Antibiotic utilization and outcomes for patients with clinically suspected ventilator-associated pneumonia and negative quantitative BAL culture results

Chest. 2005 Oct;128(4):2706-13. doi: 10.1378/chest.128.4.2706.


Objective: To evaluate antibiotic utilization and clinical outcomes among patients with clinically suspected ventilator-associated pneumonia (VAP) and culture-negative BAL (CNBAL).

Design: Prospective observational cohort study.

Setting: A medical ICU from a university-affiliated urban teaching hospital employing a previously described antibiotic discontinuation guideline for the management of VAP.

Patients: One hundred one patients with a clinical suspicion of VAP and CNBAL were evaluated between July 2002 and December 2004.

Interventions: Prospective patient follow-up and data collection. Antibiotic discontinuation was determined by the clinical guideline and not the results of BAL cultures.

Results: The average age of the patients was 60.4 +/- 17.9 years and the mean APACHE II score was 23.2 +/- 8.7 (+/- SD). The mean duration of mechanical ventilation prior to clinically suspected VAP was 2.9 +/- 1.9 days. Nineteen patients (18.8%) received antibiotics for other indications prior to BAL. Empiric antibiotic therapy for VAP was begun in 65 patients (64.4%) following BAL. The duration of empiric antibiotic treatment following BAL was 2.1 +/- 0.8 days. None of these patients received antibiotics for > 3 days (median, 2 days; range, 1 to 3 days). Six patients (5.9%) were treated with antibiotics for a secondary episode of VAP or hospital-acquired pneumonia developing at least 72 h after the CNBAL was performed and discontinuation of the empiric antibiotic therapy prescribed for the initially suspected episode of VAP. Overall, 35 patients (34.7%) died during hospitalization. Two deaths occurred in patients with a secondary episode of VAP following CNBAL and discontinuation of empiric antimicrobial therapy. Neither of these two deaths was attributed to VAP.

Conclusions: Although the decision to discontinue antibiotic treatment was based on clinical criteria and not BAL culture results, this study suggests that patients with a clinical suspicion of VAP and CNBAL can have empiric antimicrobial therapy safely discontinued within 72 h or in some cases withheld altogether. Prospective studies are needed to determine the safety of employing CNBAL as the primary criterion for the discontinuation of empirically begun antibiotic treatment for VAP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Anti-Bacterial Agents / therapeutic use*
  • Bronchoalveolar Lavage Fluid / cytology*
  • Female
  • Hospitals, Teaching
  • Humans
  • Male
  • Middle Aged
  • Pneumonia / drug therapy*
  • Pneumonia / etiology*
  • Ventilators, Mechanical / adverse effects*


  • Anti-Bacterial Agents