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

Abstract

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 (<&#x2009;0.5). There was a weak positive correlation between hematocrit and CT (p&#x2009;<&#x2009;0.042), a weak negative correlation between platelet count and CFT (p&#x2009;<&#x2009;0.01), and a weak positive correlation between platelet count and alpha (p&#x2009;=&#x2009;0.002), A10 (p&#x2009;<&#x2009;0.001), A20 (p&#x2009;<&#x2009;0.001), and MCF (p&#x2009;<&#x2009;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.