Continuous arteriovenous filtration: an effective treatment for surgical acute renal failure.

Continuous arteriovenous hemofiltration (CAVH) is a new method of renal replacement therapy that has several advantages in the surgical treatment of acute renal failure. We initially learned the technique in laboratory testing and then developed a management protocol. Since 1983 we have used CAVH to treat 61 patients with acute renal failure. This extracorporeal technique consists of arteriovenous cannulation of the femoral vessels, which provides continuous blood flow through a hollow-fiber membrane. Hydrostatic pressure (systole greater than 80 mm Hg) creates an ultrafiltrate at a typical rate of 12 L/day. Volume is replaced with an intravenous solution at a rate to achieve the desired fluid balance, usually a net loss of 1 to 2 L/day. This extracellular fluid exchange typically results in removal of 15 gm of urea nitrogen and 50 mEq of potassium per day. The technique can be used in most intensive care units and has relatively few complications. In addition to being a safe and effective means of renal replacement therapy for acute renal failure, CAVH is particularly advantageous for managing conditions of fluid overload in hemodynamically unstable patients.