What is the initial assessment and workup for a patient presenting with sharp abdominal pain?

Initial Assessment and Workup for Sharp Abdominal Pain

The initial assessment of sharp abdominal pain should include a focused history, physical examination, basic laboratory tests, and appropriate imaging based on pain location, with CT scan being the preferred imaging modality for most cases of acute abdominal pain when serious pathology is suspected. 1

History Taking - Key Elements

• Pain characteristics:

  • Onset (sudden vs. gradual)
  • Location and radiation
  • Quality (sharp, dull, cramping)
  • Severity (1-10 scale)
  • Timing (constant vs. intermittent)
  • Aggravating/alleviating factors

• Associated symptoms:

  • Nausea/vomiting
  • Changes in bowel habits
  • Fever
  • Urinary symptoms
  • Weight loss

• Red flags requiring urgent attention: 2

  • Pain out of proportion to physical exam (suggests mesenteric ischemia)
  • Sudden onset abdominal distension (suggests volvulus)
  • Unexplained weight loss
  • Pain waking patient from sleep
  • Persistent fever

Physical Examination - Critical Components

• Vital signs: Temperature, heart rate, blood pressure, respiratory rate
• General appearance: Signs of distress, dehydration
• Abdominal examination:
  • Inspection: Distension, visible peristalsis, scars
  • Auscultation: Bowel sounds (increased, decreased, absent)
  • Percussion: Tympany, dullness
  • Palpation: Tenderness, guarding, rebound, rigidity
• Complete examination: Hernia orifices, rectal examination, pelvic examination in women

Laboratory Tests

• Basic tests for all patients: 2

  • Complete blood count
  • Basic metabolic panel
  • Liver function tests
  • Urinalysis
  • Pregnancy test for all women of reproductive age

• Additional tests based on clinical suspicion:

  • Lipase/amylase (suspected pancreatitis)
  • Lactate (suspected ischemia)
  • Arterial blood gas (suspected acidosis)

Imaging Studies

The American College of Radiology recommends imaging based on pain location: 1

• Right upper quadrant pain:

  • First-line: Ultrasonography (especially for suspected cholecystitis)
  • Second-line: CT with contrast if ultrasound is equivocal

• Right or left lower quadrant pain:

  • First-line: CT with contrast (especially for suspected appendicitis or diverticulitis)
  • Alternative: Ultrasonography in pregnant patients or young women

• Diffuse/non-localized pain:

  • First-line: CT with contrast
  • Alternative: Plain radiographs if CT not immediately available

• Special considerations:

  • Pregnant patients: Ultrasound first, followed by MRI if needed
  • Young women: Consider transvaginal ultrasound for gynecological causes

Diagnostic Algorithm

1. Immediate assessment for hemodynamic stability

   • If unstable: Resuscitation, surgical consultation, and expedited imaging

2. Pain localization guides initial approach:

   • Right upper quadrant → Consider gallbladder disease, hepatitis, pneumonia
   • Right lower quadrant → Consider appendicitis, ectopic pregnancy, ovarian pathology
   • Left upper quadrant → Consider splenic issues, gastritis, pancreatitis
   • Left lower quadrant → Consider diverticulitis, colitis, gynecological issues
   • Diffuse pain → Consider bowel obstruction, peritonitis, mesenteric ischemia

3. Imaging selection based on location and suspected diagnosis:

   • Suspected cholecystitis → Ultrasound
   • Suspected appendicitis/diverticulitis → CT with contrast
   • Suspected bowel obstruction → CT with contrast
   • Suspected urolithiasis → Non-contrast CT

Common Pitfalls to Avoid

• Dismissing pain as functional without adequate workup 2
• Administering antibiotics without evidence of infection
• Delaying imaging in patients with significant pain
• Failing to consider extra-abdominal causes of pain
• Relying solely on laboratory tests without appropriate imaging
• Overlooking gynecological causes in women of reproductive age
• Failing to recognize atypical presentations in elderly patients

Special Populations

• Elderly patients: 2

  • Often present atypically (only 50% of elderly with diverticulitis have lower quadrant pain)
  • Lower threshold for advanced imaging
  • Higher risk of serious pathology despite minimal symptoms

• Women of reproductive age:

  • Always perform pregnancy test
  • Consider gynecological causes (ectopic pregnancy, PID, ovarian torsion)

• Pregnant patients:

  • Ultrasound first, followed by MRI if inconclusive
  • Avoid CT when possible

By following this structured approach to the assessment and workup of sharp abdominal pain, clinicians can efficiently identify life-threatening conditions requiring urgent intervention while appropriately managing less serious causes.