ABSTRACT

Nosocomial pneumonia is a frequent and often underestimated complication of critically ill patients.1-4 Rapid accurate diagnosis is essential to guide appropriate antibiotic therapy which will effectively treat the infection but not increase the risk of resistant organisms. Studies have shown that inadequate antibiotics at the onset worsens prognosis,5-6 yet broad-spectrum antibiotics may lead to infections with more virulent micro-organisms such as Pseudomonas aeruginosa or Acinetobacter calcoaceticus.2, 7-9

The optimal strategy for diagnosing nosocomial bacterial pneumonia in hospitalized patients, especially those requiring mechanical ventilation, remains elusive and a source of considerable debate. Prior antibiotic use reduces sensitivity and specificity.10-11 Frequent oropharyngeal colonization by potential pathogens in hospitalized patients can lead to misinterpretation of samples obtained by methods that do not bypass the oropharynx. ‘Invasive’ bronchoscopic and non-bronchoscopic techniques have been developed to try to avoid contamination with colonizing organisms.