Steroids in severe pneumonia: a literature review

Despite more than sixty years of scientific medical research, severe pneumonia, either community-acquired or nosocomial, remains a leading cause of death regardless of the patients' immunity state. The clinical introduction of new and more potent antibiotic molecules and the continuous development of efficient respiratory assistance devices may not be able to radically improve the clinical outcome of pneumonia. Adjunctive therapies based on the physiopathological mechanisms of lung damage in severe pneumonia have been strongly advocated, and corticosteroids, which present many properties that theoretically interfere with these pathways, have been widely used, with conflicting results. The aim of this review is to examine existing literature data on steroid use in severe pneumonia. Molecular, endocrinological and clinical studies will be described to help physicians to clarify the reasons for the historical debate about steroid use as an adjunctive treatment in severe pneumonia. There is growing evidence that, during lung infection, an excessive inflammatory response can have deleterious effects and contribute to tissue damage mechanisms. Because of their immunomodulatory properties, glucocorticoids have been suggested as a useful tool for regulating the complex balance of cytokine networks, and they are commonly used as an adjunctive therapy during serious infections. In severe pneumonia, preclinical data, including cytokine level detection and animal studies, have shown encouraging results, although the clinical data is controversial. Moreover, large randomized controlled trials have not been conducted to determine steroid side effects and the risk of immunosuppression-induced superinfections. The benefits of steroid use in patients with severe pneumonia have not been proven by current literature, but ongoing investigations of anti-inflammatory molecules probably represent the key point of severe infection management in the near future.