Presence of Squamous Epithelial Cells Indicates Upper Airway Secretion Contamination: epithelial cells >5% indicates that sample is suboptimal (BAL cellular pattern should be interpreted with caution)
Need for Bronchoalveolar Lavage (BAL) Cellular Analysis Based on Appearance of HRCT (Am J Respir Crit Care Med, 2012) [MEDLINE]
HRCT with Extensive Honeycombing: BAL cellular analysis is not required
HRCT with Diagnostic Pattern: BAL cellular analysis is not required
HRCT with Non-Diagnostic Pattern: BAL cellular analysis is recommended
Etiology of Bronchoalveolar Lavage (BAL) Lymphocytosis (>15%) (Am J Respir Crit Care Med, 2012) [MEDLINE]
Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome, [[Acute Respiratory Distress Syndrome]]): BAL neutrophilia may be >50%
Etiology of Bronchoalveolar Lavage (BAL) Eosinophilia (>1%) (Am J Respir Crit Care Med, 2012) [MEDLINE]
General Comments
Although Pathologic Examination of the Lung is the Gold Standard for Diagnosing Eosinophilic Pneumonia, BAL is a Widely-Accepted Noninvasive Surrogate of Lung Biopsy for Diagnosis in Patients with High-Resolution Features of Eosinophilic Pneumonia
However, No Study Has Definitely Established a Correlation Between the Presence of BAL Eosinophilia and the Finding of Eosinophilic Pneumonia on Lung Pathology
BAL Eosinophil Percentage in Various Disease States
Normal: BAL eosinophil <1%
BAL Eosinophilia 3-40% (and Especially Between 3-9%): may be found in various disorders
BAL Eosinophilia >40%: found predominantly in patients with chronic eosinophilic pneumonia
BAL Eosinophil Percentage Proposed Cut-Off Values
Diagnosis of Idiopathic Acute Eosinophilic Pneumonia: BAL Eosinophilia >25%
Diagnosis of Idiopathic Chronic Eosinophilic Pneumonia: BAL Eosinophilia >40%
Eosinophilic Pulmonary Syndromes of Known Etiology
Parasitic Infection
General Comments: parasite-associated eosinophilic pneumonias represent the most common etiologies of pulmonary infiltrates with eosinophilia worldwide
Capillaria Aerophila (see Capillariasis, [[Capillariasis]])
Epidemiology: rare etiology of eosinophilic pulmonary infiltrates
Clonorchis Sinensis (see Clonorchiasis, [[Clonorchiasis]])
Epidemiology: rare etiology of eosinophilic pulmonary infiltrates
Epidemiology: rare etiology of eosinophilic pulmonary infiltrates
Schistosomiasis (see Schistosomiasis, [[Schistosomiasis]]): the manifestations of schistosomiasis in the lung vary dependent on the stage of disease
Early Acute Schistosomiasis: transient, multiple small pulmonary nodules with peripheral eosinophilia
Chronic Schistosomiasis: embolization of ova in small arteries of the lung results in granuloma formation, occlusion and remodeling of pulmonary arteries, and further pulmonary hypertension mediared by portopulmonary hypertension
Post-Treatment of Schistosomiasis: eosinophilic pneumonitis (lung shift, verminous pneumonia, reactionary Loffler-like pneumonitis) due to antigen release following treatment
Ascaris Lumbricoides (or Ascaris Suum): most common etiology of simple pulmonary eosinophilia (Loffler syndrome)
Necator Americanus
Ancylostoma Duodenale
Ancylostoma Brazliense or Canium
Entamoeba Histolytica
Fasciola Hepatica
Schistosomiasis (see Schistosomiasis, [[Schistosomiasis]]): the manifestations of schistosomiasis in the lung vary dependent on the stage of disease
Early Acute Schistosomiasis: transient, multiple small pulmonary nodules with peripheral eosinophilia
Chronic Schistosomiasis: embolization of ova in small arteries of the lung results in granuloma formation, occlusion and remodeling of pulmonary arteries, and further pulmonary hypertension mediared by portopulmonary hypertension
Post-Treatment of Schistosomiasis: eosinophilic pneumonitis (lung shift, verminous pneumonia, reactionary Loffler-like pneumonitis) due to antigen release following treatment
Strongyloides Stercoralis: simple pulmonary eosinophilia (Loffler syndrome) may occur when larvae migrate through the lungs after acute infection
Strongyloides Stercoralis Hyperinfection Syndrome (see Strongyloides Stercoralis, [[Strongyloides Stercoralis]])
Epidemiology: occurs in 20% of patients hospitalized with strongyloidiasis and coexisting chronic lung disease (COPD, asthma)
Diagnosis: rhabditiform larvae may be recovered via bronchoalveolar lavage, bronchial wash, or sputum sample
Clinical: cough/wheezing/dyspnea with bilateral patchy infiltrates and variable degree of eosinophilia
Epidemiology: case reports of eosinophilic pneumonia [Eosinophilia and pneumonitis in chronic brucellosis: a report of two cases. Ann Intern Med. 1942;16:995-1001]
Clinical: chronic cough with sputum eosinophilia (about 40%)
Normal Lung Function with Absence of Bronchial Hyperreactivity: although it may evolve over time into either fixed airflow obstruction without asthma or into true asthma
