Characterization and correction of pressure drift in theManoScan(™) high-resolution manometry system: In vitro and invivo.

Abstract

A substantial pressure drift in high-resolution manometry (HRM) has been reported; however, fundamental questions remain regarding the origin and management of this drift. The aim of this study was to provide critical in-depth analyses of ManoScan(™) HRM drift invitro and invivo. A total of sixteen 15-min studies and twelve 5-h studies were performed in a water bath at 37°C at 4.0cm depth (2.9mmHg) with ESO and ESO Z catheters. Six 5-h invitro studies were performed similarly at a depth of 9.0cm (6.6mmHg). Eight 15-min studies and nine 8-h invivo studies were performed with healthy participants. Two correction methods - thermal compensation (TC) and interpolated thermal compensation (ITC) - were tested. Overall pressure drift varied both between studies (p<0.01) and within sensors (p<0.01). Drift resulted from thermal shock, an initial pressure change at intubation, and baseline drift, a linear drift over time (R(2) >0.96). Contrary to previous reports, there was no correlation between drift and average (r=-0.02) or maximum pressure exposure (r=-0.05). Following data correction, ITC had the lowest median error but persisted with a maximum error of 2.5mmHg (IQR=3.0). The substantial drift in the ManoScan(™) HRM system is highly variable and not corrected via the standard operating instructions. ITC has superior performance but requires communication with the manufacturer to enable this option. This has a substantial impact on clinical diagnosis, utility of existing normative data, and future research of HRM.