ObjectiveTo evaluate the effectiveness of continuous arteriovenous hemodiafiltration (CAVHD) using citrate as the anticoagulant for the treatment of lactic acidosis in patients with renal failure.DesignCase series with careful monitoring of the clinical course of patients being treated in a medical or surgical ICU.SettingUniversity hospital ICU.PatientsTwo patients with lactic acidosis are described, along with our experience using CAVHD and citrate in other clinical settings.InterventionsCAVHD was used to manage renal failure, while a continuous infusion of citrate was administered to maintain patency of the extracorporeal circuit.MeasurementsTotal and ionized serum calcium concentrations and citrate concentrations were monitored.Main ResultsCAVHD with citrate as the anticoagulant proved to be a convenient means of managing vascular volume, serum electrolyte concentrations, acid-base balance, and replacement renal function requirements in the setting of severe lactic acidosis, oliguric renal failure, and hemorrhagic diathesis.ConclusionsCAVHD with citrate as the anticoagulant can be recommended as effective therapy for selected patients, but careful monitoring is needed to avoid serious complications.