///2009 Abstract Details
2009 Abstract Details2019-08-03T15:55:31-06:00

Thromboelastography to assess the relationship between coagulation changes and blood loss in patients undergoing elective Caesarean delivery.

Abstract Number: 62
Abstract Type: Original Research

Vicki W. Ting M.D.1 ; Lindsey M. Atkinson M.D.2; Scott M. Harter M.D.3; Edward T. Riley M.D.4; Alexander J. Butwick M.D.5

Introduction: Coagulation disturbance has been shown to occur in patients with severe post-partum hemorrhage.1 However, it is unclear whether coagulation changes are associated with blood loss occurring during uncomplicated Caesarean delivery (CD). The study aim was to determine the relationship between coagulation changes using thromboelastography (TEG) and peri-operative bleeding in patients undergoing elective CD.

Methods: Following IRB approval, 21 of 52 patients with uncomplicated singleton pregnancies for elective CD with spinal anesthesia have been enrolled. Kaolin-activated TEG was performed with blood drawn from an 18G IV cannula pre-operatively, and post-operatively from venipuncture for TEG analysis. One mL of blood was placed into a vial containing kaolin and, after mixing, 360 μL of kaolin-activated whole blood was pipetted into a plastic cup in a pre-warmed TEG machine. Total estimated blood loss (EBL) included: blood in the suction chamber and surrounding the surgical field (assessed by visual inspection by obstetric and anesthesia attendings) and weight of blood-soaked surgical swabs. Pearsons correlation coefficient was used to identify post-operative TEG parameters and EBL. Paired t-tests compared pre- and post-operative TEG values; P value <0.05 was considered significant.

Results: There were no significant correlations between post-operative TEG parameters (r time, k time, alpha angle, MA) and EBL. Furthermore, no correlations were found for post-operative kinetic parameters of thrombus generation (VCurve) and EBL. Post-operative r time, k time and time to maximum rate of thrombin generation were significantly longer than pre-operative values (P<0.05) (Figure). Post-operative Hb and platelet counts were significantly lower than pre-operative values (P<0.001) (Figure). The mean (SD) value for EBL was 797 (345) mLs.

Conclusion: Our interim results suggest that no direct association exists between the coagulation system (as assessed by TEG) and EBL in patients undergoing uncomplicated elective CD. In contrast to previously published TEG data,2 mild hypocoagulable changes using TEG were observed following CD compared to pre-operative values; decreases in clotting factors and platelets resulting from hemodilution and intraoperative blood loss may contribute to these effects.


1. J Thromb Haemost 2007;5:266-73. 2. Anesth Analg 1997;85:82-6.

SOAP 2009