Validation and implementation of an intraoperative parathyroid hormone assay and workflow: practical advice for endocrine surgery centres
Objectives
Intraoperative PTH (IOPTH) can be challenging to offer through central laboratories despite its clinical benefit. We describe the implementation of a central laboratory-based IOPTH assay and workflow in a tertiary care centre.
Methods
The Elecsys® PTH STAT assay was assessed in EDTA plasma on the Cobas® e411 analyzer. Assay validation included precision, linearity, coefficient of variation (CV), accuracy, stability, and dilution. Samples were transported to the central laboratory and resulted via telephone to the operating room. We describe a case series of patients with primary hyperparathyroidism (PHPT) who underwent parathyroid surgery using our described IOPTH workflow.
Results
Within- and between-day CV was ≤3.0 % for quality control material that ranged from 2.2–44.6 pmol/L. Passing–Bablok regression yielded a slight proportional negative bias between the two Cobas e411 instruments [Elecsys® PTH our centre=0.95 (95 % CI: 0.90–1.00) × Elecsys® PTH Toronto − 0.05 (95 % CI: −0.20 to 0.09) (n=22)], but high correlation (r=0.99) as compared to PTH measured on the Vitros® XT 7600 analyzer [Elecsys® PTH=0.91 (95 % CI: 0.73–1.1) × Vitros® PTH + 0.1 (95 % CI: −0.34 to 0.76), r=0.96 (n=40)]. The mean operating time across ten patients surgically cured for PHPT was 47.1 min (±9.1) and no patients required intraoperative frozen tissue analysis.
Conclusions
The Elecsys® PTH STAT assay demonstrated acceptable analytical performance, and the described IOPTH workflow was implemented successfully via a collaborative hospital-wide initiative. We discuss our model to help guide other institutions in implementing and improving IOPTH workflows.
