ACCS Practice Exam 2025 – Complete Test Preparation Guide

The classification of acute respiratory distress syndrome (ARDS) according to the Berlin Criteria is based on the degree of hypoxemia, specifically using the PaO2/FIO2 ratio. In this framework, a patient is deemed to have severe ARDS when their PaO2/FIO2 ratio is less than 100 mmHg. This threshold indicates a critically low level of oxygenation and is a significant marker of the severity of lung injury.

In the context of the Berlin Criteria, other classifications exist for moderate and mild ARDS. These categories include a PaO2/FIO2 ratio between 100 and 200 for moderate ARDS and between 200 and 300 for mild ARDS. Therefore, the categorization of severe ARDS with a PaO2/FIO2 ratio of less than 100 underscores the urgent need for advanced therapeutic interventions and close monitoring, as patients in this category are at high risk for significant morbidity and mortality.

Understanding these criteria is essential for healthcare professionals involved in the management of ARDS, as it aids in determining the appropriate course of treatment and predicting potential outcomes for patients with varying severities of respiratory failure.