Gunshot wounds

Features of the wound tract and pathogenesis

Gunshot wounds are fundamentally different from injuries caused by blunt or sharp objects. They are always accompanied by pronounced traumatic necrosis. An extensive zone of reduced tissue viability with massive hemorrhages forms around the primary wound tract. Particularly insidious is the zone of molecular concussion—an area where tissue death (necrosis) does not stop at the moment of trauma, but continues for a long time after the injury.

The appearance and characteristics of a wound directly depend on the type of wounding projectile:

• Bullet wounds and small shrapnel: characterized by a relatively small entry wound. Moreover, in perforating (through-and-through) wounds, the exit wound is significantly larger than the entry wound.
• Large shrapnel: cause severe lacerated wounds with extensive defects of the skin, muscles, and tendons, and are also accompanied by bone fractures. Shrapnel wounds are most often penetrating (blind), and the greatest scale of tissue damage is localized precisely in the area of the entry wound.

The pathogenesis of gunshot trauma also includes concomitant injuries to major vessels, nerves, bones, and joints. Severe systemic reactions of the body are characteristic, such as massive blood loss and traumatic shock. Due to pronounced bacterial contamination, there is an extremely high risk of developing infectious complications—purulent, putrid, or anaerobic infection.

Penetrating chest wounds

Chest wounds harbor the threat of compromising the integrity of the pleural cavity. A penetrating wound can be diagnosed by a number of striking clinical signs:

1. Noisy escape of foamy blood directly from the wound.
2. Specific whistling sound upon suction of air into the pleural cavity during breathing.
3. Release of air bubbles from the wound opening.
4. Appearance of subcutaneous emphysema (accumulation of air in the subcutaneous tissue).

The entry of air into the pleural cavity leads to the development of pneumothorax, which occurs in two main types:

• Open pneumothorax: air freely enters the thoracic cavity upon inhalation and just as freely escapes with a whistle upon exhalation.
• Tension (valvular) pneumothorax: occurs when a soft tissue flap closes the wound opening on expiration. Air is sucked in on inspiration but cannot escape back out. This leads to progressive compression of the lung and displacement of the mediastinal organs to the healthy side, making the patient's condition extremely critical.

The clinical picture of tension pneumothorax includes marked dyspnea, acrocyanosis (bluish discoloration of the extremities), and a rapid yet weak pulse. Upon inspection, bulging of the affected hemithorax and widening of the intercostal spaces are noticeable. Percussion over the affected area reveals a hyperresonant (box-like) sound, and auscultation reveals a complete absence of breath sounds.

Penetrating abdominal wounds

Clinical manifestations of penetrating abdominal wounds consist of two main pathological processes: intra-abdominal hemorrhage and developing post-traumatic peritonitis. Patients complain of severe abdominal pain, intolerable thirst, and general weakness. Examination reveals pallor of the skin and tachycardia (rapid, low-volume pulse).

Local symptoms and objective examination findings:

• The abdomen is sharply tender upon palpation.
• Marked tension of the abdominal wall muscles is noted—the so-called "board-like abdomen".
• A positive Shchetkin-Blumberg sign is detected.
• Percussion: when blood accumulates in the abdominal cavity, dullness of the percussion sound is detected in the dependent areas of the abdomen. If air has entered the cavity (pneumoperitoneum has developed), hepatic dullness disappears and is replaced by high-pitched tympany.

There are absolute (unquestionable) signs, in the presence of which the diagnosis of a penetrating abdominal wound is made unconditionally:

• Prolapse of an intestinal loop or a segment of the omentum into the wound opening.
• Escape of intestinal contents, urine, or bile from the wound to the exterior.

Class and exam questions

What else to study on this topic

• Mechanisms of formation of secondary wounding projectiles
• Principles of diagnosis of anaerobic and putrid infection
• Emergency care for tension pneumothorax
• Pathogenesis of traumatic shock in gunshot wounds
• Shchetkin-Blumberg sign: performance technique and significance

Other topics in "CHAPTER 10. GENERAL ISSUES IN TRAUMATOLOGY"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.