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Comparison of fibrin-based clot elasticity parameters measured by free oscillation rheometry (ReoRox ®) versus thromboelastometry (ROTEM ®).

Solomon C, Schöchl H, Ranucci M, Schött U, Schlimp CJ - Scand. J. Clin. Lab. Invest. (2015)

Bottom Line: Hemodilution decreased clot strength.Both Fibscreen2 G'max and FIBTEM parameters decreased proportionally to the dilution ratio when saline was used.The observed reductions in FIBTEM and Fibscreen2 parameters were more severe in samples diluted with gelatin and HES, compared to saline.

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology, Perioperative Medicine and General Intensive Care, Paracelsus Medical University , Salzburg , Austria.

ABSTRACT

Background: Whole blood viscoelastic tests such as the fibrin-based thromboelastometry (ROTEM(®)) test FIBTEM are increasingly used in the perioperative setting to quickly identify deficits in fibrin quality, and to guide hemostatic therapy. The recently developed FibScreen2 test of the ReoRox(®) method, based on free oscillation rheometry, also provides an evaluation of fibrin clot quality. To date, little information is available on the performance of this test in hemodiluted blood, by comparison to FIBTEM.

Methods: Whole blood samples from eight healthy volunteers were analyzed using FIBTEM and Fibscreen2. Native and diluted (to 33% and 50% using saline, gelatin or hydroxyethyl starch [HES]) samples were analyzed. Clot strength parameters, including FIBTEM maximum clot firmness (MCF), FIBTEM maximum clot elasticity (MCE) and Fibscreen2 maximum elasticity (G'max), were measured.

Results: In repeatedly measured samples from two volunteers, FIBTEM MCF and Fibscreen2 G'max revealed a coefficient of variation (CV) of 5.3 vs. 16.3% and 5.6 vs. 31.7% for each volunteer, respectively. Hemodilution decreased clot strength. Both Fibscreen2 G'max and FIBTEM parameters decreased proportionally to the dilution ratio when saline was used. The observed reductions in FIBTEM and Fibscreen2 parameters were more severe in samples diluted with gelatin and HES, compared to saline. Finally, a regression analysis between FIBTEM MCE and Fibscreen2 G'max revealed a poor goodness of fit (r(2) = 0.37, p < 0.0001).

Conclusions: ReoRox(®) Fibscreen2 test has a high coefficient of variation, and its application in various hemodilution conditions showed limited comparability with the ROTEM(®) FIBTEM test.

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ReoRox® and ROTEM® output traces. The ReoRox® device displays information on viscosity (dashed curve) and elasticity (plain curve) during the coagulation process (A). Viscosity parameters include the time of the initial formation of fibrin strands (COT1) and the time to complete clot formation (COT2) before the clot starts to strengthen. Clot strength is represented by the maximum elasticity parameter G'max obtained either in the absence (Fibscreen1 G'max) or presence (Fibscreen2 G'max) of platelet inhibitor. Similar coagulation parameters are obtained with the ROTEM® system (B), the equivalent of COT2 being the clotting time (CT, time from start to 2 mm amplitude). Maximum clot firmness (MCF) parameters, obtained either in the absence (EXTEM test) or presence (FIBTEM test) of platelet inhibitor, can be converted into maximum clot elasticity (MCE) parameters, using the following formula: MCE = (MCF × 100)/(100 − MCF).
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Figure 1: ReoRox® and ROTEM® output traces. The ReoRox® device displays information on viscosity (dashed curve) and elasticity (plain curve) during the coagulation process (A). Viscosity parameters include the time of the initial formation of fibrin strands (COT1) and the time to complete clot formation (COT2) before the clot starts to strengthen. Clot strength is represented by the maximum elasticity parameter G'max obtained either in the absence (Fibscreen1 G'max) or presence (Fibscreen2 G'max) of platelet inhibitor. Similar coagulation parameters are obtained with the ROTEM® system (B), the equivalent of COT2 being the clotting time (CT, time from start to 2 mm amplitude). Maximum clot firmness (MCF) parameters, obtained either in the absence (EXTEM test) or presence (FIBTEM test) of platelet inhibitor, can be converted into maximum clot elasticity (MCE) parameters, using the following formula: MCE = (MCF × 100)/(100 − MCF).

Mentions: A novel VET (ReoRox®, Medirox AB, Sweden) based on free oscillation rheometry has been developed and made commercially available. Here, the cup containing the blood sample is set into free oscillation by a torsion wire device and the damping and frequency of the change in the oscillating movement is recorded and translated by the system into viscous and elastic parameters, respectively (Figure 1A) [16–19]. Compared to ROTEM®, free oscillation rheometry allows for the detection of a wider range of elasticity changes [20]. By using a platelet inhibitor in addition to the coagulation activator thromboplastin, it is possible to measure the quality of the fibrin-based clot with the ReoRox® method. The ReoRox® Fibscreen2 test contains the platelet inhibitor abciximab, and provides an evaluation of the fibrin-based clot, comparable to the thromboelastometry FIBTEM test, which contains cytochalasin D as platelet inhibiting agent (Figure 1A, B) [20].


