Lactate point-of-care testing for acidosis: Cross-comparison of two devices with routine laboratory results

Remco van Horssen; Teska N Schuurman; Monique J M de Groot; Bernadette S Jakobs

doi:10.1016/j.plabm.2015.12.005

Lactate point-of-care testing for acidosis: Cross-comparison of two devices with routine laboratory results

Pract Lab Med. 2015 Dec 24:4:41-49. doi: 10.1016/j.plabm.2015.12.005. eCollection 2016 Apr 1.

Authors

Remco van Horssen¹, Teska N Schuurman², Monique J M de Groot¹, Bernadette S Jakobs¹

Affiliations

¹ Department of Clinical Chemistry and Hematology, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands.
² Department of Obstetrics and Gynecology, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands.

Abstract

Objectives: Lactate is a major parameter in medical decision making. During labor, it is an indicator for fetal acidosis and immediate intervention. In the Emergency Department (ED), rapid analysis of lactate/blood gas is crucial for optimal patient care. Our objectives were to cross-compare-for the first time-two point-of-care testing (POCT) lactate devices with routine laboratory results using novel tight precision targets and evaluate different lactate cut-off concentrations to predict metabolic acidosis.

Design and methods: Blood samples from the delivery room (n=66) and from the ED (n=85) were analyzed on two POCT devices, the StatStrip-Lactate (Nova Biomedical) and the iSTAT-1 (CG4+ cassettes, Abbott), and compared to the routine laboratory analyzer (ABL-735, Radiometer). Lactate concentrations were cross-compared between these analyzers.

Results: The StatStrip correlated well with the ABL-735 (R=0.9737) and with the iSTAT-1 (R=0.9774) for lactate in umbilical cord blood. Lactate concentrations in ED samples measured on the iSTAT-1 and ABL-735 showed a correlation coefficient of R=0.9953. Analytical imprecision was excellent for lactate and pH, while for pO₂ and pCO₂ the coefficient of variation was relatively high using the iSTAT-1.

Conclusion: Both POCT devices showed adequate analytical performance to measure lactate. The StatStrip can indicate metabolic acidosis in 1 μl blood and will be implemented at the delivery room.

Keywords: Blood gas; CCU, Critical Care Unit; CV, coefficient of variation; ED, Emergency Department; Fetal acidosis; Lactate; POCT, point-of-care testing; Point-of-care testing; SD, standard deviation; SEE, Standard Error of Estimate; TEa, Total Allowable Error.