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Bronchoscopy 1075

each lobar and as many segmental and/or ○ Mycoplasma and anaerobic cultures are ability to direct sampling into specific sites;
subsegmental bronchi as possible (as the processed using Amies transport media, provide no information regarding anatomic,
VetBooks.ir • Airway bifurcations beyond the carina are ○ Cytologic analysis: total white blood • A technique of passing a 5-8 Fr sterile red
structural, or functional airway abnormalities;
animal and endoscope size can allow).
or submit fluid in a sterile tube.
and offer no therapeutic capability.
cell (WBC) and differential cell counts
referred to simply as spurs. Like the carina,
they should also form a sharp V, but they
and wedging in a distal bronchus is called a
become widened and appear U-shaped with should be done. The predominant cell rubber feeding tube into the lower trachea
in all species should be the alveolar
chronic airway inflammation and/or mucosal macrophage (>70%), with usually < 3%- blind BAL. The site sampled is unknown, and
edema. 8% of all other cell types (except cats, no visual assessment of the airways is made.
• Small polypoid mucosal nodules are com- which may have ≥ 15% eosinophils and The distal tip (side holes) of the catheter
monly encountered in the bronchi of dogs still be normal). should be cut off, and the catheter is then
with chronic bronchitis. • Handling the scope passed until gently wedged in a distal airway.
• Small amounts of white or slightly opaque ○ Immediately rinse/wipe the scope down The BAL is performed as described above.
mucus may be noted in a healthy animal, when finished to prevent secretions from • Fine-needle lung aspiration biopsy has been
but larger accumulations or secretions of drying. used successfully to sample consolidated lung
unusual color are abnormal. ○ Clean and sterilize the scope as outlined lobes and larger masses that are in contact Procedures and Techniques
• The normal monopodial branching system in the manufacturer’s manual. with the chest wall.
results in a gentle, smooth tapering of the ○ Store the scope hanging up (to fully dry
airways. Changes may be focal or general- it) in a protected space/closet. Pearls
ized and include those of shape and size of • In patients with pronounced expiratory
the airway lumen, such as an intraluminal Alternatives and Their effort, it is difficult to obtain a good return
stricture/tumor, external compression (tumor Relative Merits from a BAL. These patients are more likely
or lymphadenopathy), bronchiectasis, or • Tracheal wash procedures are less expensive to experience hypoxemia during recovery.
dynamic collapse (malacia). and easier to perform, but they lack the Use very slow, gentle hand suction technique
• Whether or not abnormalities are noted,
samples should be obtained for culture
and cytologic examination. After the
initial airway evaluation, the endoscope is
removed from the animal and cleaned by
alternatively suctioning the channel with Accessory
sterile saline and air immediately before lobe
reinsertion.
• The BAL site (lobe and bronchus) is chosen
based on radiographic and gross broncho-
scopic findings. If no site is clearly abnormal, RB3D1
BALs from both middle lung lobes should
be collected. RB3D2
• To perform a BAL, the bronchoscope is first RB4V2 LB2V2
gently wedged into a segmental or smaller Right RB4D2 RB3V2 Left
bronchus. Aliquots of 10-20 mL of sterile caudal RB4V1 LB2D2 caudal
lobe
saline (depending on the size of the animal) LB2V1 lobe
are instilled into the airway (by the suction RB4D1 RB3V1 LB2d1
channel or a washing pipette) and then Right RB2C1 RB4 RB3
immediately aspirated using slow, gentle middle RB2R1 LB1V1b
lobe
hand suction.
• Ideally, at least two different sites (lung lobes) RB2 LB2 LB1V1
should be lavaged. LB1V1a Left
• A 40%-90% return of the volume instilled is RPB LPB LB1 cranial
expected. Difficulty in fluid recovery results RB1D1 lobe
when a proportionately large endoscope is Right RB1V1 RB1 LB1D1
used (prevents wedging into a small bron- cranial LB1V2
chus) or if malacic airways collapse when lobe RB1V2 LB1D2
suction is applied. RB1D2
• Collected fluid is often turbid and should
have foam indicating surfactant in the
sample.
• If there is enough time and anesthetic depth
is appropriate, the nasopharynx also should
be examined.
Postprocedure
• Provide supplemental oxygen (p. 1146) until
fully recovered.
• Crackles are commonly noted on auscultation
for a short time after a BAL procedure. Trachea
• Process samples immediately. BRONCHOSCOPY Diagrammatic representation of the normal canine tracheobronchial tree. (Reprinted with
○ Quantitated aerobic cultures should be permission from Amis T, et al: Systematic identification of endobronchial anatomy during bronchoscopy in the
made if possible. dog. Am J Vet Res 47:2649-2657, 1986.)

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