Chapter 25. Chest injuries
Deaths following injuries to the thorax usually result from a lack of oxygen (hypoxia) or lack of circulating blood volume (hypovolaemia). Injuries may be blunt or penetrating. In blunt trauma the force can be spread over a wide area. After low-energy impacts, damage is usually localised to the superficial structures. In contrast, following high-energy impacts considerable tissue disruption can be produced with severe injuries that may be difficult to manage. The significance of the local damage following penetrating trauma is dependent on both the site and the depth of penetration. In gunshot wounds the degree of injury is also determined by the amount of energy transferred to surrounding tissues.
Blast injuries cause particular injury to the lungs. The shockwave transmits through the tissues and causes injury to the alveoli within the lung tissues. This syndrome is known as blast lung and may lead to hypoxia. High blast pressures can also lead to air emboli which may precipitate sudden death if they obstruct the coronary or cerebral arteries.
Primary survey and resuscitation
The aim of the primary survey is to detect and correct any immediately life-threatening condition. In chest trauma there are six immediately life threatening conditions which can be treated.
These may be remembered using the mnemonic ATOMIC:
A – Airway obstruction
T – Tension pneumothorax
O – Open chest wound
M – Massive haemothorax
i – Fla il chest
C – Cardiac tamponade.
All trauma patients require high flow oxygen
Examination
To be confident that these conditions have been found or excluded, it is important that the chest and neck are examined.
Ideally, all the clothing covering the thorax should be removed so that a full inspection can be carried out.
The neck should be examined for the following:
• Swelling
• Surgical emphysema with crepitus
• Tracheal deviation
• Neck vein distension
• Bruising
• Lacerations.
Lacerations should only be inspected and never probed with metal instruments or fingers because catastrophic haemorrhage can be precipitated.
The chest can then be examined. This involves the following stages:
• Inspection of the chest
• Palpation of the trachea and ribs
• Auscultation of both axillae, top and bottom
• Percussion of both axillae, top and bottom
• Examination of the back: inspection, palpation, auscultation and percussion.
Inspection
The respiratory rate, depth and effort of respiration should be checked at frequent intervals. Rapid, shallow breathing and intercostal or supraclavicular indrawing are all sensitive indicators of underlying lung pathology. Both sides of the chest should be inspected and compared for symmetry of movement, bruising, abrasions and penetrating wounds. Paradoxical movement (movement of part of the chest wall in the opposite direction to the rest, inwards on inspiration and outwards on expiration) may be seen and is a sign of a flail segment.
Palpation
Starting at the top, the clavicles should be carefully palpated for deformity (which may be visible) and the chest wall should be gently felt for tenderness. Instability or crepitus may be noted. Feel down the sides of the chest and look on your gloves for any blood.
Auscultation
A stethoscope should be used to listen in both axillae in the upper and lower half of the chest to determine if the air entry is equal. Listening over the anterior chest detects air movement in the large airways which can drown out sounds of pulmonary ventilation, particularly if any secretions are present.
Percussion
If there is a difference in auscultation, the findings on percussion of both sides of the chest should be compared. The most likely findings are either hyperresonance (pneumothorax) or dullness (fluid or contusion) on one side compared with the other.
Check the back
It is important to assess the back quickly to determine if there is any evidence of a penetrating injury. If there is time, the examination should include palpation, auscultation and percussion of the posterior aspect of the chest.
Life-threatening conditions
Airway obstruction (ATOMIC)
Obstruction of a major airway can occur within the thorax. In many cases, there is little that can be done about this although cardiopulmonary resuscitation or the Heimlich manoeuvre may dislodge the obstruction.
Tension pneumothorax (ATOMIC)
• If there is a breach in either the lung or chest wall, then air can be sucked into the vacuum of the pleural space and a pneumothorax created