Adult Critical Care Specialty (ACCS) Practice Exam

Which of the following is an indicator of less severe ARDS?

1. Pao2/Fio2 ratio less than 100

2. Pao2/Fio2 ratio between 100 and 200

3. Pao2/Fio2 ratio between 200 and 300

4. Pao2/Fio2 ratio greater than 300

The correct answer is: Pao2/Fio2 ratio between 200 and 300

The Pao2/Fio2 ratio is a critical measure used to classify the severity of acute respiratory distress syndrome (ARDS). The severity categories based on this ratio are well defined within the Berlin definition of ARDS. When the ratio is between 200 and 300, it indicates a mild form of ARDS. This is significant because it informs clinicians about the patient's condition and guides treatment options and management strategies. A Pao2/Fio2 ratio less than 100 indicates severe ARDS, which represents significant impairment in gas exchange. A ratio between 100 and 200 falls into the moderate category, which demonstrates greater severity than mild ARDS but less than severe ARDS. A ratio greater than 300 indicates that the patient is not suffering from ARDS, as it suggests adequate gas exchange and indicates that the lungs are functioning better than in the context of ARDS. Thus, the ratio between 200 and 300 specifically correlates with the diagnosis of mild ARDS, making it the correct choice among the options presented. Understanding these classifications is vital for clinical decision-making in managing patients with ARDS.