Incidence and predictors of post-thyroidectomy hypocalcaemia in a tertiary endocrine surgical unit

A Study of Incidence and Management of Postoperative Hypocalcemia in Patients Undergoing Near-Total and Total Thyroidectomy

To study the incidence and management of postoperative hypocalcemia in participants undergoing near-total (NTT) and total thyroidectomy (TT) at a tertiary health care center. This is an observational prospective study. Patients posted for NTT and TT in our institute and meeting the inclusion criteria were included. A total of 45 participants were enrolled. The serum calcium was measured on postoperative day 2, at the time of discharge and on 3 months follow-up. A combination of injectable and oral calcium supplements with or without vitamin D sachet was used for the treatment of hypocalcemia. Hypocalcemia was observed in 49% cases. Women were observed to develop hypocalcemia at a higher rate than men. Incidence of hypocalcemia was more in TT patients than NTT patients. Cases with malignant pathology were more susceptible to develop hypocalcemia than those with benign pathology. Operated TT with concomitant neck dissection were at higher risk for development of hypocalcemia. There was no significant association between age and incidence of hypocalcemia. Serum calcium measured on postoperative day 2 was a reliable indicator of risk of hypocalcemia. The early measurement of serum calcium level is a reliable indicator of the risk of hypocalcemia. Standardized treatment of hypocalcemic patients with calcium and vitamin D supplements can reduce the incidence and morbidity associated with postoperative hypocalcemia.

Development of a tool to calculate the probability of hypocalcemia after total thyroidectomy: a prospective study

PURPOSE

This study aimed to evaluate the ability of the percentage of decrease in serum PTH level in the first 8 h after total thyroidectomy (TT) to predict hypocalcemia requiring Ca supplementation and develop a tool to predict it.

METHODS

97 patients who underwent TT with measurement of preoperative parathyroid hormone (PTH) levels were prospectively evaluated 1 and 8 h after TT; postoperative magnesium (Mg2PO) and phosphorus levels were evaluated on the 2nd day after surgery. The percentage of decrease in PTH level 1 h (%dPTH1h) and 8 h (%dPTH8h) postoperatively and predictors of hypocalcemia requiring Ca supplementation were evaluated and an equation was developed to predict this outcome.

RESULTS

%dPTH1h (p = 0.002), %dPTH8h (p = 0.001) and (Mg2PO) (p < 0.01) were isolated predictors of postoperative hypocalcemia requiring Ca supplementation. The data obtained led to the development of two tools to predict this complication.

CONCLUSIONS

The percentage of decrease in PTH level 1 h and 8 h postoperatively and the magnesium level on the 2nd day after surgery were predictors of more severe hypocalcemia, and an auxiliary tool for predicting this complication was developed.

Incidence and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy

PURPOSE

The incidence and risk factors for hypoparathyroidism after total thyroidectomy is well-known. However, the characteristics of hypoparathyroidism and hypocalcemia after hemithyroidectomy have not been investigated well. In this study, we aimed to evaluate the incidence, characteristics, and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy.

METHOD

We retrospectively analyzed the medical data of 321 patients who underwent hemithyroidectomy, with or without central neck dissection, from January 2012 to April 2019. We analyzed the serum intact parathyroid hormone (iPTH), calcium, and ionized calcium (iCa) levels serially (preoperatively and postoperatively on the operation day; days 1 and 3; and months 1, 3, 6, and 12) and evaluated risk factors for postoperative hypoparathyroidism and hypocalcemia.

RESULTS

The mean iPTH and calcium levels decreased significantly after hemithyroidectomy on the operation day and postoperative days 1 and 3, and returned to the preoperative level at the postoperative 1-month follow-up. The mean iCa level decreased significantly on the operation day and postoperative day 1. Transient hypoparathyroidism and transient hypocalcemia occurred in 16 (5%) and 250 (78%) participants, and they recovered to normal levels postoperatively by 1 month. Eight (2.5%) patients had mild symptoms of hypocalcemia necessitating oral calcium supplementation. No permanent hypoparathyroidism or hypocalcemia was observed. Preoperatively low serum iPTH and calcium levels were associated with transient hypoparathyroidism and hypocalcemia after hemithyroidectomy.

