curves, with 100% sensitivity and 100% specificity.

CONCLUSIONS

According to our previous study, the combined measurement of iPTH 6 h after surgery and of serum calcium 24 h after surgery are highly predictive of early postoperative hypocalcemia. These results are important in selecting the patients eligible for early discharge and those who need calcium and vitamin D supplementation.

Preoperative vitamin D deficiency and postoperative hypocalcemia in thyroid cancer patients undergoing total thyroidectomy plus central compartment neck dissection

Background

There appears to be a lack of consensus whether preoperative vitamin D deficiency (VDD) increases the risk of postoperative hypocalcemia and decreases the accuracy of postoperative parathyroid hormone (PTH) in predicting hypocalcemia in thyroid cancer patients undergoing total thyroidectomy (TT) plus central compartment neck dissection (CCND). This study aims to address these issues.

Method

All consecutive thyroid cancer patients who underwent TT plus CCND were retrospectively reviewed through a prospectively collected database between October 2015 and April 2016 in a tertiary referral hospital. The multivariate analysis was performed to identify the significant predictors for hypocalcemia. Receiver operator characteristic curve (ROC) was created and the area under the ROC was used to evaluate the predictive accuracy of postoperative PTH and compared between patients with or without VDD.

Results

A total of 186 patients were included. The incidence of VDD was 73.7% (137 patients). The incidence of biochemical and symptomatic hypocalcemia was similar in patients with or without VDD (P = 0.304 and 0.657, respectively). Multivariate analysis showed that only postoperative PTH was an independent predictor of symptomatic hypocalcemia (OR = 8.05, 95%CI = 3.99-16.22; P = 0.000). The area under the ROC was similar between patients with preoperative vitamin D level < 20 and ≥20 ng/mL (0.809 versus 0.845, P = 0.592).

Conclusion

VDD was not a significant risk factor for hypocalcemia following TT+CCND, and did not affect the accuracy of postoperative PTH as a predictor of postoperative hypocalcemia. Thus, routine preoperative screening for vitamin D seems to be unnecessary.

Postoperative hypomagnesaemia is not associated with hypocalcemia in thyroid cancer patients undergoing total thyroidectomy plus central compartment neck dissection

BACKGROUND

The literature remains scarce and controversial regarding the association of hypomagnesaemia and hypocalcemia after total thyroidectomy. This study aims to assess this association in thyroid cancer patients underwent total thyroidectomy (TT) plus central compartment neck dissection (CCND).

METHOD

All consecutive thyroid cancer patients who underwent TT plus CCND were retrospectively reviewed through a prospectively collected database between October 2015 and June 2016 in a tertiary referral hospital. The univariate and multivariate analysis were performed to identify the significant predictors for hypocalcemia.

RESULTS

A total of 237 patients were included. The incidence of postoperative biochemical and symptomatic hypocalcemia was 52.3% (124 patients) and 33.8% (80 patients), respectively. Multivariate analysis showed that only postoperative hypoparathyroidism was an independent predictor for biochemical hypocalcemia (HR = 14.37, 95%CI = 6.07-34.0; P < 0.000), while parathyroid gland autotansplantation (HR = 2.02, 95%CI = 1.04-3.91; P = 0.038) and hypoparathyroidism (HR = 7.47, 95%CI = 3.84-14.5; P < 0.000) were independent risk factor for symptomatic hypocalcemia. Postoperative hypomagnesaemia was not significantly associated with the development of hypocalcemia (P > 0.05).

CONCLUSION

Postoperative hypomagnesaemia was not an independent predictor of hypocalcemia after total thyroidectomy. It seems to be unnecessary to routinely monitor the magnesium levels before and after thyroid surgery.

Prophylactic oral calcium supplementation therapy to prevent early post thyroidectomy hypocalcemia and evaluation of postoperative parathyroid hormone levels to detect hypocalcemia: A prospective randomized study

BACKGROUND

Postoperative hypocalcemia is the most common complication after total thyroidectomy. Postoperative parathyroid hormone (PTH) measurement is one of the methods to detect or prevent postoperative hypocalcemia. Prophylactic oral calcium supplementation is another method to prevent early postoperative hypocalcemia. The aim of this study is to detect the accurate timing of PTH and evaluate efficacy of routine oral calcium supplementation for postoperative hypocalcemia.

METHODS

A total of 106 patients were performed total thyroidectomy. Rotuine oral calcium supplementation was given to group 1 and no treatment to group 2 according to randomization. Serum calcium and PTH level of patients in group 2 at postoperative 6, 12 and 24 h and patients in both groups at postoperative day 7 were evaluated. Patients were compared according to age, sex, operation findings, serum calcium and PTH levels and symptomatic hypocalcemia.

