What is an easy mnemonic to remember the approach to assessing abdominal pain in emergency medicine, including differentials, history, physical examination, and investigations?

Systematic Approach to Abdominal Pain Assessment in Emergency Medicine

Use the "ABCDE + VINDICATE" framework: stabilize with ABCDE first, then systematically work through differentials using VINDICATE while simultaneously obtaining targeted history, examination, and investigations to identify life-threatening causes within minutes.

Initial Stabilization (ABCDE Approach)

Before detailed assessment, rapidly stabilize the patient using the ABCDE sequence 1:

• Airway: Ensure patency in obtunded patients or those with severe sepsis 1
• Breathing: Assess respiratory rate, oxygen saturation; provide supplemental oxygen if SpO₂ <90% 1
• Circulation: Obtain IV access immediately; begin fluid resuscitation if hypotensive or tachycardic 2
• Disability: Check mental status (obtunded patients may have unreliable abdominal exams) 2
• Exposure: Fully expose abdomen while maintaining dignity 1

Critical timing: For patients with septic shock from intra-abdominal infection, resuscitation and antibiotics must begin immediately upon recognition 2

Life-Threatening Differentials (Mnemonic: "RUPTURED VISCUS")

Prioritize these causes that require immediate intervention 2:

• Ruptured AAA (abdominal aortic aneurysm)
• Ulcer perforation
• Peritonitis (any cause)
• Thrombosis (mesenteric arterial/venous)
• Uterine rupture/ectopic pregnancy
• Ruptured spleen/liver
• Embolic mesenteric ischemia
• Dissection (aortic)

Volvulus

• Ischemic bowel (non-occlusive)
• Septic shock from any intra-abdominal source
• Cholangitis/gangrenous cholecystitis
• Urinary obstruction with sepsis
• Strangulated hernia/bowel obstruction

Targeted History (Mnemonic: "SOCRATES + Red Flags")

SOCRATES for pain characterization 2:

• Site: Localized vs diffuse (diffuse suggests peritonitis) 2
• Onset: Sudden onset suggests perforation, embolism, or dissection 2
• Character: Sharp, cramping, tearing, burning 2
• Radiation: Back pain suggests AAA or pancreatitis 2
• Associations: Fever, vomiting, diarrhea, bleeding 2
• Time course: Constant vs intermittent 2
• Exacerbating/relieving factors: Movement, position, eating 2
• Severity: Use numerical rating scale 0-10 2

Red flag symptoms requiring immediate action 2:

• "Pain out of proportion to exam": Classic for mesenteric ischemia 2
• Hypotension, tachycardia, oliguria: Indicates septic shock or hemorrhage 2
• Syncope with abdominal pain: Ruptured AAA or ectopic pregnancy 2
• Hematemesis, melena, hematochezia: GI bleeding 2
• Fever + peritonitis: Perforated viscus or advanced infection 2

Specific historical clues 2:

• Atrial fibrillation: Mesenteric embolism (50% of embolic cases) 2
• Chronic postprandial pain + weight loss: Mesenteric arterial thrombosis 2
• Recent cardiac event or vasopressor use: Non-occlusive mesenteric ischemia 2
• Hypercoagulable state, oral contraceptives: Mesenteric venous thrombosis 2
• Immunosuppression, malignancy: High-risk for complicated infection 2

Physical Examination (Systematic Approach)

General inspection 2:

• Appearance: Diaphoresis, pallor, distress level 2
• Position: Writhing (colic) vs still (peritonitis) 2
• Vital signs: HR, BP, RR, temperature, SpO₂ 2

Abdominal examination sequence 2:

1. Inspection: Distension, surgical scars, visible peristalsis, ecchymosis 2
2. Auscultation (before palpation): Absent bowel sounds suggest ileus/peritonitis; high-pitched suggests obstruction 2
3. Percussion: Tympany (obstruction), dullness (ascites), loss of liver dullness (perforation) 2
4. Palpation:
   • Start away from pain 2
   • Assess for guarding (voluntary vs involuntary) 2
   • Rebound tenderness: Indicates peritoneal inflammation 2
   • Rigidity: Board-like abdomen suggests perforation 2
   • Masses, organomegaly, hernias 2

