What is the initial workup for a patient presenting with right upper quadrant (RUQ) pain?

Initial Workup for Right Upper Quadrant Pain

Order an abdominal ultrasound immediately as the first-line imaging study for any patient presenting with right upper quadrant pain, as it has 96% accuracy for diagnosing gallstones and can rapidly identify or exclude acute cholecystitis. 1, 2

History and Physical Examination

Key History Components

• Pain characteristics: Document onset, duration, quality, severity, and radiation pattern—biliary colic typically presents as episodic severe pain radiating to the right shoulder or back 1
• Associated symptoms: Record fever, nausea, vomiting, anorexia, jaundice, changes in bowel habits, or weight loss 1
• Medication history: Document all medications taken within 6 weeks, including prescription drugs, over-the-counter medications, herbal medicines, and supplements 1
• Medical history: Note any history of biliary disease, prior biliary surgery, liver disease, or family history of cholestatic liver disease 1
• Alcohol intake: Document consumption patterns as alcoholic liver disease can present with RUQ pain 1

Physical Examination Findings

• Vital signs: Check for fever, tachycardia, or hypotension suggesting infection or sepsis 1, 2
• Murphy's sign: Elicit pain with inspiration during palpation of the right upper quadrant—this is highly suggestive of acute cholecystitis 1, 2
• Abdominal examination: Assess for right upper quadrant tenderness, hepatomegaly, splenomegaly, abdominal distension, masses, or peritoneal signs 1, 2

Laboratory Testing

First-Line Tests (Order for All Patients)

• Complete blood count: Assess for leukocytosis indicating infection or inflammation 1, 2
• Liver function tests: Include ALT, AST, alkaline phosphatase, GGT, and bilirubin to evaluate for hepatobiliary disease 1, 2
• Pancreatic enzymes: Order amylase and lipase to rule out pancreatitis 1, 2
• Pregnancy test: Perform for all women of reproductive age before imaging to rule out ectopic pregnancy or other pregnancy-related conditions 1, 2

Imaging Algorithm

Primary Imaging: Ultrasound

Ultrasound is the mandatory first-line imaging modality for all patients with RUQ pain. 3, 1, 2, 4, 5 It provides:

• 96% accuracy for diagnosing gallstones 1, 2
• Identification of gallbladder wall thickening, pericholecystic fluid, and sonographic Murphy sign 1, 2
• Evaluation of intrahepatic and extrahepatic bile ducts 3
• Rapid, cost-effective diagnosis without radiation exposure 2, 4
• Assessment of alternative diagnoses from hepatic, pancreatic, renal, and vascular systems 4, 6

Secondary Imaging (When Ultrasound is Equivocal or Nondiagnostic)

CT abdomen with IV contrast should be performed when: 3, 2

• Ultrasound findings are equivocal or nondiagnostic
• Complications of cholecystitis are suspected (perforation, gas formation, intraluminal hemorrhage, gangrene)
• Alternative diagnoses need to be excluded

CT provides superior detection of gallbladder wall enhancement, adjacent liver parenchymal hyperemia (an early finding in acute cholecystitis), and complications. 3, 2 However, CT has only 75% sensitivity for gallstones, so negative CT does not exclude cholelithiasis. 3, 2

Cholescintigraphy (Tc-99m hepatobiliary scan) should be considered when: 3, 2

• Ultrasound and clinical findings remain equivocal for acute cholecystitis
• Higher sensitivity and specificity for acute cholecystitis is needed (gallbladder nonvisualization with delayed imaging is highly accurate)

MRI abdomen with MRCP may be used when: 3, 2

• Other imaging tests are equivocal
• The patient is difficult to examine with ultrasound
• Detailed evaluation of the biliary tree is needed (MRCP has 85-100% sensitivity for cholelithiasis/choledocholithiasis)
• Distinguishing acute from chronic cholecystitis is necessary (acute shows T2 hyperintensity from edema; chronic shows low signal intensity from fibrosis)

Critical Pitfalls to Avoid

• Never skip ultrasound and proceed directly to CT—ultrasound provides rapid, cost-effective diagnosis and avoids radiation exposure 2
• Do not order CT without IV contrast for suspected cholecystitis—important findings like wall enhancement and liver hyperemia cannot be detected without contrast 3, 2
• Do not rely on CT to exclude gallstones—CT has only 75% sensitivity for gallstone detection 3, 2
• Do not forget pregnancy testing in women of reproductive age before imaging, potentially missing ectopic pregnancy 1, 2
• Recognize that over one-third of patients initially suspected to have acute cholecystitis actually have RUQ pain from other causes—ultrasound can identify multiple alternative diagnoses 4