[Positive bronchoalveolar lavage and quantitative cultures results in suspected late-onset ventilator associated...

Bronchoalveolar lavage (BAL) with quantitative cultures has been used in order to increase ventilator associated pneumonia (VAP) diagnosis specificity, although the accurate technique for this entity diagnosis remains controversial.

To evaluate the influence of using positive BAL and quantitative cultures results in microbiologic diagnosis and treatment of patients with suspected late VAP and prior antibiotherapy.

Retrospective analysis of intensive care unit (UCI) patients, during a one year period, with clinical suspicion of late VAP and prior use of antibiotics that presented a growth in BAL cultures.

Of 243 BAL performed, there were 71 (29.2%) positive cultures (60 patients, 76.7% male, 54 ± 19 years). BAL was done after 13 days (median) of invasive mechanical ventilation, 11 days of ICU antibiotherapy and in the day in which a new antibiotic for VAP suspicion was started. Colony forming units (CFU)/ml count was performed in 71.8% and endotracheal aspirate (ETA) simultaneously collected for qualitative analysis in 85.9%. Therapeutic approach was changed in 38.0%: correction (16.9%), de-escalation (12.7%) and directed antibiotherapy start (8.4%). Therapeutic changes were made in the presence of CFU > 10(4) in 84.2% and in agreement with ETA in 70.8%. In cases in which antibiotherapy was maintained (62.0%), quantitative cultures would have allowed de-escalation in 9.1%. Changes in prescription were more frequent when CFU was > 10(4) (48.5%), comparing with situations in which counts were lower and BAL analysis was qualitative (28.9%), p = 0.091. There were no significant differences between patients submitted to different therapeutic approaches concerning to ICU mortality or length of stay.

In late onset VAP, positive BAL and quantitative cultures allowed therapeutic changes, leading to antibiotic adequacy and consumption reduction, which can however be maximised.