Fluid Balance Guided by Modified Venous Excess Ultrasonography Versus Standard Care in Patients With Acute Kidney Injury Receiving Continuous Renal Replacement Therapy

The goal of this randomised controlled trial is to compare the cumulative fluid balance over the first 72 h following inclusion guided by mVExUS versus standard of care in critically ill patients with acute kidney injury receiving CRKT . It will also compare the proportion of CRRT-related complications-including intradialytic hypotension and arrhythmias-between patients managed with mVExUS-guided fluid management and those receiving standard care. The main questions it aims to answer are: Does fluid removal rate guided by mVExUS will reduce cumulative fluid balance over the course of the first 72 h of CRRT in ICU patients compared to standard care Participants will: Get fluid assessment by mVExUS protocol or a strandard care every 8 hours for 72 hours

Inclusion Criteria: * Adults (≥ 18 years of age) * Admitted to ICU * Acute kidney injury by KDIGO criteria * Initiated CRRT by at least one of the following indications for RRT initiation: * Serum potassium ≥ 6.0 mmol/L, or * pH ≤ 7.20 or serum bicarbonate ≤ 12 mmol/L, or * Evidence of severe respiratory failure, based on a PaO2/FiO2 ≤ 200 and clinical perception of volume overload, or * Persistent severe AKI (sCr remains \> 50% the value recorded at randomization) for \> 72 hours from randomization * Participants giving informed consent Exclusion Criteria: * Refuse to participate * Previous diagnosis of end-stage kidney disease (ESKD) currently on kidney replacement therapy * Kidney transplant recipient * Receive RRT before ICU admission within 90 days * Structural kidney diseases which will interfere with intrarenal doppler ultrasound e.g. renal artery stenosis, autosomal dominant polycystic kidney disease * Patients with previously known conditions that interfere with portal doppler assessment, namely liver cirrhosis, severe tricuspid regurgitation with structural heart disease or massive ascites. * Underlying disease process with a life expectancy less than 90 days * Pregnancy * Severe cardiac rhythm disturbances (tachyarrhythmia, supraventricular tachycardia) * Intra-cardiac shunts; Ventricle septal defect, patent foramen ovale, atrial septal defect * Aortic aneurysm * Intra-abdominal hypertension (intraabdominal pressure ≥20 mmHg) * Expected life expectancy \