Continuous
hemofiltration and continuous
hemodiafiltration (CHF/CHDF) were developed as
continuous renal replacement therapy for patients with severe conditons and has come to be widely performed mainly in
critical care, taking the place of intermittent
hemodialysis. The membrane pore size of a hemofilter used for CHF/CHDF allows passage of substances ranging from 30,000 to 50,000 Da, and the method for solute removal in CHF/CHDF employs the principle of convection, which is advantageous for removing middle- to high-molecular-weight substances. As
apheresis therapy to remove pathogenic substances in blood, CHF/CHDF is therefore being investigated for its possible effect on various morbid conditions. It has recently been found that CHF/CHDF removes humoral mediators including
cytokines, particularly in severe systemic inflammatory response syndromes such as
septic shock and severe
acute pancreatitis. CHF/CHDF is thus beginning to be performed for the prevention and treatment of organ dysfunction secondary to
septic shock,
trauma, or
acute pancreatitis. CHF/CHDF is also efficacious as
artificial liver support in preventing adverse effects caused by
plasma exchange (PE) and for continuous removal of
hepatic coma-inducing substances. CHF/CHDF is effective for various morbid conditions not only as
renal replacement therapy, but also as
apheresis therapy and is expected to be applied more widely in
critical care in the future.