Abdominal Trauma

1. See Also
   1. Pediatric Blunt Abdominal Trauma
   2. Trauma Evaluation
2. Causes: Blunt Abdominal Trauma
   1. Direct blow to the Abdomen (e.g. Contact Sports, Motor Vehicle Accident)
   2. Fall from Height
   3. Cycling handlbar injury
3. Associated Conditions
   1. Liver Laceration
   2. Splenic Rupture
   3. Renal Injury
   4. Pancreatic Injury
   5. Hollow viscus (bowel perforation) or Lumbar Spine Injury
      1. Seat Belt
      2. Deceleration injury
   6. Rectum or other bowel injury
   7. Gastrointestinal Bleeding
4. Indications: Diagnostic Testing
   1. See precautions below
      1. Do not delay an exploratory laparoscopy that is clearly indicated
   2. Suspected occult internal bleeding with decreasing Hematocrit and no obvious source
   3. Non-diagnostic examination with higher clinical suspicion
      1. Equivocal peritoneal signs with abdominal tenderness and guarding
      2. Altered Level of Consciousness and suspected Abdominal Trauma
      3. Negative abdominal exam but high level of suspicion based on mechanism of injury
   4. Bony Fracture with associated abdominal tenderness or guarding
      1. Multiple lower Rib Fractures
      2. Lumbar transverse process Fracture
      3. Pelvic Fracture
5. Symptoms
   1. Persistent Abdominal Pain after injury
      1. Pain may be referred to the Shoulders
   2. Fever
   3. Nausea
   4. Vomiting
   5. Bright Red Blood Per Rectum
6. Signs
   1. Localized Abdominal Pain
   2. Abdominal guarding
   3. Abdominal Rebound Tenderness
   4. Abdominal rigidity
   5. Abdominal wall Bruising
      1. Seat Belt Sign is a red flag, and associated with enough force to cause intraabdominal injury
7. Examination
   1. Evaluate for peritonitis or hemodynamic instability
      1. Fever
      2. Hypotension
      3. Tachycardia
   2. Complete abdominal exam
   3. Rectal examination
      1. Decreased rectal tone (Spinal Injury)
      2. High riding Prostate (Urethral transection)
      3. Bloody stool on rectal exam
8. Imaging: First-line studies
   1. FAST Exam
   2. CT Abdomen and Pelvis
      1. Perform with IV contrast
      2. Consider oral water as contrast if time allows, and is not contraindicated (other Oral Contrast is not needed)
      3. May Identify Stomach and intestinal rupture
      4. Serial abdominal exams are a more sensitive marker for exploratory laparotomy indication than CT
      5. Diaphragm injury or hollow viscus injury may be missed on CT Abdomen (despite IV contrast)
         1. Bowel injuries are rare (1 to 5% of blunt Trauma cases), but catastrophic and often occult
         2. Bowel wall breaks are seen on CT in only 10% of bowel wall injuries
         3. Free air is found on CT in only 20% of bowel wall injuries
      6. Free fluid without solid organ source is suspicious for bowel or mesenteric injury
         1. Hounsfield Units (HU) may differentiate cause
         2. Water, urine and Ascites are approximately 0 HU
         3. Blood is 30 to 45 HU
      7. References
         1. Brofman (2006) Radiographics 26(4): 1119-1131 [PubMed]
9. Imaging: Abdominal XRay
   1. Rarely useful beyond demonstrating free air compared with CT Abdomen
   2. Evaluate with CT Abdomen and Pelvis (or UGI with gastrograffin) if red flags are positive
   3. General suspicious KUB findings
      1. Peritoneal free air mandates emergent laparoscopy
      2. Ileus
      3. Visceral displacement
      4. Lumbar compression Fracture
   4. Duodenum or pacreas injury signs
      1. Psoas shadow absent
      2. Retroperitoneal gas
      3. Linear air shadows at duodenum or overlying the right Kidney
   5. Splenic Injury signs
      1. Splenic shadow absent
      2. Gastric air bubble displaced medially
      3. Left psoas and left renal shadows obscured
      4. Left upper quadrant soft tissue density
10. Diagnostics
    1. Diagnostic Peritoneal Lavage (not recommended)
       1. Rarely performed now in United States where Ultrasound and CT Scans are readily available
       2. Typically FAST Exam followed by CT Abdomen and Pelvis is performed in Trauma
11. Precautions
    1. Do not delay emergent exploratory laparotomy when indicated
    2. Blunt wound probing may miss peritoneal violation
       1. Consider local wound exploration under sterile conditions
       2. Dissect to base of wound to determine if it penetrates abdominal wall fascia
       3. Intact fascia on exploration reliably excludes penetration
    3. Peritoneal cavity extends well into chest
       1. Anterior superior diaphragm boundary: Nipple Line
       2. Posterior superior diaphragm boundary: 4th intercostal space
    4. Although distracting injury may theoretically hide abdominal findings on exam, it still has 90% Test Sensitivity
       1. Rostas (2015) J Trauma Acute Care Surg 78(6):1095-100 +PMID:26151507 [PubMed]
    5. Manage secondary conditions
       1. Hemorrhagic Shock
       2. Peritonitis
          1. Broad spectrum antibiotic coverage for intraabdominal infection
          2. Sepsis management including Intravenous FluidResuscitation
12. Management: Emergency Exploratory Laparotomy Indications
    1. Unexplained shock or hemodynamic instability
    2. Visceral Trauma (e.g. evisceration)
    3. Gastrointestinal Bleeding
       1. Blood in Stomach
       2. Blood aspirated via Nasogastric Tube
       3. Rectal Bleeding
    4. Peritoneal signs or peritonitis on examination
       1. Abdominal Distention
       2. Absent bowel sounds
    5. Suspicious findings on adominal XRay or CT Abdomen (e.g. Abdominal free air)
    6. Retained Foreign Body into the peritoneal cavity
       1. All abdominal gun shot wounds should be surgically explored
       2. Stabbing weapon with peritoneal violation
13. References
    1. (2012) ATLS Manual, 9th ed, American College of Surgeons
    2. Dreis (2020) Crit Dec Emerg Med 34(7):3-21
    3. Calwell and Werner in Herbert (2021) EM:Rap 21(6): 5-6