ARDS & Acute Respiratory Failure

Acute respiratory distress syndrome (ARDS) is a severe, diffuse inflammatory lung injury — often triggered by sepsis, severe pneumonia, aspiration, trauma, or pancreatitis — that causes widespread alveolar damage and capillary leak, flooding the alveoli with fluid rather than blood loss or heart failure being the cause. The hallmark feature is severe hypoxemia that does not improve with supplemental oxygen alone, reflecting the underlying problem: the alveoli themselves are filled with fluid and inflammatory debris, not simply under-oxygenated air, so more oxygen delivery doesn't fix a lung that can't move oxygen across a damaged membrane. Chest imaging classically shows bilateral infiltrates ("white-out" pattern) without evidence of fluid overload from heart failure, which is an important distinction, since the management differs completely from cardiogenic pulmonary edema.