Abdominal Trauma, Blunt

Abdominal Trauma, Blunt

Basics

Description

• Injury results from a sudden increase of pressure to abdomen.
• Solid organ injury usually manifests as hemorrhage.
• Hollow viscous injuries result in bleeding and peritonitis from contamination with bowel contents.

Etiology

• Sixty percent result from motor vehicle collisions.
• Solid organs are injured more frequently than hollow viscous organs.
• The spleen is the most frequently injured organ (25%), followed by the liver (15%), intestines (15%), retroperitoneal structures (13%), and kidney (12%).
• Less frequently injured are the mesentery, pancreas, diaphragm, urinary bladder, urethra, and vascular structures.

Pediatric Considerations

• Children tend to tolerate trauma better because of the more elastic nature of their tissues.
• Owing to the smaller size of the intrathoracic abdomen, the spleen and liver are more exposed to injury because they lie partially outside the bony rib cage.

Diagnosis

Signs and Symptoms

• Spectrum from abdominal pain, signs of peritoneal irritation, to hypovolemic shock
• Nausea or vomiting
• Labored respiration from diaphragm irritation or upper abdominal injury
• Left shoulder pain with inspiration (Kehr sign) from diaphragmatic irritation owing to bleeding
• Delayed presentation possible with small bowel injury

Essential Workup

• Evaluate and stabilize airway, breathing, and circulation (ABCs).
• Primary objective is to determine need for operative intervention.
• Examine abdomen to detect signs of intra-abdominal bleeding or peritoneal irritation.
• Injury in the retroperitoneal space or intrathoracic abdomen is difficult to assess by palpation.
• Remember that the limits of the abdomen include the diaphragm superiorly (nipples anteriorly, inferior scapular tip posteriorly) and the intragluteal fold inferiorly and encompass entire circumference.
• Abrasions or ecchymoses may be indicators of intra-abdominal injury:
  • Roll the patient to assess the back.
• Bowel sounds may be absent from peritoneal irritation (late finding).
• Foley catheter (if no blood at the meatus, no perineal hematoma, and normal prostate exam) to obtain urine and record urinary output
• Plain film of the pelvis:
  • Fracture of the pelvis and gross hematuria may indicate genitourinary injury.
  • Further evaluation of these structures with retrograde urethrogram, cystogram, or intravenous pyelogram
• CT most useful in assessing need for operative intervention and for evaluating the retroperitoneal space and solid organs:
  • Patient must be stable enough to make trip to scanner.
  • Also useful for suspected renal injury
• FAST (focused abdominal sonography for trauma) to detect intraperitoneal fluid
  • Ultrasonography is rapid, requires no contrast agents, and is noninvasive.
  • Operator dependent
• Diagnostic peritoneal lavage (useful for revealing injuries in the intrathoracic abdomen, pelvic abdomen, and true abdomen) primarily indicated for unstable patients:
  • Positive with gross blood, RBC count of >100,000/mm³, WBC count of 500/mm³, or presence of bile, feces, or food particles

Tests

Lab

• Hemoglobin/hematocrit, which initially may be normal owing to isovolemic blood loss
• Type and cross is essential.
• Urinalysis for blood:
  • Microscopic hematuria in the presence of shock is an indication for genitourinary evaluation.
• Arterial blood gases:
  • Base deficit may suggest hypovolemic shock and help guide the resuscitation.

Imaging

See Essential Workup.

Diagnostic Procedures/Surgery

See Essential Workup.

Differential Diagnosis

Lower thoracic injury may cause abdominal pain.

Treatment

Pre Hospital

• Aggressive fluid resuscitation is still considered standard of care.
• Normal vital signs do not preclude significant intra-abdominal pathology.

Initial Stabilization

• Ensure adequate airway:
  • Intubate if needed.
  • O₂ 100% by nonrebreather face mask
• Two large-bore intravenous lines with crystalloid infusion
• Begin infusion of packed RBCs if no response to 2 L of crystalloid.
• If patient is in profound shock, consider transfusion of O-negative or type-specific blood.

ED Treatment

• Continue stabilization begun in field.
• Nasogastric tube to evacuate stomach, decrease distention, and decrease risk of aspiration:
  • May relieve respiratory distress if caused by a herniated stomach through the diaphragm

Medication (Drugs)

• Tetanus toxoid booster: 0.5 mL IM for patients with open wounds
• Tetanus immune globulin: 250 units IM for patients who have not had complete series
• Intravenous antibiotics: broad-spectrum aerobic with anaerobic coverage such as a second-generation cephalosporin

Pediatric Considerations

• Crystalloid infusion is 20 mL/kg if patient in shock.
• Packed RBC dose is 1 mL/kg.

Follow-Up

Disposition

Admission Criteria

• Postoperative cases
• Equivocal findings on diagnostic peritoneal lavage, FAST exam, or CT
• Many blunt abdominal trauma patient benefit from admission, monitoring, and serial abdominal examinations.

Discharge Criteria

No patient in whom you suspect intra-abdominal injury should be discharged home without an appropriate period of observation despite negative examination or imaging studies.