Abstract
Background: To evaluate the value of the 3-hour post-ERCP serum amylase level for early prediction of post-ERCP pancreatitis (PEP).
Method:
A study of 206 patients performed ERCP was analysed. The patients with PEP were recorded. ROC curves were used to statistically analyze the data.
Results: PEP occurred in 21 patients (10.19%). The 3-hour post-ERCP pancreatic amylase level was used as the test variable, and the PEP occurrence as the state variable to plot ROC curve. The area under the curve (AUC) was 0.816 , and was statistically significant (P<0.001). The standard error (SE) was 0.0507, the 95% confidence interval (CI) was 0.756-0.866, and the optimal cut-off value was 351U/L (sensitivity 76.19%, specificity 83.24%, positive likelihood ratio 4.55, negative likelihood ratio 0.29, Youden index 59.43%). The ROC curves were plotted for both serum amylase and lipase respectively. The areas under the ROC curves were statistically significant(P<0.001). The area under the ROC curve for the 3-hour post-ERCP lipase was 0.778, the 95% confidence interval was 0.673-0.862, and optimal cut-off value was 1834 U/L. The area under the ROC curve for the 3-hour post-ERCP serum amylase was 0.780, and the 95% confidence interval was 0.676-0.864. The optimal cut-off is 380U/L, and there was no statistically significant difference between the two for diagnostic accuracy. According to gender, there was no statistically significant difference in the diagnostic accuracy. In the male group, 436 U/L serum amylase provided the greatest diagnostic accuracy with sensitivity(SE) of 70.5%, specificity(SP) of 89.2%, positive predictive value (PPV) 87.5%, and negative predictive value (NPV) 78.1%. Whereas, in the female group, 357U/L serum amylase provided the greatest diagnostic accuracy with sensitivity of 76.9%, specificity of 81.2%, positive predictive value of 80.4%, negative predictive value of 77.9%.
Conclusions: 1. The 3-hour post-ERCP serum amylase level is a useful measurement for predicting post-ERCP pancreatitis. 2. There was no significant difference between serum amylase and lipase 3-hour post-ERCP for predicting PEP. 3. There was no statistically significant difference between male and female using the 3-hour post-ERCP serum amylase level to predict PEP. For female, the optimal cut-off value was 357 U/L, whereas male 436U/L .
Relationship between post-ERCP pancreatitis and the change of serum amylase level after the procedure
