Systematic evaluation of evidence on veterinary viscoelastic testing Part 5: Nonstandard assays

Abstract

Nontraditional assays identified included thrombelastography (TEG)-PlateletMapping (PM), functional fibrinogen assessment, and rapid-TEG (r-TEG). Direct veterinary evidence was found for only the ADP-activated PM, which appears to generate valid data in dogs but not cats or horses. Arachidonic acid activated PM shows high variability and requires further assessment and validation in veterinary species. Functional fibrinogen assays may be performed in veterinary species but may require modification due to species differences in response to abciximab. While tissue factor (TF)-activated TEG has been well described in the veterinary literature, the specific r-TEG assay has not been assessed, but presumably would be effective for generating TEG tracings and values for maximum amplitude and angle in shorter periods of time than some traditional assays.

Thromboelastographic monitoring of the effect of unfractionated heparin in healthy dogs

“…RapidTEG is a dual‐activated TEG that uses native (whole blood) or citrated and recalcified blood along with a proprietary combination of both kaolin and tissue‐factor to more quickly produce a TEG tracing (generally 10 minutes faster than traditional TEG assays) . Its use in human medicine is primarily in the setting of trauma or cardiac surgery where rapid results are required .…”

Assessment of method reliability and determination of reference intervals for rotational thromboelastometry in horses

“…In human samples, significant differences were found for some variables, but the magnitude was small when compared to the normal range variation and the differences between tests . To address these issues, the “Partnership on Rotational ViscoElastic Test Standardization” (PROVETS) was established, which published a series of review articles on different aspects of TEG and ROTEM, providing guidelines for veterinary TEG/ROTEM analysis …”

“…Although the different assays seem to perform similarly, test‐retest variability, which is likely influenced by operator errors (eg, differences in sample handling, pipetting errors, mixing errors), might differ between the 2 systems. There is a high need for standardization and it is recommended that every institution should validate its assays and develop its own reference intervals …”

Multicenter in vitro thromboelastography and thromboelastometry standardization

“…To address this, the partnership for rotational viscoelastic test standardization (PROVETS) collaboration was established from an international group of veterinary clinicians and investigators, and was based on a similar project undertaken in human medicine . The PROVETS collaboration devised evidence‐based guidelines for assay performance and reporting, in an attempt to improve consistency in assay conduct, interpretation, and reporting between centers.…”