Hypocalcaemia after total thyroidectomy: Could intact parathyroid hormone be a predictive factor for transient postoperative hypocalcemia?

ABSTRACT Aims Total thyroidectomy is significantly complicated by parathyroid dysfunction and hypocalcemia. These aspects impact the decision regarding the timing of discharge and quantum of calcium supplementation required. Therefore, we aimed at evaluating the accuracy of next-day parathyroid hormone (PTH) level as a predictor of post-thyroidectomy hypocalcemia. Secondly, we aimed at establishing our institution's postoperative PTH level, which can accurately predict the development of post-thyroidectomy hypocalcemia to help us ensure the safe and early discharge of patients. Materials and methods A prospective observational study of 50 continuous patients undergoing thyroidectomy was conducted at a tertiary hospital in South India. Postoperative blood samples were collected for estimation of PTH, calcium, albumin, and phosphorous. The data were collated and results analyzed using Stata I/C 10.1. Results A total of 30% (15/50) of the patients had postoperative hypocalcemia (serum calcium <8 mg/dL). Postoperative PTH was low (<8 pg/mL) in 40% (20/50) of patients. There was a significant association between PTH < 8 pg/mL and the presence of postoperative hypocalcemia (p = 0.029). The area under the receiver operating characteristic (ROC) curve was 0.7, and a next-day PTH of <6 pg/mL showed the highest sensitivity and specificity (83 and 60% respectively) for the development of postoperative hypocalcemia, with a positive predictive value (PPV) and negative predictive value (NPV) of 83 and 60 respectively. Conclusion The PTH assessment performed the day after surgery is an acceptable test to predict post-thyroidectomy hypocalcemia; PTH <6 pg/mL can be used as our institution's cutoff value. Department protocols for calcium and vitamin D supplementation following total thyroidectomy may be formulated based on the appropriately timed local postoperative PTH value to assist safe and early discharge of patients. Clinical significance Discharge protocols for patients undergoing thyroidectomy may be formulated based on the postoperative PTH values, thus enabling safe and early discharge of patients. How to cite this article Cherian AJ, Ramakant P, Paul TV, Abraham DT, Paul MJ. Next-day Parathyroid Hormone as a Predictor of Post-thyroidectomy Hypocalcemia. World J Endoc Surg 2016;8(3):203-207.

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Measurement of serum intact parathyroid hormone (iPTH) at the end of total thyroidectomy: A reliable parameter for hypocalcemia?

British Journal of Surgery ◽

10.1093/bjs/znab202.033 ◽

2021 ◽

Vol 108 (Supplement_4) ◽

Author(s):

A Lalos ◽

K Linke ◽

M von Flüe ◽

B Kern

Keyword(s):