CONCLUSION

Approximately 5% and 2.5% of participants showed transient hypoparathyroidism and mild symptomatic hypocalcemia after hemithyroidectomy. The risk factors for transient hypoparathyroidism and hypocalcemia include preoperative low serum iPTH and calcium levels.

Indocyanine green (ICG) angiography-guided thyroidectomy: description of surgical technique

Background

Postoperative hypoparathyroidism is the most common complication after total thyroidectomy and, when becomes permanent, lead to a myriad of clinical symptoms, long-term need of calcium and vitamin D supplementation and negative impact on the patient's health-related quality of life. Any surgical innovation that could reduce complications and improve outcomes of patients undergoing total thyroidectomy deserves to be considered. Angiography-Guided Thyroidectomy has been proposed as a modification of the standard technique of thyroidectomy aimed to identifying the vascular pattern of the parathyroid glands to maximize efforts for preserving functioning glands at the time of operation. Our aim is to provide a technical description of this procedure based on the use of indocyanine green (ICG) angiography to standardize this technique.

Methods

The surgical steps that are followed during a total thyroidectomy are modified due to previous visualization of the feeding vessels of the parathyroid glands according to fluorescence of the vascular mapping obtained by ICG angiography prior to thyroidectomy. The first step is to perform an ICG angiography to assess anatomical features of the feeding vasculature of the parathyroid glands, which allows precise surgical dissection for preservation of the glands. Once the viability of the parathyroids has been evaluated angiographically, thyroidectomy is performed in a second step.

Conclusions

ICG angiography-guided thyroidectomy may be effective to preserve the largest number of better perfused parathyroid glands, which would contribute to reduce the risk of postoperative and permanent hypoparathyroidism. It can be successfully and safely implemented in thyroid surgery and standardization of the technique is necessary to homogenize this procedure in the future, allowing a better comparation of the results to be published.

Transoral endoscopic thyroidectomy vestibular approach: Results after 53 first cases

INTRODUCTION

Trans Oral Endoscopic Thyroidectomy through Vestibular Approach (TOETVA) allows access to the thyroid with the best cosmetic results as there are no visible scars.

METHODS

Here we present a prospective observational study of 53 patients which underwent TOETVA from July 2017 to June 2021.

RESULTS

Fifty-two cases (98.1%) cases were women (median age 44 years old). Thyroid nodule was the main surgical indication accounting 73.6% of cases. We performed 42 lobectomies and 11 total thyroidectomies; 4 left Central Neck Dissection (CND) were also associated. The median surgical time for port placement was 14 min and for lobectomy, total thyroidectomy and left CND were 80, 140 and 30 min, respectively. The median of hospital stay was 2 days. Dysphonia was present in 4 patients; however, laryngoscopy only confirmed laryngeal nerve impairment in 2 cases, one of them classified as permanent (1.6%). In those patients that underwent total thyroidectomy, the rate of transient hypoparathyroidism was 18.2% whereas permanent was 0%. Regarding complications associated to the new approach, transient chin numbness appeared in all patients with a variable degree of intensity.

CONCLUSTIONS

Transoral surgery is a recent approach in our Unit. Our results, based on the first 53 patients, show that it is a safe and effective approach when performed in appropriately selected patients offering the best cosmetic result. Besides, new complications associated to the approach has been shown to be transient.

