What is the appropriate management for a patient presenting with abdominal pain?

Management of Abdominal Pain

For patients presenting with acute abdominal pain, obtain a focused history and physical examination to localize the pain, then proceed directly to CT abdomen/pelvis with IV contrast for nonlocalized or diffuse pain, as this is the most accurate initial imaging modality that changes management in approximately 50% of cases. 1

Initial Clinical Assessment

Critical History Elements

• Pain location is the single most important factor determining diagnostic workup and imaging selection 2, 3
• Document onset (acute vs. chronic), duration, quality, radiation pattern, and aggravating/alleviating factors 3
• Identify associated symptoms: fever (suggests infection/inflammation), nausea, vomiting, diarrhea, constipation 3
• Check pregnancy status in ALL women of reproductive age - this fundamentally changes imaging decisions 2, 3

Physical Examination Priorities

• Assess vital signs for fever (infection/inflammation) and hemodynamic instability (hemorrhage/sepsis) 3
• Perform systematic abdominal exam: look for distension, peritoneal signs (guarding, rebound tenderness), localized tenderness 3
• Presence of peritoneal signs = acute abdomen requiring immediate surgical evaluation 2

Laboratory Workup

Order these tests based on clinical presentation:

• Complete blood count for leukocytosis (infection/inflammation) 3
• Pregnancy test (mandatory for reproductive-age women) 3
• C-reactive protein as inflammation marker 3
• Liver function tests and hepatobiliary markers for right upper quadrant pain 3
• Serum electrolytes, creatinine, BUN for renal function 3
• Stool studies and C. difficile toxin if diarrhea present 3

Special Population Considerations

• Elderly patients: Atypical presentations are common; laboratory tests may be normal despite serious infection 3
• Immunocompromised/neutropenic patients: Typical signs of sepsis may be masked; neutropenic enterocolitis (28%) and small bowel obstruction (12%) are most common causes 1

Imaging Strategy by Pain Location

Nonlocalized or Diffuse Abdominal Pain

• CT abdomen/pelvis with IV contrast is the primary imaging modality 1, 3
• CT changes leading diagnosis in 49% of cases, alters admission status in 24%, and changes surgical plans in 25% 1
• CT demonstrates superior sensitivity for appendicitis (94%), diverticulitis (81%), and abscess detection (88% sensitivity, 93% specificity) compared to ultrasound 1
• Plain abdominal radiographs have limited diagnostic value and should NOT be routinely used 1, 3

Right Upper Quadrant Pain

• Ultrasound is the initial imaging test of choice 3

Right or Left Lower Quadrant Pain

• CT scan is recommended 3

Alternative Imaging Options

• MRI abdomen/pelvis: Use for pregnant patients or when CT is contraindicated 1, 3

  • Rapid noncontrast MRI protocols demonstrate 99% overall accuracy for acute abdominal pathology 1
  • MRI shows 100% sensitivity for appendicitis and can distinguish infected from noninfected fluid 1
  • Caveat: MRI feasibility depends on institutional expertise, availability, and rapid acquisition protocols 1

• Ultrasound limitations: Less sensitive than CT for nonlocalized pain (75% vs. 88% sensitivity for abscess detection) 1

Special Clinical Scenarios

Abdominal Pain with Fever

• Primary concern is intra-abdominal abscess - proceed directly to CT with IV contrast 1
• CT reveals sepsis source in infectious/inflammatory conditions and guides percutaneous drainage 1
• Common etiologies: abscess, diverticulitis, appendicitis, cholecystitis, pelvic inflammatory disease, C. difficile colitis 1
• Code both conditions separately (R10.x for pain location, R50.9 for fever) 2

Postoperative Abdominal Pain with Fever

• CT with IV contrast is essential to evaluate for abscess, anastomotic leak, bowel obstruction 1
• MRI demonstrates 100% accuracy for detecting abdominal abscesses and can distinguish infected from noninfected fluid 1

Neutropenic Patients

• CT with IV contrast is the initial imaging study given high frequency of neutropenic enterocolitis and small bowel obstruction 1
• Infectious/inflammatory small bowel and colon processes are well-depicted, including abscess and perforation 1

Critical Pitfalls to Avoid

• Do not rely solely on laboratory tests without appropriate imaging - many conditions require imaging for definitive diagnosis 3
• Do not order plain radiographs for nontraumatic abdominal pain - they demonstrate low sensitivity and CT has superior diagnostic yield 1
• Do not repeat ultrasound after negative CT in most scenarios - CT is more sensitive and follow-up ultrasound rarely adds diagnostic value 1
• Do not perform repetitive testing once functional disorder is diagnosed - refer for psychological support and pharmacological management 4

Management Algorithm

1. Localize the pain through focused history and physical examination 2, 3
2. Assess for peritoneal signs - if present, immediate surgical consultation 2
3. Order pregnancy test for all reproductive-age women 2, 3
4. Select imaging based on pain location:
   • Nonlocalized/diffuse → CT with IV contrast 1, 3
   • Right upper quadrant → Ultrasound 3
   • Lower quadrant → CT 3
   • Pregnant patients → Ultrasound first, then MRI if needed 3
5. Obtain targeted laboratory studies based on clinical presentation 3
6. Initiate treatment based on imaging findings: surgery, antibiotics, percutaneous drainage, or outpatient management 5