Protocol of Diaz-Aguirregoitia et al for Documenting Complete Removal of a Parathyroid Adenoma By a Fall in the Serum Total Calcium Concentration

 

Protocol:

(1) Measure serum total calcium prior to surgery.

(2) Measure serum total calcium every 5 minutes after removal of an adenoma.

 

Interpretation:

• If the adenoma is completely removed the first 5 minute total serum calcium level will be within the normal limit.

• If in doubt the serum calcium will continue to drop at 10, 15 and 20 minutes after adenoma removal then will level off.

 

Performance:

• The authors found this method was cheaper and faster than performing serum parathyroid hormone determinations with comparable findings.

• The method can complement measurements of parathyroid hormone if there is any clinical uncertainty.

 

Limitations:

• The serum calcium prior to surgery should be above the upper limit of the normal reference range.

• The analytical method for measuring total calcium should be accurate and reliable. If the method has a high coefficient of variation then the difference in calcium levels could just be normal method variability.