Intact Parathyroid Hormone Levels in Predicting Postoperative Hypocalcaemia After Total Thyroidectomy in South Indian Population: Cross Sectional Study

Hypocalcaemia being one of the most common complications after total thyroidectomy may not be avoidable in all cases. This study evaluated the effectiveness of intact Parathyroid hormone (iPTH) measured at 1-h after total thyroidectomy in predicting postoperative hypocalcaemia in early postoperative period in South Indian population. Patients who underwent total thyroidectomy in our institute from 2016 to 2018 were included. Preoperative calcium and iPTH levels were measured. Patients' iPTH level was measured 1 h after surgery and serum calcium level was measured at 24 h after surgery. Patients were also monitored clinically for any symptoms and signs of hypocalcaemia. A total of 57 patients were studied. The malignant causes accounted for 75.4% with papillary carcinoma thyroid being the most common cause. 65.7% of patients who underwent total thyroidectomy and 100% of patients who underwent total thyroidectomy with neck dissection developed hypocalcaemia. 70% of patients with low iPTH developed hypocalcaemia and none of the patients who had normal iPTH developed hypocalcaemia. This relation was statistically significant with p value of 0.018 (< 0.05). The positive predictive value is 70% and negative predictive value is 100%. Though our study supports the hypothesis that iPTH is effective in predicting hypocalcaemia after total thyroidectomy in the early postoperative period, a larger sample study is needed to further support this. It can be used to consider patients for early discharge or to prophylactically start oral calcium and Vitamin D supplementation based on iPTH levels at 1 h after surgery.

Late Recovery of Parathyroid Function after Total Thyroidectomy in Children and Adults: Is There a Difference?

BACKGROUND

Parathyroid failure after total thyroidectomy is the commonest adverse event amongst both children and adults. The phenomenon of late recovery of parathyroid function, especially in young patients with persistent hypoparathyroidism, is not well understood. This study investigated differences in rates of parathyroid recovery in children and adults and factors influencing this.

METHODS

A joint dual-centre database of patients who underwent a total thyroidectomy between 1998 and 2018 was searched for patients with persistent hypoparathyroidism, defined as dependence on oral calcium and vitamin D supplementation at 6 months. Demographic, surgical, pathological, and biochemical data were collected and analysed. <F00_Regular>Parathyroid Glands Remaining</F00_Regular> in Situ (PGRIS) score was calculated.

RESULTS

Out of 960 patients who had total thyroidectomy, 94 (9.8%) had persistent hypoparathyroidism at 6 months, 23 (24.5%) children with a median [range] age 10 [0-17], and 71 (75.5%) adults aged 55 [25-82] years, respectively. Both groups were comparable regarding sex, indication, extent of surgery, and PGRIS score. After a median follow-up of 20 months, the parathyroid recovery rate was identical for children and adults (11 [47.8%] vs. 34 [47.9%]; p = 0.92). Sex, extent, and indication for surgery had no effect on recovery (all p > 0.05). PGRIS score = 4 (HR = 0.48) and serum calcium >2.25 mmol/L (HR = 0.24) at 1 month were associated with a decreased risk of persistent hypoparathyroidism on multivariate analysis (p < 0.05).

CONCLUSION

Almost half of patients recovered from persistent hypoparathyroidism after 6 months; therefore, the term persistent instead of permanent hypoparathyroidism should be used. Recovery rates of parathyroid function in children and adults were similar. Regardless of age, predictive factors for recovery were PGRIS score = 4 and a serum calcium >2.25 mmol/L at 1 month.

PTH after Thyroidectomy as a Predictor of Post-Operative Hypocalcemia

Post-thyroidectomy hypocalcemia is a frequent complication with significant morbidity, and has been shown to increase hospital stay and readmission rates. The evaluation of serum parathyroid hormone (PTH) levels after thyroidectomy represents a reliable method to predict post-thyroidectomy hypocalcemia, but it remains infrequently used. This retrospective study investigates serum PTH values 3 h after thyroidectomy as a predictor of hypocalcemia. In this study, we enrolled 141 patients aged between 27 and 71 years eligible for total thyroidectomy who presented with multinodular goiter, suspicious nodule on cytological examination, Graves’ disease, or toxic multinodular goiter. Three hours after total thyroidectomy, 53 patients (37.6%) showed a reduction in serum PTH. Of these patients 75.5% developed hypocalcemia by 24 h after surgery and 100% were hypocalcemic after 48 h (p < 0.001). There was no significant difference attributable to the different thyroid diseases, nor to the age of the patients. PTH at 3 h after total thyroidectomy accurately predicts post-operative hypocalcemia. The early detection of patients at risk of developing post-operative hypocalcemia allows for prompt supplementation of calcium and Vitamin D in order to prevent symptoms and allows for a safe and timely discharge.

