3796 A controlled study of the effect of midazolam on the hypertensive sphincter of oddi.

Abstract

Midazolam HCl (Versed) is increasingly used for conscious sedation in endoscopic sphincter of Oddi (SO) manometry. The effect of medications on normal and abnormal SO motility should be fully characterized if they are to be used during SO manometry (SOM). Controversy exists as to whether midazolam influences SO motility. Aim: To determine the effect of midazolam on the hypertensive SO. Methods: Thirty-six patients presenting with recurrent abdominal pain and sphincter Oddi dysfunction (basal pressure >40 mm Hg) were studied. ERCP and SOM were performed in standard fashion with a perfused triple lumen catheter. The test group (n=18) received 2 mg midazolam IV while the control group (n=18) received IV saline. Basal, phasic and duct pressures as well as phasic amplitude and frequency were recorded before and three minutes after the IV infusion. Changes in these parameters before and after IV infusions were compared. Results: See table below. Midazolam caused a significant reduction in basal and peak SO pressure as compared to saline (16 and 27 mm Hg respectively). Diagnostic concordance (abnormal vs. normal) of the basal sphincter pressure before and after midazolam was seen in only 83% of patients. Conclusions: Midazolam significantly decreased basal and peak pressures of the hypertensive SO. This effect was clinically significant in that it would have altered diagnosis and management in 3 of 18 patients.We propose that midazolam not be used when sedating patients for sphincter of Oddi manometry.