Con: Corticosteroids Are Not Indicated for Treatment of Acute Lung Injury from H1N1 Viral Pneumonia
Authors: Michael A. Matthay, Kathleen D. Liu
Journal: American Journal of Respiratory and Critical Care Medicine (2011)

Con: Corticosteroids Are Not Indicated for Treatment of Acute Lung Injury from H1N1 Viral Pneumonia Severe viral pneumonia has been recognized for decades as an important cause of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) (1), and therefore it is not surprising that the A/H1N1 2009-2010 influenza pandemic was associated with substantial morbidity and mortality from acute respiratory failure (2, 3).In addition to antiviral therapy and other supportive measures, many clinicians administered corticosteroids to patients with ALI/ARDS, hoping that steroid therapy would reduce lung inflammation and improve clinical outcomes (4).However, no randomized clinical trials have been performed to test the potential benefit or harm of steroid therapy for ALI/ARDS from acute viral pneumonia.In this issue of the Journal, two articles (pp.1200-1206 and 1207-1214) report the results of steroid therapy in critically ill patients with proven or strongly suspected H1N1 viral infection (5,6).Since neither study was a randomized clinical trial, the investigators used several analytic techniques to adjust for differences in the steroid-treated versus non-steroid-treated patients to compare clinical outcomes.Given the acute nature of the H1N1 influenza pandemic, a prospectively designed, randomized clinical trial of steroids was not feasible.The study by Brun-Buisson and colleagues (5) focused on patients with ARDS.To try to eliminate potential differences between patients who received steroid therapy and those who did not, all analyses were restricted to individuals who were not chronic steroid users.To avoid differences in timing of steroid administration, patients who received steroids more than 14 days after the diagnosis of ARDS were also not included.The final cohort was made up of 208 patients, and steroid therapy was associated with death both in the unadjusted analysis (34% versus 17%, P 5 0.004) and also in the propensity score-adjusted analysis (hazard ratio, 2.82; 95% confidence interval [CI], 1.5-5.4;P 5 0.002).Early steroid therapy (< 3 d of mechanical ventilation) was associated with higher mortality.Patients who received steroids had more hospital-acquired pneumonia and a trend for longer duration of mechanical ventilation.In the study by Kim and coworkers (6), 245 critically ill patients were included in the cohort; of these, 136 patients met criteria for ARDS.The crude 90-day mortality for patients who received steroids was higher than in the patients who did not receive steroids (58% versus 27%, P , 0.001).As in the Brun-Buisson study, the steroid-treated group was more likely to develop bacterial pneumonia or invasive fungal infection, and had significantly prolonged ICU stays.However, in contrast to the Brun-Buisson study, there were significant differences between the steroid-treated and untreated groups; specifically, severity of illness scores and the incidence of prior corticosteroid use, underlying immunosuppressive conditions, and mechanical ventilation were all higher in the steroid-treated group.The authors used two statistical methods to control for these differences, multivariable adjustment (in which the analysis is controlled for variables that are different between the two groups, and which can include the propensity score) and propensity score matching (in which patients who received steroids are matched to participants who did not).In the propensity score-matched analysis, steroid treatment was associated with an increase in 90-day mortality (odds ratio [OR], 2.63; 95% CI,