During critical illness, patients experience a hypercatabolic state. This hypercatabolic state causes muscle wasting in patients, resulting in intensive care unit acquired weakness (ICU-AW). ICU-AW is associated with prolonged mechanical ventilation (MV) weaning, extubating failure and extended length of stay. Previously recognized risk factors for ICU-AW include shock, sepsis, multiple organ failure, hyperglycemia, and prolonged exposure to corticosteroids, sedatives, or paralytic agents.

Critical illness is complicated by the development of acute kidney injury (AKI). AKI causes muscle wasting by increasing protein degradation and decreasing protein synthesis. Furthermore, patients with severe AKI often require renal replacement therapy (RRT), which contributes to additional protein loss. Studies have estimated that amino acid losses associated with RRT may range from 5 to 19 g/d, with greater losses observed in patients undergoing continuous renal replacement therapy (CRRT). AKI requiring CRRT has recently been proposed to contribute to an increased risk of ICU-AW.

Therefore, critically ill patients with AKI may require increased protein intake to compensate for these metabolic alterations. However, higher protein intake, particularly during the early acute phase of critical illness, may be associated with prolonged need for RRT or delayed kidney recovery.

The objective of this trial is to compare the effects of a high protein intake versus a standard protein intake on muscle mass change in critically ill patients with AKI requiring CRRT.

The goal of this clinical trial is to learn if high protein intake (1.5-1.7 g/kg/d) can reduce ICU associated weakness in critically ill patients with AKI requiring CRRT. The main questions it aims to answer is:

• Does High protein intake (1.5-1.7 g/kg/d) reduce the change in RF-CSA, as measured by ultrasonography at day 7 in critically ill patients with AKI requiring CRRT Researchers will compare drug high protein intake to standard protein intake to see if high protein intake effect on muscle mass by ultrasonography.

Participants will:

• Receive high protein group (1.5-1.7 g/kg/d) in High protein group and standard protein intake (1.0-1.2 g/kg/d) in control group for 7 days
• Rectus femoris ultrasonography was performed twice on day 1 and day 7

Inclusion Criteria:

• Adult (≥18 years old)
• AKI receiving CRRT within 7 days after ICU admission
• Achieve and tolerate calories 70% of target daily caloric requirement (20 kcal /kg/d) within 7 days after ICU admission by enteral feeding
• Participant or their surrogates is willing and able to give informed consent for participation in the study

Exclusion Criteria:

• Moribund or withholding of treatment
• Kidney transplant recipient
• Previously diagnosed end-stage kidney disease (ESKD) currently on kidney replacement therapy
• Pregnancy or breastfeeding
• Hepatic encephalopathy (West Haven grade 3-4)
• Burn patients
• Patients whom the responsible clinician felt that the patient either needed low or high protein
• Severe complications of diabetes such as ketoacidosis, hyperosmolar coma
• Had pre-existing neuromuscular disorders
• Previously leg amputations

Rectus femoris ultrasonography was performed twice on day 1 and day 7 after randomization by one expert musculoskeletal radiologist blinded to clinical information

Both feeds are isocaloric and isovolemic and identical in terms of color, odor and consistency