A penetrating abdominal injury is the result of trauma from an object puncturing the skin, entering the body, and creating a wound.
- Can often cause damage that results in shock and infection
- Severity depends on which body organs are involved, the characteristics of the object, and the amount of energy transmitted.
- 90% of cases involve men.
- While 20-to-24-year-old individuals make up 7% of the population, 22.5% of gunshot deaths affect this age group.
- By settings:
- 35% of trauma patients are admitted in urban trauma centers.
- Up to 12% of those admitted are in suburban or rural centers.
- 40% of homicides and 16% of suicides by gun involve injuries in the torso.
- Common organs injured:
- Small bowel (50%)
- Large bowel (40%)
- Liver (30%)
- Intra-abdominal vascular (25%)
- Gunshot wounds (65% of cases)
- Stab wounds
- Foreign objects from motor vehicle collisions or other trauma
- Fractured bones
Pathophysiology and Clinical Presentation
Mechanism of injury
- The projectile passes through tissue and decelerates, transferring kinetic energy into the tissue.
- ↑ Velocity leads to more damage than mass, and kinetic energy increases with the velocity
- A cavity in the tissue is formed by the penetrating object → permanent cavitation
- Medium- and high-velocity projectiles create secondary cavitation injuries as the object enters the body:
- A pressure wave pushes tissue out of the way.
- The tissues move back, filling the cavity in, but considerable damage has been created by the cavitation.
- Abdominal bleeding
- Bowel evisceration
- Abdominal bruising
- Signs of peritonitis (abdominal tenderness, distension, rigidity, guarding, fever)
- Hemodynamic instability
Because of the wide variety and severity of injuries associated with penetrating abdominal trauma, a prompt but careful history and physical exam are necessary to direct investigation with imaging studies.
- Mechanism of trauma:
- May suggest severity of injury
- Gunshot wounds:
- Caliber and type of ammunition used
- Degree of fragmentation of the bullet
- Distance from shooter (closer → higher kinetic energy)
- Stab wounds:
- More predictable patterns of injury than gunshot wounds
- Type of knife and length of blade
- Associated with lower incidence of intra-abdominal injuries
- History of previous trauma
- Drug (illicit and prescription) or alcohol use by patient
- Prior surgical history
- Amount of blood loss (on scene per paramedics and in hospital)
- Airway, breathing, circulation (ABC) assessment:
- Look for foreign objects blocking the airway.
- Assess for injury to the trachea (tracheal injury means intubation will be complex).
- Listen for unusual breathing sounds (stridor suggests narrowing by a foreign body or edema).
- Look at chest wall movement for even and spontaneous breathing (uneven chest movement suggests flail chest).
- Listen to breath sounds (muffled or uneven breath sounds may suggest pneumothorax or hemothorax).
- Palpate pulses on all 4 extremities (tachycardia suggests hemodynamic instability or pneumothorax).
- Assess capillary refill on extremities.
- Secondary survey:
- Examine the patient head to toe.
- External injury should prompt investigation for corresponding internal injury:
- Note entrance wounds (and exit wounds if present).
- There is no exit wound in a puncture wound, only in a penetrating injury.
- Base the imaging decision on exam findings.
- Signs concerning for severe intra-abdominal injury:
- Hypotension (with or without abdominal distention)
- Narrow pulse pressure
- Respiratory distress
- Signs of inadequate perfusion
- Peritoneal signs
- Generalized abdominal pain that fails to resolve
- FAST: used in all patients (stable or unstable) to look for intraperitoneal blood and pericardial effusion
- Hemodynamically unstable patients:
- Positive FAST → emergent laparotomy
- Negative FAST → search for extra-abdominal bleeding sources (e.g., femur fracture)
- Equivocal FAST → diagnostic peritoneal lavage (DPL) or stabilize patient and obtain CT scan
- Hemodynamically stable patients:
- Positive FAST → emergent laparotomy
- Negative FAST, low risk for intra-abdominal injury → observation
- Negative or equivocal FAST with high risk for intra-abdominal injury → CT scan
- Hemodynamically unstable patients:
- X-ray: directed by exam findings
- Chest X-ray: can show free intraperitoneal air, herniation of abdominal contents
- Pelvic X-ray: Pelvic bone fractures can be a source of bleeding or bladder injury.
- X-ray can help locate bullets and shrapnel left from a penetrating injury.
- CT scan abdomen with contrast:
- Imaging of choice for stable patients
- Provides information regarding retroperitoneal structures, diaphragm, and solid abdominal organs
- Most sensitive and specific study in identifying liver and spleen injury severity
Other diagnostic studies
- < 30% suggestive of intra-abdominal injury
- Normal Hct does not rule out severe injury.
- Urinalysis: blood suggestive of serious renal injury
- Liver function tests
- Invasive procedure used to evaluate presence of blood in abdominal cavity: A catheter is placed into the peritoneal cavity, and then fluid is aspirated and evaluated.
