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Bronchoalveolar Lavage, Blind 1073

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Possible Complications and
Difficulty level: ♦♦
Common Errors to Avoid ○ Slowly withdraw the catheter further
while continuing to pull back the syringe
Synonym • Hypoxia is expected but typically resolves plunger until no more fluid is retrieved.
Blind bronchoalveolar lavage (BAL) quickly. Time of insertion to completion should
• More serious complications can include take no more than 30-60 seconds.
Overview and Goal bronchospasm or pneumothorax (p. 797). ○ The volume of saline retrieved ranges from
Simple technique, requiring no special equip- Risk is minimized by pre-treating cats with 30%-80% of the volume instilled; a good
ment, to obtain bronchoalveolar lavage fluid terbutaline and by using a soft (i.e., red sample is > 50% recovered.
(BALF) for cytology and culture in animals rubber) catheter. • Remove the catheter from the ET, and access
with respiratory disease • The distal end of the catheter must be wedged sample quality grossly.
into a small airway to retrieve instilled saline. ○ A good sample should contain surfactant, Procedures and Techniques
Indications Inadequate wedging at the time of catheter which appears as foam that rises to the
• Cats and small dogs suspected of having placement or due to movement of the top of the fluid.
infectious or inflammatory respiratory dis- catheter after saline infusion may result in ○ If a good-quality sample is not achieved,
eases based on clinical signs and radiographic poor fluid return. the procedure can be repeated once,
findings • Excessive suction applied to the syringe may assuming the animal is oxygenating well
• Most useful for diffuse lower airway or collapse the small airway and impede fluid (pulse oximetry is useful) and appears
alveolar disease or when disease causes a return. stable.
productive cough ○ Flip the patient to the opposite side, and
Procedure administer oxygen for several minutes
Contraindications • Apply topical lidocaine on the aryte- before repeating procedure.
• Contraindication: coagulopathy. Respiratory noids to minimize laryngospasm; cats • When an adequate sample has been collected,
distress is a relative contraindication. especially the patient’s hindquarters can be elevated so
• Not recommended for larger dogs (≥12 kg; • Intubate the patient while taking care to that an assistant can perform coupage to aid
difficult to obtain sample) avoid contact with the oral cavity to prevent in drainage of fluid remaining the airways.
• For animals with disease localized to a contamination. • Oxygen supplementation can be administered
specific lung lobe, collection of BALF by • Provide supplemental oxygen for several by ET until extubation
bronchoscopy is preferred (p. 1074). minutes before saline installation.
• Place the animal in lateral recumbency (either Postprocedure
Equipment, Anesthesia side) with the neck outstretched. • Oxygen supplementation (p. 1146) must
• Laryngoscope • Attach a syringe prefilled with warm saline be provided after the procedure during
• Lidocaine or other topical anesthetic for to the red rubber, always keeping the distal anesthetic recovery.
laryngeal application (cats) end sterile. • Patients should be monitored closely for
• Sterile endotracheal tube (ET) ○ 10-25 mL aliquots are typical, depending evidence of respiratory distress or cyanosis for
• 8-12 Fr red rubber catheter on size (most cats require 15-20 mL). 10 minutes after the procedure. Measurement
• Warm 0.9% sterile saline ○ Hold the red rubber catheter with the of SpO 2 can be useful.
• 20-mL syringes open distal end up, and flush a small ○ Cyanosis or distress associated with
• Two sterile collection tubes without additives amount (≈0.5 mL) of saline through the reduced lung sounds suggests pneumotho-
• Anesthesia: short-acting anesthesia (e.g., red rubber to wet the end. rax (consider thoracocentesis [p. 1164]).
propofol) is sufficient. • Insert the red rubber into the ET while ○ Cyanosis or distress with wheeze suggests
• Oxygen source avoiding contact with the outer portion of bronchospasm (consider albuterol inhaler
• Ideally, pulse oximeter monitor the ET (see Video). or terbutaline injection).
• Bronchodilator (e.g., terbutaline for injec- • Advance the red rubber until resistance is • Auscultation of pulmonary crackles after the
tion, albuterol metered-dose inhaler); cats encountered, indicating that it is wedged in procedure is expected.
especially place. • The BALF aliquots are submitted for cyto-
• Emergency supplies in case resuscitation, ○ When resistance is first encountered, logic evaluation and culture/susceptibility
ventilation, or thoracocentesis are required. give the catheter a small twist followed tests; other special tests (e.g., fungal antigen
by gentle pressure; sometimes it catches tests, viral polymerase chain reaction [PCR])
Anticipated Time on an airway bifurcation without wedging, may be warranted in some cases.
Depending on experience, 10 minutes or less and this helps avoid that error. • BALF samples should be analyzed promptly
• Once wedged, quickly infuse the entire to avoid cell distortion. If the samples are sent
Preparation: Important volume of saline. to an outside laboratory, prepare an unstained
Checkpoints • Without changing the syringe or moving the slide by cytocentrifugation to submit along
• Ensure that all supplies are available, includ- catheter, draw back on the syringe plunger with the fluid sample.
ing emergency needs. in a gentle pulsatile fashion.
• While maintaining sterility, cut the distal tip ○ If the catheter is wedged, there may be Alternatives and Their
of the catheter using sharp sterile scissors or negative pressure. Continue to draw back Relative Merits
a blade to create an open end. in a pulsatile fashion while very slowly • Transtracheal wash: less invasive, does not
• Trim the other end of the red rubber catheter withdrawing the red rubber. require anesthesia
to ensure a tight fit with a 20-mL syringe. ○ After saline is flowing into the syringe, • Bronchoscopic-assisted BAL: allows visualiza-
• Pretreat cats with bronchodilator to minimize hold the catheter in the same spot, and tion of the airways and direct sampling of
bronchospasm (e.g., terbutaline 0.02-0.04 continue aspirating until the flow is specific lung lobes; preferred to blind BAL
mg/kg SQ 15-20 minutes before procedure). reduced or stops. for medium to large dogs (p. 1074)

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