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Bronchoalveolar Lavage (BAL) for Research; Obtaining Adequate Sample Yield
Published on: March 24, 2014
Subthreshold quantitative bronchoalveolar lavage: clinical and therapeutic implications
Ajai K Malhotra1, Omer J Riaz, Therese M Duane
1Department of Surgery, Division of Trauma/Critical Care/Emergency General Surgery, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA. akmalhot@vcu.edu
The Journal of Trauma
|September 12, 2008
Summary
Quantitative bronchoalveolar lavage (qBAL) has an 11% false-negative rate, indicated by bloodstream invasion. Certain organisms and longer hospital stays increase this risk, impacting patient outcomes and requiring careful antimicrobial therapy consideration.
Area of Science:
- Critical Care Medicine
- Infectious Diseases
- Pulmonary Medicine
Background:
- Quantitative bronchoalveolar lavage (qBAL) is crucial for diagnosing ventilator-associated pneumonia (VAP).
- False-negative (FN) results from qBAL can lead to delayed or inadequate treatment.
- Understanding the incidence and impact of FN qBAL is essential for improving patient care.
Purpose of the Study:
- To determine the incidence of false-negative qBAL results.
- To investigate the outcomes associated with FN qBAL.
- To define the therapeutic implications of FN qBAL findings.
Main Methods:
- Bronchoscopic qBAL was performed on ventilated patients suspected of VAP.
- VAP diagnosis was based on qBAL >10^5 CFU/mL.
- FN qBAL was identified by matching subthreshold qBAL growth (<10^5 CFU/mL) with positive blood cultures for the same organism.
Main Results:
- Over 39 months, 246 patients underwent 365 qBALs.
- An 11% false-negative rate was observed, as indicated by bloodstream invasion.
- Bacteremia associated with FN qBAL worsened patient outcomes, including increased mortality and longer hospital stays.
Conclusions:
- Quantitative bronchoalveolar lavage has an 11% false-negative rate.
- Factors like organism type (Staphylococcal, hospital-acquired gram-negatives) and hospitalization duration influence false-negative results.
- Prompt antimicrobial therapy should be considered for organisms found in BAL, regardless of growth strength, after the first week of hospitalization.
