American Board of Internal Medicine (ABIM) Certification Practice Exam

What PaO2/FIO2 ratio defines a mild case of ARDS?

1. Less than 100 mm Hg

2. Greater than 200 mm Hg but less than 300 mm Hg

3. Less than 200 mm Hg

4. Greater than 300 mm Hg

The correct answer is: Greater than 200 mm Hg but less than 300 mm Hg

The PaO2/FIO2 ratio is a crucial metric used to classify the severity of Acute Respiratory Distress Syndrome (ARDS). According to established criteria, a mild case of ARDS is characterized by a PaO2/FIO2 ratio between 200 mm Hg and 300 mm Hg. This classification is part of the Berlin definition for ARDS, which categorizes the condition into three groups based on the severity of hypoxemia. In the context of this classification: - Mild ARDS is defined by the ratio being above 200 mm Hg but below 300 mm Hg. - Moderate ARDS is indicated by a PaO2/FIO2 ratio between 100 mm Hg and 200 mm Hg. - Severe ARDS is characterized by a ratio of 100 mm Hg or less. Understanding this stratification is essential for clinicians, as it helps guide treatment decisions and assesses the prognosis for patients suffering from ARDS. The correct identification of the mild category can prompt timely interventions aiming to improve oxygenation and support respiratory function. This knowledge is integral for effective management in acute care settings.