Comparison of thrombelastography with common coagulation tests in preeclamptic and healthy parturients

Epidural analgesia/anesthesia is often beneficial in the management and treatment of preeclampsia. However, some preeclamptic patients have a coagulopathy that is a contraindication to regional anesthesia. A routine coagulation battery (RCB) consisting of prothrombin time, partial thromboplastin time, platelet count, and bleeding time, is commonly performed to assess coagulation status. Thrombelastography (TEG) is a measure of clotting that allows evaluation of overall coagulation activity. The goal of this study was to examine whether TEG can predict normal and abnormal coagulation as diagnosed by RCB in healthy and preeclamptic parturients.

Forty-seven parturients participated in this prospective study, performed early in the first stage of labor. Twenty healthy parturients (group I), 19 mild (group II), and 8 severe preeclamptic/eclamptic parturients (group III) had RCB and TEG performed.

Five patients (1, group I; 3, group II; 1, group III) had a normal RCB, but a mildly abnormal TEG (prolonged K, small alpha) (specificity = 0.88). Five of 27 preeclamptic parturients (1, group II; 4, group III) had abnormal RCBs. Three of these 5 patients had thrombocytopenia with normal bleeding times and TEGs. Two patients had thrombocytopenia and prolonged bleeding times and abnormal TEGs (sensitivity = 0.40).

Thrombelastography is not an effective means of predicting abnormal coagulation, as diagnosed by RCB, in preeclamptic parturients, using currently defined normal TEG values for nonpregnant patients. However, an abnormal TEG maximum amplitude value always correlated with a prolonged bleeding time. Therefore, TEG may be useful in assessing platelet function in the presence of thrombocytopenia. Further studies are warranted.