New-Generation Thromboelastography: Comprehensive Evaluation of Citrated and Heparinized Blood Sample Storage Effect on Clot-Forming Variables

Abstract

Context.-Thromboelastography (TEG) is a whole blood, real-time analyzer measuring the viscoelastic properties of the hemostasis process and allowing for individualized goal-directed therapy. However, routine use of TEG requires validation of sample storage effect on clot parameters.Objectives.-To establish the minimum time required for equilibration time and the maximum time for sample storage for all commercially available TEG tests for the new-generation TEG 6s and to determine how those times compare with the older generation TEG 5000.Design.-Citrated and heparinized whole blood samples obtained from 20 healthy donors were analyzed for clot parameters at multiple time points for both the TEG 6s and the TEG 5000. Samples were activated with the citrated multichannel cartridge or the platelet-mapping cartridge in the TEG 6s or with recalcified kaolin in the TEG 5000.Results.-All blood samples yielded TEG parameter results within reference ranges and had a tendency toward hypercoagulable profiles with increased storage time. Sample storage resulted in increased platelet inhibition with significant differences at 4 hours in the plateletmapping cartridge (arachidonic acid percentage of inhibition, P ¼ .002; adenosine diphosphate percentage of inhibition, P ¼ .02).Conclusions.-For nonemergent cases or in a central laboratory setting, all tests provided reliable results for up to 4 hours in the citrated multichannel cartridge and for 3 hours for platelet function information in the plateletmapping cartridge. In emergent/urgent situations in which the sample needs to be run immediately, RapidTEG and functional fibrinogen tests may be preferred.

Detection of individual responses to clopidogrel: Validation of a novel, rapid analysis using thrombelastography 6s

“…Nearly all parameters proved to be significantly different, leading to the conclusion that TEG 6s results are susceptible to movement. Finally, Dias et al assessed the reliability of either citrated multichannel cartridge or the PM cartridge in the TEG 6s or with kaolin in the TEG 5000 system in 20 volunteers and found that reliable results can be obtained up to 4 hours in the citrated multichannel cartridge and up to 3 hours in the PM cartridge.…”

Comparison of catheter thrombogenicity in a modified chandler loop model using goat blood

“…The modification to the study design was due primarily to practical limitations on the number of loops that could be processed within our lab in a reasonable amount of time. There are multiple published studies which indicate that time after blood collection and storage conditions before testing can significantly alter coagulation related testing outcomes . The importance of conducting tests with minimal delay following blood collection has also been indicated in previous reports of in vitro hemocompatibility testing .…”

“…There are multiple published studies which indicate that time after blood collection and storage conditions before testing can significantly alter coagulation related testing outcomes. [20][21][22] The importance of conducting tests with minimal delay following blood collection has also been indicated in previous reports of in vitro hemocompatibility testing. 23 We determined that it was important to minimize the time between blood collection and beginning loop rotation.…”

External Quality Assurance of Platelet Function Assays: Results of the College of American Pathologists Proficiency Testing Program

“…The TEG 6s next-generation, automated cartridge-based device (Haemonetics Corp) reduces the possibility of user error and provides accurate, reliable results. 11,12 Although Chandler et al 1 cite a number of critical articles, they do not mention research supporting the usefulness and accuracy of the TEG technology in experienced clinicians' hands. A more balanced discussion should mention the 3 recent method validation studies.…”