Page 336 - Small Animal Internal Medicine, 6th Edition

308 PART II Respiratory System Disorders

the tube to a length slightly greater than the distance from then is passed again, until resistance is consistently felt at the
the open end of the dog’s endotracheal tube to the last rib. A same depth. Rotating the tube slightly during passage may
VetBooks.ir syringe adapter is placed within the proximal end of the tube help achieve a snug fit. Remember that if the endotracheal
tube is not much larger than the stomach tube, ventilation is
(Fig. 20.23).
Recovery of BAL fluid can be improved by tapering the
pleted expediently.
distal end of the tube. Tapering is readily achieved using a restricted at this point and the procedure should be com­
metal, single­blade, handheld pencil sharpener that has been For medium­size dogs and larger, two 35­mL syringes are
autoclaved and is used only for this purpose (see Fig. 20.23, prepared in advance, each with 25 mL of saline and 5 mL of
A and B). air. While the modified stomach tube is held in place, a
The dog may be premedicated with atropine (0.05 mg/kg 25­mL bolus of saline is infused through the tube, followed
subcutaneously) or glycopyrrolate (0.005 mg/kg subcutane­ by the 5 mL of air, by holding the syringe upright during
ously) to minimize oral secretions and is anesthetized using infusion (Fig. 20.24). Gentle suction is applied immediately
a short­acting protocol that will allow intubation, such as after infusion, using the same syringe. It may be necessary
with propofol, a short­acting barbiturate, or the combination to withdraw the tube slightly if negative pressure is felt. The
of medetomidine and butorphanol. If the dog is of sufficient tube should not be withdrawn more than a few millimeters.
size to accept a size 6 or larger endotracheal tube, the dog is If it is withdrawn too far, air will be recovered instead of
intubated with a sterile endotracheal tube placed as cleanly fluid. The second bolus of saline is infused and recovered in
as possible to minimize oral contamination of the specimen. the same manner, with the tube in the same position. The
The modified stomach tube will not fit through a smaller dog is cared for as described in the next section.
endotracheal tube, so the technique must be performed In very small dogs, it is prudent to reduce the volume of
without an endotracheal tube, or a smaller stomach tube saline used in each bolus, particularly if a smaller­diameter
must be used. If no endotracheal tube is used, extreme care stomach tube is used. Overinflation of the lungs with exces­
must be taken to minimize oral contamination in passing the sive fluid volumes should be avoided.
modified stomach tube, and an appropriately sized endotra­
cheal tube should be available to gain control of the airway RECOVERY OF PATIENTS AFTER BAL
in case of complications and for recovery. Regardless of the method used, BAL causes a transient
Oxygen (100%) is provided through the endotracheal decrease in the arterial oxygen concentration. In most
tube or by face mask for several minutes. The modified patients this hypoxemia responds to oxygen supplementa­
stomach tube is passed through the endotracheal tube using tion. Patients are monitored with pulse oximetry (discussed
sterile technique until resistance is felt. The goal is to wedge later in this chapter) before and throughout the procedure
the tube snugly into an airway rather than have it abut an and during recovery. Immediately after the procedure, 100%
airway division. Therefore the tube is withdrawn slightly, oxygen is provided through an endotracheal tube for as long
as the dog or cat will allow intubation. Several gentle “sighs”
are performed with the anesthesia bag to help expand any
collapsed portions of lung. Bronchospasms are a reported

FIG 20.23
The catheter used for nonbronchoscopic bronchoalveolar FIG 20.24
lavage in dogs is a modified 16F Levin-type stomach tube. Bronchoalveolar lavage using a modified stomach tube in a
The tube is shortened by cutting off both ends. A simple dog. The tube is passed through a sterile endotracheal tube
pencil sharpener (inset A) is used to taper the distal end of and is lodged in a bronchus. A syringe preloaded with
the tube (inset B). A syringe adapter is added to the saline and air is held upright during infusion so that saline
proximal end. Sterility is maintained throughout. is infused first, followed by air.