Lack of usefulness of blood cultures to diagnose ventilator-associated pneumonia

Since ventilator-associated pneumonia is a common complication in ventilated patients and is associated with very high mortality [1,2], the precise identification of causative organisms and the accurate selection of antimicrobial treatment represent important clinical goals [3].However, the usefulness of blood cultures in ventilator-associated pneumonia is not yet well known.During a period of thirty months, we prospectively studied 129 episodes of ventilator-associated pneumonia in our intensive care unit.Ventilator-associated pneumonia was diagnosed when a patient developed new infiltrates on the chest radiograph, excluding those of noninfectious origin, after 48 h on mechanical ventilation, plus two of the following items: fever >38"C, leucocytosis >10 x 10 9 •[•1, purulent secretions from endotracheal tubes.Identification of the causative agent was possible in 92 (71%) episodes by means of highly specific techniques (telescoping plugged catheters (TPC), blood cultures, and/or necropsy).In only 10 (8%) of