Hemodynamics during hemodialysis, sequential ultrafiltration and hemofiltration.

Circulatory parameters were determined by cardiac catheterization in patients on maintenance hemodialysis. They were studied in three groups during conventional hemodialysis, sequential ultrafiltration and hemofiltration. All three groups revealed significant reduction of cardiac output, stroke volume, pulmonary artery pressure and plasma volume. In the hemodialysis group hemodynamic parameters were unstable; specifically, hypotension, increased heart rate, and only minimal increase of peripheral resistance were observed. The other two groups showed only minor changes in circulatory parameters despite high ultrafiltration rates. Blood pressure and heart rate remained stable. On the other hand, peripheral vascular resistance increased remarkably. There is compelling evidence that during hemofiltration and sequential ultrafiltration, the patient's ability for vasoconstrictive counterregulation is better maintained than during conventional hemodialysis.