The study evaluate the effect of a membrane in polysulfone covered with vitamin E (ViE15-A, ASAHI Kasey, Tokyo, Japan) versus non-vitamin E polysulfone membrane (REXEED-15A, ASAHI Kasey, Tokyo, Japan) in critically ill patients admitted to intensive care undergoing continuous extracorporeal dialysis (CRRT).

The current randomized study is designed to assess the effect on the levels of oxidative stress, pro and anti-inflammatory cytokines and the mode and amount of death of monocytic cell lines using ViE 15-A in comparison withe REXEED-15A.

The investigators hypothezise that the ViE15-A versus REXEED-15A will have different effect on the levels of oxidative stress, pro and anti-inflammatory cytokines and the mode and amount of death of monocytic cell lines.

The study evaluate the effect of a membrane in polysulfone covered with vitamin E (ViE15-A, ASAHI Kasey, Tokyo, Japan) on the levels of oxidative stress, pro and anti-inflammatory cytokines and the mode and amount of death of monocytic cell lines in critically ill patients admitted to intensive care undergoing continuous extracorporeal dialysis (CRRT).

This membrane will be compared with a non-vitamin E polysulfone membrane (REXEED-15A, ASAHI Kasey, Tokyo, Japan) and already intended for use in continuous renal support therapy.

The current randomized study is designed to assess the effect on the levels of oxidative stress, pro and anti-inflammatory cytokines and the mode and amount of death of monocytic cell lines using ViE 15-A in comparison withe REXEED-15A.

Precisely, will be evaluated

1. the effect of the filter on the reduction of the plasma levels of two pro-inflammatory cytokines (IL-1β and IL-6) and of two anti-inflammatory cytokines (IL-10, IL-8);
2. the analysis of the life modality of the monocytic cells: the patient's plasma will be used, incubated for 24 hours with U937 cells (monocyte precursor cells), necrosis cells and the percentage of apoptotic cells. The apoptotic cells will also evaluate the apoptotic pathway (evaluation of activated caspases) that led to cell death. The differences that are highlighted in the two different sampling moments become expressed Δ% with respect to the initial value Secondary outcomes will be to evaluate the clinical outcomes (haemodynamic and hematochemical parameters) in the short and long term deriving from the application of a membrane with vitamin E; for this reason, for the whole duration of the extracorporeal dialysis therapy, the same filter assigned to the patient at the time of enrollment will be used.

All the other parameters of the extracorporeal treatment that can influence the results will be standardized; in particular, the flows will be fixed according to the dialysis dose criteria and re-infusion methods according to the table in the paragraph "treatment characteristics".

Inclusion Criteria:

• Age > 18 years
• Acute Kidney Injury
• ICU patients with clinical indication for Continuous Renal Replacement Therapy
• Clinical decision to begin CVVH for at least 24 hours with high flux filter (defined as membranes with an ultrafiltration coefficient KUF > 25ml/Kg/h)
• Obtain the informed consent

Exclusion Criteria:

• Hemodialysis patients, peritoneal dialysis patients and transplant recipient;
• Hypothermia (T < 36°C)
• Regional Anticoagulation with Citrate
• Septic Shock;
• Neoplasm in Chemotherapy
• Extra-Corporeal Membrane Oxygenation
• Cardio Circulatory Arrest
• Autoimmune disease or immunosuppressed patients;
• Life expectancy < 24 hr
• Pregnancy;
• Informed Consent refused by the patient or surrogate decision-maker

The randomization list will be kept in a special lockable closet, not accessible to the other investigators involved in the study. The one who will create the list will not be involved in any other role in the present study.

The filter label, and hence the name, will be covered by a white covering label. Each kit of filters needed to perform a single treatment will be prepared in a closed box and the patient number will be written on it, so that the user who performs the treatment will not be able to understand which filter it is.

All the other investigators involved in the present study (nurses in the Nephrology department who will follow the treatment, the researchers who will collect the clinical data, the biologists who will analyze the samples and the statisticians who will analyze the data) will not know which filter has been applied in each treatment.