Plasma lactate concentrations and comparison of two point-of-care lactate analyzers to a laboratory analyzer in a population of healthy cats

Abstract

Objective: To establish a reference interval for plasma lactate in a population of healthy adult cats on a laboratory analyzer (Nova Biomedical Critical Care Xpress [CCX]) and 2 commercially available point-of-care (POC) analyzers (Abbott i-STAT [i-STAT] and Nova Biomedical Lactate Plus [LP]), and to compare the level of agreement of lactate measurement between the laboratory analyzer and POC analyzers.

Design: Prospective observational study.

Setting: University veterinary teaching hospital.

Animals: Forty-seven healthy adult cats.

Interventions: Jugular phlebotomy.

Measurements and main results: In this population, plasma lactate reference interval was 0.67-5.44 mmol/L for the CCX, 0.65-5.16 mmol/L for the i-STAT, and 0.68-4.39 mmol/L for the LP. Comparisons were made between lactate measurements on 2 point-of-care analyzers and the laboratory analyzer using the Bland-Altman method. For the comparison of CCX and i-STAT, the bias was -0.10 mmol/L; for the CCX and LP, the bias was -0.24 mmol/L.

Conclusions: Measurements of plasma lactate in cats using the i-STAT showed acceptable agreement with the CCX. The LP showed weaker agreement. However, both POC analyzers are suitable for measurement of lactate in cats, provided results from different POC analyzers are not directly compared. This study identified a larger reference interval for plasma lactate concentration in cats than what has been previously reported.

Keywords: acidemia; point-of-care; shock.