Page 193 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery

Lung trauma a chest tube), exploratory thoracotomy is indicated. Other
indications for exploratory thoracotomy include: rib frac-
VetBooks.ir categories: gross contamination of the thoracic cavity is suspected;
ture that impales lung tissue; penetrating wounds in which
Causes of traumatic injuries to the lungs fall into two broad
the presence of penetrating objects within the thorax; or
• Blunt, e.g. road traffic accident, kick, fall from a height
Bite wounds over the thorax always require careful and
• Penetrating, e.g. gunshot, stick, knife, arrow, deep bite haemothorax producing ml kg h for 3 4 hours.
from a large dog on a small dog, secondary to thorough exploration once the patient is stable, particularly
displaced ends of fractured ribs. where a large dog has attacked and shaken a small dog
(Figure 14.5) (see Chapter 11).
These injuries can result in pneumothorax (see Chapter Puncture wounds that appear to be innocuous on the
12), haemothorax, pulmonary contusions, rib fractures, surface may be associated with large intercostal muscle
lung lacerations and diaphragmatic hernia (see Chapter 17). tears and rib fractures. Deep palpation of the affected area
In all cases, life-threatening problems must be addressed of the thorax under anaesthesia can reveal large defects in
initially. Once the patient is sufficiently stable, plain thoracic the thoracic wall, beneath the skin. Plain radiographs may
radiographs should be taken, preferably without the use of prove useful in locating the site of lung and thoracic
general anaesthesia, to assess for the presence of frac- trauma; otherwise, a median sternotomy may be neces-
tured ribs, lung contusions, oedema, or free air and fluid in sary. Absence of pneumothorax on thoracic radiographs
the thorax. does not rule out significant thoracic pathology in bite
If the patient has an open chest wound, the area wound cases.
should be clipped, prepared and dressed as quickly as When performing surgery for traumatic lung injury, air
possible to maintain the continuity of the thoracic wall. leaks should be located by filling the thorax with warm
Objects that penetrate the thorax should be left in situ,
where possible, to be removed via a lateral thoracotomy or
median sternotomy once the patient is stable.

PRACTICAL TIP
Some projectiles may be seen on thoracic radiographs
as an incidental finding. There is no perfect guideline
regarding when to explore a penetrating chest wound.
The risk for contamination and infection must be
considered on a case-by-case basis

Occasionally, lung lacerations can occur when the chest
is compressed laterally by trauma with the glottis closed;
this may lead to a dramatic increase in intra-airway pressure
and cause rupture of the conducting airways or alveoli of
the lung. Another mechanism of injury is tearing of the
trachea, mainstem bronchi or pulmonary parenchyma due
to shearing forces generated by rapid acceleration or decel-
eration (e.g. road traffic accidents, ‘high-rise syndrome’).
The majority of animals that sustain thoracic trauma
do not require surgical intervention. Pulmonary contusion (a)
and mild pneumothorax as a result of road traffic acci-
dents are common and are frequently managed with sup-
portive care. Most lung lacerations self-seal as a result
of clot formation, elastic recoil and transpulmonary pres-
sure. If the patient shows signs of respiratory distress
(increased respiratory rate and effort) despite appropriate
pain management, or the degree of pneumothorax is
moderate or severe (based on plain thoracic radiographs),
periodic thoracocentesis should be performed (see
Chapter 12) in combination with serial thoracic radio-
graphs to monitor resolution.

PRACTICAL TIP
The severity of pulmonary contusions may not be fully
appreciated until 6 1 hours after lung trauma
(b)
(a) Radiograph showing severe subcutaneous emphysema
If pneumothorax persists, worsens or fails to respond, 14.5
and multiple rib fractures in a 2-year-old Miniature Poodle that
a thoracostomy tube may be placed (see Chapter 12). If had sustained thoracic bite ounds. b t surgery severe damage to
intermittent suction of a thoracostomy tube fails to empty ribs and thoracic wall musculature can be appreciated. The dog also
the pleural space, continuous suction will be necessary. If sustained a traumatic impalement of a lung lobe caused by the sharp
the pneumothorax still fails to resolve (after 3 days with ends of one of the fractured ribs.

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