We thank Dr. Omert and Dr. Popovsky from Haemonetics for their interesting comments on our recent article, “Diagnostic Performance and Therapeutic Consequence of Thromboelastometry Activated by Kaolin versus  a Panel of Specific Reagents,”1and appreciate this opportunity to clarify some of the aspects of the study.

Most importantly, this study was not a comparison of thromboelastography (TEG®; Haemonetics, Braintree, MA) and thromboelastometry (ROTEM®; Tem International GmbH, Munich, Germany) equipment, but as clearly stated throughout the article (including the title), the scope was to evaluate monoactivation with kaolin against a panel of specific reagents.

The study was stimulated by the principles adopted by renowned centers when using the methodology. The diagnostic conclusions and derived treatment strategies were compared based on two de facto  published algorithms: one using the TEG routinely applying only kaolin activation,2and the other using a panel of dedicated reagents on the thromboelastometry platform.3 

Currently, we have not observed good evidence that a single standard whole blood coagulation profile, whether activated by kaolin or other activators, might distinguish the need to transfuse platelets against fibrinogen-rich plasma-based products, and the shortcomings of relying on a single kaolin-activated profile clearly demonstrated in our recent study were in line with our general experience.

Dr. Omert and Dr. Popovsky hold on to the undocumented argument that inherent properties of the TEG in unspecified ways should provide additional information on clot formation. However, other groups have nicely demonstrated that TEG and thromboelastometry provide similar data when activated with the same assays,4,5proposing anything else is only in the interest of the manufacturers.

On the other hand this also implies that we absolutely agree with Dr. Omert and Dr. Popovsky that the TEG platform carries a diagnostic potential similar to thromboelastometry if applying well-supported algorithms based on a panel of specific reagents, with particular attention to a functional fibrinogen assay. Thus, we are pleased that Dr. Omert and Dr. Popovsky forward the potential value of such supplemental assays, which is in line with our main conclusions. Unfortunately, because of the lack of published algorithms based on a panel of available assays on the TEG instrument, we were unable to explore this further at present, but we clearly mentioned the availability of such assays in the article. Therefore, we see no reason to acknowledge the suggested omissions. In addition, we wish to mention that Dr. Omert and Dr. Popovsky refer to two specific studies that were not available at the time of our publication.

We do recognize that more work needs to be done. If our findings would lead to increased exploration of the supplemental Haemonetics assays and help forward the development of algorithms based on a panel of specific reagents on the TEG platform, we would be most delighted, and we shall be happy to assist investigations on the advantages and potential shortcomings of such proposed algorithms when they are available, we hope in the near future.

The general feedback to the data provided in our recent article suggests that it has been an eye-opener to many clinicians with regard to some potential pitfalls of the methodology, and the comments from Dr. Omert and Dr. Popovsky only assure us that our recent study represents a highly requested addition to the existing literature.

Larsen OH, Fenger-Eriksen C, Christiansen K, Ingerslev J, Sørensen B: Diagnostic performance and therapeutic consequence of thromboelastometry activated by kaolin versus  a panel of specific reagents. ANESTHESIOLOGY 2011; 115:294–302
Johansson PI, Stensballe J: Effect of haemostatic control resuscitation on mortality in massively bleeding patients: A before and after study. Vox Sang 2009; 96:111–8
Theusinger OM, Spahn DR, Ganter MT: Transfusion in trauma: Why and how should we change our current practice? Curr Opin Anaesthesiol 2009; 22:305–12
Nielsen VG: A comparison of the Thrombelastograph and the ROTEM. Blood Coagul Fibrinolysis 2007; 18:247–52
Scharbert G, Auer A, Kozek-Langenecker S: Evaluation of the Platelet Mapping Assay on rotational thromboelastometry ROTEM. Platelets 2009; 20:125–30