What is the best approach to manage a patient presenting with abdominal pain?

Management of Abdominal Pain: A Systematic Approach

Begin with immediate vital sign assessment and proceed with a structured evaluation based on pain location and severity, prioritizing imaging over laboratory tests for definitive diagnosis, with CT scan being the preferred modality for most presentations except right upper quadrant pain where ultrasound is first-line. 1

Immediate Assessment and Stabilization

Vital Signs and Red Flags

• Check vital signs immediately to identify tachycardia, fever, hypotension, respiratory distress, or decreased urine output—these are alarming signs requiring urgent intervention 1
• Hemodynamically unstable patients require immediate IV fluid resuscitation with crystalloid solutions and surgical consultation 1, 2
• Patients with peritoneal signs (guarding, rebound tenderness), signs of perforation, or septic shock require emergency surgical exploration 1

Critical History Elements

• Document pain location, onset (sudden vs. gradual), duration, quality, radiation pattern, and aggravating/alleviating factors 1
• Assess associated symptoms: nausea, vomiting, diarrhea, constipation, fever 1
• Note current medications, especially steroids, immunomodulators, or anti-TNF-α agents, which mask symptoms and increase infection risk 2
• Mandatory pregnancy test for all women of reproductive age before any imaging 1

Physical Examination Priorities

• Perform complete abdominal examination: inspection for distension, auscultation for bowel sounds, percussion, and palpation for tenderness, guarding, or rebound 1
• Look for specific findings that guide diagnosis: distension suggests obstruction, localized tenderness suggests organ-specific pathology 1

Laboratory Investigations

Order these tests strategically, not routinely:

• Complete blood count for leukocytosis (infection/inflammation) or anemia 2
• C-reactive protein and ESR to assess inflammation severity 2
• Basic metabolic panel for electrolyte abnormalities and renal function 2
• Liver function tests and hepatobiliary markers specifically for right upper quadrant pain 1
• Lactate level if sepsis or bowel ischemia suspected 2

Imaging Strategy Based on Pain Location

This is the critical decision point—imaging choice depends on pain location:

Right Upper Quadrant Pain

• Ultrasonography is first-line (sensitivity 81%, specificity 83% for cholecystitis) 1

Right Lower Quadrant Pain

• CT scan with IV contrast (sensitivity >95% for appendicitis) 1

Left Lower Quadrant Pain

• CT scan with IV contrast (for suspected diverticulitis) 1

Diffuse or Nonlocalized Abdominal Pain

• CT scan of abdomen and pelvis with IV contrast is preferred 1
• This is the most common scenario in urgent care and CT provides the broadest diagnostic yield 3

Pelvic Pain

• CT of abdomen and pelvis with contrast 1

Suspected Kidney Stones

• Non-contrast CT of abdomen and pelvis 1

Limited Role for Plain Radiographs

• Plain films have minimal diagnostic value except for suspected bowel obstruction 1
• Do not routinely order plain films—they delay definitive diagnosis 1

Antibiotic Therapy Guidelines

Antibiotics are NOT routine—use only when indicated:

• Do not routinely administer antibiotics 3, 1
• Indications for antibiotics: suspected intra-abdominal infection, confirmed abscess, or sepsis 3, 1
• For intra-abdominal abscesses or superinfection: cover Gram-negative aerobic/facultative bacilli, Gram-positive streptococci, and obligate anaerobic bacilli 3
• Combination therapy: fluoroquinolone or third-generation cephalosporin PLUS metronidazole 3
• Clinical improvement should occur within 3-5 days; if not, repeat imaging and consider drainage repositioning or surgery 3

Management Based on Specific Findings

Intra-abdominal Abscesses

• Abscesses >3 cm: percutaneous drainage with antimicrobial therapy 1
• Abscesses <3 cm without fistula and no steroid use: may respond to antibiotics alone, but expect high recurrence rates 3
• Close clinical observation required—deterioration mandates drainage or surgery 3

Inflammatory Bowel Disease Presentations

• Multidisciplinary approach with gastroenterology and acute care surgery 3
• All IBD patients with acute abdomen: adequate IV fluids, low molecular weight heparin for thromboprophylaxis, correct electrolytes and anemia 3
• Severe active ulcerative colitis (if hemodynamically stable): IV corticosteroids 3
• Assess steroid response by day 3; non-responders may need medical rescue therapy (infliximab with thiopurine or ciclosporin) 3

Special Population Considerations

Elderly Patients

• Often present with atypical symptoms and may have normal laboratory tests despite serious pathology 1
• Lower threshold for imaging in this population 3
• Higher risk of serious conditions with subtle presentations 1

Women of Childbearing Age

• Always consider gynecologic conditions: ectopic pregnancy, ovarian torsion, pelvic inflammatory disease 1
• Pregnancy test is mandatory before imaging 1
• For pregnant patients: ultrasound first-line; if additional imaging needed, MRI preferred over CT 1

Immunocompromised Patients

• May have masked signs of abdominal sepsis 1
• Diagnosis often delayed with higher mortality 1
• Lower threshold for imaging and surgical consultation 2

Disposition Decisions

Admit to hospital if:

• Severe pain with hemodynamic instability 1
• Peritoneal signs (guarding, rebound tenderness) 2
• Suspected surgical conditions 1
• Free air or fluid on imaging 2
• Bowel obstruction 2
• Failed conservative management 2

Critical Pitfalls to Avoid

• Do not rely solely on laboratory tests without appropriate imaging—many conditions require imaging for definitive diagnosis 1
• Do not delay surgical consultation in patients with peritonitis or septic shock 1
• Do not overlook gynecological causes in women of reproductive age 1
• Do not assume elderly patients with normal labs are fine—they frequently present atypically 1
• Do not overuse CT scans in young patients unnecessarily—consider radiation exposure 1
• Do not order repetitive testing once functional pain is diagnosed 1

Key Algorithmic Summary

1. Vital signs → Unstable? → Resuscitate + Surgery consult
2. Stable? → Pregnancy test (if applicable) → Pain location assessment
3. Pain location → Appropriate imaging (NOT labs first)
4. Imaging results → Surgical condition? → Surgery consult
5. Medical condition? → Targeted antibiotics ONLY if infection/abscess
6. No clear diagnosis? → Consider special populations and atypical presentations