Diagnostic strategies for nosocomial pneumonia

PURPOSE OF REVIEW: This review describes advances in clinical and microbiological modalities for diagnosis of nosocomial pneumonia and the role of biological markers. RECENT FINDINGS: Serial assessments with the clinical pulmonary infection score identifies nonsurvivors and allows discontinuation of antibiotics when there is low suspicion of pneumonia. Studies evaluating its clinical utility show mixed results. A meta-analysis revealed that an invasive approach does not affect mortality but reduces costs, antibiotic exposure, and multidrug resistance. In contrast to these findings, a recent trial comparing nonquantitative endotracheal aspirate and quantitative bronchoalveolar lavage cultures showed similar clinical outcomes and antibiotic utilization. The role of quantitative endotracheal aspirate for diagnosis of pneumonia not related to mechanical ventilation was recently evaluated. Procalcitonin and soluble triggering receptor expressed on myeloid cells-1 aid in diagnosis, identify sepsis related to ventilator-associated pneumonia and patients with worst outcomes. SUMMARY: The diagnostic modality chosen depends on availability, personnel experience, and the patient's clinical status. Recent guidelines support the use of quantitative cultures in an integrated clinical and microbiological algorithm. The decision to adjust antibiotics involves clinical reassessment and interpretation of culture results. Biological markers have a potential role as screening and prognostic tools.