-
1. What does ventilation of the lungs depend on?
Show Answer
Correct answer:
A patent main airway and pulmonary alveoli, a rigid bony skeleton of the thorax, and the integrity of the nerves and muscles that control the movements of the ribs and diaphragm.
-
2. What are the dangerous complications of chest injury?
Show Answer
Correct answer:
Paradoxical respiration; pneumothorax; penetration of the lung; haemothorax; cardiac tamponade due to laceration of the heart; large vessel damage. Serious damage can also result from blunt (crush) injuries that do not penetrate the chest; thus, a main bronchus or the aorta may be ruptured, the lung contused and papillary muscles of the heart or the coronary arteries may be damaged.
-
3. Which ribs are most often fractured?
Show Answer
Correct answer:
The commonest injury to the chest is fracture of the ribs by a direct blow. The most commonly affected ribs are the seventh, eighth and ninth, in which the fracture occurs in the region of the midaxillary line. The patient complains of pain in the chest overlying the fracture and this pain is intensified by springing the ribs with gentle but sharp pressure on the sternum.
-
4. Which ribs are most commonly fractured?
Show Answer
Correct answer:
Seventh, eighth and ninth ribs in the midaxillary line.
-
5. How would you investigate a patient with a suspected fractured rib?
Show Answer
Correct answer:
Chest X-ray may confirm rib fractures, and will identify underlying lung damage or haemorrhage that might not have been suspected from the trivial nature of the patient's symptoms. A chest X-ray may not always demonstrate a fracture, and, if the patient has clinical signs of fractured ribs, he should be treated for this condition in spite of a negative X-ray. A repeat X-ray at 2 weeks may show a fracture callus to confirm the diagnosis. Bone scan is more sensitive at detecting fractures, especially pathological fractures, when it may reveal metastatic tumour deposits elsewhere in the skeleton, or be suggestive of metabolic bone disease.
-
6. What are the main complications of a fractured rib?
Show Answer
Correct answer:
(1) Flail chest. (2) Pneumothorax. (3) Subcutaneous emphysema (surgical emphysema). (4) Sucking wound of the chest. (5) Haemothorax. (6) Other visceral injury. (7) Traumatic asphyxia.
-
7. What is a flail chest?
Show Answer
Correct answer:
Crush injuries of the chest, in which the whole sternum is loosened by fractured ribs on either side or several ribs are fractured in two places, result in the condition of flail chest. On inspiration, the flail part of the chest wall becomes indrawn by the negative intrathoracic pressure, as it is no longer in structural continuity with the bony thoracic cage. Similarly, in expiration the flail part of the chest is pushed out while the rest of the bony cage becomes contracted. This is termed paradoxical movement. The patient becomes grossly hypoxic due to failure of adequate expansion of the affected side and also because of shunting of deoxygenated air from the lung on the side of the fracture into the opposite side. The pendulum movements of the mediastinum also produce cardiovascular embarrassment so that the patient becomes rapidly and progressively shocked.
-
8. Why might a patient with a flail chest become anoxic?
Show Answer
Correct answer:
This is because of failure of adequate expansion of the affected side and also because of shunting of deoxygenated air from the lung on the side of the fracture into the opposite side. The pendulum movements of the mediastinum also produce cardiovascular embarrassment so that the patient becomes rapidly and progressively shocked.
-
9. What is a tension pneumothorax?
Show Answer
Correct answer:
In the context of rib fractures a bony spicule may penetrate the lung, which results in air escaping into the pleural cavity to cause a pneumothorax. A tension pneumothorax results if the pleural tear is valvular, allowing air to be sucked into the pleural cavity at each inspiration but preventing air returning to the bronchi on expiration. A tension pneumothorax produces rapidly increasing dyspnoea; the trachea and the apex beat are displaced away from the side of the pneumothorax and, on the left side, cardiac dullness may be absent. The chest on the affected side gives a tympanitic percussion note with bulging of the intercostal spaces.
-
10. In the case of a tension pneumothorax, in which direction is the trachea deviated?
Show Answer
Correct answer:
The trachea will be deviated away from the affected side.
-
11. What is surgical emphysema?
Show Answer
Correct answer:
This is an alternative name for subcutaneous emphysema. In the context of rib fractures, the rib tears the overlying soft tissues and allows air to enter the subcutaneous tissues, resulting in subcutaneous emphysema. The skin over the trunk, neck and sometimes face gives a peculiar crackling feel to the examining fingers (crepitation) and, in severe cases, the face and neck may become grossly swollen. The alternative name, surgical emphysema, is misleading as it is rarely caused by surgeons.
-
12. What is a sucking wound of the chest?
Show Answer
Correct answer:
A pneumothorax will also result from a penetrating wound of the chest wall produced, for example, by a knife stab or gunshot wound. The lips of the wound may also have a valvular effect so that air is sucked into the cavity at each inspiration, but cannot escape on expiration, thus resulting in another variety of tension pneumothorax, which has been vividly named a sucking wound of the chest.
-
13. What is a haemothorax?
Show Answer
Correct answer:
A haemothorax often accompanies a chest injury and may be associated with a pneumothorax (haemopneumothorax). The bleeding is usually from an intercostal artery in the lacerated chest wall or from underlying contused lung, but on occasions may result from injury to the heart or great vessels. Retropleural bleeding may compress the thoracic viscera without breaching the pleural cavity.
