Correlation of conventional thrombelastography and rapid thrombelastography in trauma

Conventional thrombelastography has been in use for over 6 decades and provides a functional assay of coagulation. Rapid thrombelastography was developed to provide more rapid comprehensive analysis of coagulation status in an emergency setting. The purpose of this study was to determine the correlation of rapid thrombelastographic values with conventional thrombelastographic values in trauma patients.

We performed a prospective study on trauma patients at a university level 1 trauma center. Conventional thrombelastography and rapid thrombelastography were performed on 190 consecutive major trauma patients upon admission between 2010 and 2012. Conventional thrombelastographic and rapid thrombelastographic parameters were analyzed using bivariate analysis with Pearson correlation. Group comparisons were performed using the Mann-Whitney U test.

Patients were predominantly male (71.6%, P < .05) with a median Injury Severity Score of 17 (range 10 to 29) and a median age of 43 years (range 29 to 53 years). There were significantly more patients with blunt trauma than penetrating trauma (72% vs 28%, P < .05). There was a strong correlation between the rapid thrombelastographic and conventional thrombelastographic maximal amplitude value, which represents platelet function (r = .80). There was a moderate correlation between the G (overall clot strength, r = .70), k (speed of clot formation, r = .66), and α-angle (r = .38), which reflects the degree of fibrin cross-linking. Lysis at 30 minutes correlated poorly (r = .19).

Overall, there is a strong correlation between rapid thrombelastography and conventional thrombelastography in terms of overall clot strength and platelet function. There is a moderate correlation in assessing the degree of fibrin cross-linking and a poor correlation in evaluating thrombolysis. These correlations should be considered when evaluating coagulation status using rapid thrombelastography.