This is a randomized controlled study that will be conducted on acute kidney injury (AKI) patients, who are mechanically ventilated, to assess the impact of implementation of early renal replacement therapy (RRT) compared to late RRT on patients outcome.

The study subjects will be randomly divided into two groups (arms).

The first one will be patients who will receive early renal replacement therapy (RRT) according to predefined criteria that will be illustrated later.

The other group of patients will be those who receive late RRT according to the absolute indications of emergency hemodialysis i.e. severe hyperkalemia, life-threatening acidosis, uremic encephalopathy or pericarditis in addition to intractable pulmonary edema.

Appropriate randomization technique will be applied. A computer-based program will be used to perform the randomization procedure.

Inclusion Criteria:

• All patients must be on invasive mechanical ventilation.
• Patients in AKI stage 2 , according to KDIGO classification.
• Recruited subjects will include either those who present with AKI on their ICU admission or those who develop AKI during their ICU stay

Exclusion Criteria:

• Those who are known to be in grade 5 CKD according to KDIGO classification. All other grades of CKD from 1 to 4 will be included only if they develop or present with stage 2 AKI on top of their CKD grade
• Those who develop AKI due to obstructive or traumatic causes.
• Patients with septic shock who are on high doses of vasopressors or inotropes (norepinephrine infusion more than 1 mcg/kg/minute, dopamine or dobutamine infusion more than 5 mcg/kg/minute).
• Pregnant females