Use of pre-operative calcium and vitamin D supplementation to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy: a systematic review

OBJECTIVE

This systematic review aimed to establish the evidence behind the use of pre-operative calcium, vitamin D or both calcium and vitamin D to prevent post-operative hypocalcaemia in patients undergoing thyroidectomy.

METHOD

This review included prospective clinical trials on adult human patients that were published in English and which studied the effects of pre-operative supplementation with calcium, vitamin D or both calcium and vitamin D on the rate of post-operative hypocalcaemia following total thyroidectomy.

RESULTS

Seven out of the nine trials included reported statistically significantly reduced rates of post-operative laboratory hypocalcaemia (absolute risk reduction, 13-59 per cent) and symptomatic hypocalcaemia (absolute reduction, 11-40 per cent) following pre-operative supplementation.

CONCLUSION

Pre-operative treatment with calcium, vitamin D or both calcium and vitamin D reduces the risk of post-operative hypocalcaemia and should be considered in patients undergoing total thyroidectomy.

Determination of calcium and parathyroid hormone levels following hemithyroidectomy

Background and objective

Hypocalcemia is one of the main complications of thyroid surgery. We hypothesized that hemithyroidectomy may have an impact on serum parathyroid hormone (PTH) and calcium levels despite only one thyroid lobe is manipulated. The objective of this study was to analyze changes in serum PTH and calcium levels following hemithyroidectomy.

Methods

This is a prospective study of 53 patients who underwent thyroid lobectomy. The serum PTH level was determined in the preoperative period, 15 min after extraction of the surgical specimen, and 24 h and 3 weeks after surgery. Serum ionized calcium was also measured in the preoperative period and at 6 h, 24 h and 3 weeks after surgery. We assessed the postoperative calcium value and its relationship with the extent of fall in PTH levels in the postoperative period.

Results

None of the patients had the postoperative serum ionised calcium level less than 4 mg/dl. The decrease in postoperative calcium was statistically significant at 6 and 24 h after surgery; there was no difference at 3 weeks post-surgery. The change in post-operative serum PTH levels followed a similar trend to postoperative serum calcium levels.

Conclusions

Although serum calcium level decreased after a lobectomy, it always remained above 4 mg/dl. We conclude that hypocalcaemia is rare following hemithyroidectomy.

Post-Operative Permanent Hypoparathyroidism and Preoperative Vitamin D Prophylaxis

Permanent hypoparathyroidism, a feared thyroidectomy complication, leads to significant patient morbidity, medical treatment, and monitoring. This study explores whether preoperative high-dose vitamin D loading decreases the incidence of permanent hypoparathyroidism. In a subgroup analysis, the study examines the predictive utility of day 1 parathyroid hormone (PTH) in permanent hypoparathyroidism. Patients (n = 150) were previously recruited in the VItamin D In Thyroidectomy (VIDIT) trial, a multicentre, randomised, double blind, placebo-controlled trial evaluating the role of 300,000 IU cholecalciferol administered orally a week before total thyroidectomy. Patients were contacted postoperatively beyond six months through a telephonic questionnaire. The primary outcome was permanent hypoparathyroidism, strictly defined as the need for activated vitamin D six months postoperatively. Out of 150 patients, 130 (86.7%) were contactable. Permanent hypoparathyroidism occurred in 11/130 (8.5%) patients, with a lower incidence of 5.3% (3/57) in the cholecalciferol group compared to 11% (8/73) in the placebo group; however, this was non-significant (p = 0.34). In a subgroup analysis, no relationship between day 1 PTH level and the incidence of permanent hypoparathyroidism was found (p ≥ 0.99). There was a lower rate of permanent hypoparathyroidism in the cholecalciferol group, which was not significant. The predictive utility of day 1 postoperative PTH levels may be limited to transient hypoparathyroidism.

