The Association Between Thromboelastographic Parameters and Total Estimated Blood Loss in Patients Undergoing Elective Cesarean Delivery

BACKGROUND: In this study, we assessed the relationship between coagulation parameters using kaolin-activated thromboelastography (TEG (R)) and total estimated blood loss (EBL) in patients undergoing elective cesarean delivery (CD). METHODS: TEG (R) parameters were recorded in 52 patients before and after elective CD. Laboratory markers of coagulation (prothrombin time, activated partial thromboplastin time, fibrinogen) were also assessed in a smaller subset (21 patients). Correlation and linear regression analysis was used to assess the relationship among TEG (R) parameters, relevant clinical variables, and total EBL. Secondary analysis included comparisons of TEG (R) and coagulation profiles pre-CD versus post-CD. RESULTS: EBL weakly correlated with percentage change in maximum amplitude (r = 0.3; P = 0.04) and post-CD maximum rate of thrombus generation (r = 0.31; P = 0.02). Post-CD values for split point, reaction time, time to maximum rate of thrombin generation, prothrombin time, and activated partial thromboplastin time were significantly increased compared with baseline values (P < 0.05). Post-CD alpha angle, maximum amplitude, total thrombus generation, fibrinogen, and platelet counts were significantly decreased compared with baseline values (P < 0.05). CONCLUSIONS: There is a weak association between clot strength (as assessed by kaolinactivated TEG (R)) and EBL in patients undergoing elective CD under neuraxial anesthesia, and a modest reduction in the degree of maternal hypercoagulability occurs in the early postpartum period after elective CD. (Anesth Analg 2011;112:1041-7)