What is the appropriate workup for lower abdominal pain following a motor vehicle collision (MVC)?

From the Guidelines

The workup for lower abdominal pain after a motor vehicle collision (MVC) should begin with a thorough physical examination, focused assessment with sonography for trauma (FAST), and contrast-enhanced abdominal CT, as recommended by the WSES guidelines on blunt and penetrating bowel injury 1. The initial assessment should include a primary survey to evaluate for life-threatening injuries, followed by a secondary survey to assess for other potential injuries.

• The physical examination should include inspection for signs of trauma, such as the "seatbelt sign," which should prompt a high index of suspicion for bowel injury 1.
• Laboratory tests should include complete blood count, comprehensive metabolic panel, urinalysis, and pregnancy test for females of childbearing age.
• Imaging studies should start with a CT scan of the abdomen and pelvis with IV contrast, which is the gold standard for identifying solid organ injuries, hollow viscus injuries, and retroperitoneal bleeding 1.
• Additional studies may include pelvic X-rays to evaluate for fractures if pelvic instability is noted on exam, and a CT cystogram for patients with hematuria to evaluate for bladder injury.
• Serial physical examinations and vital sign monitoring are crucial, as some injuries may not be immediately apparent.
• Pain management should include acetaminophen and, if needed, opioids such as morphine 4-6mg IV or hydromorphone 0.5-1mg IV, while avoiding NSAIDs initially until internal bleeding is ruled out. The workup is essential because blunt abdominal trauma can cause injuries to solid organs, hollow viscera, or vascular structures that may not present with immediate symptoms but can lead to significant morbidity if not identified promptly 1.
• The presence of highly specific CT findings, such as extraluminal air or bowel-wall defects, warrants prompt surgical exploration 1.
• In patients with high-risk mechanisms and non-specific CT findings, admission for observation, including serial clinical examination, is recommended 1.
• Repeat CT scans may be considered in selected cases, such as patients with equivocal signs on initial CT scan or those who demonstrate evolving clinical signs suspicious for bowel injury 1.

From the Research

Lower Abdominal Pain Workup after MVC

• The workup for lower abdominal pain after a motor vehicle collision (MVC) involves a combination of physical examination, laboratory tests, and imaging studies 2, 3, 4.
• Physical examination findings, such as the seat belt sign, abdominal bruising, abdominal wound, and abdominal tenderness, are significant predictors of the need for abdominal exploration after MVC in children 2.
• In adults, the location of pain is a useful starting point for further evaluation, with right lower quadrant pain strongly suggesting appendicitis 4.
• Laboratory tests and radiographic findings may not be significant in differentiating between patients who require abdominal surgery and those who do not 2.
• Computed tomography (CT) is recommended for assessing abdominal pain based on pain location, with ultrasonography recommended for right upper quadrant pain and CT for right and left lower quadrant pain 4, 5.
• CT is the best first-line imaging tool to identify abdominal hemorrhage, especially when the bleeding rate is low, and can help identify the location and severity of the hemorrhage 6, 5.

Imaging Studies

• CT scans can help clinicians provide accurate information even in hemodynamically unstable trauma patients 6.
• The use of CT scans can identify the bleeding site and guide further management, including the need for emergent operation or embolization 6.
• Recognizing acute hemorrhage and identifying its location and severity are key to expediting management, and CT scans can help identify characteristic appearances of abdominopelvic hemorrhage, such as the "sentinel clot" sign or the "triangle sign" 5.

Special Considerations

• Special populations, such as women and the elderly, may require additional consideration in the workup for lower abdominal pain after MVC, as they may be at risk of genitourinary disease or present with atypical symptoms of a disease 4.
• Hemodynamically unstable patients may require emergent exploratory laparotomy, but CT scans can still provide valuable information to guide management 6.