Extended daily veno-venous high-flux haemodialysis in patients with acute renal failure and multiple organ dysfunction syndrome using a single path batch dialysis system

Background. In the treatment of acute renal failure in patients with multip le organ dysfunction syndrome (MODS), continuous renal replacement therapie s (CRRT) are increasingly used because of excellent volume control in the p resence of improved cardiovascular stability. Patients with MODS, however, are frequently catabolic and have a high urea generation rate requiring eit her cost-intensive high-volume CRRT or additional intermittent haemodialysi s to provide adequate clearance of small-molecular waste products. We teste d the closed-loop batch haemodialysis system (called Genius(R)) for the tre atment of acute renal failure in patients with MODS in the intensive care u nit. Methods. Blood flow and countercurrent dialysate flow were reduced to 70 ml /min. Thus the 75 l dialysate tank of the Genius(R) system lasts for 18 h o f extended single-path high-flux haemodialysis (18 h-HFD) using polysulphou s F60 S(R) dialysers. Blood pressure, body temperature, and venous blood te mperature in the extracorporeal circuit (no heating of the dialysate), ultr afiltration rate, serum urea levels, dialyser urea clearance, and total ure a removal were monitored. In addition we tested the bacteriological quality of the spent dialysate at the end of 18-h treatments. Results. Twenty patients with acute renal failure and MODS were investigate d. Averaged dialyser urea clearance was 59.8 ml/min (equal to 3.6 l/h or 64 .8 l/day). Total removal of urea was 14.1+/-6.5 g/day keeping serum levels of urea below 13 mmol/l. Mean arterial pressure remained stable during the 18-h treatments with a mean ultrafiltration rate of 120 ml/h. The temperatu re in the venous blood tubing dropped by 5+/-0.5 degrees C during the 18-h treatment (0.28 degrees C/h) in the presence of unchanged core temperature in the patients. There was no bacterial growth in 2.5 l of spent dialysate (<0.0004 colony forming units/ml). Conclusions. Extended high-flux dialysis using the Genius(R) system combine s the benefits of CRRT (good cardiovascular stability, sterile dialysate) w ith the advantages of intermittent dialysis (high urea clearance, low treat ment costs). High efficiency, simplicity and flexibility of the system offe rs the unique opportunity to use the same dialysis machine for extended tim e periods (18 h) as well as for shorter intermittent renal replacement ther apy in critically ill patients.