Comparison of Procedural Yield of Bronchoalveolar Lavage Using Three Different Techniques in Subjects Undergoing Flexible Bronchoscopy
Condition: Bronchoalveolar Lavaage; Diffuse Lung Disease
MeSH terms: Lung Diseases
Study type: Interventional

Summary: 
      Bronchoalveolar lavage (BAL) via flexible bronchoscopy is a method used to sample the
      cellular and microbiological components of the alveolar space. It is a procedure in which 2-3
      measured aliquots of sterile normal saline are instilled after wedging the scope to the
      suitable segmental bronchus. BAL is performed from the segments/ lobes showing ground-glass
      opacities (GGO), tree-in-bud lesions or focal consolidations guided by HRCT. In diffuse lung
      involvement, BAL is performed either from RML or the lingula.[3] It is recovered through the
      bronchoscope via different suction methods so as to get a sample of epithelial lining fluid
      of small airways and alveoli. Either manual suction or wall suction can be used for
      aspiration of fluid during BAL. The fluid recovered is then sent for cytology and
      microbiology examination studies including AFB, MGIT, GeneXpert, Galactomannan, fungal
      cultures to diagnose various conditions like PAP, eosinophilic pneumonia, bacterial or fungal
      infections, specific forms of ILD.

      Three techniques have been described to perform BAL. To the best of our knowledge no previous
      study has compared the three methods of obtaining the BAL in the same cohort of subjects.The
      authors believe that the procedural yield of BAL will be best by manual suction using rubber
      tubing compared to manual suction without rubber tubing or wall suction. Herein, the
      investigators compare the three methods of obtaining BAL in subjects undergoing BAL for
      various respiratory diseases
    

Detailed description: 
      Bronchoalveolar lavage (BAL) via flexible bronchoscopy is a method used to sample the
      cellular and microbiological components of the alveolar space. It is a procedure in which 2-3
      measured aliquots of sterile normal saline are instilled after wedging the scope to the
      suitable segmental bronchus. BAL is performed from the segments/ lobes showing ground-glass
      opacities (GGO), tree-in-bud lesions or focal consolidations guided by HRCT. In diffuse lung
      involvement, BAL is performed either from RML or the lingula.[3] It is recovered through the
      bronchoscope via different suction methods so as to get a sample of epithelial lining fluid
      of small airways and alveoli. Either manual suction or wall suction can be used for
      aspiration of fluid during BAL. The fluid recovered is then sent for cytology and
      microbiology examination studies including AFB, MGIT, GeneXpert, Galactomannan, fungal
      cultures to diagnose various conditions like PAP, eosinophilic pneumonia, bacterial or fungal
      infections, specific forms of ILD Normal BAL cellular components are specified as: Alveolar
      macrophages (AM) 85%, Lymphocytes 5-15%, Neutrophils <= 3%, eosinophils <1%. The presence of
      squamous epithelial cells indicates contamination by oropharyngeal secretions. [4]
      Additionally, BAL can be a tool for pulmonary toilet in rare diseases such as pulmonary
      alveolar proteinosis by helping to remove the abnormal surfactant material that accumulates
      with this disease.

      Manual suction: It can be done using the same syringe used for instillation of the normal
      saline. At least 100 ml normal saline should be instilled while performing BAL and should not
      exceed 200 ml.

      According to the studies, Modification of the manual suctioning technique (by connecting
      small tubing attached to syringe) provides higher percentage of BAL fluid [5].

      Wall suction: During suctioning the instilled fluid, negative pressure is applied using
      continuous wall suction. The pressure should be <100mmHg or should be adjusted to prevent
      airway collapse.[6] In a study conducted by Aruna D. Herath[7], 73 pediatric patients were
      enrolled for a RCT undergoing flexible bronchoscopy and BAL. Two different suctioning
      techniques were compared for % of BAL fluid recovery. Sterile normal saline according to
      1ml/kg was instilled and 100-150mmHg of negative pressure was applied for wall suction
      method. Thus it concluded that wall suction had better BAL fluid recovery than handheld
      syringe suction. Diagnostic yield was the same for both techniques.

      Luis M. Seijo[8], conducted a prospective randomized study of total 220 patients undergoing
      BAL. Study comparing manual and wall suction in performance of BAL resulted that manual
      aspiration is superior to wall suction yielding larger quantity of BAL. Additionally, extra
      tubing with 50 ml syringe was added in manual suction technique and 50mmHg negative pressure
      was used in wall suction method.

      A prospective clinical study of 66 patients by Naghmeh Radhakrishna[9], comparing techniques
      for optimal BAL performance used 100ml NS (with 4 aliquots) resulted in no significant
      difference between both techniques.

      Another study to compare two aspiration techniques of BAL in children was conducted by
      Christian Rosas-Salazar[10] on approximately 540 procedures. Their results suggested that
      handheld syringe suction provide higher % of fluid return when compared to continuous wall
      suction.

      K.S Woods[11], did a randomized, blinded prospective clinical trial on 18 dogs comparing
      manual and suction pump aspiration techniques for BAL. 35 ml syringe was used to instill
      2ml/kg volumes per site for manual aspiration. Negative pressure of maximum 50mmHg was
      applied for SPA. Thus, concluded the study showing higher % of BALF return by SPA than manual
      suction with or without tubing. There was no significant difference in diagnostic yield.

      One more multicenter randomized study by Antoni Rosell[12] was conducted to recover BAL fluid
      comparing only syringe and syringe with attached plastic tube (40cm), for more fluid return.
      Thus, it resulted in 8% more fluid recovery, more yield and less complications with syringe
      with tubing suction technique.

      To the best of author's knowledge no previous study has compared the three methods of
      obtaining the BAL in the same cohort of subjects. The investigators believe that the
      procedural yield of BAL will be best by manual suction using rubber tubing compared to manual
      suction without rubber tubing or wall suction. Herein, the investigators compare the three
      methods of obtaining BAL in subjects undergoing BAL for various respiratory diseases.

      Study question: Is the procedural yield of BAL different between manual suction using rubber
      tubing compared to manual suction without rubber tubing or wall suction?
    

Intervention name(s): Bronchoalveolar lavage using wall mount suction; Bronchoalveolar lavage using manual suction; Bronchoalveolar lavage using manual suction with rubber tubing
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): BAL will be performed using wall mount suction with a pressure <100 mmHg; A 50-mL syringe will be used to apply suction through the working channel of a bronchoscope; A 50-mL syringe with an attached rubber tubing will be used to apply suction through the working channel of a bronchoscope
Intervention MeSH terms: Dimercaprol
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Three arm parallel group study
Masking: Single (Investigator)
Primary purpose: Diagnostic