A17. Blunt injuries of the abdominal wall. Penetrating trauma to the abdomen
Blunt abdominal trauma
Blunt trauma to the abdomen occur in most cases due to motor vehicle accidents, crime, or falls. This form of trauma may cause organ contusion, rupture, and/or crushing. Any abdominal or pelvic organ may be affected, but injuries to the spleen and liver are most common.
Patients may be haemodynamically unstable due to large intraabdominal bleeding, requiring urgent stabilisation.
Accidents, especially motor vehicle accidents, is the number one killer of teenagers and young adults worldwide.
Pathomechanism
Injury may occur due to compression and rupture (from the impact of the steering wheel, for example), or due to rapid deceleration, causing tearing.
Diagnosis, evaluation, and management
As with all trauma patients, the initial trauma primary survey (ABCDE) and stabilisation is essential.
Even patients with major intra-abdominal injury may present with only mild complaints, and so it’s important to retain a high index of suspicion. It’s also important to keep in mind the possibility of head and spinal injury. The following signs and symptoms are associated with intra-abdominal injury:
- Abdominal pain
- Rebound tenderness
- Hypotension
- Abdominal distension
- Abdominal guarding
Intraabdominal bleeding can rapidly cause shock and death, and so investigations should be directed at uncovering this ASAP. The so-called eFAST (extended Focused Assessment with Sonography for Trauma) is the standard screening examination for intraabdominal free fluid (like blood), pneumothorax, hemopericardium, and tamponade. eFAST takes only a few minutes to perform and can rapidly diagnose the mentioned conditions. However, it should be kept in mind that a negative eFAST doesn’t rule out intraabdominal injury, as eFAST cannot discern diaphragmatic tears, pancreatic injury, bowel perforation, and small amounts of free fluid. The sensitivity of eFAST is also limited. The main objective of eFAST is to decrease the number of people who require a CT scan, thereby shortening their time to surgery.
In case eFAST detects intraabdominal free fluid, the patient has likely suffered large injuries which require surgery, and so the patient should be taken to emergency laparotomy.
In case eFAST does not detect any pathology, an abdominal CT scan should be performed if the risk for intra-abdominal injury isn’t low. If the abdominal CT shows injury, emergency laparotomy should be performed.
Laparotomy allows for direct visualisation of all abdominal organs, providing the best visualisation of any possible injuries. It is indicated if intra-abdominal bleeding is detected (on US or CT), the patient is haemodynamically unstable, or there are signs of peritonitis. In the operating room, tears and lacerations may be sutured or compressed to stop bleeding, and injured parts of organs may be resected.
Penetrating abdominal trauma
Penetrating injury to the abdomen is most commonly a result of stabbing or gunshot. The mortality of penetrating injury is slightly lower than that of blunt injury. The most commonly affected organs are the liver and small intestine.
Diagnosis, evaluation, and management
As with all trauma patients, the initial trauma primary survey (ABCDE) and stabilisation is essential.
In the physical examination of a penetrating injury victim, it’s important to completely undress the patient and examine the whole body to look for hitherto unknown wounds.
Contrary to what may be instinctual, a penetrating object which remains implanted in the patient should not be removed until in a setting where definitive care is possible, like the operating room. Penetrating objects often tamponade the wound and so removing them may worsen the clinical condition.
Due to the high risk of small bowel injury, broad spectrum antibiotics should be administered prophylactically. Tetanus prophylaxis may also be necessary.
Emergency laparotomy is indicated in:
- Evisceration
- Impalement (foreign object remaining)
- Signs of peritonitis
- Haemodynamic instability
If none of the above indications are present, eFAST and/or abdominal CT should be performed, which may show evidence of an injury which is an indication for emergency laparotomy. Patients who remain haemodynamically stable and with a negative eFAST and CT should be admitted for observation.