- Not often used but can be an alternative when CT scan and FAST are not available
Penetrating injuries may affect more than just the area that is obviously injured externally, and damage to the adjacent structures needs to be investigated.
- Back and flank:
- Check retroperitoneal and intraperitoneal structures.
- Diaphragmatic injury is possible.
- In thoracoabdominal area, need to check:
- Intra-abdominal organs/structures
- Diaphragmatic involvement
- Cardiac structures (e.g., pericardial tamponade) especially if injury is near xiphoid process
- In lower chest injuries (from the nipple line anteriorly—4th intercostal space (ICS)—or scapular tip), highly consider intraperitoneal injury.
Historical and standard management of penetrating abdominal trauma is laparotomy. Recent improvements in imaging and better understanding of injury patterns have resulted in more-conservative strategies.
Assessment of patient stability, correlation with diagnostic tests, and determination of the need for immediate surgery:
- Fluid resuscitation:
- Insertion of 2 large IV lines
- IV fluid administration
- Replenish blood
- Leave any foreign objects in situ until definitive management (e.g., surgical removal) is established.
- Broad-spectrum antibiotics:
- For those requiring surgical management
- Not warranted in cases requiring nonoperative management
- Tetanus prophylaxis
- Indications for immediate laparotomy:
- Hemodynamic instability (systolic blood pressure < 90 mm Hg)
- Signs of peritonitis
- Bowel evisceration
- Frank blood on rectal exam or nasogastric (NG) tube
- Emergent laparotomy:
- The keys of laparotomy are to control bleeding and prevent GI contamination.
- All 4 quadrants of the abdomen are packed with laparotomy pads to identify localized bleeding and injuries and to prevent GI contents from spreading.
- Injured organs such as the liver can be manually compressed to tamponade bleeding.
- Severe cases of bleeding may require ligation of arteries.
- In hemodynamically stable patients:
- Secondary survey
- Recommended action dependent on the result
- If there is a positive FAST, the patient is intoxicated, or unresponsive ➝ proceed with laparotomy.
- Local wound exploration (LWE):
- Preferably performed by 2 individuals
- Requires sedation and local anesthesia
- If wound in the anterior abdomen does not penetrate the anterior rectus fascia → wound care and consider discharge (depending on associated injuries).
- CT scan and/or other indicated imaging
- Alternatives to laparotomy:
- Regular rechecks in stable patients
- Observation for at least 24 hours recommended in:
- Age > 65 years
- Those with medications that are anticoagulants or antiplatelet therapy.
- Other significant injuries
- Medical comorbidities
- Interventional radiology procedures for spleen and liver lacerations with active bleeding
- Blunt abdominal trauma: typically involves the violation of the abdominal cavity by deceleration, crushing, or external compression injuries. The most injured structures are the liver and spleen. Management depends on the patient’s hemodynamic stability and severity of the injury.
- ABC assessment: airway, breathing, and circulation assessment is the mainstay approach used in managing critically ill patients. The ABCs are the essential first steps to perform in many situations, including unresponsive patients, cardiac arrests, and critical medical or trauma patients. For the trauma patient, ABC is included in the primary survey, the initial evaluation, and the management of injuries.
- Splenic injury: in blunt injuries, the liver and spleen are the most commonly injured organs. Usually, splenic injury is associated with lower left rib fractures. The features of splenic injury include hypotension, tachycardia, abdominal pain, left chest wall pain, and left shoulder pain (referred pain due to phrenic nerve irritation from splenic hemorrhage).
- Pelvic injury: pelvic injuries and pelvic fractures are among the worst complications of blunt abdominal injuries. Clinical features include hypotension, pain with movement, gross hematuria, and peripelvic ecchymoses. A digital rectal exam is important to identify injury to the rectum and locate the prostate. Treatment is usually limited to supportive care, but surgical stabilization may sometimes be necessary.
- Benjamin, E. (2020). Traumatic gastrointestinal injury in the adult patient. UpToDate. Retrieved January 8, 2021, from https://www.uptodate.com/contents/traumatic-gastrointestinal-injury-in-the-adult-patient
- Colwell, C, & Moore, E. (2020). Initial evaluation and management of abdominal stab wounds in adults. UpToDate. Retrieved January 7, 2021, from https://www.uptodate.com/contents/initial-evaluation-and-management-of-abdominal-stab-wounds-in-adults
- Lotfollahzadeh, S, & Burns, B. (2021). Penetrating abdominal trauma. StatPearls. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK459123/
- Phillips, B, et al. (2017). Trauma to the bladder and ureter: A review of diagnosis, management, and prognosis. Eur J Trauma Emerg Surg. 43(6), 763–773. https://pubmed.ncbi.nlm.nih.gov/28730297/
- Sakamoto, R, et al. (2018). Nonoperative management of penetrating abdominal solid organ injuries in children. J Surg Res. 228, 188–193. https://pubmed.ncbi.nlm.nih.gov/29907210/