The diagnostic dilemma of ventilator-associated pneumonia in critically ill children.

OBJECTIVE: A review of the existing literature on ventilator-associated pneumonia in children with emphasis on problems in diagnosis. DATA SOURCES: A systematic literature review from 1947 to 2010 using Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, and ISI Web of Science using key words "ventilator associated pneumonia" and "children." Where pediatric data were lacking, appropriate adult studies were reviewed and similarly referenced. STUDY SELECTION: Two hundred sixty-two pediatric articles were reviewed and data from 48 studies selected. Data from 61 adult articles were also included in this review. DATA EXTRACTION AND SYNTHESIS: Ventilator-associated pneumonia is the second most common nosocomial infection and the most common reason for antibiotic use in the pediatric intensive care unit. Attributable mortality is uncertain but ventilator-associated pneumonia is associated with significant morbidity and cost. Diagnosis is problematic in that clinical, radiologic, and microbiologic criteria lack sensitivity and specificity relative to autopsy histopathology and culture. Qualitative tracheal aspirate cultures are commonly used in diagnosis but lack specificity. Quantitative tracheal aspirate cultures have sensitivity (31-69%) and specificity (55-100%) comparable to bronchoalveolar lavage (11-90% and 43-100%, respectively) but concordance for the same bacterial species when compared with autopsy lung culture was better for bronchoalveolar lavage (52-90% vs. 50-76% for quantitative tracheal aspirate). Staphylococcus aureus and Pseudomonas species are the most common organisms, but microbiologic flora change over time and with antibiotic use. Initial antibiotics should offer broad-spectrum coverage but should be narrowed as clinical response and cultures dictate.
CONCLUSIONS: Ventilator-associated pneumonia is an important nosocomial infection in the pediatric intensive care unit. Conclusions regarding epidemiology, treatment, and outcomes are greatly hampered by the inadequacies of current diagnostic methods. We recommend a more rigorous approach to diagnosis by using the Centers for Disease Control and Prevention algorithm. Given that ventilator-associated pneumonia is the most common reason for antibiotic use in the pediatric intensive care unit, more systematic studies are sorely needed.