Adjunctive aerosolized antibiotics for treatment of ventilator-associated pneumonia.

STUDY OBJECTIVE: To determine clinical and microbiologic success in patients receiving adjunctive aerosolized antibiotics for the treatment of ventilator-associated pneumonia (VAP).

DESIGN: Retrospective medical record review.

SETTING: Level I trauma intensive care unit of a large academic medical center.

PATIENTS: Forty-nine patients (mean +/- SD age 42 +/- 19 yrs) who received aerosolized antibiotics for the treatment of a total of 60 episodes of VAP caused by Pseudomonas aeruginosa and/or Acinetobacter baumannii between January 2001 and July 2007.

MEASUREMENTS AND MAIN RESULTS: Patients were identified by using an existing database of patients with documented VAP at the study center. To receive a diagnosis of VAP, patients had to have bacterial growth of 10(5) or more colony-forming units/ml from a bronchoscopic bronchoalveolar lavage and new or changing infiltrate on chest radiograph, plus at least two of the following: abnormal body temperature (> 38 degrees C or < 36 degrees C), abnormal white blood cell count (> 10 or < 4 x 10(3)/mm(3), or > 10% immature bands), or macroscopically purulent sputum. By reviewing patient data, we evaluated clinical and microbiologic success using standard definitions. The median (interquartile range) Injury Severity Score and admission Acute Physiology and Chronic Health Evaluation II score were 40 (29-45) and 17 (9-21), respectively. Pseudomonas aeruginosa, A. baumannii, or both were isolated in 45, 14, and 1 episode(s), respectively. Eighteen VAP episodes included additional bacteria. Aerosolized tobramycin, amikacin, and colistimethate were used in 44, 9, and 9 episodes, respectively. Systemic antibiotics were used in 59 (98%) of the 60 episodes. Clinical success was achieved in 36 (73%) of the 49 first episodes of VAP, 8 (73%) of 11 subsequent episodes, 17 (85%) of 20 episodes that were failing intravenous monotherapy, and 30 (79%) of 38 episodes with multidrug-resistant P. aeruginosa or A. baumannii. Microbiologic success was achieved in 29 (71%) of 41 evaluable episodes. Six patients died from VAP.

CONCLUSION: Treatment with adjunctive aerosolized antibiotics was associated with a good response rate in critically ill trauma patients with VAP due to nonfermenting gram-negative bacilli. It is noteworthy that episodes of VAP that followed intravenous therapy failure and/or that were due to multidrug-resistant organisms responded well.