02 MII accurately.pdf

Multichannel intraluminal impedance accurately detects fasting, recumbent reflux events and their clearing STEVEN S. SHAY, STEVEN BOMELI, AND JOEL RICHTER Gastroenterology Service, Cleveland Clinic Foundation, Cleveland, Ohio 44195 Received 5 November 2001; accepted in final form 1 April 2002 Shay, Steven S., Steven Bomeli, and Joel Richter. Multichannel intraluminal impedance accurately detects fasting, recumbent reflux events and their clearing. Am J Physiol Gastrointest Liver Physiol 283: G376–G383, 2002. First published April 10, 2002; 10.1152/ajpgi.00470.2001.— Multichannel intraluminal impedance (MII) is a new diag- nostic test for gastroesophageal reflux disease (GERD). The objective of this report is to determine the accuracy of MII in detecting individual reflux events (REs) identified by pH probe and manometry, as well as their clearing in patients with severe GERD compared with normal volunteers. Ten severe GERD patients and 10 normal volunteers underwent simultaneous manometry [7 sites: gastric, lower esophageal sphincter, esophagus (4), pharynx], pH, and MII (6 sites in esophagus) for 15 min in the left and right recumbent posture while fasting. We found that patients had 30-fold more REs than normal volunteers (41
11 vs. 1.3
0.4), and 95% of all REs were detected by MII. An average 15-fold fall in imped- ance with liquid and fivefold rise with gas made REs and their composition easy to detect with MII. In the right re- cumbent posture, nearly all REs detected by MII were liquid (98%, 98/100). In contrast, all 283 REs detected by MII in the left recumbent posture were gas. Nearly all REs detected by MII were cleared (98%, 368/374). Mean acid clearing time was threefold longer (47 s) than clearing time by either manometry (15 s) or MII (13 s), primarily due to acid rereflux, i.e., additional acid REs during acid clearing. We conclude that MII is accurate in detecting REs identified by manom- etry and/or pH probe, their composition, and their clearing