Comparison of fibrin-based clot elasticity parameters measured by free oscillation rheometry (ReoRox ®) versus thromboelastometry (ROTEM ®).

Solomon C, Schöchl H, Ranucci M, Schött U, Schlimp CJ - Scand. J. Clin. Lab. Invest. (2015)

ReoRox® and ROTEM® output traces. The ReoRox® device displays information on viscosity (dashed curve) and elasticity (plain curve) during the coagulation process (A). Viscosity parameters include the time of the initial formation of fibrin strands (COT1) and the time to complete clot formation (COT2) before the clot starts to strengthen. Clot strength is represented by the maximum elasticity parameter G'max obtained either in the absence (Fibscreen1 G'max) or presence (Fibscreen2 G'max) of platelet inhibitor. Similar coagulation parameters are obtained with the ROTEM® system (B), the equivalent of COT2 being the clotting time (CT, time from start to 2 mm amplitude). Maximum clot firmness (MCF) parameters, obtained either in the absence (EXTEM test) or presence (FIBTEM test) of platelet inhibitor, can be converted into maximum clot elasticity (MCE) parameters, using the following formula: MCE = (MCF × 100)/(100 − MCF).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4389733&req=5

Figure 1: ReoRox® and ROTEM® output traces. The ReoRox® device displays information on viscosity (dashed curve) and elasticity (plain curve) during the coagulation process (A). Viscosity parameters include the time of the initial formation of fibrin strands (COT1) and the time to complete clot formation (COT2) before the clot starts to strengthen. Clot strength is represented by the maximum elasticity parameter G'max obtained either in the absence (Fibscreen1 G'max) or presence (Fibscreen2 G'max) of platelet inhibitor. Similar coagulation parameters are obtained with the ROTEM® system (B), the equivalent of COT2 being the clotting time (CT, time from start to 2 mm amplitude). Maximum clot firmness (MCF) parameters, obtained either in the absence (EXTEM test) or presence (FIBTEM test) of platelet inhibitor, can be converted into maximum clot elasticity (MCE) parameters, using the following formula: MCE = (MCF × 100)/(100 − MCF).
Mentions: A novel VET (ReoRox®, Medirox AB, Sweden) based on free oscillation rheometry has been developed and made commercially available. Here, the cup containing the blood sample is set into free oscillation by a torsion wire device and the damping and frequency of the change in the oscillating movement is recorded and translated by the system into viscous and elastic parameters, respectively (Figure 1A) [16–19]. Compared to ROTEM®, free oscillation rheometry allows for the detection of a wider range of elasticity changes [20]. By using a platelet inhibitor in addition to the coagulation activator thromboplastin, it is possible to measure the quality of the fibrin-based clot with the ReoRox® method. The ReoRox® Fibscreen2 test contains the platelet inhibitor abciximab, and provides an evaluation of the fibrin-based clot, comparable to the thromboelastometry FIBTEM test, which contains cytochalasin D as platelet inhibiting agent (Figure 1A, B) [20].

Bottom Line: Hemodilution decreased clot strength.Both Fibscreen2 G'max and FIBTEM parameters decreased proportionally to the dilution ratio when saline was used.The observed reductions in FIBTEM and Fibscreen2 parameters were more severe in samples diluted with gelatin and HES, compared to saline.

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology, Perioperative Medicine and General Intensive Care, Paracelsus Medical University , Salzburg , Austria.

ABSTRACT

Background: Whole blood viscoelastic tests such as the fibrin-based thromboelastometry (ROTEM(®)) test FIBTEM are increasingly used in the perioperative setting to quickly identify deficits in fibrin quality, and to guide hemostatic therapy. The recently developed FibScreen2 test of the ReoRox(®) method, based on free oscillation rheometry, also provides an evaluation of fibrin clot quality. To date, little information is available on the performance of this test in hemodiluted blood, by comparison to FIBTEM.

Methods: Whole blood samples from eight healthy volunteers were analyzed using FIBTEM and Fibscreen2. Native and diluted (to 33% and 50% using saline, gelatin or hydroxyethyl starch [HES]) samples were analyzed. Clot strength parameters, including FIBTEM maximum clot firmness (MCF), FIBTEM maximum clot elasticity (MCE) and Fibscreen2 maximum elasticity (G'max), were measured.

Results: In repeatedly measured samples from two volunteers, FIBTEM MCF and Fibscreen2 G'max revealed a coefficient of variation (CV) of 5.3 vs. 16.3% and 5.6 vs. 31.7% for each volunteer, respectively. Hemodilution decreased clot strength. Both Fibscreen2 G'max and FIBTEM parameters decreased proportionally to the dilution ratio when saline was used. The observed reductions in FIBTEM and Fibscreen2 parameters were more severe in samples diluted with gelatin and HES, compared to saline. Finally, a regression analysis between FIBTEM MCE and Fibscreen2 G'max revealed a poor goodness of fit (r(2) = 0.37, p < 0.0001).

Conclusions: ReoRox(®) Fibscreen2 test has a high coefficient of variation, and its application in various hemodilution conditions showed limited comparability with the ROTEM(®) FIBTEM test.

Show MeSH
Related in: MedlinePlus