Normal values of high-resolution manometry parameters with provocative maneuvers

Background/Aims Incorporation of complementary and provocative test swallows to the high-resolution manometry (HRM) protocol offers potential to address limitations posed by HRM protocols that involve only a single swallow type. The aim of this study is to describe normal findings of a comprehensive HRM testing protocol performed on healthy asymptomatic volunteers. Methods Thirty healthy asymptomatic volunteers completed HRM with 5-mL liquid swallows in the supine position. They also completed 5-mL liquid swallows in the upright position, viscous swallows, solid test swallows, multiple rapid swallows, and a rapid drink challenge. HRM studies were analyzed via Chicago classification version 3.0. Results The median (5th-95th percentiles) for integrated relaxation pressure (IRP) on supine swallows was 11 (4-16) mmHg; IRP was lower than supine on upright liquid 9 (0-17) mmHg, viscous 6 (0-15) mmHg, solid 9 (1-19) mmHg, multiple rapid swallows 3 (0-12) mmHg, and rapid drink challenge 5 (-3-12) mmHg; P < 0.005. While an "elevated"IRP value was observed on 1 to 2 test maneuvers in 8/30 (27%) subjects, all 30 subjects had an IRP value < 12 mmHg on at least one of the test maneuvers. Conclusions Normal values and findings from a comprehensive HRM testing protocol are reported based on evaluation of 30 healthy asymptomatic volunteers. Isolated "abnormalities"of IRP and contractile parameters were observed in the majority (80%) of these asymptomatic subjects, while all subjects also had normal features observed. Thus, the definition of "normal"should be recalibrated to focus on the entirety of the study and not individual metrics.