Specific indications for bronchoscopy include chronic coughing, hemoptysis, unexplained pulmonary infiltrates, and suspicion
of an airway mass or foreign body. Bronchoscopy allows visualization of dynamic airway changes such as tracheal or bronchial
collapse6 and foreign body retrieval. Also, lower airway samples for cytologic examination and culture can be obtained by brush cytology
or by performing a bronchoalveolar lavage. Samples collected by bronchoscopy for cytologic examination and culture consistently
have a greater diagnostic sensitivity than those obtained with a transtracheal wash.7,8
Since bronchoscopy requires general anesthesia, patients with respiratory distress often cannot safely undergo the procedure.
Patients with advanced cardiopulmonary disease or marked metabolic derangements are also at higher risk during any procedure
that involves general anesthesia.
Bronchoscopy is best performed by using a flexible fiberoptic endoscope or videoendoscope. Most bronchoscopy procedures in
dogs and cats can be performed with a 5-mm-diameter, 55-mm-long endoscope; however, small patients may require a 3.7-mm-diameter
endoscope. A three-dimensional map of the endobronchial anatomy of the veterinary patient is especially helpful in navigating
the bronchoscope.9,10 Bronchoscopy can be performed with inhalation anesthesia if the endotracheal tube lumen is large enough to allow passage
of the bronchoscope without occluding gas flow through the endotracheal tube. For smaller endotracheal tubes, injectable anesthesia
or repeated temporary intubation must be used. The biopsy channel of the bronchoscope can be used to deliver oxygen during
the procedure, pass biopsy forceps or cytology brushes, and perform bronchoalveolar lavage.6 Culture samples can be obtained from the bronchoalveolar lavage fluid or by using a guarded culturette, which can be passed
through the biopsy channel (Figure 10).9
Figure 10. A guarded culturette (Boston Scientific Microvasive microbiology specimen brush) with a carbon wax plug (arrow)
that expels just before sampling to help reduce the risk of contamination.
"Endoscopy Brief" was contributed by William R. Lee, DVM; John W. Tyler, DVM, DACVIM; and H. Dan Cantwell, DVM, MS, DACVR,
Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762.
Dr. Lee's current address is College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27695-8401.
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malignant lymphoma. J Am Vet Med Assoc 1993;203:1418-1425.
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10. Amis TC, McKiernan BC. Systematic identification of endobronchial anatomy during bronchoscopy in the dog. Am J Vet Res 1986;47:2649-2657.