Pain at 24 hours associated with amylase levels greater than 5 times the upper normal limit as the most reliable indicator of post-ERCP pancreatitis

Background: The frequency of post-ERCP/sphincterotomy pancreatitis is between 1.3% and 7.6% in prospective studies. This range likely reflects differences in definitions of pancreatitis and methods of data collection. Methods: To identify clinical findings and enzymatic values consistent for clinical pancreatitis at 24 hours, the post-ERCP/sphincterotomy course of 1185 procedures was prospectively recorded. Patients were evaluated for pancreatic-type pain, white blood cell count, and serum amylase before and 24 hours after the procedure; pain and amylase levels were also recorded 6 to 8 hours after the procedure. CT was performed in all patients with pain associated with amylase levels greater than 3 times normal. All patients were evaluated clinically at 48 hours. Results: Pancreatic-type pain never occurred in cases with amylase levels lower than 3 times normal; it was significantly (p < 0.001) associated with amylase levels greater than 5 times normal, either 6 to 8 hours or 24 hours after the procedure. Leukocytosis and CT findings consistent with pancreatitis were observed only in patients (41.7% and 29.5%, respectively) with 24-hour amylase levels greater than 5 times normal, None of the 18 patients with pain at 24 hours and serum amylase lower than 5 times normal had symptoms that persisted at 48 hours, Twenty-five (41.7%) of the 60 patients with pain at 24 hours and amylase higher than 5 times normal had 48-hour pain at 48 hours and hyperamylasemia. Conclusions: Features consistent with clinical pancreatitis were present only among patients with pancreatic-type pain at 24 hours and amylase levels higher than 5 times normal. Additional follow-up is required for these patients.