To which extent can we decrease antibiotic duration in critically ill patients?

Introduction: Inadequate empirical antibiotic therapy is associated with higher mortality in critically ill patients with severe infections. Nevertheless, prolonged duration of antibiotic treatment is also potentially harmful. Development of new infections with more resistant pathogens is one of the arguments against the administration of prolonged courses of antibiotics. Areas covered: We aim to describe the optimal duration of antimicrobial therapy in the most common infections affecting critically ill patients. A literature search was performed to identify all clinical trials, observational studies, meta-analysis, and reviews about this topic from PubMed. Expert commentary: Diverse observational studies have reported a poor outcome in critically ill patients without a documented infection who receive prolonged antibiotic therapy. We summarize the available information about the optimal duration of antimicrobial therapy in critically ill patients with severe infections including community-acquired pneumonia, intra-abdominal infections, bacteremia, meningitis and urinary-tract infections as well as the clinical consequences of short antimicrobial courses in certain severe infections. The utility of procalcitonin to reduce the duration of antibiotics is also discussed. Finally, we give clear recommendations about the length of treatment for the most common infections in critically ill patients.