Value of thrombelastography in monitoring coagulation state of trauma patients with lower limb venous thrombosis

Abstract

Objective To investigate the efficacy of thrombelastography (TEG) in monitoring the coagulation state of trauma patients with lower limb venous thrombosis. Methods A total of 64 trauma patients surgically treated from March 2015 to April 2015 were analyzed by retrospective case-control study. There were 32 males and 32 females, with an age range of 17-79 years (mean, 53.44 years). None had significant vascular damage. The average time between injury and surgery was 8.8 days (range, 2-20 days). The patients were divided into lower limb venous thrombosis group(thrombosis group, n=10) and non-venous-thrombosis group (non-thrombosis group, n=54) according to the diagnosis of color Doppler ultrasound. The causes of trauma included tumbling in 33 cases, fall from height in 8, traffic accident in 15, and compression injury in 8. The data were reviewed including variables of TEG [reaction time (R value), clot formation time (K value), α angle, maximum amplitude (MA)], platelet (PLT) count and variables of conventional coagulation tests (CCTs) [plasma prothrombin time (PT), activated partial thromboplastin time (APTT), and international normalized ratio (INR)]. The correlation between R, K and CCTs and the correlation between α angle, MA and PLT were investigated. The variations of the two methods between two groups were investigated by receiver operating characteristic curve (ROC). Area under the curve (AUC), sensitivity and specificity of R value, K value, PT and APTT were analyzed. Results R value of thrombosis group was lower than that in non-thrombosis group [5.55(4.78, 5.85) min vs. 6.20(5.30, 7.03) min] (P 0.05). The R value was positively correlated PT (r=0.65, P<0.05) and INR (r=0.69, P<0.05), but had no significant correlation with APTT or PLT count. The K value was not significantly correlated with PT, APTT, INR or PLT count, and PLT was not significantly correlated with α angle or MA. AUC was 0.73 in R value, 0.66 in K value, 0.58 in PT, and 0.60 in APTT. The sensitivity values to detect lower limb venous thrombosis in trauma patients were 87.04% in R value (<5 min), 79. 63% in K value (<1.00 min), 0.00% in PT (<11.4 s), and 90.74 in APTT (<27.4 s). The specificity values were 40.00% in R value (<5 min), 40.00% in K value (<1.00 min), 100.00% in PT (<11.4 s), and 20.00% in APTT (<27.4 s). Conclusion TEG is considered to be much more sensitive than CCTs for monitoring the coagulation state, and can be selected as the supplementary screening test for trauma patients with lower limb venous thrombosis. Key words: Thrombelastography; Wounds and injuries; Lower extremity; Venous thrombosis; Conventional coagulation tests