Progressive Care Nursing Certification (PCCN) Practice Exam

What hallmark sign is indicative of acute respiratory distress syndrome (ARDS)?

1. Refractory hypercapnia

2. Refractory hypoxemia

3. Refractory hypotension

4. Refractory acidosis

The correct answer is: Refractory hypoxemia

The hallmark sign indicative of acute respiratory distress syndrome (ARDS) is refractory hypoxemia. In ARDS, the lungs experience significant inflammation and damage, leading to impaired gas exchange. This results in the inability to maintain adequate oxygen levels despite the administration of supplemental oxygen. Refractory hypoxemia specifically refers to persistent low oxygen levels that do not improve with supplemental oxygen alone, which is a critical characteristic of ARDS. This condition is often associated with a decline in lung compliance and can lead to severe respiratory failure if not addressed. Other factors, such as poor ventilation-perfusion matching and the presence of pulmonary edema, contribute to this oxygenation issue. While the other choices may relate to respiratory or systemic distress, they do not specifically capture the defining feature of ARDS as robustly as refractory hypoxemia does.