An alternate method for calibrating the thrombelastograph

Objective: This study evaluated various substances that could be used to ca librate the Thrombelastograph. Design: Prospective, controlled comparison. Setting: Operating room laboratory at a tertiary care university hospital. Participants: None. Interventions: Six substances commonly available in the operating room sett ing (ointments, cream, and gels) were analyzed by thromboelastography for 3 minutes. Sixty measurements were made for each substance. Measurements and Main Results: Thromboelastographic analysis of the ointmen ts and cream preparations had an amplitude variability that exceeded 10 mm within the 3-minute recording period. The conductive gel had the most repro ducible thromboelastography tracing with a mean amplitude of 62.5 +/- 1.1 m m (analysis of variance, p < 0.0005). There was a significant correlation b etween the reported viscosity of the three gels and the deflection amplitud e (linear regression, R-2 = 0.97;p < 0.0001). Conclusion: Conductive gel is a useful substance for quickly checking the f unctional status of the Thrombelastograph at an operational stage. Ca libra tion of the Thrombelastograph using a gel of known viscosity is clinically relevant and may be more practical than testing with thromboelastographic-d efined normal and abnormal blood analogs. Copyright (C) 1998 by W.B. Saunde rs Company.