Intensive care unit (ICU) patients are often prescribed systemic corticosteroids for a wide variety of indications, including chronic obstructive lung disease and multiple trauma injuries. To assess the characteristics and outcomes of patients with ICU-acquired pneumonia that received steroids, Ranzani and colleagues performed a prospective observational study at a major university teaching hospital in Barcelona, Spain. Their findings were published in the September issue of Critical Care Medicine.
Of the 316 consecutive patients included, 125 (40%) received steroids at the time ICU-acquired pneumonia was diagnosed. A wide variety of statistical techniques, including Cox regression with propensity scores for steroid use, Kaplan-Meier analysis and several sensitivity analyses, were used to evaluate the primary outcome of 28-day survival, as well as additional secondary outcomes. The American Thoracic Society guidelines, the Infectious Diseases Society of America guidelines, and the Clinical Pulmonary Infectious Score (CPIS) were used to establish the diagnosis of ICU-acquired pneumonia.
In the steroid group, unadjusted mortality was 39% (n=49) compared to 28% in the group that did not receive steroids. After adjustment for multiple independent variables, steroid treatment was statistically significantly associated with decreased 28-day survival (adjusted hazard ratio, 2.503; 95% confidence interval [CI], 1.17-5.33; p=0.017). Kaplan-Meier analysis also revealed decreased survival in patients with ICU pneumonia at 28 days when treated with steroids (log-rank test, 4.006; p=0.045). Steroid-treated patients had lower levels of inflammatory markers such as C-reactive protein, procalcitonin and interleukin-6. Patients treated with steroids had a higher rate of microbiological late-onset pneumonia (74% vs. 58%; p=0.020).
One major strength of this study is the use of multiple robust methods to control for known confounders given the nonrandomized design, but several limitations are noted. The authors did not present a power calculation to ensure that the study was adequately powered to make conclusions about mortality. Although the effect estimate for increased risk of death with steroid treatment was significant, the confidence interval was wide. Additional limitations included the use of different types of corticosteroids and the single-center study design.
The results of Ranzani et al appear to conflict with those reported by Roquilly et al last year in The Journal of the American Medical Association. In the Hydrocortisone Polytraumatise (HYPOLYTE) randomized controlled study, hydrocortisone therapy was found to significantly decrease the risk of pneumonia in intubated trauma patients; however, the HYPOLYTE study was not adequately powered to detect differences in mortality. Ranzani et al included only a minority of multiple trauma patients (n=21). Based on the present results, caution should be exercised until larger studies are conducted to define the effects of steroid use on mortality. Attenuation of the host inflammatory response by systemic corticosteroids may not be beneficial for all critically ill patients with ICU-acquired pneumonia.
Concise Critical Appraisal is a regular feature authored by SCCM member Samuel M. Galvagno Jr., DO, PhD. Each installment highlights journal articles most relevant to the critical care practitioner.