Parathyroid Hormone ◽

Total Thyroidectomy ◽

Clinical Symptoms ◽

Parathyroid Tissue ◽

Postoperative Management ◽

Parathyroid Glands ◽

Intact Parathyroid Hormone ◽

Postoperative Hypoparathyroidism ◽

Symptomatic Hypocalcemia ◽

The Mean

Abstract Objective Total thyroidectomy represents the gold standard surgical procedure for patients with malignant thyroid disease. Over the past decades, the total thyroidectomy gradually replaced the subtotal thyroidectomy for benign thyroid disorders as well. Postoperative hypocalcemia remains the most frequent complication. The close proximity of parathyroid glands to the thyroid capsule leads often to devascularization or adventitious removal of parathyroid tissue. Clinical symptoms like paresthesia, tingling, muscle cramps or seizures often occur. Combined measurement of intact parathyroid hormone (iPTH) and calcium after the operation are used worldwide to predict postoperative hypoparathyroidism. The purpose of this study was to find out the incidence of decreased iPTH at the end of surgery and its reliability in predicting hypocalcemia. Methods We performed a retrospective analysis of 534 patients who underwent total thyroidectomy at our institution between 2000 and 2019. Medical records were reviewed to analyze the patient characteristics, indication of the procedure, laboratory and histological results, postoperative management and complications. The iPTH was measured before and at the end of the surgery, while the calcium was measured at the first postoperative day. The iPTH assay at our hospital has a normal range between 15.0 and 80.0 pg/ml. Meanwhile hypocalcemia was defined as a calcium measurement < 2.2 mmol/l. Results The mean age of the patients was 55.34 years. The female to male ratio was 4.6:1. The mean preoperative iPTH of our cohort was 48.35 pg/ml, while the postoperative iPTH was 31.74 pg/ml, indicating a mean reduction of 35.75%. A total of 174 patients (32.6%) had a iPTH < 15.0 pg/ml at the end of the surgery, indicating a reduction of 75.6%. 22 of these 174 patients (12.6%) developed clinical symptoms of hypocalcemia. In contrast only 3 patients (0.08%) with normal iPTH developed symptoms. Whole parathyroid glands were identified in 95/534 (17.8%), whereas from the 174 patients with iPTH < 15.0 pg/ml, 56 (32.2%) had at least one parathyroid gland in the operative specimens. Conclusion Measurement of iPTH at the end of total thyroidectomy is a good predictor to detect patient who are at risk for developing symptomatic hypocalcemia and calcium substitution can be started at the same day. A normal iPTH almost excludes symptomatic hypocalcemia.

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Parathyroid hormone and serum calcium levels measurements as predictors of postoperative hypocalcemia in total thyroidectomy

Gland Surgery ◽

10.21037/gs.2017.06.12 ◽

2017 ◽

Vol 6 (5) ◽

pp. 428-432 ◽

Cited By ~ 1

Author(s):

Mohammed Algarni ◽

Rajab Alzahrani ◽

Gianlorenzo Dionigi ◽

Al-Hakami Hadi ◽

Haia AlSubayea

Keyword(s):

Parathyroid Hormone ◽

Total Thyroidectomy ◽

Serum Calcium ◽

Postoperative Hypocalcemia

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Role of intraoperative parathyroid hormone in predicting postoperative hypocalcemia following total thyroidectomy

Journal of the American College of Surgeons ◽

10.1016/j.jamcollsurg.2014.07.724 ◽

2014 ◽

Vol 219 (4) ◽

pp. e127

Author(s):

David S. Kim ◽

Annabel E. Barber ◽

Robert C. Wang

Keyword(s):

Parathyroid Hormone ◽

Total Thyroidectomy ◽

Postoperative Hypocalcemia ◽

Intraoperative Parathyroid Hormone

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Serum intact parathyroid hormone as a predictor of hypocalcaemia after total thyroidectomy

ANZ Journal of Surgery ◽

10.1111/j.1445-2197.2005.03593.x ◽

2005 ◽

Vol 75 (11) ◽

pp. 977-980 ◽

Cited By ~ 40

Author(s):

Patsy S. H. Soon ◽

Christopher J. Magarey ◽

Peter Campbell ◽

Bin Jalaludin

Keyword(s):

Parathyroid Hormone ◽

Total Thyroidectomy ◽

Intact Parathyroid Hormone

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MON-LB73 Incidence Rate of Post-Thyroidectomy Immediate Hypocalcemia and Its Relation to Pre-Operative Vitamin D and Parathyroid Hormone Levels

Journal of the Endocrine Society ◽

10.1210/jendso/bvaa046.2052 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

Author(s):

Khadeeja Sirajuddin ◽

Alwin Robert Asirvatham ◽

Eman Alharbi ◽

Fatima Sirajuddin ◽

Nasir Al Khahtani ◽

...

