Comparative Study Between Airway Pressure Release Ventilation and Pressure Regulated Volume Control (PRVC) in Protective Lung Strategy as a Recruitment Maneuver for Severe ARDS Mechanically Ventilated Patients Using Lung Ultrasound Score

Inclusion Criteria: * Age between 18-60 years old. * Sex: both males and females * Accepts health volunteers: No * all Patients who were mechanically ventilated and diagnosed to have ARDS due to sepsis according to Berlin definition. During the course of the study, a new global definition for ARDS was introduced. To ensure our findings align with the most updated classification, we modified our inclusion criteria to incorporate the new global definition. Patients meeting the Berlin Definition or the new definition were included. Berlin Definition of the acute respiratory distress syndrome (ARDS) Acute Respiratory Distress Syndrome Timing Within 1 week of a known clinical insult or new or worsening respiratory Symptoms Chest imaging Bilateral opacities - not fully explained by effusion, lobar/lung collapse, or nodules. Origin of edema Respiratory failure not fully explained by cardiac failure or fluid overload need objective assessment (eg, echocardiography) to exclude hydrostatic edema if no risk factor present. Oxygenation Mild 200 mmHg \<Pao2/Fio2 \< 300 mmHg with PEEP or CPAP \> 5 cmH2O. Moderate 100 mmHg \<Pao2/Fio2 \< 200 mmHg with PEEP \> 5 cmH2O. Severe Pao2/Fio2 \< 100 mmHg with PEEP \> 5 cmH2O. (Gordon D, et al; 2012). Diagnostic Criteria for the New Global Definition of ARDS Acute Respiratory Distress Syndrome Risk factors and origin of edema Precipitated by an acute predisposing risk factor, such as pneumonia, non-pulmonary infection, trauma, transfusion, aspir…