Page 412 - Small Animal Internal Medicine, 6th Edition

384 PART II Respiratory System Disorders

lidocaine is dripped gently into the nasal cavity through the
naris with the animal’s nose pointed upward. The catheter is
VetBooks.ir then passed through the naris and is initially aimed dorso-
medially through the naris, then immediately ventromedi-
ally. Once the correct length of catheter has been inserted, it
is gently bent beneath the lateral cartilage and sutured to the
muzzle no farther than 1 cm caudal to the exit from the
naris. The catheter can be further anchored to the face with
sutures securing its path between the eyes to behind the
animal’s head. An Elizabethan collar is placed on the patient
to prevent the animal from removing the catheter.
A sterile intravenous set can be connected to the catheter.
The intravenous line can be attached to a half-filled bottle of
sterile saline solution and positioned above the fluid level.
Oxygen is then delivered through the bottle, below the fluid
level, providing some moisture as the oxygen bubbles
through the saline.

Transtracheal Catheters
Oxygen can be administered through a jugular catheter
placed with sterile technique through the trachea. This
FIG 25.2
An oxygen hood can be used for recumbent animals as a approach is particularly useful for the emergency stabiliza-
substitute for an oxygen mask. In this patient, oxygen is tion of animals with an upper airway obstruction. The cath-
being delivered through an opening in the top of the hood, eter is placed as for transtracheal washing (see Chapter 20).
and the light blue opening that will accommodate standard
anesthesia tubing is left open for circulation of air. Endotracheal Tubes
Regardless of the method used to increase the oxygen in Endotracheal tubes are used to administer oxygen during
inspired air, a means for escape of expired CO 2 is essential surgical procedures and cardiopulmonary resuscitation.
(Disposa-Hood, Utah Medical Products, Inc.).
They can be used to bypass most upper airway obstructions
for emergency stabilization. Pure oxygen can be adminis-
tered for short periods. Longer supplementation requires the
mixing of 100% oxygen with room air. Ventilation can be
provided with a cuffed endotracheal tube. Trauma to the
trachea is decreased by using high-volume, low-pressure
cuffs and by inflating the cuff with the least amount of pres-
sure necessary to create a seal. If positive-pressure ventila-
tion is not being used, the cuff can remain deflated.
Because endotracheal tubes are not tolerated by alert
animals, tracheal tubes are preferred for long-term manage-
ment. Conscious animals in which endotracheal tubes are
used must be given sedatives, analgesics, paralyzing agents,
or a combination of these drugs. The cuff should be deflated
when possible to minimize tracheal damage. The tube must
be cleaned periodically to remove secretions (see the recom-
mendations for tracheal tube cleaning), and frequent flush-
ing of the oral cavity is performed. Moisture must be added
to the inspired gases, as previously discussed.

Tracheal Tubes
Tracheal tubes are placed through the tracheal rings and are
readily tolerated by conscious animals. It is rare that an
FIG 25.3 animal requires an emergency tracheostomy. Nearly all such
Dog with intranasal catheter in place for delivery of oxygen. animals can be stabilized by other techniques, allowing the
The catheter is sutured to the muzzle less than 1 cm from its
exit from the naris and is further anchored with sutures to tracheal tube to be subsequently placed using a careful,
the face so that it exits behind the animal’s head. An sterile surgical technique. Tracheal tubes are generally used
Elizabethan collar is routinely used to prevent the animal for the management of animals with an upper airway
from removing the catheter. obstruction. Room air often contains adequate oxygen for