Impression and Plan: RUQ Pain with Marked Transaminitis
Impression
This presentation of right upper quadrant pain with marked transaminitis in a middle-aged or older adult strongly suggests biliary obstruction, most likely choledocholithiasis, requiring urgent imaging to identify the level and cause of obstruction. 1
The marked elevation in transaminases (transaminitis) indicates biliary obstruction or cholestasis rather than simple cholecystitis, which typically causes only mild transaminase elevation. 1 The combination of RUQ pain and significantly elevated liver function tests points to bile duct pathology requiring anatomic visualization of the biliary tree. 1
Diagnostic Plan
Immediate Imaging
Order right upper quadrant ultrasound immediately as the first-line imaging study. 1, 2 The American College of Radiology recommends ultrasound as the initial evaluation for suspected biliary obstruction, with specificities of 71-97% for confirming or excluding mechanical obstruction. 1
Ultrasound will detect biliary dilatation (the critical first step), identify gallstones with 96% accuracy, assess gallbladder wall thickening, and evaluate both intrahepatic and extrahepatic bile ducts. 1
Advanced Imaging Based on Ultrasound Results
If ultrasound demonstrates biliary dilatation or is equivocal, proceed directly to MRCP (MRI abdomen with MRCP). 1 MRCP is the preferred advanced imaging modality for detecting choledocholithiasis and biliary obstruction, with sensitivity of 85-100% and specificity of 90%. 1
MRCP excels at visualizing the common bile duct and cystic duct—a significant advantage over ultrasound—and can identify the level and cause of biliary obstruction with accuracy of 91-100%, including stones, strictures, masses, and lymph nodes. 1, 3
Do not order HIDA scan as the primary test for elevated liver function tests and RUQ pain. 1 HIDA scan evaluates gallbladder function but does not provide anatomic visualization of the bile ducts, which is essential when transaminases are markedly elevated. 1
When to Consider CT
Reserve CT abdomen/pelvis with IV contrast for critically ill patients with peritoneal signs or suspected complications beyond simple biliary obstruction (such as emphysematous cholecystitis, gallbladder perforation, or abscess formation). 1, 2
CT has lower sensitivity (39-75%) for detecting gallstones compared to ultrasound, and up to 80% of gallstones are noncalcified, limiting CT's utility for detecting the most common cause of biliary obstruction. 1
Laboratory Evaluation
Obtain complete blood count, comprehensive metabolic panel including liver function tests (AST, ALT, alkaline phosphatase, total and direct bilirubin), and inflammatory markers (CRP, ESR). 2
Check lipase to evaluate for concurrent pancreatitis, which can occur with choledocholithiasis. 2
Therapeutic Considerations
If MRCP confirms choledocholithiasis with biliary obstruction, proceed to therapeutic ERCP. 1, 2 ERCP should only be performed after non-invasive imaging has confirmed biliary obstruction requiring intervention, due to risks of pancreatitis and perforation. 1
Initiate antibiotic therapy if there are signs of acute cholangitis (fever, jaundice, RUQ pain—Charcot's triad). 1
Important Clinical Caveats
The patient's history of duodenal ulcer and GERD does not explain marked transaminitis. 4, 5 While these conditions can cause RUQ discomfort, they do not cause significant liver enzyme elevation and should not distract from the biliary workup. 4
The well-controlled type 2 diabetes increases risk for asymptomatic GERD due to visceral neuropathy, but this is unrelated to the acute presentation of RUQ pain with transaminitis. 6, 7
A normal common bile duct caliber on ultrasound has a 95-96% negative predictive value for choledocholithiasis, but if clinical suspicion remains high with marked transaminitis, proceed to MRCP regardless. 1
Do not delay imaging—hepatobiliary complications can progress rapidly to sepsis. 2