Keyword(s):

Vitamin D ◽

Alkaline Phosphatase ◽

Parathyroid Hormone ◽

Total Thyroidectomy ◽

Incidence Rate ◽

Calcium Level ◽

Small Sample ◽

Postoperative Hypocalcemia ◽

Benign Pathology ◽

The Mean

Abstract Aim: To find out the incidence rate of post-thyroidectomy immediate hypocalcemia within 48 hours and explore the association of pre-operative vitamin D and parathyroid hormone (PTH) levels.Methods: This retrospective study was conducted among 122 patients who underwent total thyroidectomy over one year (from January 2018 to December 2018) in Prince Sultan Military Medical City, Riyadh, Saudi Arabia. After thyroidectomy, all patients were admitted and observed for at least 24-48 hours. The postoperative hypocalcemia, alkaline phosphatase (ALP), phosphate (PO4), parathyroid hormone (PTH), and vitamin D level were collected.Results: During 2018 a total of 122 (mean age 41.6±1.2 years; females 90.2%) patients underwent total thyroidectomy. The mean calcium level in the first two days was 2.07 mmol/L and 2.01 mmol/L. Most of the cases of hypocalcemia occurred on day 1 postoperatively. Hypocalcemia mainly occurs in patients with benign pathology. The level of vitamin D in those patients with benign pathology was significantly lower as compared to those with malignant pathology (49±23 vs 62±25; P=0.009). The overall mean level of vitamin D was 54.6±25 (50-150 nmol/L). Interestingly, there were no correlation between pre-operative vitamin D, PTH level and postoperative hypocalcemia. There were no statistically significant differences between postoperative hypocalcemia with other parameters except for pre-operative alkaline phosphatase which was barely positive (P=0.052).Conclusion: The outcomes of this study manifestly illustrated that a significant decline in calcium level after the surgery. In contrast to previous studies, our findings did not show a significant correlation between vitamin D level and hypocalcemia. This could be due to small sample size. Furthermore, the mean level of vitamin D in our cohort was 54 which was within the normal range. Further, well-designed randomized controlled trials with greater sample sizes are necessary to validate our findings.

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S139 – Intact Parathyroid Hormone as a Predictor of Hypocalcaemia

Otolaryngology ◽

10.1016/j.otohns.2008.05.312 ◽

2008 ◽

Vol 139 (2_suppl) ◽

pp. P123-P123

Author(s):

Yuk Hui Ng ◽

Dawn Tw Teo ◽

Mark Li-Chung Khoo

Keyword(s):

Vitamin D ◽

Parathyroid Hormone ◽

Prospective Study ◽

Total Thyroidectomy ◽

Clinical Symptoms ◽

High Sensitivity ◽

Intact Parathyroid Hormone ◽

Completion Thyroidectomy ◽

Single Institution ◽

Ipth Level

Objectives 1) To investigate intact Parathyroid Hormone (ipth) as a predictor of hypocalcaemia in post-total thyroidectomy patients. 2) To determine the sensitivity and specificity of ipth as a predictor of hypocalcaemia. Methods Prospective study involving 65 patients in a single institution accrued over 2 years. All patients scheduled for total thyroidectomy were empirically started on calcium and vitamin D replacement on the day of surgery. Intact Parathyroid Hormone (ipth) levels were taken 4–6 hours after completion of operation. Corrected calcium levels were also obtained 4–6 hours after completion of operation and 24 hours later. All patients were subsequently monitored for development of hypocalcaemia. Hypocalcaemia is defined as corrected serum calcium of < 1.9 mmol/L or clinical symptoms of cramps or peri-oral numbness. Results 18 of 65 patients developed hypocalcaemia. All patients who developed hypocalcaemia had a ipth level of < 0.6 pmol/L. Using 0.6 as a cut-off value, ipth has a sensitivity of 100% and specificity of 76% in our study. Conclusions Using a cut-off value of 0.6pmmol/L, early postoperative intact parathyroid hormone has a high sensitivity and good specificity in identifying patients who subsequently develop hypocalcaemia post-total or completion thyroidectomy and can be used identify patients who need close calcium monitoring in the postoperative period.

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