If a patient exhibits a PaO2/FiO2 ratio below 300, what stage of ARDS may they be classified into?

A PaO2/FiO2 ratio below 300 indicates that the patient is experiencing moderate ARDS (Acute Respiratory Distress Syndrome). The ARDS classification system is based on this ratio, which helps to assess the severity of hypoxemia.

In ARDS, the PaO2/FiO2 ratio is divided into three categories: mild, moderate, and severe. A ratio of 200 to 300 mmHg is specifically designated as moderate ARDS. This classification is crucial for determining the appropriate management strategies and interventions. It reflects the degree of gas exchange impairment and helps guide clinical decisions in the care of patients with ARDS.

Understanding the ranges is essential for the appropriate treatment and prognostic assessment of patients with respiratory failure. Therefore, the classification into moderate ARDS due to a PaO2/FiO2 ratio below 300 is well-established in clinical practice.