Berlin Criteria for Acute Respiratory Distress Syndrome (ARDS)

Berlin Criteria explained

The Berlin Criteria helps with Acute Respiratory Distress Syndrome diagnosis and severity grading based on clinical signs and symptoms grouped in required criteria, risk factors and severity factors.

The criteria was originally published in 2012 and has since been validated and can be used to better inform clinical care and health services.

ARDS positive diagnosis by Berlin Criteria is fulfilled as follows:

1. All three required criteria are present:

• Timing within 1 week of clinical insult or new/worsening respiratory symptoms
• Chest XR shows bilateral opacities not fully explained by effusions, lobar/lung collapse, or nodules
• Respiratory failure not fully explained by cardiac failure/fluid overload

AND

2. At least one of the below is present:

• Risk factor for ARDS present (e.g. pneumonia, trauma, sepsis, pancreatitis) OR Objective assessment (Echo) excludes hydrostatic edema if no risk factor present;

AND

3. At least one of the below severity descriptions is met:

• Mild: PaO₂/FiO₂ >200 to ≤300 mmHg with PEEP OR CPAP ≥5 cm H₂O
• Moderate: PaO₂/FiO₂ >100 to ≤200 mmHg with PEEP ≥5 cm H₂O
• Severe: PaO₂/FiO₂ ≤100 mmHg with PEEP ≥5 cm H₂O

About the original study

In 2012, at the initiative of the European Society of Intensive Care Medicine endorsed by the American Thoracic Society and the Society of Critical Care Medicine, a panel of experts convened to develop a definition for diagnosis of ARDS and to test its feasibility, reliability, validity and performance.

Three mutually exclusive categories of ARDS were proposed based on degree of hypoxemia. The study then tested the definition using patient-level meta-analysis of 4188 patients with ARDS from 4 multicenter clinical data sets and 269 patients with ARDS from 3 single-center data sets containing physiologic information.

Using the Berlin Definition, stages of mild, moderate, and severe ARDS were associated with varying degrees of increased mortality and increased median duration of mechanical ventilation in survivors.

The Berlin model was compared with the AECC definition and was found to have a better predictive validity for mortality (Berlin ROC AUC = 0.577 compared to 0.536 for AECC).

Limitations of the criteria

This model has been criticised for not including in its factors any information on underlying aetiology and for the fact that it lacks a direct measure of lung injury.

It also does not allow for early identification of patients who may be candidates for therapies before ARDS becomes established.

Berlin Criteria still encourages CXR findings to be used for diagnosis, whilst CT chest has subsequently been found to be a more reliable diagnosis method.

A study by Thille et al. on autopsies of 365 patients with clinical criteria for ARDS found that the model has a sensitivity of 89% and a specificity of 63% to identify ARDS (evidence of diffuse alveolar damage used as gold standard).

References

Original reference

ARDS Definition Task Force, Ranieri VM, Rubenfeld GD, Thompson BT, Ferguson ND, Caldwell E, Fan E, Camporota L, Slutsky AS. Acute respiratory distress syndrome: the Berlin Definition. JAMA. 2012 Jun; 307(23):2526-33.

Other references

Fan E, Brodie D, Slutsky AS. Acute Respiratory Distress Syndrome: Advances in Diagnosis and Treatment. JAMA. 2018; 319(7):698-710.

Phillips CR. The Berlin definition: real change or the emperor’s new clothes? Crit Care. 2013 Aug 1;17(4):174.

Figueroa-Casas JB, Brunner N, Dwivedi AK, Ayyappan AP. Accuracy of the chest radiograph to identify bilateral pulmonary infiltrates consistent with the diagnosis of acute respiratory distress syndrome using computed tomography as reference standard. J Crit Care. 2013; 28(4):352-7.

Thille AW, Esteban A, Fernández-Segoviano P, Rodriguez JM, Aramburu JA, Peñuelas O, Cortés-Puch I, Cardinal-Fernández P, Lorente JA, Frutos-Vivar F. Comparison of the Berlin definition for acute respiratory distress syndrome with autopsy. Am J Respir Crit Care Med. 2013; 187(7):761-7.