Page 32 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 2 · Emergency management of respiratory distress

In very dyspnoeic animals, bilateral nasal oxygen lines Oxygen cages and incubators
can be used. Some animals can be best managed using Oxygen cages are now widely available to the veterinary
VetBooks.ir less into the nasal cavity (Figure 2.5). Inspired oxygen con- market. As well as providing a higher concentration of
human bilateral nasal ‘prongs’ that penetrate only 1 cm or
inspired oxygen, a good oxygen cage should also allow
centrations of 30–50% can easily be achieved using this
control of internal cage temperature and humidity. An
type of system. If the nasal catheter is guided further into
the nasopharynx under sedation, oxygen concentrations oxygen cage should be capable of reaching oxygen
of up to 80% may be achieved in some animals. concentrations >80% for use with severely dyspnoeic
A nasal catheter is easy to place and is well tolerated animals. Poor-quality oxygen cages will reach concentra-
by most patients. It also allows patient mobility and tions of only about 50–60%.
permits examination of the animal without discontinuing Oxygen cages and incubators can be invaluable for
therapy. Some animals, however, will not tolerate the severely dyspnoeic cats, where the ability to administer a
nasal line, and inspired oxygen concentrations may not high oxygen concentration non-invasively is essential
be high enough for very dyspnoeic animals, particularly if (Figure 2.6). Oxygen cages can be expensive to purchase
they are mouth breathing. It is also not a useful technique and potentially wasteful of oxygen, since each time the
in brachy cephalic animals or patients with facial disease door is opened the oxygen inside is lost. This is less of an
or pain. issue with incubators, many of which have access ports.

An oxygen cage in use.
2.6
(Reproduced from the BSAVA Manual of Canine and Feline Emergency and
Critical Care, 2nd edn)
Nasal oxygen prongs for oxygen supplementation.
2.5
(Reproduced from the BSAVA Manual of Canine and Feline Emergency and Intubation and ventilation
Critical Care, 3rd edn)
Orotracheal intubation and ventilatory support may be
required if respiratory failure is already present or is
Transtracheal oxygen pre dicted on the basis of the condition of the patient.
Anaes thesia, intubation and positive pressure ventilation
For administration of transtracheal oxygen, a catheter may be required to allow vital diagnostic tests, such as
is placed transcutaneously into the trachea, and oxygen is radiography, to be performed, especially in animals that
insufflated directly into the airway. For placement of a are in extreme distress and not responding to non-
tracheal catheter, a small patch of skin on the ventral mid- specific therapy. Dys pnoeic patients should only be
line of the neck is clipped and scrubbed. Lidocaine is used anaesthetized and ven tilated as a last resort, to support
to provide local anaesthesia. A through-the-needle cath- respiratory function whilst diagnostic tests are performed
eter is placed into the airway using the same method as and definitive therapy is pursued.
may be used for a transtracheal wash. The catheter is
secured in place with glue, sutures or tape, and humidified
oxygen is administered via a delivery system at rates of References and further reading
50–100 ml/kg/min. Higher oxygen concentrations can be
achieved in the airway using this technique because there Lisciandro GR (2014) The Thoracic FAST3 (TFAST3) exam. In: Focused
is less mixing with inhaled room air. Ultrasound Techniques for the Small Animal Clinician, ed. GR Lisciandro, pp.
140–165. Wiley-Blackwell, Indianapolis
Transtracheal oxygen administration is a useful tech-
Villiers E and Ristic J (2016) BSAVA Manual of Canine and Feline Clinical
nique in patients with upper airway obstructive disease. It Pathology, 3rd edn. BSAVA Publications, Gloucester
is usually well tolerated and will withstand moderate Waddell L and King L (2007) General approach to dyspnoea. In: BSAVA Manual
patient movement. However, it is invasive, and dislodge- of Canine and Feline Emergency and Critical Care, 2nd edn, ed. L King and A
Boag, pp. 85–113. BSAVA Publications, Gloucester
ment or kinking of the catheter can occur. Oxygen must
Waddell L and King L (2018) General approach to respiratory distress. In: BSAVA
be humidified if it is delivered directly into the trachea, to
Manual of Canine and Feline Emergency and Critical Care, 3rd edn, ed. L King
prevent desiccation of the tracheal epithelium. and A Boag, pp. 93–122. BSAVA Publications, Gloucester

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