What is the appropriate evaluation and management for a patient with right upper quadrant abdominal pain that is tender to palpation?

Evaluation and Management of Right Upper Quadrant Abdominal Pain with Tenderness

Immediate First-Line Imaging

Right upper quadrant ultrasound is the mandatory initial imaging study for any patient presenting with RUQ pain and tenderness, rated 9/9 (usually appropriate) by the American College of Radiology. 1

• Ultrasound should be performed immediately as it is both sensitive and specific for demonstrating gallstones, biliary dilatation, and features suggesting acute inflammatory disease 2
• This modality serves as a fast, cost-effective, and dynamic tool that can provide a definitive diagnosis or considerably narrow the differential diagnosis 3
• Ultrasound is the primary imaging modality for assessment of acute RUQ pain and allows differentiation of medical versus surgical causes 4

Essential Laboratory Testing

Obtain a complete metabolic panel with liver function tests (transaminases, alkaline phosphatase, GGT, total/direct bilirubin) to assess for hepatobiliary pathology. 1

• In women of reproductive age, obtain beta-hCG (pregnancy test) before any imaging to avoid missing ectopic pregnancy and guide imaging choices 1
• Laboratory testing should complement, not replace, appropriate imaging—ultrasound remains the initial test regardless of lab values 1

Specific Ultrasound Evaluation Points

The ultrasound examination must specifically assess for:

• Cholelithiasis (gallstones) with 96% accuracy 5
• Gallbladder wall thickening and pericholecystic fluid suggesting acute cholecystitis 1
• Bile duct dilatation (both intrahepatic and extrahepatic) 5
• Hepatic parenchymal abnormalities 1
• Sonographic Murphy sign (though this has relatively low specificity and is unreliable if pain medication was given) 5

Algorithm Based on Ultrasound Findings

If Ultrasound Shows Gallstones and/or Acute Cholecystitis

• Proceed with appropriate surgical consultation for cholecystectomy, as urgent surgical removal is the treatment of choice for uncomplicated acute cholecystitis 2
• If complications are suspected (perforation, abscess), CT abdomen/pelvis with IV contrast may be warranted to confirm extent and nature of complications 2

If Ultrasound Shows Biliary Dilatation or Suspected Choledocholithiasis

Order MRCP as the next diagnostic step—it has 85-100% sensitivity and 90% specificity for detecting choledocholithiasis and provides superior visualization of the entire biliary tree compared to CT. 5

• MRCP excels at visualizing the common bile duct and cystic duct better than ultrasound 5
• MRCP can identify the level and cause of biliary obstruction with 91-100% accuracy, including stones, strictures, masses, and lymph nodes 5
• Non-contrast MRCP sequences alone provide diagnostic information for bile duct stones; IV gadolinium is optional and primarily helps detect complications like cholangitis 5

If Ultrasound is Negative or Equivocal

Proceed to MRCP for comprehensive evaluation of the biliary tree, as over one-third of patients with acute RUQ pain do not have acute cholecystitis and require evaluation for alternative diagnoses. 2, 3

• MRCP is superior to CT for assessing suspected biliary sources of RUQ pain 6
• If acute cholecystitis is still suspected despite equivocal ultrasound (particularly with fever and elevated WBC), consider HIDA scan, which has 96% sensitivity and 90% specificity for acute cholecystitis 1
• CT abdomen/pelvis with IV contrast should be reserved for critically ill patients, those with peritoneal signs, or when complications beyond simple biliary pathology are suspected 6, 5

Critical Clinical Pitfalls to Avoid

Do not skip ultrasound and proceed directly to CT unless the patient is hemodynamically unstable—ultrasound is more appropriate for initial evaluation and avoids unnecessary radiation exposure. 1

• CT has limited value for detecting gallstones, with only ~75% sensitivity and many gallstones being non-radiopaque (up to 80% are noncalcified) 6, 5
• Do not order HIDA scan as the primary test for elevated liver function tests and RUQ pain unless acute cholecystitis is the primary clinical concern 5
• Elevated liver function tests indicate biliary obstruction or cholestasis, which requires anatomic visualization of the bile ducts—something MRCP provides but HIDA scan does not 5
• ERCP is a therapeutic intervention, not a diagnostic test, and should only be performed after non-invasive imaging has confirmed biliary obstruction requiring intervention due to risks of pancreatitis (3-5%), bleeding (2%), cholangitis (1%), and mortality (0.4%) 5

Alternative Diagnoses to Consider

Ultrasound can identify multiple non-biliary causes of RUQ pain, including:

• Hepatic pathology (abscess, mass, cirrhosis with sensitivity 65-95%) 5, 3
• Renal pathology (nephrolithiasis, pyelonephritis) 3
• Pancreatic inflammation 3
• Vascular conditions 3
• Gastrointestinal sources 3

If ultrasound, MRCP, and initial workup are negative, consider an empiric trial of a proton-pump inhibitor (omeprazole 20-40 mg daily for 4-8 weeks) to address possible gastroesophageal reflux disease or peptic ulcer disease. 5