Comparison of Viscoelastic Testing by Rotational Torsion and Harmonic Resonance Methods.

OBJECTIVES To compare the performance of the TEG 5000 and TEG 6S Global Hemostasis cartridge. METHODS We reviewed validation data of the TEG 5000 and TEG 6S Global Hemostasis cartridge. The specimens were analyzed in parallel according to the manufacturer's operating instructions. RESULTS Fifty-four healthy donors and 13 donors with known hemostatic abnormalities were included. The correlations between instrument types were only moderate-the Spearman rank correlations were 0.55, 0.62, 0.64, and 0.72, respectively, for CK R, K, angle, and maximum amplitude (MA) parameters. Using the manufacturer's device-specific reference ranges to classify results as normal/abnormal, there was weak agreement in the qualitative interpretation of all parameters (Cohen's κ for agreement for CK R, K, angle, and MA was 0.418, 0.154, -0.083, and 0.127, respectively). This could lead to discordant transfusion decisions. CONCLUSIONS These findings indicate that the TEG 5000 and TEG 6S may not be used interchangeably.