A-376 Performance of Viscoelastic testing on the ROTEM sigma

Abstract Background Our laboratory was asked to perform Viscoelastic testing on the Rotem Sigma (Point of Care) (Werfen, Munich, Germany), currently performed by the Anesthesia Department on the Rotem Delta (Benchtop) analyzer to support liver transplantation surgery. This testing, performed on citrated whole blood, supports transfusion management and optimization of hemostasis. The semi-quantitative assays performed on each test cartridge consist of INTEM C (to monitor coagulation via the intrinsic pathway), EXTEM C (to monitor coagulation via the extrinsic pathway), FIBTEM C (to monitor coagulation via the extrinsic pathway, assessing fibrinogen status and fibrin polymerization by blocking platelet contribution to clot firmness), and HEPTEM C (to monitor coagulation via the intrinsic pathway, after inactivating heparin). Each assay provides several parameters including Clotting Time (CT), Amplitude (up to 20 minutes after clotting time), Maximum Clot Formation (MCF), and Lysis Index after 60 minutes (LI60). We also evaluated the impact on specimens during transportation through the pneumatic tube. Methods Precision studies were performed using Quality Control materials ROTROL N and P (Werfen, Munich, Germany). Comparison studies were performed on citrated whole blood against the Rotem Delta (Werfen, Munich, Germany), and between citrated whole blood samples that were carried by hand versus being sent to the lab by pneumatic tube. Results Precision studies for Rotem Sigma (n=38) for ROTROL N and P, respectively, were: EXTEM C-(Amplitude, shown as a range) 5.6%-6.8% and 3.2-4.2%; EXTEM C-CT 9.2% and 5.4%; FIBTEM C-(Amplitude, shown as a range) 4.4%-5.1% and 5.1%-6.7%; HEPTEM C-(Amplitude, shown as a range) 5.7%-7.4% and 4.3%-8.3%; HEPTEM C-CT 9.5% and 6.6%; INTEM C-(Amplitude, shown as a range) 2.0-2.4% and 2.9%- 3.2%; INTEM C-CT 4.2% and 3.3. Method Comparison results were EXTEM C-(Amplitude, shown as a range) R=0.7607-0.7667; EXTEM C-CT R=0.7090; EXTEM C-MCF R=0.7026; FIBTEM C-(Amplitude, shown as a range) R=0.9160-0.9290; FIBTEM C-MCF R=0.9265; HEPTEM C-(Amplitude, shown as a range) R=0.8525-0.8751; HEPTEM C-CT R=0.7719; HEPTEM C-MCF R=0.8343 (Table 1). Comparison of hand-carried specimens to those sent by pneumatic tube demonstrated a maximum difference of <|8.0|% for all assays and parameters. Conclusion The Rotem Sigma showed good precision and acceptable correlation to the Rotem Delta and is considered acceptable for testing patient samples. In addition, the pneumatic tube has been shown to be an acceptable means of transportation for samples intended to be tested on the Rotem Sigma.