Page 26 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 2 · Emergency management of respiratory distress

the animal is not stable enough for more definitive diag- difficulty, whilst intrathoracic dynamic airway obstructions
nostics. The empirical localization of the respiratory lesion (e.g. intrathoracic tracheal collapse or feline asthma) cause
VetBooks.ir any algorithmic approach in medicine, exceptions exist, loud stertorous (rostral to the larynx) or stridorous (larynx
expiratory difficulty.
lends itself to an algorithmic approach (Figure 2.1). As with
Disorders involving the upper airway commonly cause
and the empirical determination of the lesion using the
algorithm should also be influenced by clinical judgement
and experience. and caudally) respiration. Noise in one phase of the res-
piratory cycle suggests a dynamic obstruction (such as
laryngeal paralysis); noise that persists throughout the
History cycle suggests a fixed obstruction (mass, foreign body).
Exaggerated respiratory effort with a normal to slow res-
Once an animal’s respiratory distress has been alleviated, piratory rate and paradoxical abdominal motion are also
a detailed history should be obtained. The duration and
features of large airway disease.
dynamics of the respiratory distress, and association with Pleural space disorders commonly cause fast, shallow
trauma, coughing (especially in cats), vomiting or other obvi-
respiration with increased inspiratory effort and para -
ous complaints, may indicate the underlying nature of the dox ical abdominal motion (particularly with longstanding
problem. Unwitnessed trauma and access to toxins (espe-
pleural effusions). Exaggerated respiratory effort with little
cially rodenticides) are common and should be anticipated.
actual airflow is also a hallmark of pleural space disease.
Fast, shallow respiration with paradoxical abdominal
Observation motion can also occur because of poor lung compliance
Observation of the respiratory pattern can sometimes help as a result of pulmonary parenchymal disease. However,
localize the lesion but is rarely definitive, since lesions in pulmonary parenchymal disease has also been associated
different parts of the respiratory tract can have similar with slow, laboured respiration and hyperpnoea, often with
patterns. An irregular respiratory rhythm is associated with marked inspiratory and expiratory effort. Disorders involv-
brain or brainstem injury. Animals with abnormal respira- ing the small airways commonly cause hyperpnoea with
tory rhythms secondary to brain injury have other obvious end-expiratory abdominal effort due to gas trapping in the
signs of brain dysfunction. small airways. Coughing may also be a feature of small
Dynamic obstructions result in resistance to airway flow airway disease, especially in cats.
during inspiration or expiration. Extrathoracic dynamic air- It is important to remember that these categories and
way obstructions (e.g. laryngeal paralysis) cause inspiratory clinical signs are not exclusive.

Algorithm for
2.1 localization of the
respiratory lesion in animals
Respiratory distress with respiratory distress. This
chart should be used in
conjunction with clinical
judgement and experience to
optimize assessment of the
Provide supplemental oxygen patient.

Physical examination of respiratory tract

Loud upper Increased lower Decreased
airway sounds airway sounds lung sounds

Consider conducting airway Auscultate Consider pleural
disease: nasopharyngeal area; heart space disease
larynx; trachea to carina

Abnormal heart sounds Normal heart sounds

Consider congestive Consider pulmonary parenchymal
heart failure or small airway disease

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