Postoperative elevation of amylase/ creatinine clearance ratio in patients without pancreatitis

An elevated C_Am C_Cr ratio has been used as evidence for the frequent occurrence of acute pancreatitis in the postoperative period. We measured C_Am C_Cr preand postoperatively in 28 patients undergoing extraperitoneal surgical procedures. None of the patients had clinical evidence of pancreatitis, although 2 of the 28 patients had elevated C_Am C_Cr ratios preoperatively. Mean C_Am C_Cr rose from a preoperative level of 2.3 ± 0.3% (1 SE) to 3.2 ± 0.3% on the first postoperative day (P < 0.001). Of the 26 patients with normal preoperative C_Am C_Cr, 12% (3 of 26) developed a clearly abnormal ratio and 12% (3 of 26) developed borderline elevated values. An elevated C_Am C_Cr appears to be a nonspecific postoperative finding and cannot be used as evidence of acute pancreatitis during this period.