The role of liver function tests in evaluating common bile duct stones in patients with cholelithiasis has been studied widely.
However, it is not clear whether these predictive models are useful in inflammatory gallstone disease.
Dr Peng undertook a review of 385 consecutive patients admitted as an emergency for acute calculous gallbladder disease.
The diagnosis of calculous cholecystitis was confirmed by ultrasonography or histological confirmation of acute or chronic inflammation of the gallbladder.
|Glutamyl transpeptidase at 90 units/l produced a specificity of 75%|
|British Journal of Surgery|
Patients with obvious jaundice, defined as a bilirubin level above 80 µmol/l, and gallstone pancreatitis were excluded.
The researchers reported that 216 patients met the inclusion criteria, of whom 28 were found to have common bile duct stones.
The research team found that liver function test results were not significantly different in patients with chronic, acute or complicated acute cholecystitis.
Using several cut-off levels, the team noted that glutamyl transpeptidase had the highest specificity.
The team also found that glutamyl transpeptidase had positive predictive value and negative predictive value.
The results were comparable to a scoring system that combined all liver function tests.
The researchers observed that bilirubin was the least specific and predictive.
A cut-off point for glutamyl transpeptidase at 90 units/l produced a sensitivity of 86%.
The team noted that a cut-off point for glutamyl transpeptidase at 90 units/l produced specificity of 75%.
The researchers found that glutamyl transpeptidase at 90 units/l produced positive and negative predictive values of 33% and 97%, respectively.
This represented a 1 in 3 chance of common bile duct stones when the glutamyl transpeptidase level was above 90 units/l.
The team observed that there was a 1 in 30 chance when the level was less than 90 units/l.
Dr Peng's team concluded, “Selection criteria based on glutamyl transpeptidase can be used in acute calculous cholecystitis to identify high-risk patients who would benefit most from further imaging to exclude choledocholithiasis.