Body Fluids- BAL

Bronchoscopy

Procedure using a fiber-optic instrument to visualize and sample the airway

Fiber optic bronchoscope

Flexible instrument with light source used for airway examination

Rigid bronchoscope

Older instrument now mainly used for biopsy or foreign body removal

Bronchial wash

Specimen obtained from the proximal bronchial tree

Bronchoalveolar lavage

Specimen obtained from distal bronchioles and alveoli

Primary difference between wash and BAL

BAL samples deeper lung structures and yields more cells

Site sampled bronchial wash

Large proximal airways

Site sampled BAL

Terminal bronchioles and alveolar spaces

BAL specimen collection

Saline is instilled and aspirated through bronchoscope

Volume of saline used in BAL

Aliquots of approximately 20 to 60 milliliters

First BAL aliquot

Contains highest number of cells and best for cytology

Subsequent BAL aliquots

Better represent alveolar contents

Indications for BAL

Evaluation of pulmonary disease when sputum is inadequate

BAL use in immunocompromised patients

High diagnostic yield for opportunistic infections

BAL use in interstitial lung disease

Assesses inflammatory and cellular patterns

BAL use in airway disease

Evaluates infection, malignancy, and inflammation

BAL advantage over sputum

Less contamination from oral flora

BAL limitation

Invasive procedure requiring bronchoscopy

Normal BAL appearance

Clear to slightly cloudy

Abnormal BAL appearance

Cloudy or bloody indicating pathology

Bloody BAL

May indicate malignancy, trauma, or hemorrhage

Predominant normal BAL cell

Macrophages

BAL macrophages

Indicate normal alveolar lining cells

BAL neutrophils

Increased in acute bacterial infection

BAL lymphocytes

Increased in interstitial lung disease and viral infections

BAL eosinophils

Associated with allergic or parasitic disease

BAL plasma cells

Suggest chronic inflammation

Ciliated columnar epithelial cells

Normal bronchial lining cells seen in BAL

Increased epithelial cells

Suggest airway irritation or contamination

Opportunistic organisms detected by BAL

Pneumocystis jirovecii and Aspergillus species

BAL sensitivity for Pneumocystis

Higher than bronchial wash

BAL in fungal infections

Useful for detecting filamentous fungi

BAL cytology

Used to detect malignant cells

Malignant cells in BAL

Suggest lung carcinoma or metastatic disease

BAL in lung cancer

Adjunct to biopsy for diagnosis

BAL microbiology testing

Gram stain, cultures, fungal stains, and AFB stains

AFB stain in BAL

Used to detect Mycobacterium tuberculosis

BAL cultures

Confirmatory for infectious organisms

BAL specimen handling

Process promptly to preserve cellular morphology

Delayed BAL processing

Leads to cell degeneration and reduced diagnostic yield

Correlation of BAL findings and disease

Cell patterns help guide diagnosis

BAL neutrophilia

Associated with bacterial pneumonia

BAL lymphocytosis

Associated with hypersensitivity pneumonitis

BAL eosinophilia

Associated with eosinophilic lung disease