Comparison of whole blood fibrin-based clot tests in thrombelastography and thromboelastometry.
BACKGROUND
Fibrin-based clot firmness is measured as maximum amplitude (MA) in the functional fibrinogen (FF) thrombelastographic assay and maximum clot firmness (MCF) in the FIBTEM thromboelastometric assay. Differences between the assays/devices may be clinically significant. Our objective was to compare clot firmness parameters through standard (FF on a thrombelastography device [TEG®]; FIBTEM on a thromboelastometry device [ROTEM®]) and crossover (FF on ROTEM®; FIBTEM on TEG®) analyses.


METHODS
Whole-blood samples from healthy volunteers were subjected to thrombelastography and thromboelastometry analyses. Samples were investigated native and following stepwise dilution with sodium chloride solution (20%, 40%, and 60% dilution). Samples were also assessed after in vitro addition of medications (heparin, protamine, tranexamic acid) and 50% dilution with hydroxyethyl starch, gelatin, sodium chloride, and albumin.


RESULTS
FF produced higher values than FIBTEM, regardless of the device, and TEG® produced higher values than ROTEM®, regardless of the assay. With all added medications except heparin 400 U/kg bodyweight, FF MA remained significantly higher (P < 0.05) than FIBTEM MCF, which was largely unchanged. FF MA was significantly reduced (P = 0.04) by high-dose heparin and partially restored with protamine. Fifty percent dilution with hydroxyethyl starch, albumin, and gelatin decreased FIBTEM MCF and FF MA by >50%.


CONCLUSIONS
These results demonstrate differences when measuring fibrin-based clotting via the FF and FIBTEM assays on the TEG® and ROTEM® devices. Point-of-care targeted correction of fibrin-based clotting may be influenced by the assay and device used. For the FF assay, data are lacking.
Department of Anaesthesiology and Intensive Care, Salzburger Landeskliniken SALK, 48 Müllner Hauptstrasse, 5020 Salzburg, Austria. Solomon.Cristina@googlemail.com
Cristina
C
Solomon
Benny
B
Sørensen
Gerald
G
Hochleitner
Jeffry
J
Kashuk
Marco
M
Ranucci
Herbert
H
Schöchl
D000328:Adult; D001780:Blood Coagulation Tests / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D005337:Fibrin / Q000032:analysis*; D005340:Fibrinogen / Q000032:analysis; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013916:Thrombelastography / Q000379:methods*
D005337:Fibrin; D005340:Fibrinogen; D006493:Heparin