Post-ERCP pancreatitis: randomized, prospective study comparing a low- and high-osmolality contrast agent.

Diagnostic and therapeutic ERCPs are complicated by pancreatitis in 1% to 10% of patients, and evidence suggests that the contrast agent used for ERCP may be important in the pathogenesis of such pancreatitis. This prospective, double-blind study was undertaken to determine whether the use of a low-osmolality, nonionic contrast agent (Omnipaque 300; iohexol, 672 mOsm/kg H2O) would reduce the frequency and severity of postprocedure pancreatitis as compared to a high-osmolality, ionic contrast agent (Hypaque 50%; diatrizoate sodium, 1515 mOsm/kg H20). Six hundred ninety patients undergoing diagnostic ERCP (pancreatogram, cholangiogram, or both) either with or without sphincter of Oddi manometry and therapy were randomized to iohexol or diatrizoate sodium. Postprocedure pancreatitis was diagnosed when the serum amylase or lipase level was elevated to at least four times the upper limits of normal at 18 hours and was associated with increased abdominal pain persisting for at least 24 hours after the procedure that required administration of narcotic analgesics. The pancreatitis was graded as mild, moderate, or severe depending on the length of hospital stay and the need for intervention. The overall frequency (7.2% versus 7.5%) and severity (4.3% mild, 2% moderate, 0.9% severe for the diatrizoate sodium group versus 4.3% mild, 2.6% moderate, and 0.6% severe for the iohexol group) of postprocedure pancreatitis and the frequency and severity within each procedure category were similar for the two contrast agent groups (p > .05).(ABSTRACT TRUNCATED AT 250 WORDS)