Special signs 2:

• Psoas sign: Right lower quadrant pain with hip extension (appendicitis, psoas abscess) 2
• Murphy's sign: Arrest of inspiration with right upper quadrant palpation (cholecystitis) 2
• Rovsing's sign: Right lower quadrant pain with left lower quadrant palpation (appendicitis) 2

Critical caveat: Patients who are obtunded, have spinal cord injury, or are immunosuppressed may have minimal abdominal findings despite life-threatening pathology 2

Investigations (Stepwise Algorithm)

Immediate bedside tests (within 10 minutes) 2:

• ECG: Rule out inferior MI presenting as epigastric pain 2
• Point-of-care ultrasound: Free fluid, AAA, ectopic pregnancy 2
• Bedside glucose: Diabetic ketoacidosis can mimic acute abdomen 2

Urgent laboratory tests 2:

• Complete blood count: Leukocytosis suggests infection; anemia suggests bleeding 2
• Lactate: Elevated in mesenteric ischemia, sepsis, or shock 2
• Lipase: Pancreatitis 2
• Liver function tests: Hepatobiliary pathology 2
• Urinalysis: Urinary tract infection, nephrolithiasis 2
• Pregnancy test: All women of childbearing age 2
• Type and screen: If bleeding or surgery anticipated 2

Imaging algorithm 2:

Step 1: Determine if imaging is needed:

• Skip imaging if: Obvious diffuse peritonitis requiring immediate laparotomy 2
• Proceed with imaging if: Diagnosis uncertain or source control planning needed 2

Step 2: Choose imaging modality:

• CT abdomen/pelvis with IV contrast: Gold standard for most causes; sensitivity >95% for perforation, ischemia, abscess 2
• Ultrasound first if: Suspected cholecystitis, AAA, ectopic pregnancy, or pediatric appendicitis 2
• MRI if: Pregnant patient with inconclusive ultrasound (94% sensitivity for appendicitis) 2
• Plain radiographs: Limited utility; only if perforation suspected and CT unavailable 2

Step 3: Timing:

• Immediate (<30 minutes): Hemodynamic instability, suspected AAA, or mesenteric ischemia 2
• Urgent (1-2 hours): Sepsis, severe pain, or high suspicion for surgical pathology 2

Differential Diagnosis Framework (Mnemonic: "VINDICATE")

Organize differentials anatomically and by pathophysiology 2:

• Vascular: AAA, mesenteric ischemia (arterial/venous), aortic dissection 2
• Inflammatory/Infectious: Appendicitis, cholecystitis, diverticulitis, pancreatitis, peritonitis 2
• Neoplastic: Bowel obstruction from tumor, perforation 2
• Degenerative: (Less relevant in acute setting)
• Iatrogenic: Post-operative complications, medication-induced 2
• Congenital: Meckel's diverticulum (pediatric)
• Autoimmune: Inflammatory bowel disease flare 2
• Traumatic: Solid organ injury, bowel perforation 2
• Endocrine/Metabolic: Diabetic ketoacidosis, porphyria 2

Critical Decision Points

When to start antibiotics 2:

• Immediately (before imaging): Septic shock from suspected intra-abdominal source 2
• In ED (after diagnosis): Confirmed or highly suspected complicated intra-abdominal infection 2
• Ensure therapeutic levels during any source control procedure 2

When to consult surgery 2:

• Peritonitis with hemodynamic instability: Immediate consultation 2
• Free air on imaging: Urgent consultation 2
• Mesenteric ischemia: Emergent consultation (mortality increases hourly) 2
• Complicated infection requiring source control: Urgent consultation 2

Common pitfalls to avoid 2:

• Assuming normal exam rules out serious pathology in high-risk patients (elderly, immunosuppressed) 2
• Delaying antibiotics in septic patients to "get cultures first" 2
• Missing mesenteric ischemia by focusing only on common causes 2
• Attributing all symptoms to known chronic conditions without excluding acute pathology 2