Bronchial alveolar lavage Flashcards
How to perform BAL
1) Wedge the scope
2) Ideal position in diffuse disease: RML, L lingula
3) Flush with 20-60mls aliquot, to total of 100-240mls (lesser than this may cause contamination by bronchial spaces)
4) After each flush, fluid to be immediately recovered by hand gentle suction into the syringe or gentle wall suction into fluid trap
5) Return must be >30% of instilled volume (usu 40-70%)
6) Bx to be done after BAL to avoid contamination with blood
7) The aliquot should be send to lab asap (<1h at room temp), coz cells are not well preserved in saline.
8) High epithelial cells (>5%) = contamination by bronchial cells
Risk factors for developing side-effects following BAL are:
- PaO2 <60 mmHg, oxygen saturation below 90%,
- FEV1 below 1.0 L,
- prothrombin time <50 s, platelet count <20000 mL–1,
- significant comorbidity, and
- bronchial hyperreactivity.
Normal ranges of differential cell counts in healthy subjects
- macrophages>80%
- lymphocytes≤15%
- neutrophils≤3%
- eosinophils≤0.5%
- mast cells ≤0.5%
- plasma cells 0%
Diagnostic BAL findings
BAL cellular pattern
In lymphocytic BAL, CD4/CD8 may help to differentiate causes such as?
BAL yield in ILD
BAL cellular pattern