ARDS

A 52-year-old man with a history of type 2 diabetes mellitus is admitted to the ICU following aspiration of gastric contents during an emergency laparotomy for perforated peptic ulcer. On postoperative day 2, he develops acute dyspnea, tachypnea (RR 32/min), and hypoxemia (SpO₂ 88% on room air). Chest X-ray shows bilateral diffuse infiltrates. Arterial blood gas reveals PaO₂ 55 mmHg, PaCO₂ 32 mmHg on FiO₂ 0.6. Pulmonary artery wedge pressure (PAWP) is 14 mmHg. Which of the following is the most appropriate initial ventilatory strategy?

A 38-year-old woman with severe community-acquired pneumonia is admitted to the ICU. On day 4 of hospitalization, she develops progressive hypoxemia despite antibiotics and supplemental oxygen. Chest X-ray shows new bilateral infiltrates. PaO₂ is 58 mmHg on FiO₂ 0.8, PaCO₂ is 38 mmHg, and PAWP is 12 mmHg. She is intubated and placed on mechanical ventilation. After 48 hours of lung-protective ventilation, her PaO₂/FiO₂ ratio remains 72 (severe ARDS). Which of the following interventions is most strongly supported by evidence to improve oxygenation and potentially reduce mortality?

According to the Berlin Definition, what is the minimum PaO₂/FiO₂ ratio threshold that defines moderate ARDS?

A 38-year-old woman is admitted to the ICU following a motor vehicle accident with polytrauma. On day 3, she develops acute hypoxemic respiratory failure with bilateral pulmonary infiltrates and a PaO₂/FiO₂ ratio of 150 mmHg. ARDS is diagnosed. Which is the most common non-infectious cause of ARDS in trauma patients?

Regarding the diagnostic criteria, risk factors, and prognostic indicators in ARDS, all of the following are correct EXCEPT: