Analysis of Continuous Kidney Replacement Therapy (CKRT) Treatments With multiFlux Hemofilters Using Regional Citrate Anticoagulation (RCA) or Systemic Heparin Anticoagulation

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