Measurement of Endoesophageal Pressure

Abstract
The mechanical properties of the esophageal walls were studied quantitatively in five normal adults of both sexes, in different body positions, changing at various speeds the volume of air in a balloon introduced at various levels in the esophagus and measuring the pressure obtained. It was found that only measurements made with balloons having perimeters greater than 4.8 cm express the mechanical properties of the esophageal walls. The specific elastance values, i.e. the elastance per unit length of the lower third of the esophagus, were found to be 16.0±2.6 (16.2%); this value increases progressively in the middle third of the esophagus. Because of the elastic properties of the esophageal walls and also of the balloon (when its perimeter is less than 4.8 cm), there is a difference between the intrathoracic and endoesophageal pressure variations. This depends upon: a) the volume/pressure coefficient of the measuring equipment, b) the length and perimeter of the balloon and its position in the esophagus, c) the position of the subject during the measurements and d) the specific elastance of the esophagus. Submitted on May 16, 1958