Hypocalcemia, Postoperative Complications, Thyroid Cancer, Thyroid Dysfunction, Thyroid Nodule
Conditions
Keywords
Thyroidectomy, Postoperative hypocalcemia, Hypoparathyroidism, Parathyroid gland injury, Total thyroidectomy
Brief summary
This retrospective cohort study investigates predictors of postoperative hypocalcemia following thyroidectomy procedures at Minia University Hospital over a 10-year period (2014-2024). Postthyroidectomy hypocalcemia is one of the most common complications of thyroid surgery, affecting 20-50% of patients. The study aims to identify demographic, clinical, laboratory, and surgical factors associated with the development of both transient and permanent hypocalcemia. Results will inform risk stratification, patient counseling, and perioperative management strategies.
Detailed description
Hypocalcemia is a frequent complication following thyroidectomy, resulting from inadvertent parathyroid gland injury, removal, or devascularization. While most cases resolve within 6 months (transient hypocalcemia),permanent hypocalcemia occurs in 1-3% of patients and requires lifelong calcium and vitamin D supplementation, significantly impacting quality of life. This single-center retrospective study will systematically review medical records of all patients who underwent thyroidectomy (total, subtotal, or completion) at Minia University Hospital between January 1, 2014, andDecember 31, 2024. The primary objective is to identify independent predictors of postoperative hypocalcemia using multiple logistic regression analysis. Data extraction will include: Demographics: age, gender, BMI Clinical factors: indication for surgery, thyroid disease type, presence of Graves' disease, substernal extension Preoperative laboratory values: calcium, vitamin D, PTH, thyroid function tests Surgical details: extent of thyroidectomy, central/lateral lymph node dissection, surgeon experience,operative time, parathyroid gland identification and autotransplantation Postoperative data: calcium levels (24h, 48h, 1 week, 6 weeks, 3 months, 6 months), PTH levels,supplementation requirements Pathology: thyroid weight, presence of parathyroid tissue in specimen, thyroiditis, malignancy The study will employ robust statistical methods including univariate analysis to screen potential predictors and multiple logistic regression to identify independent risk factors. A clinical risk prediction score will be developed and internally validated using split-sample methodology. Subgroup analyses will examine differences between transient and permanent hypocalcemia and stratify results by extent of surgery and surgeon experience. Target sample size of 500-600 patients was calculated using G\*Power to ensure adequate statistical power(\>80%) . Findings will contribute to evidence-based perioperative protocols, improved patient selection for outpatient thyroidectomy, tailored monitoring strategies, and informed decision-making regarding prophylactic calcium supplementation.
Interventions
None listed
Sponsors
Minia University
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* Adult patients aged 18 years or older at time of surgery * Underwent thyroidectomy at Minia University Hospital * Availability of medical records with complete surgical and postoperative data * Documented serum calcium levels measured postoperatively * Minimum follow-up of 6 months postoperatively or documented outcome status
Exclusion criteria
* Age less than 18 years at time of surgery * Preoperative hypocalcemia (serum calcium \<8.0 mg/dL or ionized calcium \<1.0 mmol/L) * Pre-existing parathyroid disorders (primary hyperparathyroidism, hypoparathyroidism, secondary or tertiary hyperparathyroidism) * Chronic kidney disease Stage 3 or higher (estimated glomerular filtration rate \<60 mL/min/1.73m²) * Malabsorption syndromes affecting calcium metabolism (celiac disease, inflammatory bowel disease,short bowel syndrome) * Concurrent planned parathyroidectomy * History of neck irradiation * Chronic use of medications significantly affecting calcium metabolism (bisphosphonates, denosumab,cinacalcet, chronic corticosteroids) * Incomplete medical records lacking essential data including surgical details, postoperative calcium levels,or follow-up data * Patients lost to follow-up before 6-month endpoint without documented outcome status
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Postoperative Hypocalcemia | Within 6 months post-surgery | Development of hypocalcemia defined as: Serum total calcium \<8.0 mg/dL (2.0 mmol/L) OR Ionized calcium \<1.0 mmol/L OR Symptomatic hypocalcemia (perioral numbness, paresthesias, carpopedal spasm, positive Chvostek's orTrousseau's sign) requiring calcium supplementation Measured at: 24 hours, 48 hours, 1 week, 6 weeks, 3 months, and 6 months postoperatively |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Transient Hypocalcemia | Up to 6 months post-surgery | Hypocalcemia that resolves within 6 months of surgery without need for continued calcium and/or vitamin D supplementation beyond 6-month follow-up |
| Incidence of Permanent Hypocalcemia | 6 months post-surgery | Hypocalcemia requiring ongoing calcium and/or vitamin D supplementation persisting beyond 6months postoperatively, indicating permanent hypoparathyroidism |
| Incidence of Symptomatic Hypocalcemia | Within 2 weeks post-surgery | Clinical manifestations of hypocalcemia including: Neuromuscular irritability (perioral tingling, paresthesias) Tetany or carpopedal spasm Positive Chvostek's sign (facial nerve twitching) Positive Trousseau's sign (carpal spasm with blood pressure cuff inflation) Seizures (rare) Cardiac manifestations: prolonged QT interval, arrhythmias (rare) |
| Hospital Length of Stay | From surgery to discharge, typically 2-5 days | Duration of hospitalization in days following thyroidectomy, measured from date of surgery to date of hospital discharge |
| Calcium and Vitamin D Supplementation Requirement | Up to 6 months post-surgery | Need for oral calcium supplementation (yes/no and total daily dose in mg) Need for vitamin D supplementation (yes/no and total daily dose in IU) Duration of supplementation (days/weeks) Need for intravenous calcium administration (yes/no) |
| Emergency Department Visits for Hypocalcemia | Within 30 days post-discharge | Unplanned emergency department visits related to symptoms of hypocalcemia or complications of calcium/vitamin D therapy |
| Hospital Readmission Related to Hypocalcemia | Within 30 days post-discharge | Unplanned hospital readmission related to symptomatic hypocalcemia or its complications |
| Postoperative Parathyroid Hormone (PTH) Level | 24 hours post-surgery | Serum intact parathyroid hormone level measured within 24 hours postoperatively (pg/mL), used as predictor of sustained hypocalcemia |
| Nadir Calcium Level | Within 7 days post-surgery | Lowest serum calcium level (total or ionized) recorded during initial hospitalization or within first week postoperatively |
| Time to Calcium Normalization | Up to 6 months post-surgery | Duration in days from surgery to sustained normalization of serum calcium levels without supplementation (for those who develop hypocalcemia) |
Countries
Egypt
Contacts
CONTACTSaleh K Saleh, MD
PRINCIPAL_INVESTIGATORSaleh K Saleh, MD
Minia University
Outcome results
None listed