Children are at a high risk of hypocalcaemia and hypoparathyroidism after total thyroidectomy

PURPOSE

Disruption of calcium homeostasis is the most common complication after total thyroidectomy in adults. We explored the incidence and risk factors of hypocalcaemia and hypoparathyroidism after total thyroidectomy in children (≤18 years of age).

METHODS

One hundred six children underwent total thyroidectomy. Patient, operative and outcome data were collected and analyzed.

RESULTS

The indication for surgery was Graves' disease in 52 children (49.1%), Multiple Endocrine Neoplasia type-2 in 36 (33.9%), multinodular goiter in 3 (2.8%) and follicular/papillary thyroid carcinoma in 15 (14.2%). Neck dissection was performed in 23 children (18.9%). In 14 children (13.2%), autotransplantation was performed; in 31 (29.2%), ≥1 glands were found in the specimen. Hypocalcaemia within 24 h of thyroidectomy was observed in 63 children (59.4%) and 52 (49.3%) were discharged on supplements. Hypoparathyroidism at 6 months persisted in 23 children (21.7%). The ratios of all forms of calcium-related-morbidity were larger among children with less than four parathyroid glands remaining in situ: hypocalcaemia within 24 h of thyroidectomy (54.0% versus 47.5%; p = 0.01), hypoparathyroidism on discharge (64.4% versus 37.7%; p = 0.004) and long-term hypoparathyroidism (31.1% versus 14.8%; p = 0.04).

CONCLUSION

The incidence of postoperative hypocalcaemia and hypoparathyroidism among children undergoing total thyroidectomy is considerable. The inability to preserve the parathyroid glands in situ during surgery seems an important factor. For optimal outcomes, the parathyroid glands should be preserved in situ.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level IV.

Impact of outcomes data on the management of postoperative hypocalcemia in head and neck endocrine surgery patients

Postoperative hypocalcemia is a well-described outcome following thyroid and parathyroid surgery with symptoms ranging from clinically insignificant laboratory findings to tetany and seizures. The aims of this study were 1. To identify the characteristics and management patterns of postoperative hypocalcemia in head and neck endocrine surgery patients and 2. To compare outcomes between patients treated with empiric calcium and patients treated using a biochemically driven calcium replacement algorithm. Clinical electronic medical record (EMR) data was collected from patients who had undergone total thyroidectomy, completion thyroidectomy, and/or parathyroidectomy at Wake Forest Baptist Medical Center (WFBMC), a tertiary referral and academic institution. Between July 1, 2016, and June 30, 2017, 298 adult patients underwent surgery by a WFBMC Head & Neck (H&N) endocrine surgeon. Objective calcium and parathyroid hormone levels, postoperative supplementation with calcium and Vitamin D, 30-day physician access line (PAL) phone call utilization, emergency department (ED) encounters, and readmission rates were queried. The overall rate of hypocalcemia was 17.4%. No statistically significant difference in PAL utilization, ED visits, or readmissions was found between the empiric supplementation group and those whose supplementation was biochemically directed (PAL 5.0% vs. 5.0% [p = 0.983], ED visit 3.3% vs. 2.5% [p = 0.744], Readmission 1.7% vs. 0% [p = 0.276]). The overall postoperative rates of hypocalcemia and hypoparathyroidism following H&N endocrine surgery were consistent with the reported literature. Neither method of calcium supplementation was superior in reducing PAL utilization, ED encounters, or readmission.

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.

