Resolved versus confirmed ARDS after 24 h: insights from the LUNG SAFE study

Area of Science:

• Critical Care Medicine
• Pulmonology
• Respiratory Medicine

Background:

• Acute Respiratory Distress Syndrome (ARDS) is a severe lung condition with significant morbidity and mortality.
• Early identification and classification of ARDS are crucial for guiding treatment and prognosis.
• The LUNG SAFE study provided extensive data on ARDS epidemiology and outcomes.

Purpose of the Study:

• To compare outcomes in patients with resolved versus confirmed Acute Respiratory Distress Syndrome (ARDS) after 24 hours.
• To identify patient subgroups at substantial risk of mortality.
• To assess the utility of reclassifying ARDS severity on day 2.

Main Methods:

• A secondary analysis of the LUNG SAFE database was performed.
• Patients meeting the ARDS definition on day 1 were categorized as resolved or confirmed ARDS on day 2.
• Statistical methods were used to identify factors associated with ARDS persistence, mortality, and the predictive value of day 2 reclassification.

Main Results:

• Of 2377 patients, 24% no longer met ARDS criteria on day 2. Hospital mortality was 38% overall, with higher rates in confirmed ARDS (41%) and severe confirmed ARDS on day 2 (57%).
• Higher tidal volume on day 1 was associated with confirmed ARDS.
• Factors associated with mortality in both resolved and confirmed ARDS included age, non-respiratory SOFA score, lower PEEP, lower P/F ratio, higher peak pressure, and higher respiratory rate.

Conclusions:

• ARDS, regardless of resolution status by day 2, is associated with high mortality.
• Reclassifying ARDS severity on day 2 provides marginal predictive value for mortality.
• Severe confirmed ARDS represents a subgroup with substantial mortality risk, potentially ideal for testing novel interventions.