Name
Bronchoscopy
Short Description
Bronchoscopy
Affected Animals:
Animals with respiratory tract diseases
that cannot be diagnosed with x-rays or ultrasound, or
those that do not respond to symptomatic treatment for
their problems, are potential candidates for bronchoscopy.
Overview:
Bronchoscopy is a diagnostic procedure
for patients with respiratory tract disease. It can be
used to identify structural abnormalities, abnormal airway
secretions, foreign bodies, and mass lesions including
certain tumors. Additional procedures combined with bronchoscopy
can allow for identification of inflammation or infection
in the respiratory tract. Specialized equipment and expertise
is required for performing bronchoscopy and for monitoring
the patients during the procedure.
Bronchoscopy does not always identify the cause of an
individual animal's problem, but at least it can rule out
many potential explanations for it.
Description:Very heavy sedation or general anesthesia
is necessary for bronchoscopy in small animal patients. Injectable
anesthetic drugs are used so that it is not necessary to
use an endotracheal tube for the inhalation of gas anesthesia
during the procedure. Without such a tube, there is more
room for the bronchoscope to be inserted into the trachea
and the bronchi. Oxygen can be delivered during the procedure
through a small catheter inserted down into the trachea or
through the bronchoscope itself. In larger patients, gas
anesthesia may be used, as the bronchoscope can pass through
larger endotracheal tubes while still allowing for the delivery
of oxygen and gas anesthetic agents to the patient. Patients
are monitored with an electrocardiogram and with pulse oximetry
during the procedure.
Once the patient is anesthetized, the bronchoscope
is passed into the trachea from the oral cavity. In
most cases, bronchoscopy is done with flexible fiberoptic
endoscopes. Many times, these are attached to a small
camera that can record findings during the procedure.
Rigid bronchoscopes are also available, but they are
not commonly used in small animal patients.
Bronchoscopy is used to visually inspect the airway
for any evidence of collapse, compression, or dilation.
Mass lesions can be seen if present within the lining
of the trachea or bronchi. Abnormal discharges such
as excessive mucus, blood, or pus may also be seen.
If a foreign object has been inhaled, it may be seen
if the scope can reach the point where it is lodged.
The procedure is useful not only for visualization
of abnormalities, but also for obtaining samples. With
bronchoscopy, biopsies can be taken if lesions requiring
biopsy are seen, and samples of abnormal discharges
can be collected and submitted for microscopic analysis
and culture. Flushing sterile saline through the endoscope
often facilitates sample collection. Special brushes
may be passed through the endoscope for collecting
samples as well. If airway foreign bodies are seen,
special grasping forceps may allow for their removal
without surgical intervention.
Prognosis:
The prognosis depends primarily on
the diagnosis and on the presence of other factors affecting
the patient. Since complications due to the procedure
are rare, the prognosis for an animal undergoing bronchoscopy
is usually good with respect to the procedure itself.
Potential problems that can arise during the procedure
include anesthesia-related complications, including death.
Heart arrhythmia and bleeding may occur. Oxygen levels
may drop temporarily but can usually be corrected quickly
by supplying additional oxygen. Fever, infection, and abnormalities
in the lungs that can be seen on chest x-rays can develop,
but these complications occur infrequently.
PreprocedureCare:
Prior to bronchoscopy, animals need
to be prohibited from eating because the procedure is
performed under anesthesia. In emergency situations this
may not be possible, particularly when bronchoscopy is
needed to attempt removal of an airway foreign body.
Since it is not usually a first-line diagnostic tool,
prior evaluation almost always includes chest x-rays.
PostprocedureCare:
Following bronchoscopy, animals are
usually given oxygen to breathe until they are awake.
Because the procedure is usually short in duration, and
since the injectable or gas anesthetic agents also tend
to be short acting, most patients that are stable at
the time the procedure is performed can be released the
same day. For those that are seriously ill, hospitalization
is usually required for ongoing treatment of their illness,
not because of the procedure itself.
Prevention:
Many complications can be avoided
by careful patient selection. Critically ill patients
with serious heart disease or metabolic conditions that
need to be stabilized first are not good candidates for
anesthesia; bronchoscopy is therefore not recommended
for them. Animals in severe respiratory distress are
not good candidates; however bronchoscopy may be indicated
in these patients when an airway foreign body or some
other type of structural airway disease is suspected
that absolutely requires bronchoscopy for an accurate
diagnosis or prompt therapeutic intervention. Patients
with severe bleeding disorders, or with very low oxygen
levels in their blood that do not respond to oxygen supplementation,
should not undergo bronchoscopy.
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