Factors contributing to unintentional parathyroidectomy during thyroid surgery

Unintentional parathyroidectomy during thyroid surgery has an incidence ranging between 1% and 31% across institutions. Many studies have identified malignancy and central neck dissection as risk factors for losing parathyroid glands, but few studies have evaluated the impact of other factors such as lymphocytic thyroiditis, hyperthyroidism, or concomitant primary hyperparathyroidism. The purpose of this study was to investigate which factors contribute to parathyroid loss during thyroid surgery. Charts of 269 patients undergoing thyroid surgery at a tertiary care medical center from 2010 to 2013 were retrospectively reviewed. Sixty-six patients (24.5%) experienced unintentional parathyroidectomy. Bivariate analysis showed no significant differences in patient characteristics. Patients with unintentional parathyroid removal had a significantly smaller largest thyroid nodule size (P = 0.002), higher rate of central neck dissection (30.3% vs 7.9%, P < 0.0001), and higher rate of malignancy (50% vs 36.0%, P = 0.04). Multivariable analysis showed that the strongest risk factor for unintentional parathyroidectomy was central neck dissection (P = 0.0008; odds ratio 4.72, confidence interval 1.91-11.71). In conclusion, central neck dissection for thyroid malignancy is the strongest risk factor for unintentional thyroidectomy. The presence of concomitant primary hyperparathyroidism, lymphocytic thyroiditis, or hyperthyroidism did not appear to increase the risk of unintentional parathyroidectomy.

Possible role of low magnesium levels in the onset of postoperative hypoparathyroidism following thyroidectomy

BACKGROUND

A positive correlation between calcium and magnesium serum levels is well known and depends upon various factors. This study aims at verifying the existence of this association in a retrospective series of patients who underwent thyroid surgery.

METHODS

Two hundred and eighty-five consecutive patients (202 female, 83 male, mean age 57 years) who underwent at least total thyroidectomy (TT) and had a complete clinical and biochemical pre- and postoperative evaluation were included in the study. Patients were evaluated with regard to: sex, age, indications for surgery, operative time, number of accidentally removed parathyroids, extent and time of surgery, thyroiditis, final histology, pre- and postoperative levels of calcium, magnesium, vitamin D, and creatinine, presence of symptoms of hypocalcemia. Statistical analysis was performed using the R software.

RESULTS

In the postoperative period, biochemical hypocalcemia (<8.5 mg/dL) was observed in 126 patients (44%) and severe hypocalcemia (<7.5 mg/dL, a level indicating the need for longer hospitalization) was seen in 40 (14%). When analyzing patients with and without postoperative hypocalcemia, the factors affecting postoperative biochemical hypocalcemia were: older age (P=0.019), longer operative time (P=0.039), and a highly significant correlation between postoperative calcium and magnesium levels (r=0.432; P<0.001).

CONCLUSIONS

The only factor among the ones we analyzed in this retrospective study that would appear to be linked to the onset of clinically relevant hypocalcemia is low magnesium levels in the postoperative period. A prospective randomized study with a group of patients undergoing magnesium replacement in the postoperative period can clarify the possible role of magnesium repletion on hypocalcemia.

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.

Frequency of Hypocalcaemia following Total Thyroidectomy

Background & Objective

Patients who undergo Total thyroidectomy are at higher risk for postoperative hypocalcaemia, which can lead to significant short and long term morbidity. The aim of this study was to determine the frequency of postoperative hypocalcaemia undergoing Total thyroidectomy.

Methods

A total of 854 patients who underwent Total thyroidectomy and completion thyroidectomy between January 2003 to December 2016 at Endocrine Surgical unit, Jinnah Postgraduate Medical Centre, Karachi, were included in this retrospective study. Data were obtained for demographics, preoperative diagnosis, postoperative calcium levels, extent of surgery and final surgical pathology.

Results

A total of 854 patients underwent Total thyroidectomy. Of these 87.58% (n=748) were malignant and 12.41% (n=106) were benign. Among the malignant and benign patients, 47.3% (n=404) underwent Total thyroidectomy and 52.69% (n=450) underwent completion thyroidectomy. Overall incidence of transient hypocalcaemia was 7% (n=60) and that of permanent hypocalcaemia was 0.11% (n= 1).

Conclusion

Hypocalcaemia is one of major concern following total- thyroidectomy. Meticulous surgical techniques, identification and preservation of vascularity of parathyroid glands are essential in preventing postoperative hypocalcaemia following total thyroidectomy.