Absence of Eosinophilic Pneumonia
Gastric Cancer with Tumor-Related Production of GM-CSF and IL-5 (see Gastric Cancer, [[Gastric Cancer]])
Desquamative Interstitial Pneumonia (DIP): mild BAL eosinophilia may occur in some cases
Non-Specific Interstitial Pneumonia (NSIP): mild BAL eosinophilia may occur in some cases
Idiopathic Pulmonary Fibrosis (IPF) (see Idiopathic Pulmonary Fibrosis, [[Idiopathic Pulmonary Fibrosis]]): mild BAL eosinophilia may occur in some cases
Diagnosis: pulmonary pathologic lesions are nodules (with bronchiolocentric stellate shape) with Langerhans cells and variable numbers of eosinophils, plasma cells, and lymphocytes
Eosinophils are Usually Present in the Initial, Active Stage of the Disease: they contribute to the eosinophilic granuloma
Eosinophils are Numerous in 25% of Cases: usually located at the periphery of the lesions
Eosinophils are Rare or Absent at the Chronic Stage of the Disease
Acute Lung Transplant Rejection (Acute Cellular Lung Transplant Rejection) (see Acute Lung Transplant Rejection, [[Acute Lung Transplant Rejection]]): peripheral eosinophilia may occur with/without pulmonary infiltrates (as acute rejection may be detected by surveillance bronchoscopy with transbronchial biopsy prior to the development of pulmonary infiltrates)
Other Abnormal Bronchoalveolar Lavage (BAL) Findings (Am J Respir Crit Care Med, 2012) [MEDLINE]
Infectious Organism: indicates presence of lower respiratory infection
Malignant Cells (by Light Microscopy or Flow Cytometry): indicates cancer
Bloody BAL Fluid in Successive Aliquots: indicates pulmonary hemorrhage (with/without diffuse alveolar hemorrhage)
Milky Fluid with Positive Periodic Acid Schiff (PAS-Positive) Staining and Amorphous Debris: indicates pulmonary alveolar proteinosis
In Vitro Lymphocyte Proliferative Response to Specific Beryllium Antigen: indicates chronic beryllium disease
Recommendations for Bronchoalveolar Lavage (BAL) in the Setting of Interstitial Lung Disease (Am J Respir Crit Care Med, 2012) [MEDLINE]
For Patients with Suspected Interstitial Lung Disease in Whom a Bronchoalveolar Lavage Can Be Tolerated, BAL Target Site Be Chosen on the Basis of an HRCT Performed Before the Procedure, Rather than Choosing a Traditional Bronchoalveolar Lavage Site (Such as the Right Middle Lobe or Lingula)
HRCT Should Be Performed within 6 wks of the BAL
For Patients with Suspected Interstitial Lung Disease Who Undergo Bronchoalveolar Lavage, a Differential Cell Count Should Be Performed on the Bronchoalveolar Lavage Fluid
Including Lymphocyte, Neutrophil, Eosinophil, and Mast Cell Counts
Remaining Sample Should Be Used for Microbiological, Virological, and/or Malignant Cell Cytology Laboratory Testing, if Indicated
For Patients with Suspected Interstitial Lung Disease Who Undergo Bronchoalveolar Lavage, Lymphocyte Subset Analysis Should Not Be a Routine Component of Bronchoalveolar Lavage Cellular Analysis
Complications of Bronchoscopy (Respirology, 2012) [MEDLINE]
Complication Rate by Pulmonary Lesion
General Comments
Overall Complication Rate: 0.51%-2.06% (with highest rates being reported for diffuse pulmonary lesions)
Complication Rate by Procedure: 0.17%-1.93% (with highest rates being reported for forceps biopsy)
Bronchoscope/Device Breakage: reported in 47.2% of centers
Patient Biting of Bronchoscope
Needle Perforation of Forceps Channel
Heat Damage to Bronchscope (During Laser, etc)
Malfunction of Biospy Forceps
Curette Breakage
Airway Perforation
Reported Frequency (with central airway lesions): 0%
Reported Frequency (with hilar/mediastinal lesions): 0%
Reported Frequency (with solitary pulmonary lesions): 0%
Reported Frequency (with diffuse pulmonary lesions): 0%
Reported Frequency (with simple bronchoscopy): 0.05%
Reported Frequency (with forceps biopsy): 0.67%
Reported Frequency (with brush biopsy): 0.03%
Reported Frequency (with bronchoalveolar lavage): 0.008%
Reported Frequency (with transbronchial needle aspiration): 0.07%
Reported Frequency (with EBUS-TBNA of hilar/mediastinal lesions): 1.52%
References
The BAL Cooperative Group Steering Committee. Bronchoalveolar lavage constituents in healthy individuals, idiopathic pulmonary fibrosis, and selected comparison groups. Am Rev Respir Dis. 1990;141(5 pt 2):S169-S202
Deaths and complications associated with respiratory endoscopy: a survey by the Japan Society for Respiratory Endoscopy in 2010. Respirology. 2012 Apr;17(3):478-85. doi: 10.1111/j.1440-1843.2011.02123.x [MEDLINE]
An Official American Thoracic Society Clinical Practice Guideline: The Clinical Utility of Bronchoalveolar Lavage Cellular Analysis in Interstitial Lung Disease. Am J Respir Crit Care Med. 2012 May 1;185(9):1004-14. doi: 10.1164/rccm.201202-0320ST [MEDLINE]
