Predictive Value in Assessment of Acute Respiratory Distress Syndrome (ARDS)

Abstract

Background: Pneumonia is a major cause of acute respiratory failure and mortality in critically ill patients. Early and accurate prediction of mortality risk is essential for guiding clinical decisions and optimizing outcomes. Several clinical scoring systems are available, including the Oxygenation Index (OI), Berlin definition, modified Murray score, and the American European Consensus Conference (AECC) definition, but their relative predictive performance in pneumonia-associated respiratory failure remains uncertain.

Patients and Methods: This prospective observational study included patients admitted with pneumonia-associated respiratory failure. Sociodemographic data, comorbidities, and risk factors were recorded. The predictive performance of four respiratory severity scores OI, Berlin definition, modified Murray score, and AECC definition were assessed on days 1 to 4 of admission. Receiver operating characteristic curves were generated, and area under the curve values with 95% confidence intervals were calculated to evaluate each score’s ability to predict 28-day mortality.

Results: The study showed a balanced gender distribution, mean age of 45.3 years, and high comorbidity burden. On day 1, all scores performed poorly (AUCs ~0.5). From day 2 onward, OI demonstrated a marked and progressive increase in predictive accuracy (AUC: 0.790 on day 2; 0.881 on day 3; 0.985 on day 4), while the modified Murray score showed moderate improvement (AUC: 0.847 on day 4). In contrast, the Berlin and AECC definitions consistently demonstrated poor and declining predictive performance, with AUCs falling below 0.5. Overall, OI outperformed all other scoring systems across all time points.

Conclusion: The Oxygenation Index is a robust and dynamic predictor of 28-day mortality in pneumonia patients, showing superior temporal improvement compared to the Berlin and AECC definitions and the modified Murray score. Routine application of OI may enhance prognostication and guide timely interventions in pneumonia-associated respiratory failure.