The goal of this clinical trial is to investigate the effects of nutrition therapy guided by indirect calorimetry and nitrogen balance among critically ill patients with acute kidney injury. The main question it aims to answer whether nutrition therapy guided by indirect calorimetry and nitrogen balance could improve 28 days mortality among critically ill patients with acute kidney injury or not.

type of study: clinical trial Participants will be provided enteral or parenteral nutrition after randomization(48-72 days after admissions) with total energy guided by indirect calorimetry measurements and total protein by nitrogen balance with maximum of 1.3 gram per kilogram per day for total of 14 days If there is a comparison group: Researchers will compare with the control groups (nutrition therapy provided by physician using clinical equation of choice or judgements to see if participants were provided with these interventions, their 28 days mortalities would be better

The gold standard for determining energy requirements was recommended by the European Society for Parenteral and Enteral Nutrition (ESPEN) guideline 2021 to use indirect calorimetry(IC), a noninvasive method that allows resting energy expenditure (REE) evaluation based on measurements of oxygen consumption and carbon dioxide production in the exhaled air.

As there are no high-quality studies that investigated energy and protein provision in hospitalized patients with acute kidney injury(AKI) or Acute kidney disease (AKD), the recommendations were based on the guidelines and clinical trials from critically ill and polymorbid internal medicine patients because these guidelines and trials included patients with kidney disease.

Moreover, there were clinical trials in critically ill patients with severe acute kidney injury found the varying of metabolic states among these patients categorized by IC measurements and no association between calorie intake and mortality outcome.

Even though the aforementioned researches did not suggest a link between calorie intake and mortality outcome, no studies were able to meet the energy targets set using indirect calorimetry measurements.

This study aims to prove the necessary and benefit of early nutrition therapy after 72 hours of admission with total energy guided by indirect calorimetry measurements aims to meet 70-100% from measurements and total protein guided by urine urea nitrogen balance aims to positive nitrogen balance with maximum of 1.3 gram per kilogram of actual body weight per day for total of 14 days on survival & renal outcomes in critically ill patients with acute kidney injury

Inclusion Criteria:

• Age 18-90 years old
• Mechanically ventilated patients with acute kidney injury by Kidney Disease Improving Global Outcomes (KDIGO) criteria
• Expected length of ICU stay more than 72 hours and accept to follow the study protocol

Exclusion Criteria:

• Underlying chronic kidney disease stage 4 or 5 according to KDIGO staging
• received renal replacement therapy prior to admission
• Post cardiothoracic surgery
• Required fraction of inspired oxygen inspired oxygen fraction (FiO2) more than 0.6
• Pregnancy
• BMI below 17 or above 35 kg/m2 or very high risk refeeding syndrome
• Cirrhosis Child-Pugh score C

Data sharing requests will be considered following publication of the primary trial data on an individual basis by the trial management committee (the data custodians). Data sharing will only be considered for investigator-initiated, independent researchers who provide a written data evaluation proposal that is judged to be methodologically sound. A data sharing agreement will be required to detail conditions under which data is shared and used. Resulting publications should appropriately cite and acknowledge the original data custodians. Requests for data sharing are to be made to wankaweej@gmail.com and the corresponding author, Dr Aphichat Chatkrailert; tengaphi@gmail.com

depend on responsible party agreements