Lower esophageal sphincter pressure measurement under standardized inspiratory maneuveurs.

BACKGROUND Through rhythmic variations, the diaphragm influence lower esophageal sphincter (LES) pressure acting as an external sphincter. LES pressure recording is characterized by increased pressure in inspiration due to contraction of the diaphragmatic crura that involves the sphincter. AIM To describe a method of measuring LES pressure during standardized inspiratory maneuvers with increasing loads. METHODS The study population comprised of eight healthy female volunteers (average age of 31.5 years). An esophageal high-resolution manometry and impedance system was used for measuring the LES pressure during 3-second inspiratory efforts under 12, 24 and 48 cm H2O loads (Threshold maneuvers). RESULTS There was a significant difference between the average maximum LES pressure and the average maximum basal LES pressure during the first (76.19±17.92 difference, p=0.0008), second (86.92±19.01 difference, p=0.0004), and third seconds of the maneuver (90.86±17.93 difference, p=0.0002), with 12, 24 and 48 cmH2O loads. CONCLUSION This maneuver is a standardization of the inspiratory LES pressure and may better differentiate patients with reflux disease from healthy individuals, and may also be useful for monitoring the treatment of these patients through inspiratory muscle training.