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A disease of the lower airways causing cough and exercise intolerance in horses

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A saline wash of the airways (Broncho) and air sacs (alveolar) for recovery of inflammatory cells.


Indicated for recovery of cells for cytologic analysis of inflammatory processes such as

  • SAID
  • Interstitial lung diseases
  • Fungal pneumonias
  • Bleeding
  • Unexplained chronic cough

Not indicated for

  • Acute pneumonia or pleuropneumonia.
  • Acute viral infections.
  • Bronchitis caused by bacterial infection.

Contraindicated in patients with

  • Severe coughing not alleviated by prior administration of bronchodilator (e.g. 450 g (5 puffs) of albuterol)
  • Dyspnea (labored breathing) or cyanosis
  • Cardiac arrhythmias
  • Tachycardia (Heart rate > 60 beats per minute)
  • Bleeding tendencies

Equipment for BAL

  1. Two 60cc syringes filled with dilute lidocaine (0.3%) without epinephrine.
  2. Bronchoalveolar lavage tube (3 meters length, 11 mm outside diameter, Bivona, Top) or endoscope (> 2.5 meters length, 11-14 mm O.D, Bottom)
    BAL tube with insets showing open end and inflation port (left) and inflatable cuff (right)
  3. Bottle (500 cc) of sterile physiological saline solution, warmed to body temperature.
  4. Vented solution administration set (from saline bottle to stopcock).
  5. Inflation bulb and short length tubing, to pressurize the saline bottle.
  6. Sterile lubricant.
  7. 10ml syringe to inflate cuff on BAL tube.
  8. Vacuum pump with collection bottle or large volume syringes (>60cc) to aspirate BAL fluid.

BAL Procedure

  1. Connect equipment as shown in diagram.
  2. Diagram of BAL setup
  3. Place a small amount of sterile lubricant on the last 5-10 cm of BAL tube.
  4. Pass BAL tube or endoscope through ventral meatus into nasopharynx.
  5. Placement of BAL tube through nasal passage
  6. Inject 30cc of dilute lidocaine onto the vocal folds / epiglottis region.
  7. Advance BAL tube into the trachea, then quickly, but gently, to the point where slight
  8. resistance and bending of the tube is felt (about 2-2.5 meters passed).
  9. Inflate cuff of BAL tube with air (10 ml).
  10. Infuse 250 ml of saline into BAL tube as rapidly as you can.
  11. Aspirate gently and slowly using a vacuum pump (-10 cm H2O pressure) or a series of large volume syringes.
  12. Repeat infusion of 250 ml of saline, and aspirate again.
  13. Expect 60 – 100 ml return from the first 250 ml aliquot, and 120-200 ml from the second.

Handling BAL Specimens

Bronchoalveolar lavage fluid
  1. Pour BAL fluid into a couple of large EDTA tubes.
  2. Centrifuge the sample at 600 x g (fastest tabletop centrifuge speed) for 5 min.
  3. Pour off supernatant thoroughly, leaving small pellet stuck to bottom.
  4. Mix pellet with saline that remains (i.e. about 1/10 ml).
  5. Prepare thin smears using the blood smear technique.
  6. DRY IMMEDIATELY – wave your hands, use fan, etc…
  7. Stain with Diff-Quik, Wright–Giemsa, May-Gruenwald, or similar stains.
  8. Check the quality of the smear before discarding BAL fluid or sending to lab.
  9. There should be a layer of cells, about as thick as a typical blood smear.
  10. To transport BAL samples from the field, pour samples into EDTA tubes or dilute 50:50 with grain alcohol or Vodka (100 Proof) and transport in clot tubes. Don't drink and drive!

Keep fluid samples cool or refrigerate until ready for staining.




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