Influence of Lung Recruitment Potential on Positive End-Expiratory Pressure (PEEP) Titration Strategies in Acute Respiratory Distress Syndrome (ARDS) Patients.

Inclusion Criteria: * Diagnosis of moderate or severe Acute Respiratory Distress Syndrome (ARDS) according to the Berlin definition: acute onset, bilateral opacities not fully explained by heart failure or fluid overload, and Partial pressure of oxygen in arterial blood/Fraction of inspired oxygen \<= 200 mmHg with Positive End-Expiratory Pressure (PEEP) \>= 5 cmH2O. * ARDS duration \< 36 hours since fully meeting Berlin consensus criteria. * Relative hemodynamic stability: absence of refractory shock, defined as norepinephrine dose \<= 0.5 mcg/kg/min. Exclusion Criteria: * Evidence of active pulmonary air leaks (bronchopleural fistula, pneumothorax, pneumomediastinum). * Severe uncorrected hemodynamic instability (norepinephrine \> 0.5 mcg/kg/min). * Contraindications for esophageal balloon placement (esophageal obstruction, known perforation, recent esophageal surgery, severe esophagitis). * Elevated intracranial pressure or conditions where hypercapnia-induced increases in intracranial pressure must be avoided (intracranial hemorrhage, cerebral contusion, cerebral edema, mass effect with midline shift on CT). * Known pregnancy. * Severe coagulopathy (platelet count \< 5,000/uL or INR \> 3). * Airway opening pressure higher than 15 cmH2O (AOP \> 15 cmH2O). * History of severe neuromuscular disease or chronic respiratory disease. * Having received invasive mechanical ventilation for more than 96 hours. * Inability to obtain informed consent or refusal by the legal representative. * Contained laparotomy (open abdomen).