The Effect of HCl Infusion in the Lower Part of the Oesophagus on the Pharyngo-oesophageal Sphincter Pressure in Normal Subjects

Abstract

A measuring unit combined with a perfused catheter has been developed for measurement of the pharyngo-oesophageal sphincter pressure. The system is able to register pressure measurements using either intermittent or continuous withdrawal of the catheter, at the same flow rate (0.5 ml/min). Repeated measurements of pharyngo-oesophageal sphincter pressure have been made on eight healthy volunteers. No differences were found in the sphincter pressures measured by the continuous and the intermittent withdrawal techniques (p > 0.10); the coefficient of variation was 0.18 for both techniques. The pharyngo-oesophageal sphincter pressure was measurec during infusion of 0.1 N HCl (5 ml/min) 5 cm proximally to the gastro-oesophageal sphincter. There was an increase in the pharyngo-oesophageal sphincter pressure after 1 min of infusion (p < 0.05). Measurements after 5 min and 10 min were no different from the initial value; thus a fall was observed between the first and the fifth minute (p <0.05). The observed rise in sphincter pressure may be explained as a response acting to prevent gastro-oesophageal reflux from entering the pharynx.

Key words:

• Acid reflux
• oesophagus
• pharynx
• pressure measurements
• sphincter pressure
• stomach