Postoperative Hypocalcemia After Thyroidectomy

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.

• Incidence of Transient Hypocalcemia [Срок оценки: Up to 6 months post-surgery]
• Incidence of Permanent Hypocalcemia [Срок оценки: 6 months post-surgery]
• Incidence of Symptomatic Hypocalcemia [Срок оценки: Within 2 weeks post-surgery]
• Hospital Length of Stay [Срок оценки: From surgery to discharge, typically 2-5 days]
• Calcium and Vitamin D Supplementation Requirement [Срок оценки: Up to 6 months post-surgery]
• Emergency Department Visits for Hypocalcemia [Срок оценки: Within 30 days post-discharge]
• Hospital Readmission Related to Hypocalcemia [Срок оценки: Within 30 days post-discharge]
• Postoperative Parathyroid Hormone (PTH) Level [Срок оценки: 24 hours post-surgery]
• Nadir Calcium Level [Срок оценки: Within 7 days post-surgery]
• Time to Calcium Normalization [Срок оценки: Up to 6 months post-surgery]