KARMA study is a hospital-based research study looking at how different ways of delivering kidney support therapy (CRRT) affect patients who are critically ill. In some cases, the kidneys may temporarily stop working in very sick patients, and machines are used to filter the blood. This study is exploring whether the way the investigators use these machines - how early to start, how much treatment to give, and what type to choose - makes a difference in how well the kidneys recover. By learning from many hospitals and hundreds of patients, KARMA hopes to improve treatment choices and help patients regain their kidney function faster.