This is a prospective observational single-center study in which the association of Protein-Energy Adequacy and 28-Days of Mortality among critically ill patients with Acute Kidney Injury, AKI will be investigated. The association of Protein-Energy adequacy with a length of ICU and hospital stay, total ventilator, and inotropic drug days among critically ill patients with AKI also will be investigated.

Patients with Acute Kidney Injury, AKI are probably more exposed to the risk of malnutrition especially if they undergo Renal Replacement Therapy, RRT. Optimization of nutrients especially energy and protein can ensure a better health outcome for critically ill patients with AKI. Moreover, there is no research on the association of Protein- Energy adequacy with mortality among critically ill patients with AKI in Malaysia. So, the main purpose of this study is to investigate the relationship of Protein-Energy adequacy with mortality among critically ill patients with AKI

Subjects will be recruited upon admission in ICU after fulfilling the inclusion and exclusion criteria. They will be follow up from day 1 until day 14 or until ICU Discharge. Data including Demographic, Clinical, Laboratory, and Nutritional Status will be recorded. On Day 28, the outcome data including Mortality, length of ICU Stay, and Length of Ventilator day will be recorded.

Inclusion Criteria:

1. Patients who are 18 years old and older
2. Patients who are admitted to the participating ICU.
3. Patients who are mechanically ventilated.

Exclusion Criteria:

1. Patients who are less than 18 years old
2. End-stage renal disease patients
3. Patients undergo kidney transplantation within 3 months before ICU admission
4. Pregnant patients
5. The patient is moribund with expected death within 24 hour or whom survival to 28 days is unlikely due to uncontrollable comorbidity (cardiac, pulmonary or hepatic end-stage disease; hepatorenal syndrome; poorly controlled cancer; severe post-anoxic encephalopathy and others)
6. Prior treatment with RRT within 30 days
7. Anticipated alive ICU discharge within 24 hours
8. Readmission to the ICU during the same hospitalization episode.

This study will be conducted in adult Intensive Care Unit, University Malaya Medical Centre (UMMC), Malaysia.