Acute respiratory distress syndrome (ARDS) is a severe, diffuse form of acute lung injury defined by refractory hypoxemia, bilateral pulmonary infiltrates, and decreased lung compliance that is NOT caused by cardiac failure or fluid overload. ARDS is a critical illness that requires intensive care, frequently mechanical ventilation, and a relentless focus on treating the underlying trigger. Reported mortality ranges from roughly 35 to 46 percent, and many survivors face long-term physical, pulmonary, and cognitive impairments collectively described as post-intensive care syndrome. The hallmark of ARDS is hypoxemia that does not correct with simple increases in inspired oxygen, because the underlying problem is intrapulmonary shunt — blood flowing past alveoli that are flooded and collapsed. This is why positive end-expiratory pressure (PEEP), which physically reopens and stabilizes alveoli, is the central oxygenation strategy rather than escalating FiO2 alone. The Berlin Definition (2012) is used to make the diagnosis and requires all of the following: - Onset within one week of a known clinical insult or new or worsening respiratory symptoms. - Bilateral chest infiltrates on imaging that are not fully explained...