Nosocomial pneumonia endotracheal aspirates

Expectorated sputum and tracheal aspirate specimens obtained by direct suctioning through the endotracheal tube in mechanically ventilated patients are easily obtained but notoriously nonspecific in the diagnosis of nosocomial pneumonia. Bartlett et al. prospectively evaluated cultures of expectorated sputum in 67 patients with nosocomial pneumonia whose final diagnosis was based on bacterial studies from uncontamined specimens (blood, transtracheal... 

Routine culture of the endotracheal aspirate also cannot be used to monitor response to antibiotic treatment in patients with nosocomial pneumonia. Finally, the only undisputable value of this diagnostic test is when results are completely negative in a patient with no modification of prior antimicrobial treatment. In that case, the negative predictive value is very high and the probability for the patient to have pneumonia is close to zero (45). 

Jourdain B, Novara A, Joly-Guillou, et al. Role of quantitative cultures of endotracheal aspirates for the diagnosis of nosocomial pneumonia. Am J Respir Grit Care Med 1995 152 241-246. 

Figure 2 Example of an intubated patient with continuous aspiration of subglottic secretions as reported by Valles and coworkers (29). Removal of subglottic secretions decreases colonization of the trachea and the risk of ventilator-associated pneumonia. This system has recently become available in the United States. Ideally, an endotracheal tube is preferred to a nasotracheal tube and placing the gastric tube through the mouth rather than the nose may reduce the risk of nosocomial sinusitis and pneumonia. (From Ref. 20, with permission.)...

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