Objective. To study the mechanisms of ECMO-associated hemorrhagic complications. Material and methods. The patients underwent veno-venous (VV-) and veno-arterial (VA-) ECMO using RotoFlow (Maquet, Rastat, Germany) or Cardiohelp (Maquet, Rastat, Germany) devices. Hemostasis was controlled using standard clotting tests and ROTEM. The period of the first 7 days of ECMO was divided into 24-hour intervals with registration of hemorrhagic complications within each interval. Each interval began with a corresponding laboratory points of traditional clotting and viscoelastic parameters. Results. The study included 21 patients: VV-ECMO 16 cases, VA-ECMO 5 cases. Duration of ECMO ranged from 2 to 33 days (mean 7.23±7.6), mean age of patients was 48.5±15.7 years (range 23 — 84). The length of ICU-stay ranged from 1 to 41 days (mean 19±8.5). ECMO-associated hemorrhagic complications developed in 12 (57.1%) observations (the second place in the overall structure of complications). 116 laboratory points and 24-hour intervals were analyzed. There were 92 hemorrhagic complications among 116 24-hour intervals. Clinically significant events were observed in 23.9% of cases. Pulmonary hemorrhage was significantly more common (n=59 (64.1%), p<0.05). ECMO-associated hemorrhage developed within the first 5 days of ECMO as a rule. The maximum number of ECMO-associated hemorrhages were registered on the second and the third day after ECMO onset. Hemorrhage was related to significantly reduced prothrombin index and platelets, increased level of fibrinogen, CTex and reduced difference MCEex—MCEfib. Increased INR (sensitivity 89.6%, specificity 55.6%), decreased MCFin (87.6% and 53.4%, respectively) and increased CFTex (sensitivity and specificity 84.9% and 65.6%, respectively) were significant predictors of hemorrhage. Conclusion. The mechanism of ECMO-associated hemorrhagic complications consists of dysfunction of extrinsic pathway factors and platelet dysfunction. INR, MCEex-MCEfib difference and the levels of MCFin and CFTex should be considered during ECMO to reduce the risk of hemorrhagic complications.
