How is ARDS diagnosed clinically?

The diagnosis of Acute Respiratory Distress Syndrome (ARDS) is primarily established through careful clinical assessment combined with the exclusion of alternative causes of respiratory failure. This approach is fundamentally grounded in the Berlin definition of ARDS, which emphasizes specific clinical features.

To diagnose ARDS, clinicians look for a set of criteria, including:

1. Timing: Symptoms typically develop within one week of a known insult or new/worsening respiratory symptoms.

2. Oxygenation impairment: ARDS is characterized by varying degrees of acute hypoxemia, which can be quantified using the PaO2/FiO2 ratio.

3. Chest imaging findings: Typically, ARDS presents as bilateral opacities on chest X-ray or CT scan, but imaging alone is not sufficient for diagnosis.

4. Exclusion of other causes: It is crucial to rule out other conditions that can cause similar respiratory failure, such as heart failure or volume overload, hence the term “exclusion” in the criteria.

While imaging studies, evidence of infection, and invasive tests can support the diagnosis, they are not standalone criteria. Effective diagnosis relies on the overall clinical picture and ensuring that no other significant pathologies are contributing to the patient's respiratory failure