What is the appropriate management of abdominal pain in the emergency department?

Emergency Department Management of Abdominal Pain

Begin with immediate pain control using IV opioids or oral NSAIDs—analgesia does not impair diagnostic accuracy and should never be delayed. 1, 2

Immediate Assessment and Resuscitation

Assess hemodynamic stability first by checking for tachycardia, hypotension, fever, respiratory distress, or decreased urine output, which require immediate resuscitation with IV crystalloid fluids and urgent surgical consultation. 2, 3

• Tachycardia alone is the most sensitive early warning sign of surgical complications and should trigger urgent investigation, even before other symptoms develop. 4
• "Pain out of proportion to exam" demands immediate suspicion for acute mesenteric ischemia (AMI) until proven otherwise—this is a surgical emergency with 50-80% mortality if untreated and requires immediate surgical consultation. 2, 3, 4
• Check for peritoneal signs (guarding, rigidity, rebound tenderness) which indicate peritonitis requiring emergency surgical exploration. 2, 4

Mandatory Initial Testing

Obtain pregnancy test immediately in all women of reproductive age before any imaging—this is mandatory and non-negotiable. 1, 2, 3, 4

Order complete blood count, basic metabolic panel, lactate level, C-reactive protein, liver function tests, and lipase for right upper quadrant or epigastric pain immediately for all patients with acute abdominal pain. 2, 3

• Elevated lactate levels are critical for detecting life-threatening conditions such as bowel ischemia, severe sepsis, or AMI. 2
• C-reactive protein has superior sensitivity and specificity compared to white blood cell count for confirming surgical disease. 3, 4

Pain Management Protocol

Administer analgesia immediately—do not delay for diagnosis. 1, 2, 5

• Use IV opioids (morphine, fentanyl, or hydromorphone) for moderate-to-severe pain. 1
• Use oral NSAIDs for mild-to-moderate pain. 1, 2
• Pain medication does not mask symptoms or impair diagnostic accuracy—withholding pain relief is both cruel and counterproductive. 1, 2, 5

Imaging Strategy Based on Pain Location

For right upper quadrant pain: Use ultrasound as first-line imaging, with sensitivity of 81% and specificity of 83% for cholecystitis. 2, 3, 4

For right lower quadrant pain (suspected appendicitis): CT with IV contrast is definitive, with sensitivity >95%. 1, 2, 3, 4

• Migratory pain from periumbilical to right lower quadrant strongly suggests appendicitis and warrants immediate CT imaging. 2
• Use clinical findings to risk-stratify patients and guide decisions about further testing, observation, or surgical consultation. 1

For diffuse or nonlocalized abdominal pain: CT abdomen/pelvis with IV contrast is the imaging modality of choice, identifying pathology across multiple organ systems and changing management in 51% of cases. 1, 2, 3

Antibiotic Administration

Administer broad-spectrum antibiotics immediately if infection, perforation, or peritonitis is suspected, covering gram-negative organisms and anaerobes with amoxicillin/clavulanate or ceftriaxone + metronidazole. 2

Surgical Consultation Criteria

Emergency surgical consultation for laparotomy is necessary if:

• Overt peritonitis is present 2, 3
• Perforation is suspected 2, 3
• Septic shock is present 2
• Hemodynamic instability with large peritoneal effusion 3
• Suspected mesenteric ischemia 3, 4

Disposition Decisions

Admit to hospital if:

• Hemodynamic instability is present 2
• Peritoneal signs are present 2
• Suspected surgical conditions are identified 2

If discharging with negative imaging:

• Ensure 24-hour follow-up, as approximately 30% of ED abdominal pain cases remain undiagnosed. 1, 2
• Provide strict verbal and written return precautions. 6
• Close reassessment of pain, vital signs, and physical examination are necessary to ensure safe discharge. 6

Critical Pitfalls to Avoid

Never delay analgesia—pain medication does not mask symptoms or impair diagnostic accuracy. 1, 2, 5

Never rely solely on clinical exam or labs without imaging when diagnosis is unclear—imaging changes management in 51% of cases and admission decisions in 25%. 1, 2

Never miss the "window of opportunity" in appendicitis—delays beyond 24 hours increase perforation risk and complications. 2

Never overlook gynecologic emergencies (ectopic pregnancy, ovarian torsion, PID) in women of reproductive age. 1, 2, 4

Never discharge patients with "pain out of proportion to exam" without CTA—this is AMI until proven otherwise. 2, 3, 4

Never over-rely on normal laboratory values early in disease—this can lead to missed diagnoses. 4

Special Population Considerations

Elderly patients have higher likelihood of malignancy, diverticulitis, and vascular causes, with symptoms often atypical—require more extensive evaluation even if laboratory tests are normal. 3

Post-bariatric surgery patients often present with atypical symptoms, and classic peritoneal signs are frequently absent—tachycardia is the most critical warning sign in this population. 3