ECMO Complications

ECMO complications develop where the patient, cannulae, and artificial circuit meet. Three processes operate simultaneously: blood contacting nonendothelial circuit surfaces activates coagulation, platelets, complement, and inflammation; mechanical shear from the pump and oxygenator can destroy red cells and reduce high-molecular-weight von Willebrand factor; and the ECMO configuration changes normal blood flow and cardiac loading. The result is a patient who can clot in the circuit while bleeding from a cannulation site, develop hemolysis while receiving apparently adequate flow, or have reassuring lower-body oxygenation while the brain and coronary arteries remain hypoxemic. The first bedside question is therefore not simply whether the patient is unstable. Identify whether support is VV or VA, where blood is drained and returned, which organs still depend on native function, and whether the change began in the patient, cannula, circuit, or gas exchanger. That frame turns a long list of complications into a sequence of observable clinical problems with different first actions.