Evaluation of the Accutrend for lactate measurement in dogs

Lactate concentrations are increasingly quantified in dogs using point-of-care instruments, but often without canine-specific method evaluation and instrument-specific reference intervals.

The objectives of this study were to 1) determine the precision of the Accutrend (Roche Diagnostics) for lactate determination in dogs, 2) determine the accuracy of the Accutrend using the Rapidlab 865 (Bayer Diagnostics) as the reference method, and 3) establish and compare reference intervals for lactate concentration in clinically healthy dogs for both instruments.

Precision was evaluated using low and high control materials, and variable (1 drop) and fixed (25 microL) sample volumes. Accuracy was determined by comparing lactate concentrations obtained with the Accutrend with those from the Rapidlab 865 in 273 heparinized canine jugular venous blood samples from 100 clinically healthy dogs and 107 systemically ill dogs (173 samples). Lactate reference intervals were established for both analyzers using data from the 100 clinically healthy dogs.

The precision of the Accutrend was good (coefficients of variation, < or = 5.3%) for 25-microL samples but not when a drop was used. Lactate concentrations obtained on the Accutrend correlated poorly with those from the Rapidlab 865 (r = 0.864, mean bias = 0.66 mmol/L, 95% confidence interval [CI] = 0.57-0.76 with 95% limits of agreement = -0.87 (lower limit, 95% CI = -1.03 to -0.71) and 2.20 (upper limit, 95% CI = 2.04 to 2.36). The reference interval for canine lactate concentration on the Accutrend was 1.2-3.1 mmol/L compared with 0.46-2.31 mmol/L on the Rapidlab.

Although precision was good with fixed sample volumes, blood lactate concentrations obtained on the Accutrend were significantly different than those on the Rapidlab 865, with systematic and random errors resulting in a positive bias. Further evaluation of the Accutrend is required before its use in dogs can be recommended.