The goal of this observational study is to assess the performance of the multiFlux hemofilterwith regional or systemic anticoagulation during CKRT treatments. The multiFlux hemofilter is a single use device within the extracorporeal blood circuit during extracorporeal blood purification treatments for acute renal replacement therapies.

Patients enrolled in this clinical investigation will be treated either with citrate anticoagulation in Continuous venovenous hemodialysis (CVVHD) or Continuous venovenous hemodiafiltration (CVVHDF) in post-dilution mode (RCA-post-CVVHDF) with RCA using 4% citrate with Ci-Ca dialysate (without gas barrier)) or with heparin in any of the possible CKRT modes (pre-, post- or pre-post CVVH, CVVHD, pre-, post- or pre-post CVVHDF) for up to 10 days based on investigator´s decision (data beyond 10 days will not be collected within the study) or until withdrawal of informed consent or death.

For the study, treatment data will be documented for a maximum of 10 days.

The selection of the filter size depends on the prescription of the attending physician. The body weight limitations as shall be considered:

Mutiflux 160 ≥ 40 kg, Multiflux 130 ≥ 30 kg, Multiflux 60 ≥ 8 kg

Inclusion Criteria:

General:

Patients ≥ 18 years:

• Informed consent signed and dated by the investigator; and

  1. if patient is able to give consent: by the study patient

  2. if patients unable to give consent: by the legal representative/spouse according to § 1358 BGB or

  3. if an emergency situation is determined: by an independent consultant physician.

     Pediatric Patients < 18 years:

• Informed consent signed and dated by legal representative and investigator/ authorized physician.

• The minors have received the information referred to in Article 63(2) Medical Device Regulation (MDR) in a way adapted to their age and mental maturity and from investigators or members of the investigating team who are trained or experienced in working with children. If able, the minors have to sign the informed consent, too.

• The explicit wish of a minor who is capable of forming an opinion and assessing the information referred to in Article 63(2) MDR to refuse participation in, or to withdraw from, the clinical investigation at any time, is respected by the investigator

Study specific:

• Body weight ≥ 8kg
• Acute Kidney Injury (AKI) with clinical indication for CKRT
• Clinically estimated life expectancy greater than 3 days

Exclusion Criteria:

• Any conditions which could interfere with the patient's ability to comply with the study
• Patient or legal representative or authorized physician during emergency situation is not able to give informed consent according to European Medical Device Regulation and corresponding national regulations
• Participation in a different interventional clinical study during the preceding 30 days
• Previous participation in the same study
• Uncontrolled bleeding and coagulation disorders

The study population consists of critically ill patients (adults and children) requiring continuous kidney replacement therapy (CKRT).