THROMBOELASTOGRAPHY AND SONOCLOT ANALYSIS IN THE HEALTHY PARTURIENT

Study Objective: To compare values for two whole blood viscoelastic coagulation tests, thromboelastography (TEG) and Sonoclot analysis (Sonoclot R Coagulation Analyzer, Sienco, Inc., Morrison, CO), between healthy parturients and nonparturients. Design: Prospective study. Setting: University hospital. Patients: 41 healthy, nonpregnant females and full-term nonlaboring and laboring parturients. Interventions: Blood samples for TEG and Sonoclot analysis were taken from all patients. TEG tracings were analyzed for reaction time (R), coagulation time (RK), the difference between RK and R (K), clot formation rate (alpha-degrees), and maximum amplitude (MA) values. Sonoclot tracings were analyzed for onset, rate up, peak, and rate down values. Measurements and Main Results: All TEG values were significantly different between nonpregnant females and parturients (p < 0.05). Sonoclot analysis showed that the parturients had a significantly decreased onset and increased primary slope (rate up) in comparison to the nonpregnant females (p < 0.05). Conclusion: The differences found in the parturients reflect a hypercoagulable state. If these tests are to be used in evaluating obstetric patients, the results should be compared with values obtained for healthy parturients, not healthy nonparturients.