RESULTS

Half of the patients (50%) were in group 1. Most of the patients were female (83%). The most common etiology of thyroid disease was multinodular goiter (64.1%). Oral calcium supplementation was given to 18 (33.9%) patients in group 2. Symptomatic hypocalcemia for group 1 and 2 was found to be 1.9 and 33.9% respectively (p < 0.05). No statistical difference can be observed regarding the timing of serum biomarkers.

CONCLUSION

Serum PTH levels at postoperative 12 and 24 h can predict early post-thyroidectomy hypocalcemia. Prophylactic oral calcium supplementation therapy can prevent early post-thyroidectomy hypocalcemia with advantages of being cost effective and safe.

Risk of Complications after Thyroidectomy and Parathyroidectomy: A Case Series with Planned Chart Review

OBJECTIVE

To develop a predictive model for the risk of complications after thyroid and parathyroid surgery.

STUDY DESIGN

Case series with planned chart review of patients undergoing surgery, 2007-2013.

SETTING

Kaiser Permanente Northern California and Kaiser Permanente Southern California.

SUBJECTS AND METHODS

Patients (N = 16,458) undergoing thyroid and parathyroid procedures were randomly assigned to model development and validation groups. We used univariate analysis to assess relationships between each of 28 predictor variables and 30-day complication rates. We subsequently entered all variables into a recursive partitioning decision tree analysis, with P < .05 as the basis for branching.

RESULTS

Among patients undergoing thyroidectomies, the most important predictor variable was thyroid cancer. For patients with thyroid cancer, additional risk predictors included coronary artery disease and central neck dissection. For patients without thyroid cancer, additional predictors included coronary artery disease, dyspnea, complete thyroidectomy, and lobe size. Among patients undergoing parathyroidectomies, the most important predictor variable was coronary artery disease, followed by cerebrovascular disease and chronic kidney disease. The model performed similarly in the validation groups.

CONCLUSION

For patients undergoing thyroid surgery, 7 of 28 predictor variables accounted for statistically significant differences in the risk of 30-day complications; for patients undergoing parathyroid surgery, 3 variables accounted for significant differences in risk. This study forms the foundation of a parsimonious model to predict the risk of complications among patients undergoing thyroid and parathyroid surgery.

Clinical Pathway for Thyroidectomy

Clinical pathways are care plans applicable to patient care procedures that present variations in practice and a predictable clinical course. They are designed not as a substitute for clinical judgment, but rather as a means to improve the effectiveness and efficiency of the procedures. This clinical pathway is the result of a collaborative work of the Sections of Endocrine Surgery and Quality Management of the Spanish Association of Surgeons. It attempts to provide a framework for standardizing the performance of thyroidectomy, the most frequently performed operation in endocrine surgery. Along with the usual documents of clinical pathways (temporary matrix, variance tracking and information sheets, assessment indicators and a satisfaction questionnaire) it includes a review of the scientific evidence around different aspects of pre, intra and postoperative management. Among others, antibiotic and antithrombotic prophylaxis, preoperative preparation in hyperthyroidism, intraoperative neuromonitoring and systems for obtaining hemostasis are included, along with management of postoperative hypocalcemia.

Postoperative hypoparathyroidism after thyroidectomy: efficient and cost-effective diagnosis and treatment

BACKGROUND

To describe a standardized, efficient, and cost-effective protocol for the diagnosis of temporary/persisting postoperative hypoparathyroidism after (total) thyroidectomy.

METHODS

We included 237 consecutive patients who underwent (total) thyroidectomy without central neck dissection for various indications. Serum calcium (sCa) and intact parathyroid hormone (iPTH) levels were measured prospectively on the morning of postoperative day 1 to predict the long-term parathyroid metabolism. On the morning of postoperative day 2, measurements were repeated. Follow-up was performed at 1 and 6 months postoperatively.

RESULTS

On the morning of postoperative day 1, patients with iPTH ≥ 15 pg/mL (178/237; 75%) and sCa > 2.0 mmol/L were normocalcemic, and "normal" parathyroid metabolism was predicted. iPTH levels of <10 pg/mL and sCa levels of ≤2.0 mmol/L were present in 33 of the 237 patients ("disturbed" parathyroid metabolism; 14%). A "gray zone" included patients with "uncertain" parathyroid metabolism demonstrating iPTH levels between 10 and 15 pg/mL (26/237; 11%). Patients with "disturbed" and "uncertain" parathyroid metabolism were given oral calcium and vitamin D. On the morning of the second postoperative day, iPTH turned to "normal" in 10 of those 26 (38%) patients, and no further calcium or vitamin D was given. During follow-up, supplemental calcium and vitamin D was able to be stopped in all but 2 patients ("permanent" hypoparathyroidism; 2/237; 0.8%).

CONCLUSION

Measurement of iPTH on the morning after operation allows accurate prediction of postoperative parathyroid function in ≥99% of cases. This simple recommendation is practicable in all surgical units, and is an efficient and cost-effective way to recognize patients who require calcium and vitamin D supplementation.