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

Management of Abdominal Pain

For patients presenting with acute abdominal pain, begin with a focused assessment of pain location, vital signs, and peritoneal signs to determine imaging strategy, with CT abdomen/pelvis with IV contrast as the preferred initial imaging for nonlocalized pain, followed by targeted treatment based on the underlying diagnosis. 1, 2

Initial Clinical Evaluation

Critical First Steps

• Document pain location precisely (right upper quadrant, right/left lower quadrant, epigastric, periumbilical, or diffuse) as this directly determines imaging selection 2
• Assess for peritoneal signs (guarding, rebound tenderness, rigidity) which indicate potential surgical pathology requiring immediate evaluation 2
• Check vital signs immediately - fever suggests infection/inflammation, hemodynamic instability suggests hemorrhage or sepsis 2
• Obtain pregnancy test in all women of reproductive age before any imaging decisions 2

Key History Elements

• Pain characteristics: onset (sudden vs. gradual), duration, quality, radiation, aggravating/alleviating factors 2
• Associated symptoms: fever, nausea, vomiting, diarrhea, constipation 2
• Recent surgery or immunocompromised status (these patients require different management approaches) 1

Laboratory Workup

Order these tests systematically:

• Complete blood count (leukocytosis indicates infection/inflammation) 2
• C-reactive protein (inflammatory marker) 1, 2
• Liver function tests and hepatobiliary markers for right upper quadrant pain 2
• Serum electrolytes, creatinine, BUN (assess renal function and volume status) 2
• Pregnancy test (mandatory for reproductive-age women) 2
• Stool studies and C. difficile toxin if diarrhea present 2

Imaging Strategy Based on Pain Location

For Nonlocalized or Diffuse Abdominal Pain

CT abdomen/pelvis with IV contrast is the preferred initial imaging modality 1, 2

• Demonstrates 99% overall accuracy for detecting intra-abdominal pathology 1
• Superior to ultrasound for nonlocalized pain (CT sensitivity 88-100% vs. US 75% for abscesses) 1
• Do not obtain plain abdominal radiographs - they have limited diagnostic value and low sensitivity 1, 2

For Localized Pain

• Right upper quadrant pain: Start with ultrasound 2
• Right or left lower quadrant pain: CT scan 2
• Pregnant patients: Ultrasound first, then MRI if needed (avoid CT radiation) 1, 2

MRI as Alternative

• MRI with rapid acquisition protocols shows 99% accuracy for acute abdominal pathology 1
• Can detect appendicitis (100% sensitivity), diverticulitis, small bowel obstruction, pyelonephritis, and abscesses 1
• Use MRI when CT contraindicated (pregnancy, contrast allergy) or when institutional expertise and availability permit rapid protocols 1
• Noncontrast MRI with T2-weighted and diffusion-weighted imaging can distinguish infected from noninfected fluid with 96.6-100% sensitivity 1

Initial Medical Management

Supportive Care (All Patients)

• Adequate IV fluid resuscitation 1
• Low molecular weight heparin for thromboprophylaxis 1
• Correct electrolyte abnormalities and anemia 1

Antibiotics - Use Selectively, Not Routinely

Do not routinely administer antibiotics - only give when superinfection or intra-abdominal abscess is confirmed 1

When antibiotics are indicated:

• Cover Gram-negative bacteria, anaerobes, Gram-positive streptococci 1
• Combination options: fluoroquinolone or third-generation cephalosporin PLUS metronidazole 1
• Expect clinical improvement within 3-5 days; if no improvement, repeat imaging to assess for inadequate drainage 1

Pain Management

• Provide analgesia early - it reduces patient discomfort without impairing diagnostic accuracy 3
• Acetaminophen can be used for pain relief (adults: 2 caplets every 8 hours, maximum 6 caplets/24 hours) 4
• Stop and reassess if pain worsens or lasts >10 days, or if new symptoms develop 4

Special Population Considerations

Postoperative Patients with Fever

• CT with IV contrast is the primary modality for detecting postoperative abscesses, anastomotic leaks, or other complications 1
• Ultrasound is difficult in surgical regions due to pain, staples, and bandages 1
• Concomitant fever primarily suggests postoperative abscess requiring cross-sectional imaging 1

Neutropenic/Immunocompromised Patients

• CT with IV contrast is extremely useful due to high spatial resolution 1
• Most frequent causes: neutropenic enterocolitis (28%) and small bowel obstruction (12%) 1
• Typical signs of infection may be masked - maintain high index of suspicion 1, 2
• Cover atypical and opportunistic infections in antibiotic selection 1

Inflammatory Bowel Disease Patients

• Multidisciplinary approach with gastroenterology and surgery 1
• For severe active ulcerative colitis: IV corticosteroids if hemodynamically stable 1
• Assess steroid response by day 3; consider infliximab or ciclosporin for non-responders 1
• For Crohn's disease with abscess: percutaneous drainage first, then delayed surgery to decrease resection extent 1
• Preoperative immunomodulators, anti-TNF agents, and steroids increase risk of intra-abdominal sepsis 1

When to Pursue Surgical Consultation

Immediate surgical consultation for:

• Peritoneal signs (acute abdomen) 2
• Hemodynamic instability 2
• Free air or perforation on imaging 1
• Small bowel obstruction (though laparoscopic management increasingly feasible) 3
• Abscess not amenable to percutaneous drainage 1
• Clinical deterioration despite appropriate medical management 1

Common Pitfalls to Avoid

• Do not rely solely on laboratory tests without imaging - many conditions require imaging for definitive diagnosis 2
• Do not delay analgesia waiting for diagnosis - judicious analgesia is safe and improves patient comfort 3
• Do not obtain plain radiographs for nonlocalized pain - they have poor sensitivity and CT is superior 1, 2
• In elderly patients, expect atypical presentations with potentially normal labs despite serious pathology 2
• Do not give routine antibiotics - reserve for confirmed infection or abscess 1