This study aims to assess the clinical relevance of renal artery duplex ultrasound in critically ill patients with acute kidney injury (AKI) in terms of the renal resistive index (RRI).

Diagnosis of acute kidney injury (AKI) is based on rising creatinine as late phenomenon. Intrarenal vasoconstriction occurs earlier, so measuring flow resistance in the renal circulation, renal resistive index (RRI), could become part of vital organ function assessment using Doppler ultrasound.

Inclusion Criteria:

• Patients age >18 years.
• Both sexes.
• Patients within 24 hours after intensive care unit (ICU) admission.

Exclusion Criteria:

• Patients presented with poor abdominal echogenicity.
• Chronic kidney disease, especially with estimated creatinine clearance less than 30 ml/min/1.73m.
• Patients with dialysis dependency.
• Patients with renal transplantation.
• Patients with known renal artery stenosis.
• If there is a pregnancy.
• Patients with any congenital kidney diseases as mono-kidney, anatomic kidney abnormalities.

One hundred patients admitted to the intensive care unit (ICU), all the studied populations will be diagnosed to have AKI, with no past medical history of chronic renal disease.

The data will be available upon a reasonable request from the corresponding author after the end of study for one year.

After the end of study for one year.

The data will be available upon a reasonable request from the corresponding author.