Comparison of Citrated Whole Blood to Native Whole Blood for Coagulation Testing Using the Viscoelastic Coagulation Monitor (VCM Vet™) in Horses.
Authors: Vokes Jessica R, Lovett Amy L, de Kantzow Max C, Rogers Chris W, Wilkins Pamela A, Sykes Benjamin W
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Citrated vs Native Whole Blood for Equine Viscoelastic Coagulation Testing Whilst viscoelastic monitoring offers distinct advantages over conventional coagulation assays in equine practice, the optimal blood collection method remains uncertain. Researchers compared native whole blood (NWB) tested immediately with citrated whole blood (CWB) stored at room temperature and tested at 1 and 4 hours post-collection using the VCM Vet™ device in 70 horses, establishing reference intervals from 20 clinically healthy animals. All measured viscoelastic parameters differed clinically between CWB and NWB, with inconsistent variation between the 1-hour and 4-hour timepoints, indicating that storage time substantially influences results and must be standardised if CWB is used. Notably, CWB testing generated significantly more machine errors than NWB, potentially rendering measurements uninterpretable in clinical cases. These findings suggest that whilst CWB might theoretically offer practical advantages, the current evidence does not support its interchangeability with NWB, and practitioners should continue using fresh native blood for viscoelastic analysis until further refinement of citration protocols resolves these technical and interpretative limitations.
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Practical Takeaways
- •For equine practice using VCM Vet™, stick with native whole blood (NWB) sampling; citrated whole blood cannot be substituted without invalidating your coagulation results
- •If considering CWB in the future, resting time must be rigorously controlled and standardized, as results shift significantly between 1-4 hours—consistency matters more than the specific interval chosen
- •Expect more machine errors and failed readings with CWB preparation, which reduces reliability in clinical decision-making compared to NWB testing
Key Findings
- •Citrated whole blood (CWB) produced clinically relevant differences in all viscoelastic parameters compared to native whole blood (NWB) and cannot be used interchangeably
- •CWB results varied between 1 and 4 hours post-collection, indicating resting time significantly influences measurements and must be standardized
- •CWB testing resulted in more machine errors compared to NWB, producing potentially uninterpretable measurements
- •Reference intervals were established for CWB at 1 and 4 hours post-collection in 20 clinically healthy horses