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Keywords:

  • Accuracy;
  • Bovine;
  • Portable lactate meter;
  • Precision;
  • Sensitivity;
  • Specificity

Background

Despite being used commonly in bovine medicine, information on reliability of point-of-care (POC) lactate meters is limited.

Objective

To determine the validity of 4 commercially available POC lactate meters in cattle.

Animals

Cattle with various diseases (n = 120).

Methods

Blood samples collected from the jugular vein were processed immediately on POC lactate meters. Plasma l-lactate concentration was measured by the enzymatic-colorimetric method (ELISA). Data were subjected to Friedman's test for comparison, Passing-Bablok regression and Bland-Altman plot analyses for reliability, and receiver operating characteristics analysis for sensitivity (Se) and specificity (Sp).

Results

The POC lactate meters were highly correlated with ELISA (r = 0.98–0.99) despite disagreements among units. When regressed on ELISA, blood l-lactate concentrations generated from Accutrend Plus and Lactate Pro were linear up to 16.6 and 15.7 mmol/L, respectively, whereas those generated from i-STAT and Lactate Scout were linear up to 19.5 and 19.7 mmol/L, respectively. All POC lactate meters had a Se of 100% with Sp of 95.7–98.6% at a plasma l-lactate cut-off concentration of 4 mmol/L. i-STAT had the best accuracy (99.0%) and precision (99.8%), the best linear fit (y = −0.13 + 1.04X) yielding the lowest bias (−6.6%) as well as the highest Se (100%) and Sp (98.6%).

Conclusions and Clinical Importance

Despite high correlation with the reference method, dilution is needed for Accutrend Plus/Lactate Pro and i-STAT/Lactate Scout if concentrations >15 and 20 mmol/L, respectively. i-STAT provided the most accurate and precise results.