The incidence of post-thyroidectomy hypocalcaemia: a retrospective single-centre audit

INTRODUCTION

The aim of this single centre retrospective observational record-based audit was to assess the incidence of post-thyroidectomy hypocalcaemia. The setting was a district general hospital in Hertfordshire covering a population of 500,000 people. A total of 196 patients who had had total or completion thyroidectomy during a five-year period were included in the study.

MATERIALS AND METHODS

The primary outcome measure was to determine the rate of biochemical and symptomatic hypocalcaemia in patients undergoing total or completion thyroidectomy. Secondary outcome measures assessed time taken for biochemical and clinical hypocalcaemia to resolve, whether malignancy affected the rate of hypocalcaemia and if removal of parathyroid glands during surgery were a predictor of hypocalcaemia.

RESULTS

The overall incidence of post-thyroidectomy hypocalcaemia (PTHC) within 24 hours was 21.4%. The incidence increased from 6 hours (13.8%) to 24 hours post-thyroidectomy (15.8%) and there was evidence of both transient and delayed PTHC within the first 24 hours. By 6 months post-surgery, 3.6% remained hypocalcaemic and required continual oral supplementation. Patients with benign thyroid disease had a higher risk of PTHC (P = 0.04) and patients younger than 50 years of age had a higher risk of symptomatic hypocalcaemia (P = 0.016). Other clinical factors including sex, type of surgery, neck dissection, oral calcium and/or vitamin D supplementation and inadvertent histological parathyroid gland excision were not associated with an increased incidence of PTHC or symptomatic hypocalcaemia.

CONCLUSIONS

Our audit shows that the rate of PTHC within our population was below the national average with higher risk in benign thyroid disease.

Modification, validation and implementation of a protocol for post-thyroidectomy hypocalcaemia

Introduction The management of post-thyroidectomy hypocalcaemia should facilitate early discharge, and reduce risks of hypocalcaemia, readmission and treatment related hypercalcaemia. This paper describes the implementation, evaluation and revision a protocol for the optimal management of this condition. Methods Day 1 parathyroid hormone (PTH) measurements in addition to calcium measurements were commenced following review of the unit's outcomes and literature on post-thyroidectomy hypocalcaemia. Outcomes from a three-year cohort of patients undergoing thyroid surgery helped amend this protocol (revision 1) to reduce biochemical tests, stipulate the need, nature and dose of vitamin D/calcium supplements, and encourage early discharge. This was further validated over seven months to assess compliance, episodes of hyper and/or hypocalcaemia after discharge, readmissions and need for treatment changes. Further revisions were made (revision 2) and implemented. Results The temporary and long-term postoperative hypocalcaemia rates were 29.1% and 3.2% respectively. Repeat calcium measurements on the first day altered management in only 1.4% of cases. The revised protocol was adhered to in 90% of cases. One patient had hypocalcaemia (due to non-compliance) and one had hypercalcaemia. Revision 2 involved reducing the dose of calcium. Conclusions This is a good example of a unit protocol for post-thyroidectomy hypocalcaemia being developed and modified on the basis of the literature and local experience. Day 1 PTH and calcium levels determine the need for treatment and frequency of follow-up visits, facilitate early discharge, reduce risk of over and/or undertreatment, and are good indicators of permanent hypocalcaemia.

Epidemiology, management and outcomes of Graves' disease-real life data

PURPOSE

Treatment options in Graves' disease are clearly defined, but management practices and the perceptions of success are varied. The outcomes of treatment in large consecutive cohorts of Graves' disease have not been well characterised. The study describes the epidemiology, management strategies and medium term outcomes following anti-thyroid drug treatment, radio-iodine ablation and surgery in Graves' disease.

METHODS

All patients (n = 659) who received treatment for a new diagnosis of Graves' disease in secondary care over a 5 year period were included with a median (interquartile range) follow-up of 42.9 (29-57.5) months.

