Figure 4.

Net ultrafiltration rate is independently associated with mortality in patients treated with CKRT. The relationship between mortality and net ultrafiltration (UF_NET) in patients in the intensive care unit (ICU) with AKI is J shaped. In a post hoc analysis of >1400 patients from the Randomized Evaluation of Normal versus Augmented Level Replacement Therapy study comparing high versus low dose of CKRT for AKI in the ICU,⁶ low UF_NET rates <1.01 ml/kg per hour and high UF_NET rates >1.75 ml/kg per hour were associated with higher risk-adjusted 90-day mortality compared with UF_NET rates in a middle range of 1.01–1.75 ml/kg per hour. It has been proposed that these effects are mediated by harms of organ edema in those treated with low UF_NET rates and by organ ischemia in those treated with high UF_NET rates, but no prospective trial data yet exist to demonstrate that targeting a moderate rate of UF_NET improves outcomes. Data from Murugan et al.⁶⁶ Reprinted from ref. 65, with permission.