a. Subcutaneous Emphysema.

Subcutaneous emphysema is caused by air from a damaged lung becoming trapped in the soft tissues of the chest wall. The trapped air forms little bubbles that cause a crackling sensation when palpated. A casualty with subcutaneous emphysema should be given respiratory support and evacuated.

b. Pulmonary Contusion.

A pulmonary contusion is a bruise of the lung, usually caused by a blunt instrument or fall. Edema fluid and blood accumulates in the lung tissue. This accumulation interferes with the respiratory process and results in hypoxia (oxygen deficiency). A casualty with a pulmonary contusion should be given respiratory support and evacuated.

c. Myocardial Contusion.

A myocardial contusion is a bruise of the heart muscle and is usually caused by a blunt injury to the chest. The casualty will have an irregular pulse with occasional pauses between heartbeats at times and a very rapid pulse at other times. A casualty with a suspected myocardial contusion should be evacuated immediately.

d. Pericardial Tamponade.

Pericardial tamponade is caused by blood or other fluid accumulating in the pericardial sac that surrounds the heart. The fluid compresses the heart and interferes with its function. Pericardial tamponade is a life threatening condition that requires respiratory support and immediate evacuation.

Signs and symptoms of pericardial tamponade include the following.

(1) Very soft, faint heart sounds, which may be hard to hear even with a stethoscope.

(2) Congested and distended veins in the head and neck.

(3) Difficulty in breathing.

(4) Tachycardia (weak and rapid pulse).

(5) Rapidly decreasing blood pressure with the systolic and diastolic readings coming closer and closer together.

NOTE: The major differentiating factor between a tension pneumothorax and the pericardial tamponade is the presence or absence of breath sounds. In pericardial tamponade, the patient would still have equal and bi-lateral breath sounds.

e. Massive Internal Bleeding.

Injury to the great blood vessels located within the chest can cause a rapid loss of blood. The casualty will show signs and symptoms of hypovolemic shock.

f. Laceration of a Major Airway.

Injury to the trachea or bronchi can result in tension pneumothorax, hemoptysis (coughing up blood), and respiratory distress. Provide respirator support and evacuate the casualty. This patient will need immediate aggressive airway support that may not be feasible even during tactical field care.

g. Abdominal Injuries.

Injuries to the lower ribs may indicate abdominal injuries, such as damage to the kidneys.