The semirecumbent position for high-resolution esophageal manometry. Results of a feasibility study

Normative values for high-resolution manometry (HRM) have been obtained with the patient lying supine. The aim of the study was to compare supine, semirecumbent and sitting positions during HRM in terms of variation in normative metrics, diagnostic yield, and patient's comfort.

A prospective, single-center feasibility study was planned in consecutive patients referred to the esophageal function laboratory. In each of the three positions, 10 consecutive 5 ml water swallows and three 10 ml multiple rapid swallows were administered. Validated reflux questionnaires were administered prior to the test, and a visual analogue scale (VAS) assessing the patient's comfort after the test.

Twenty patients presenting with gastroesophageal reflux symptoms completed the study protocol. The intra-abdominal segment of the lower esophageal sphincter was significantly longer in the sitting position (P = 0.013), and the multiple rapid swallow distal contractile integral was lowest in the supine position (P = 0.012). The VAS comfort score did not significantly differ in the three body positions (P = 0.295). The concordance in the final diagnosis was 80% for semirecumbent vs. sitting (kappa = 0.15; P = 0.001), 70% for supine vs. sitting and 65.0% for semirecumbent vs. supine.

Compared to the supine position, both the semirecumbent and sitting position seems to provide similar advantages. HRM metrics and the final manometric diagnosis may be affected by body position, but complementary maneuvers, such are the rapid drink challenge, can resolve diagnostic discrepancies and improve the overall accuracy of the test.