Will liver function tests be abnormal in patients with biliary colic?

Liver Function Tests in Biliary Colic

Yes, liver function tests are frequently abnormal in patients with biliary colic, with approximately 30% of patients showing elevated alkaline phosphatase (ALP) and/or bilirubin, and about 50% showing elevated aminotransferases (ALT/AST). 1

Patterns of Liver Function Test Abnormalities in Biliary Colic

• In patients with acute calculous cholecystitis (ACC) without common bile duct stones (CBDS), approximately 30% have elevated ALP and/or bilirubin, while about 50% have abnormal aminotransferase levels 1
• When biliary colic is associated with CBDS (choledocholithiasis), the percentage of patients with abnormal liver tests increases significantly: 77% have elevated ALP, 60% have abnormal bilirubin, and 90% have elevated aminotransferases 1
• During acute pain episodes in biliary colic, AST elevations may equal or even exceed ALP elevations, contrary to the conventional wisdom that ALP rises more than AST in obstructive jaundice 2

Diagnostic Value of Liver Function Tests in Biliary Colic

• Abnormal liver function tests during episodes of biliary colic can help identify patients who might benefit from endoscopic sphincterotomy, with 90% of patients with abnormal LFTs responding favorably to this procedure 3
• By multivariate analysis, increased common bile duct size and elevated ALP and ALT are excellent predictors of having ACC with concomitant CBDS 1
• However, the 2020 World Society of Emergency Surgery guidelines strongly recommend against using elevated LFTs or bilirubin as the only method to identify CBDS in patients with ACC, as further diagnostic tests are needed 4

Specific Patterns and Clinical Significance

• During maximum liver enzyme derangement in biliary colic patients, median AST elevation (4.4× normal upper limit) often exceeds that for ALP (2.4× normal upper limit) 2
• The normal LFTs have a negative predictive value of 97% for CBDS, whereas the positive predictive value of any abnormal LFTs is only 15% 4
• In patients with ACC without CBDS, LFTs may be altered due to the acute inflammatory process of the gallbladder and biliary tree, rather than direct biliary obstruction 4

Diagnostic Approach When Biliary Colic is Suspected

• Abdominal ultrasound should be the first-line imaging modality for patients with suspected biliary colic and abnormal liver function tests 4
• If ultrasound shows common bile duct stones, patients should proceed directly to ERCP 4
• If ultrasound is negative but ALP remains elevated, MRI with MRCP is recommended as the next step 4
• The visualization of a stone in the common bile duct at transabdominal ultrasound is a predictor of CBDS in patients with ACC 4

Important Caveats

• An increased diameter of the common bile duct alone is not sufficient to identify ACC patients with CBDS 4
• Liver function tests may be normal in up to 87% of patients with uncomplicated symptomatic cholelithiasis 5
• The diagnostic accuracy of serum bilirubin for CBDS increases with the duration and severity of obstruction, with specificity of 60% at a cut-off level of 1.7 mg/dL and 75% at 4 mg/dL 4
• Routine LFTs in preoperative assessment of uncomplicated symptomatic cholelithiasis are not good predictive markers for detecting silent CBD calculi 5