Comparison of Different Sampling Methods on Viscoelastic Test Results Using a Point-of-Care Coagulation Monitor in Healthy Dogs.

BACKGROUNDS: Studies investigating the influence of sampling methods on point-of-care viscoelastic test (VCM Vet) results are limited.

OBJECTIVES

Investigating the impact of blood sampling methods on VCM Vet results in dogs, and determining if results are affected by hematological parameters, and blood sampling difficulty.

METHODS

Two VCM assays were performed on 52 healthy dogs. Blood sample was first collected from a direct jugular venipuncture on all dogs to run a baseline VCM Vet assay, perform a CBC, and measure fibrinogen concentration. A second VCM Vet assay was performed one hour later with blood sampling methods randomized as follows: contralateral jugular using a vacutainer, direct stick in a saphenous vein, or blood sampling via a cephalic intravenous catheter.

RESULTS

Reference intervals were established for each VCM Vet parameter with the first blood sample. The intra-class correlation (ICC) between sampling methods was poor (< 0.5). There was a weak positive correlation between hematocrit and CT (p < 0.042), a weak negative correlation between platelet count and CFT (p < 0.01), and a weak positive correlation between platelet count and alpha (p = 0.002), A10 (p < 0.001), A20 (p < 0.001), and MCF (p < 0.001).

CONCLUSIONS

Sampling protocols influence VCM Vet results. Each sampling method is reliable but not correlated. Follow-up on a patient should be performed using the same sampling method and site. CBC results should be known before interpreting results.