What is the appropriate evaluation and management of left upper abdominal pain?

Evaluation and Management of Left Upper Abdominal Pain

Initial Diagnostic Approach

CT abdomen and pelvis with IV contrast is the preferred initial imaging modality for acute left upper quadrant pain, as it provides rapid, comprehensive evaluation of the broad differential diagnosis including splenic, pancreatic, gastric, renal, and vascular pathology. 1

Clinical Assessment Priority Points

• Obtain pregnancy test immediately in all women of reproductive age to exclude ectopic pregnancy before proceeding with imaging 2
• Assess for peritoneal signs (involuntary guarding, rebound) indicating surgical emergency 3
• Document fever, which raises concern for abscess, infection, or inflammatory process requiring urgent intervention 1
• Consider atypical presentations: appendicitis can present in the left upper quadrant with intestinal malrotation 3

Laboratory Workup

Order these tests for all patients with acute left upper quadrant pain: 2

• Complete blood count (leukocytosis suggests infection/inflammation)
• Comprehensive metabolic panel including liver enzymes
• Amylase and lipase (pancreatitis is a common LUQ pain etiology)
• Pregnancy test for women of reproductive age

Add these tests based on clinical suspicion: 2

• Lactate level if mesenteric ischemia suspected
• Coagulation studies (PT/INR, PTT) if splenic rupture or hematoma suspected
• Urinalysis for renal stones or infection

Laboratory Interpretation Pitfalls

• Elevated lipase/amylase strongly suggests pancreatitis 2
• Leukocytosis with left shift indicates infection (splenic abscess, pancreatitis, diverticulitis) 2
• Normal laboratory values do not exclude serious pathology—proceed with imaging based on clinical presentation 2

Imaging Strategy

First-Line Imaging: CT Abdomen/Pelvis with IV Contrast

CT with IV contrast is rated 8/9 (usually appropriate) by ACR guidelines and should be performed in most cases of acute left upper quadrant pain. 1

Key advantages of CT: 1

• Detects broad spectrum of pathology (splenic injury, pancreatitis, abscess, bowel perforation, vascular emergencies)
• Changes leading diagnosis in 49% of cases and alters management in 25% of patients 1
• Rapid acquisition suitable for acute presentations
• Superior to all other modalities for detecting extraluminal air, abscesses, and most intra-abdominal pathology 1

Oral contrast is generally not necessary and delays scan acquisition without clear diagnostic advantage 1

Unenhanced CT may be appropriate if renal stone is primary suspicion (sensitivity/specificity near 100% for urolithiasis) 1

Alternative Imaging Modalities

Ultrasound (transabdominal): 1

• May be used as initial test to reduce CT utilization in select cases
• Real-time, directed to area of maximal tenderness
• Less commonly used in United States for non-gynecologic LUQ pain
• Rated 4/9 (may be appropriate) by ACR

Plain radiography: 1

• Rated 4/9 (may be appropriate)
• Limited utility—can identify large volume free air or bowel obstruction but CT is more sensitive and specific
• May have role in triaging severely ill patients but CT preferred in most cases

MRI abdomen/pelvis: 1

• Rated 4/9 (may be appropriate)
• Not useful for initial evaluation of acute pain
• Less sensitive for free air and urinary calculi
• Time-consuming, requires screening for devices/metal
• More prone to motion artifact in symptomatic patients

Fluoroscopic studies: 1

• Not useful as initial imaging test
• No recent literature supports use for acute LUQ pain evaluation

Differential Diagnosis Considerations

Common causes of left upper quadrant pain requiring imaging confirmation: 1

• Splenic pathology (rupture, infarct, abscess)
• Pancreatitis (elevated lipase/amylase)
• Gastric perforation or ulcer
• Renal colic or pyelonephritis
• Colonic pathology (splenic flexure diverticulitis, perforation)
• Pneumonia (lower lobe)
• Vascular emergencies (splenic artery aneurysm)

Rare but critical presentations: 3, 4

• Appendicitis with intestinal malrotation (can present as LUQ pain)
• Internal hernias through foramen of Winslow
• Perforated viscus within lesser sac

Management Algorithm

1. Immediate assessment: Vital signs, pregnancy test (women of reproductive age), assess for peritoneal signs 2

2. Laboratory workup: CBC, CMP with liver enzymes, lipase/amylase, pregnancy test 2

3. Imaging decision:

   • Most cases: CT abdomen/pelvis with IV contrast 1
   • Suspected renal stone only: Unenhanced CT acceptable 1
   • Premenopausal women with possible gynecologic cause: Consider pelvic ultrasound first 1

4. Post-imaging management: Based on CT findings—may require surgery, interventional drainage, or medical management 1

Critical Pitfalls to Avoid

• Never skip pregnancy testing in reproductive-age women before imaging 2
• Do not rely on clinical diagnosis alone—misdiagnosis rates are 34-68% for conditions like diverticulitis 1
• Do not delay CT for oral contrast administration in acute presentations 1
• Do not assume normal labs exclude serious pathology—proceed with imaging based on clinical suspicion 2
• Consider atypical anatomy (malrotation) if presentation doesn't fit typical patterns 3
• In elderly patients, typical signs may be absent despite serious infection—maintain high index of suspicion 1