Description

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

Etiology

• Motor vehicle collisions are the greatest cause of blunt abdominal trauma
• Solid organs are injured more frequently than hollow viscus organs
• The liver and spleen are the most frequently injured organs, followed by the intestines and retroperitoneal structures
• Less frequently injured are the mesentery, pancreas, diaphragm, urinary bladder, urethra, and vascular structures

• Children can lose large amounts of intra-abdominal blood quickly due to smaller blood volumes
• Owing to the smaller size of the intrathoracic abdomen, the spleen and liver are more exposed to injury because they lie partially outside the boney rib cage
• Unrecognized pediatric abdominal trauma is a significant contributor to mortality among traumatic injuries in children

Signs and Symptoms

• Patients present with a spectrum of symptoms from abdominal pain, signs of peritoneal irritation to hypovolemic shock
• Nausea or vomiting
• Labored respiration can be present 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
• Associated injuries (fractures, abdominal wall injuries) may mimic abdominal injuries
• Abrasions or ecchymosis may be indicators of intra-abdominal injury:
  • Lap-belt abrasions can be indicative of significant intra-abdominal injuries
  • Flank and periumbilical bruising can represent retroperitoneal hemorrhage (late finding)
• Bowel sounds may be absent from peritoneal irritation (late finding)

Essential Workup

• Evaluate and stabilize airway, breathing, and circulation
• Primary objective is to determine need for operative intervention
• Examine abdomen to detect signs of intra-abdominal bleeding or peritoneal irritation, but the examination is limited in detecting intraperitoneal blood
• Injury in the retroperitoneal space or intrathoracic abdomen is difficult to assess by palpation
• The limits of the abdomen include the diaphragm superiorly (nipples anteriorly, inferior scapular tip posteriorly) and the intragluteal fold inferiorly and encompass entire circumference
• Rectal exam should be done to assess for boney trauma or blood
• Insert Foley catheter (if no blood at the meatus, no perineal hematoma, and normal prostate exam) to obtain urine and record urinary output
• CT is most useful in assessing the need for operative intervention and for evaluating the retroperitoneal space and solid organs
• There are few indications for diagnostic peritoneal lavage in a hemodynamically stable patient when CT is readily available
• CXR can aid in detection of pneumoperitoneum or ruptured diaphragm
• Pelvis radiograph:
  • Fracture of the pelvis and gross hematuria may indicate genitourinary injury
  • Further evaluation of these structures with retrograde urethrogram or cystogram
• Focused abdominal sonography for trauma (FAST) to detect free intraperitoneal fluid:
  • Ultrasound is rapid, requires no contrast agents, and is noninvasive
  • Operator dependent
  • Does not exclude intra-abdominal injury

Diagnostic Tests and Interpretation

• Check hemoglobin/hematocrit, which initially may be normal owing to isovolemic blood loss
• Check coagulation markers (platelets, prothrombin, and partial thromboplastin time). Effects of some anticoagulants may not be accurately reflected in lab values
• Type and screen is essential. Cross-match packed red blood cell units for unstable patients
• Urinalysis for blood:
  • Microscopic hematuria in the presence of shock should prompt genitourinary evaluation
• Pregnancy test for females of child-bearing age
• Ethanol concentration
• Arterial blood gas:
  • Base deficit may suggest hypovolemic shock and help guide the resuscitation

Differential Diagnosis

• Lower thoracic injury may cause abdominal pain
• Fractures (rib, pelvis) may cause abdominal pain

Pre Hospital

• Titrate fluid resuscitation to clinical response. Target SBP of 90–100 mm Hg
• Normal vital signs do not preclude significant intra-abdominal pathology

Initial Stabilization/Therapy

• Ensure adequate airway:
  • Intubate if needed
  • O₂ 100% by nonrebreather face mask
• 2 large-bore IV lines with crystalloid infusion
• Begin infusion of packed red blood cells if no hemodynamic response to 1 L of crystalloid
• If patient is in profound shock, consider immediate transfusion of O-negative blood
• Consider TXA for hemorrhage
• Surgical intervention with laparotomy by a qualified surgeon is indicated for uncontrolled shock, findings of hemoperitoneum, clinical signs of peritonitis, or clinical deterioration during observation

Ed Treatment/Procedures

• See Essential Workup
• 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

• Tetanus toxoid booster: 0.5 mL IM for patients with open wounds
• Tetanus immunoglobulin: 250 U IM for patients who have not had complete series
• Intravenous broad-spectrum antibiotics should be administered when laparotomy is indicated
• Correct coagulopathy when clinically indicated
• Administered analgesia when needed. Avoid nonsteroidal anti-inflammatory drugs due to risk of bleeding

• Initial volume resuscitation consists of a 20 mL/kg crystalloid fluid bolus (can be repeated)
• If abnormal hemodynamics persist, administer 10 mL/kg PRBC

Disposition

• Patients who require surgical intervention
• Equivocal findings on FAST exam or CT

• Patients with isolated blunt abdominal trauma who are clinically stable and have a negative abdominal CT (with intravenous contrast) can be considered for safe discharge
• No patient with suspected intra-abdominal injury should be discharged