Prediction of post-idroidectomy hypocalcemia through rapid PTH determination

The Role of Parathyroid Hormone Level as a Predictor of Hypocalcemia After Total Thyroidectomy for Thyroid Cancer: A Cross-Sectional Study

This study aimed to investigate the utility of measuring parathyroid hormone (PTH) levels as a predictor of hypocalcemia in a population of patients undergoing total thyroidectomy for thyroid cancer between 2016 and 2019. We conducted an observational, analytical, descriptive, cross-sectional investigation, assessing PTH levels as a predictor of hypocalcemia following thyroidectomy. Among patients with hypoparathyroidism, 25.5% experienced hypocalcemia, while 74.5% had normal serum calcium levels. The likelihood of hypocalcemia was five times higher in patients with hypoparathyroidism (OR: 5.43; 95% CI: 1.89-15.6), a statistically significant finding (p < 0.05). Additionally, PTH values at 24 hours post-surgery averaged 28.9 pg/mL (SD: 30.8 pg/mL), ranging from 0.01 to 235 pg/mL. Serum calcium levels averaged 8.31 mg/dL (SD: 0.74), with values ranging from 6.5 to 10.6 mg/dL. The study demonstrates a statistically significant association between PTH levels and post-surgical serum calcium levels, albeit with moderate predictive power. These findings support the utility of PTH measurement in predicting hypocalcemia following thyroidectomy, underscoring its potential clinical relevance in patient management.

Evaluation of an early detection protocol, intensive treatment and control of post-surgical hypoparathyroidism in the first month after total thyroidectomy

BACKGROUND AND OBJECTIVE

Hypoparathyroidism is the most common complication of total thyroidectomy and usually requires monitoring of calcaemia, whereby it is one of the factors that most contributes to hospital stay. The objective of the study is to evaluate the clinical usefulness of the application of our protocol for early detection, intensive treatment and control of hypoparathyroidism in the first month after thyroidectomy.

PATIENTS AND METHOD

Retrospective observational cross-sectional study of 79 patients who underwent total thyroidectomy in whom parathormone (PTH) and calcemia determinations were performed at 6-8 h and 18-24 h post-surgery. When the PTH value was lower than inferior limit of the reference (15 pg/ml), oral treatment was started with 1000 mg of calcium and 0.25 μg of calcitriol every 8 h followed by calcemia controls.

RESULTS

Twenty-six cases (32.9%) of normocalcemic hypoparathyroidism were detected in whom treatment prevented their progression to hypocalcaemia, except for 3 cases that had an episode of mild asymptomatic hypocalcaemia. There were no cases of moderate/severe hypocalcaemia and only one case of asymptomatic mild hypercalcaemia. There were no readmissions due to calcium abnormalities. No case with PTH > 15 pg/ml had hypocalcaemia. The protocol allowed a hospital stay of 24 h. The prevalence of permanent hypoparathyroidism was 5.1%.

CONCLUSIONS

The application of our protocol during the first month after thyroidectomy is very useful because it avoids the appearance of moderate/severe hypocalcaemia and hypercalcaemia, allows a short hospital stay and is associated with a low prevalence of permanent hypoparathyroidism.