High-Volume Hemofiltration in the Intensive Care Unit

Definition of High Volume

Twenty years ago, standard hemofiltration often was given at 1 or 2 L/hr of ultrafiltration treatment and only in predilution mode. Practices began to change with the Ronco et al. study in 2001, which proved the beneficial effect on outcome of increasing the ultrafiltration rate to 35 mL/kg/hr in patients with acute kidney injury (AKI). At that time, the old definition of HVHF became the standard of care, and volumes used for high volume increased dramatically from 35 mL/kg/hr to 100 mL/kg/hr. Two latest large RCTs, the VA/NIH study and the RENAL study, demonstrated that high intensity of hemofiltration was not beneficial compared with 25 mL/kg/hr, the dose currently recommended. Furthermore, two different HVHF methods became common: continuous high-volume treatment providing 50 to 70 mL/kg/hr 24 hours a day and intermittent HVHF with brief, very high-volume treatment at 100 to 120 mL/kg/hr for 4 to 8 hours, which used to be called “pulse” HVHF. Both came under the heading HVHF despite their concepts, and the results are somewhat different, as described later in this chapter. In the 2015 Vicenza Nomenclature Standardization Initiative (NSI), they defined HVHF as a continuous convective treatment with a (prescribed) target dosage greater than 35 mL/kg/hr. A dosage exceeding 45 mL/kg/hr represents very HVHF (VHVHF). Intermittent procedures using brief VHVHF episodes (100–120 mL/kg/hr for 4–8 hr), followed by conventional continuous venovenous hemofiltration (CVVH), are identified as “pulse” HVHF.