Effect Of Venous Sampling Methods And Sites On Thromboelastography For Patients Underwent Thoracic Surgery

This study was assigned to assess the influence of different blood collection methods and sites on the results of thromboelastography (TEG) in patients underwent thoracic surgery. Forty patients, who underwent lobectomy or esophagectomy in our hospital from May 2014 to March 2015, were randomly divided into two groups (group A and group B; n = 20 in each group). In group A, blood was collected from femoral vein and internal jugular vein by direct venipuncture. In group B, femoral vein blood was sampled by direct venipuncture, and then blood from internal jugular vein was drawn via a deep venous catheter. Kaolin-activated TEG analyses were performed, and clotting time (R), clot kinetics (K), a angle and maximal amplitude (MA) were compared using paired t-test. All tested parameters were within the normal range. In group A, no significant differences in R, K, alpha angle and MA values were found between samples obtained by direct venipuncture from femoral and jugular vein (P > 0.05). In group B, however, the R value of blood sample collected by femoral vein puncture was significantly lower than that of sample captured via an indwelling internal jugular vein catheter (P < 0.05), while differences in K, a angle and MA values did not reach statistical significant (P > 0.05). In summary, all of these sampling routes were acceptable for thromboelastographic analysis. Howbeit, to avoid bias, the sampling method and site should be the same when conducting clinical dynamic observation.