Introduction

Emergency surgery is a challenge to the practising veterinarian. Often these cases are presented without warning and they need immediate attention. During this seminar, the most common surgical thoracic emergencies are presented in a interactive manner. Active participation of the audience is expected. Many of the best solutions to surgical problems are revealed by suggestions of the audience.

Historical assessment and physical examination

The most important step in treating thoracic patients (dogs and cats) is the initial assessment and examination. Thoracic trauma patients are always an emergency and your speed of action depends on how dyspnoeic they are. In the ABC's the respiratory system has our main attention!

ABCD

The basic life support of a patient should follow the following steps:

1.  Establishment of airway/oxygen

2.  Breathing support/thoracic wall

3.  Circulatory support/MM/Pulse

4.  Disabilities/neurologic/posture

After your basic life support, you will have more time to perform a more complete physical examination. Often little dogs are bitten by large dogs and may have multiple puncture holes. Always clip the entire affected area in search of these little punctures. Other common causes for thorax trauma are hit by car incidents and blunt and penetrating traumatic events. Clinical signs may include contusions, lung trauma, fractured ribs, rupture of the intercostal muscles, penetrating injury to the chest, hernias (diaphragmatic and ventral), and haemorrhage in or outside of the chest.

Initial therapy

Initial therapy should include providing oxygen, calming down the patient and addressing the wounds. Especially, in open chest wounds or in case of a flail chest, supportive bandage may prevent a tension pneumothorax and asphyxia.

Diagnosis

Radiographs are essential in diagnosing the extent of damage (Fig. 1). It is important to evaluate both sides of the chest for lung contusions, pneumothorax, rib fractures, hernias, and pleural fluid. In case of pneumothorax and obvious dyspnoea, chest drains will have to be placed or the air should be evacuated using centesis. Often the wounds are small on the outside but the internal damage is extensive. Don't let yourself be fooled by the fact that the external wounds are easy to close. Broad-spectrum antibiotics are always indicated in thoracic trauma cases. Intravenous administration is the preferred method.

Figure 1. Radiographs of the thorax in a dog that was shot. The bullet went through the thorax and is lodged in the muscles on the left side.

Surgical intervention

Exploratory surgery always needs to be performed in dogs with thoracic/abdominal trauma and

1.  There is an open connection to the pleura or peritoneum

2.  Extensive flail chest

3.  Progressing emphysema of neck and chest

4.  Free gas in the abdominal cavity

5.  Extensive herniation of abdominal or thoracic organs (like lungs)

6.  Any signs of internal organ damage or uncontrollable haemorrhage

The dog should be stabilised, however, before surgery is performed. In case of abdominal wounds, a ventral approach is preferred. Thoracic trauma is often approached laterally. After the initial skin incision the damage to the subcutis, muscles and ribcage is evaluated. Simple muscle tears can be sutured primarily but extensive rib fractures and avulsions often need innovative reconstruction technique. The goal is reinstatement of the negative pleural pressure to allow full lung expansion. After reconstruction of an airtight thoracic wall, the other tissues are primarily sutured over Penrose drains. External coaptation for the management of flail chest has been described, with variable success (Fig. 2). Immediate intervention of diaphragmatic hernias is seldom necessary, except if the stomach is located in the chest. In these cases, the stomach will fill with air and severely impede breathing. In other cases, a delayed surgery is better to allow demarcation of the diaphragmatic wound edges.

Figure 2. A supportive bandage may be helpful in certain thoracic trauma dogs.

Postoperative care

Postoperative care is as important as the surgery itself. Respiratory support (oxygen tube or cage) is essential in these cases. Most of the dogs are small, hypothermic and in shock. Heating pads, temperature controlled environment and fluid support will be necessary. Analgesia is of extreme importance in any trauma case. Pain prevents good function of almost any body system.

References

1.  Orton EC. Small Animal Thoracic surgery. Williams and Wilkins, Malvern, PA 1995:55-83.