Plus-Hex CLINICAL
Introduction Patient signalment
Pneumothorax is defined as the accumulation of air within the pleural space and often develops as a result of blunt force trauma to the thorax [ 1 ]. Thoracic injuries caused by blunt trauma are known to be a major cause of mortality in both human and veterinary medicine [ 2 ].
A retrospective study evaluating 140 dogs involved in road traffic accidents demonstrated that thoracic injuries, including pneumothorax and lung contusions, were associated with a higher mortality rate [ 2 ]. This article discusses the approach to caring for a young canine patient with a traumatic tension pneumothorax secondary to a road traffic accident.
Name Species Breed Sex Age Weight
History
Duke Dog Cocker spaniel Male 1 year, 6 months 15 kg
Pathophysiology
The pleural space is a potential space between the membranes that surround and protect the lungs, which are known as the visceral and parietal pleura. The pleura and pleural space aid the lungs during normal respiration. The pleural space normally contains a small amount of lubricating fluid, which helps to eliminate friction between the lungs and the thoracic wall during inspiration and expiration. The pleural space normally maintains a sub-atmospheric pressure of between −3 and −5 cmH 2
O [ 1 ]. Alterations in this pressure occur when air or fluid inappropriately enters the pleural space, impairing ventilation [ 1 ].
The patient( Figure 1) was presented 24 hours after a witnessed road traffic accident. Initial treatment by the primary care practice consisted of thoracic radiographs under sedation, and placement of a right-sided thoracostomy tube under local analgesia.
Traumatic pneumothorax can be caused by a tear in the trachea, bronchi or pulmonary parenchyma. In some cases, small traumatic wounds may seal quickly, negating the need for further intervention [ 1 ]. Larger traumatic wounds often require intervention. Spontaneous pneumothorax can occur because of multiple aetiologies such as pulmonary blebs and bullae, neoplasia, inhaled foreign bodies or any other condition where a diseased lung may begin to leak [ 1 ].
Pneumothorax can be further classified as open, closed or tension( Table 1).
Figure 1. The patient, Duke.
Table 1. Classification of pneumothorax.
Classification
Cause
Open pneumothorax
Closed pneumothorax
Often a result of a penetrating injury to the chest resulting in loss of negative pressure in the thoracic cavity due to entry of environmental air
A result of air leakage from within the thoracic cavity as opposed to the external environment [ 1 ]
Tension pneumothorax A result of a large pulmonary leakage of air that acts as a ball valve during ventilation, allowing progressive entry and entrapment of air within the pleural space. This leads to a significant increase in intrapleural pressure, compression of the lungs and a subsequent reduction in lung volume. Compression of large blood vessels can also occur, preventing venous return to the heart [ 1 ]
Volume 41( 5) • October 2026
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