Assessment of the amylase--creatinine clearance ratio in postoperative patients.

The value of the amylase--creatinine clearance ratio (ACCR) in the diagnosis of postoperative pancreatitis was prospectively assessed. In 77 patients undergoing operations known to have a significant incidence of postoperative pancreatitis (gastric, biliary or pancreatic) i.e. "high risk" group, the ACCR was abnormally elevated postoperatively in 36 patients (47%). However, overt clinical pancreatitis occurred in only eight patients (10%). In 60 other patients undergoing nonabdominal operations (orthiipedic, head and neck, varicose vein surgery etc.) i.e. "low risk" group, the ACCR was abnormally elevated postoperatively in 23 patients (38%). No patient in this group developed clinical pancreatitis. We conclude, therefore, the ACCR is often abnormally elevated nonspecifically following any type of surgery, and cannot be used as evidence of postoperative pancreatitis. These data do suggest, however, that a normal ACCR, especially on successive daily determinations, might help to exclude the diagnosis of postoperative pancreatitis.