2. Introduction:
BAL is performed with the FOB in a wedge position within the selected
broncho-pulmonary segment.
The total instilled volume of normal saline should be from 100-300ml, repeated 2 to 6 times with 20-50ml
saline each.
To obtain an adequate specimen 40-60 mL (usually 40-70% recovery of the total instillate) must be
drawn back.
Aspirates and washings provide information on the status of the
respiratory tract in small bronchi beyond reach of the bronchoscopic
brush.
3.
4. Area That Is Lavaged
Procedures were usually performed in the right
middle lobe or lingula
But lavage can be done in the most affected areas
of the lung
(In evaluating BAL in patients with Pneumocystis jirovecii
pneumonia, it was found that lavage in the upper lobes
had a higher yield than the traditional right middle lobe
or lingula)
5. Handling of Aspirated Fluid
At the time of the lavage cells should be stored in
silicone-coated or similar containers
Cell counts should probably be made on
unfiltered, unwashed, and unconcentrated
samples (If concentration is performed, the method should be
specified)
6. Centrifugation to concentrate proteins and cells
can lead to loss of cells
Washing the cells can change the differential
count considerably
7. Satisfactory Sample
1. A total of 2×106
cells is considered a minimum requirement
2. Furthermore, more than 10 macrophages should be
present in a high-powered microscopic field
3. Degenerative changes should cover less than 20% of the
specimen area on the slide
4. If the number of squamous epithelial cells, bronchial cells,
RBCs, or inflammatory cells exceeds that of macrophages,
the specimen is considered unsatisfactory
8. The Storage of Fluid
Cells stored at 4̊ C can be analyzed up to 24
hours after the procedure without significant
changes in the count and differentials
Certain proteins may be temperature sensitive
and the samples may need to be stored at -80̊ C
9. Correcting for Bronchoalveolar
Lavage Dilution
Instilled fluid is mixed with the endogenous fluid in the
alveoli
Alveolar space is also in contact with a vascular space-
So water and solutes can transfer into the alveolar space
This process leads to the uncertainty of any measurement
of the concentration of any material in the alveolar space
10. Solution
One method has been to report per mL of
aspirated fluid.
Using this correction method has allowed clinicians
to quantitate the number of bacteria in the alveolar
space and to therefore diagnose bacterial
pneumonia
11. Unsatisfactory BAL specimen that shows squamous epithelial
cells (large cells) and degenerating columnar epithelial cells
(arrow)
12. Steps in Handling Cellular Population
of Bronchoalveolar Lavage Fluid
14. Wright-Giemsa stain:
-Good at differentiating between inflammatory cells
Diff-Quik (modification of the Wright-Giemsa stain):
-Is a rapid method allowing staining of the slide within a
few minutes
Limitations:
-The cells must be adequately adhered to the slide prior
to fixation
-Some cells are underestimated by these techniques
15. Oil red O stain:
-In fat embolism
Fat and Lipid stain (e.g. Sudan III):
-Lipoid pneumonia (aspiration)
Lipid-laden alveolar macrophage index > 100
(Sensitivity of 100%, Specificity 57%)
Periodic acid-Schiff (PAS):
-Pulmonary alveolar proteinosis
17. Modified acid fast stain (Kinyoun): Nocardia
Silver methenamine: Pneumocystis jirovecii
pneumonia, fungal
Direct fluorescent antibody testing (DFA) for
Legionella
18. Number of Cells Counted
De Brauwer et al determined that between 300 and
500 cells counted provided a good representation
of the number of nucleated cells for a BAL sample
19. Different cell
types in respiratory tract
Upper respiratory tract
Ciliated pseudostratified columnar cells
Squamous cells
Trachea and bronchi
Peudostratified Ciliated columnar cells
Goblet cells
20. Terminal bronchioles
Low columnar or cuboidal-may be ciliated
Club cells (Clara cells)-nonciliated, secretory
cuboidal cells
Alveoli
Type I pneumocytes-simple squamous alveolar cells
Type-II pneumocytes-great alveolar cells
Dust Cell-in the alveoli
Alveolar macrophages- in the connective
tissue of alveolar walls or interalveolar septa
21.
22. General indications for BAL:
-Non-resolving pneumonia
- Diffuse lung infiltrates (interstitial and/or
alveolar)
- Infiltrates in an immunocompromised host
- Suspected alveolar hemorrhage
- Quantitative cultures for VAP
- Exclusion of diagnosable conditions by BAL
- Research
23. Gross examination-
Pulmonary alveolar proteinosis
-Opaque or translucent brownish or sandy colored fluid
-Sediments out into two layers if left to sit
Alveolar hemorrhage
-Sequentially more hemorrhagic with each aliquot
38. Elevated CD4/CD8:
Active sarcoidosis (>4:1 up to 10:1)
Asbestosis
Berylliosis
Crohn's disease
Connective tissue disorders
Sometimes in normal persons (inc. with age)
40. Erythrocytes
◦ Elevated erythrocyte count - early sign of alveolar
hemorrhage (first several hours)
◦ Phagocytosed erythrocytes - alveolar hemorrhage
within 48 hrs
◦ Hemosiderin laden macrophages - alveolar
hemorrhage > 48hrs
41. Foamy macrophages:
Non specific finding
May be seen in amiodarone use
Malignancies (sensitivity ranges from 35% to 70%)
◦ Lymphangitic carcinomatosis
◦ Lymphoma
◦ Bronchoalveolar carcinoma and other primary lung malignancies
◦ Extrapulmonary malignancies
42. Hemosiderin Laden Macrophages:
20% is highly specific and sensitive for alveolar hemorrhage
Langerhans cells
>5% suggestive of Pulmonary Langerhans cell histiocytosis
Cytomegalic cells
Viral pneumonias (cytomegalovirus, herpes)
Sulfur granules: Actinomycetes
49. Complications/Adverse events:
No complications in up to 95%
Cough
Transient fever (2.5%)
Transient chills and myalgias
Transient infiltrates in most (resolves in 24 hours)
Bronchospasm (<1%)
50. Transient fall of lung function
Transient decrease in baseline PaO2
In patients with already severely compromised respiratory status, the loss of
lung function may necessitate the need for Mechanical Ventilation
51. Pulmonary alveolar
microlithiasis
Calcospherites can be demonstrated in BAL fluid
(one of the tiny round bodies formed during calcification by chemical union of calcium particles and
albuminous matter of cells)
