A Ten-Year Cohort Study of Clinical and Surgical Predictors for Hypocalcemia Post-Thyroidectomy
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Enrollment
- 600
- Locations
- 1
- Primary Endpoint
- Incidence of Postoperative Hypocalcemia
Study Overview
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%) .
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Retrospective
Eligibility Criteria
- Ages
- 18 Years to 75 Years (Adult, Older Adult)
- Sex
- All
- Accepts 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
Outcomes
Primary Outcomes
Incidence of Postoperative Hypocalcemia
Time Frame: 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 Outcomes
- Hospital Length of Stay(From surgery to discharge, typically 2-5 days)
- Calcium and Vitamin D Supplementation Requirement(Up to 6 months post-surgery)
- Emergency Department Visits for Hypocalcemia(Within 30 days post-discharge)
- Hospital Readmission Related to Hypocalcemia(Within 30 days post-discharge)
- Postoperative Parathyroid Hormone (PTH) Level(24 hours post-surgery)
- Nadir Calcium Level(Within 7 days post-surgery)
- Time to Calcium Normalization(Up to 6 months post-surgery)
- Incidence of Transient Hypocalcemia(Up to 6 months post-surgery)
- Incidence of Permanent Hypocalcemia(6 months post-surgery)
- Incidence of Symptomatic Hypocalcemia(Within 2 weeks post-surgery)
Investigators
Saleh Khairy Saleh MD
Lecturer
Minia University