Analytical performance of three whole blood point-of-care lactate devices compared to plasma lactate comparison methods and a flow-injection mass spectrometry method

作者：Tolan Nicole V; Wockenfus Amy M; Koch Christopher D; Crews Bridgit O; Dietzen Dennis J; Karon Brad S

来源：Clinical Biochemistry, 2017, 50(4-5): 168-173.

DOI：10.1016/j.clinbiochem.2016.11.004

• Lactate
• Point of care
• Critical care testing
• Mass spectrometry
• Method comparison

Objectives: Point of care (POC) whole blood lactate testing may facilitate rapid detection of sepsis. We evaluated three POC methods against both plasma lactate comparison methods and a flow-injection mass spectrometric (MS) method.
Design and Methods: Nova StatStrip, Abbott i-STAT CG4 + and Radiometer ABL90 POC lactate methods were evaluated against the mean of Cobas Integra 400 and Vitros 350 plasma lactate. POC methods were also compared to a flow-injection mass spectrometric assay measuring lactate in ZnSO4-precipitated whole blood extracts. Intra-and inter-assay precision was determined using quality control material. Method comparison included specimens from normal donors at rest, after exertion, and after spiking with lactic acid.
Results: Intra-and inter-assay coefficient of variation was <5% for i-STAT and ABL90; but ranged from 3.1-8.2% on two StatSttip meters. Mean (+/- SD) bias between POC and plasma lactate ranged from -0.2 +/- 0.9 (i-STAT and ABL90) to -0.4 +/- 12 (StatStrip) mmol/L. At concentrations >6 mmol/L, all POC methods showed proportional negative bias compared to plasma methods; but this bias was not observed when compared to the MS method. Despite proportional negative bias, all POC methods demonstrated acceptable concordance (94-100%) with plasma lactate within the reference interval (<2.3 mmol/L) and >4 mmol/L, commonly used clinical cut-offs for detection of sepsis.
Conclusions: POC lactate methods demonstrate acceptable concordance with plasma lactate across commonly used clinical cut-offs for detection of sepsis. Due to systematic negative bias at higher lactate concentrations, POC and plasma lactate should not be used interchangeably to monitor patients with elevated lactate concentrations.

• 出版日期2017-3