RESULTS

The age adjusted incidence of adult onset Graves' disease in Sheffield, UK was 24.8 per 100,000 per year. Excluding 35 patients lost to follow-up, 93.1% (n = 581) were controlled on anti-thyroid drug treatment. Of these, 73.6% went into remission following withdrawal of anti-thyroid drugs; 5.2% were still undergoing initial therapy; 13.3% lost control whilst on anti-thyroid drugs; and 7.9% went on to have either surgery or radio-iodine ablation whilst controlled on anti-thyroid drugs. Of the 428 patients who achieved remission, 36.7% relapsed. Of 144 patients who had radio-iodine ablation treatment, 5.6% relapsed and needed further treatment. Of 119 patients having surgery, 5.2% had long-term hypoparathyroidism and none had documented long-term recurrent laryngeal nerve palsy.

CONCLUSIONS

In the follow-up, 39.9% of patients underwent surgery or radio-iodine ablation with little morbidity. Up to two-thirds of patients who achieved remission did not relapse. Data on effectiveness and risks of treatments for Graves' disease presented in this study will help clinicians and patients in decision making.

Analysis of the incidence and factors predictive of inadvertent parathyroidectomy during thyroid surgery

BACKGROUND

Inadvertent (or incidental) parathyroidectomy can occur during thyroidectomy. However, the factors associated with inadvertent parathyroidectomy remain unclear. This study aimed to report the rate of inadvertent parathyroidectomy during thyroidectomy and associated risk factors.

METHODS

Variables including fine needle aspiration cytology findings, age, sex, thyroid weight, concurrent neck dissection, extent of thyroidectomy, and the presence of cancer and parathyroid tissue within the specimen were recorded for 266 patients. The incidence of post-operative hypocalcaemia was also recorded. Univariate and multivariate analysis were performed to identify factors associated with inadvertent parathyroidectomy.

RESULTS

The inadvertent parathyroidectomy rate was 16 per cent. Univariate analysis revealed that cancer and concurrent neck dissection predicted inadvertent parathyroidectomy. On multivariate analysis, only concurrent neck dissection remained an independent predictor of inadvertent parathyroidectomy: it was associated with a fourfold increase in inadvertent parathyroidectomy.

CONCLUSION

The inadvertent parathyroidectomy rate was 16 per cent and concurrent neck dissection was identified as an independent predictor of inadvertent parathyroidectomy.

One-hour PTH after thyroidectomy predicts symptomatic hypocalcemia

BACKGROUND

A major morbidity after total thyroidectomy is hypocalcemia. Although many clinical factors and laboratory studies have been correlated with both biochemical and symptomatic hypocalcemia, the ideal use and timing of these tests remain unclear. We hypothesize 1-h (PACU) parathyroid hormone (PTH) will identify patients at risk for symptomatic hypocalcemia.

METHODS

This prospective study evaluated 196 patients undergoing total thyroidectomy. Serum calcium and PTH levels were measured 1 h after surgery and on postoperative day 1 (POD1). Performance of a central compartment lymph node dissection, parathyroid autotransplantation, indication for procedure, pathology, and presence of parathyroid tissue in the pathology specimen were recorded.

RESULTS

Of 196 patients, nine (4.6%) developed symptomatic hypocalcemia. Thirty four (17.3%) had a 1-h PACU PTH ≤10 pg/dL, whereas 31 (15.8%) had a POD1 PTH of ≤10. Five (56%) of the nine symptomatic patients underwent central compartment lymph node dissection, four (44%) had parathyroid autotransplantation, and four (44%) had a PACU PTH ≤10. PACU and POD1 PTH levels were correlated (R(2) = 0.682). Multivariate regression identified central compartment dissection, autotransplantation, and PACU or POD1 PTH correlated with symptomatic hypocalcemia. PACU PTH, POD1 PTH, PACU Ca, malignant final pathology, and age ≤45 y correlated with biochemical hypocalcemia.

CONCLUSIONS

A 1-h postoperative PACU PTH is equivalent to POD1 PTH in predicting the development of symptomatic hypocalcemia. Biochemical hypocalcemia was not predictive of symptoms in the immediate postoperative period. Lymph node dissection and parathyroid autotransplantation correlated with symptomatic hypocalcemia and improve the sensitivity of biochemical screening alone.