PERIOPERATIVE THROMBOELASTOGRAPHY AND SONOCLOT ANALYSIS IN MORBIDLY OBESE PATIENTS

Purpose: To investigate perioperative coagulation in morbidly obese (M O) patients with the thromboelastography (TEG) and Sonoclot analyzer. Methods: Twenty-six consecutive morbidly obese and 26 consecutive lean patient presenting for elective surgery were enrolled in this prospec tive observational study. Blood was sampled for and Sonoclot analysis immediately after anaesthetic induction and at the end of surgery in t he MO group, and immediately after anaesthetic induction in the lean g roup. The R and K times, alpha angle, maximum amplitude and percentage fibrinolysis at 30 and 60 min were recorded from the TEG. The Sonoclo t ACT, initial clot rate, peak amplitude and time to peak amplitude we re recorded from the Sonoclot. Results: The TEG in the MO group demons trated decreased R and K times (8.6 +/- 4.8 vs 11.7 +/- 3.9 mm, and 2. 8 +/- 1.2 vs 3.5 +/- 0.9 mm respectively (P < 0.05)), and increased al pha angle (73.7 +/- 6.0 vs 66.7 +/- 6.0 degrees, P < 0.05) and maximum amplitude (72.0 +/- 5.4 vs 67.9 +/- 4.4 mm, P < 0.05), without change in fibrinolysis, Sonoclot variables in the MO group included increase d clot rate (37.5 +/- 11.5 vs 23.9 +/- 7.7%, P < 0.05) and decreased t ime to peak impedance (11.7 +/- 5.0 vs 17.5 +/- 7.2 min, P < 0.05, wit hout change in Sonoclot ACT or peak signature impedance. Conclusion: T he MO group demonstrated accelerated fibrin formation, fibrinogen plat elet interaction, and platelet function compared with lean controls bu t no difference in fibrinolysis, Viscoelastic measures of coagulation may be useful in MO patients, who are are at increased risk of thrombo embolic events.