BRONCHIAL ALVEOLAR LAVAGE, CULTURE, AEROBIC BACTERIA
Test Code: BALQ
Bronchial alveolar lavage is a technique used to obtain cells and fluid from the bronchioles and lung alveoli to assist in the diagnosis of pulmonary diseases, including infections. Briefly, a bronchoscope is wedged into a bronchus, sterile saline is injected then removed, and the fluid is sent to the laboratory for analysis.
Indications for performing a bronchial alveolar lavage related to infectious diseases include the following:
1. Non-resolving pneumonia (i.e., failure of standard therapy)
2. Diffuse lung infiltrates (alveolar or interstitial) of uncertain etiology
3. Pulmonary infiltrates in an immunocompromised host
4. Quantitative cultures for diagnosis of ventilator-associated pneumonia (NB. Current North American guidelines on the management of patients with hospital-acquired and ventilator-associated pneumonia favor non-invasive respiratory sampling methods such as endotracheal aspirates over invasive sampling methods including bronchial alveolar lavage.)
5. Detection of Mycobacterium tuberculosis when spontaneous sputum and induced sputum are unavailable, or are smear negative and a high index of suspicion remains.
Clearly indicate on the microbiology requisition the specimen type (bronchial alveolar lavage or BAL) and the test(s) requested. A quantitative culture will be performed on fluid obtained by bronchial alveolar lavage that is submitted to the microbiology laboratory for bacterial culture. Note that bronchial alveolar lavage fluid is not appropriate for recovery of anaerobes and requests for anaerobe culture will be rejected.
If Nocardia, Legionella, Mycobacteria, and/or Fungi are suspected, these should be specifically requested on the microbiology requisition. Quantitative culture is not performed for these organisms.
If infection with a systemic fungus (e.g., Blastomyces dermatitidis, Coccidioides imitis, Histoplasma capsulatum, Talaromyces marneffei, Paracoccidioides brasiliensis) is suspected, notify the laboratory in advance.
The laboratory will automatically perform a Gram stain where appropriate. This does not need to be requested on the microbiology requisition.
Please indicate what antimicrobial therapy the patient is currently receiving on the microbiology requisition (clinical details section).
For information on other microbiology tests on bronchial alveolar lavage fluid not performed by Shared Health Clinical Microbiology Laboratories (e.g., Pneumocystis jiroveci detection, virus detection), please refer to the relevant laboratory that performs the testing.
Patient Preparation Instructions:
Follow the procedure outlined by your healthcare facility.
Accurate patient identification must be made prior to sample collection. Patient identification should be done in accordance with site policy.
Samples and requisitions must be labeled/completed in accordance with the Shared Health Specimen Acceptance Policy.
Respiratory secretions/fluid obtained by bronchial alveolar lavage (Adult and Pediatric)
40-80 mL of specimen is required for quantitative analysis
A descriptive report will be sent. Quantitative cultures will only be performed for bacteria. Samples that are negative for bacterial culture will be incubated for 48 hours before being reported as "No growth at 10^5 cfu/L".
For further details on mycobacteria culture and fungal culture, refer to the LIM entries for these.
FUNGI, CULTURE, ALL SPECIMEN TYPES EXCLUDING BLOOD (E.G., CORNEAL SCRAPINGS/FLUID/TISSUE/BONE MARROW)
Transport to the laboratory as soon as possible.
If transport will occur within 2 hours, it is acceptable to store the specimen at room temperature (although 4°C is optimal).
If transport to the laboratory will be delayed up to 24 hours, store the specimen at 4°C. Ensure samples that are being sent to a referral laboratory are packaged in accordance with Transport of Dangerous Goods recommendations for diagnostic samples.
2. Mandell LA, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27-72.
3. Kalil AC et al. Management of adults with hospital-acquired pneumonia and ventilator-associated pneumonia: 2016 clinical practice guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis 2016;63:e61-111.
4. Canadian Tuberculosis Standards, 7th edition.
5. Jorgensen JH, et al. (editors). Manual of Clinical Microbiology, 11th edition.