© 2000 Canadian Medical Association or its licensors CMAJ Specialty Spotlight Critical care medicine Technology: Continuous venovenous hemodiafiltration

Use: CVVHD is a form of continuous renal replacement therapy that is used for critically ill patients with multisystem organ failure in whom acute renal failure develops. This form of dialysis differs from intermittent hemodialysis in that it is a slower, continuous mode of dialysis that permits the clear-ance of blood solutes both by diffusion across a semiperme-able membrane (dialysis) and by convection of solutes across a membrane as they are separated from whole blood in re-sponse to hydrostatic pressure.1 Hydrostatic pressure is gen-erated by simultaneously circulating fluid in conjunction with blood through a dialysis circuit before it enters the dialysis hemofilter. History: Continuous renal replacement therapy was first de-scribed by Scribner and associates2 in 1960. It was initially performed through an arteriovenous circuit that incorpo