Fig. 1

During the first 12 h after ECMO cannulation, the algorithm was identical in the two study groups. After the first 12 h according to randomization, the anticoagulation management was modified according to the assigned study group: In the TEG group (intervention group), heparin infusion was titrated to reach a target TEG-K reaction time (R-K) of 16–24 min (normal values: 4–8 min); in the aPTT group (standard of care–control group), heparin infusion was titrated to reach a target aPTT ratio value of 1.5–2. Under-target levels of anticoagulation were corrected with either heparin bolus plus increase in infusion or with increase in infusion only; similarly, over-target levels of anticoagulation were corrected with either heparin infusion stop for 30 or 60 min and restart with a reduced dose or with decrease in infusion only. Time to the next control varied according to the degree of derangement from target values of anticoagulation. In case of surgery, minimal levels of anticoagulation (i.e., R-K of 8–12 min and aPTT ratio of 1.2–1.3, in the study and control group, respectively) were tolerated during the first 24 h after the operation. In case of bleeding, heparin infusion was reduced to the lower value of the target range or interrupted based on the severity of bleeding