Aerophagia, gastric, and supragastric belching: a study using intraluminal electrical impedance monitoring

Abstract

Background: Patients with aerophagia are believed to have excessive belches due to air swallowing. Intraluminal impedance monitoring has made it possible to investigate the validity of this concept.

Methods: The authors measured oesophageal pH and electrical impedance before and after a meal in 14 patients with excessive belching and 14 healthy controls and identified patterns of air transport through the oesophagus. The size of the gastric air bubble was measured radiographically. In four patients prolonged oesophageal manometry was performed simultaneously.

Results: In all subjects, impedance tracings showed that a significant amount of air is propulsed in front of about a third of the swallow induced peristaltic waves. Two types of retrograde gas flow through the oesophagus (belch) were observed. In the first type air flowed from the stomach through the oesophagus in oral direction ("gastric belch"). In the second type air entered the oesophagus rapidly from proximal and was expulsed almost immediately in oral direction ("supragastric belch"). The incidence of air-containing swallows and gastric belches was similar in patients and controls but supragastric belches occurred exclusively in patients. There was no evidence of lower oesophageal sphincter relaxation during supragastric belches. Gastric air bubble size was not different between the two groups.

Conclusions: In patients with excessive belching the incidence of gaseous reflux from stomach to oesophagus is similar to that in healthy subjects. Their excess belching activity follows a distinct pattern, characterised by rapid antegrade and retrograde flow of air in the oesophagus that does not reach the stomach.

Figure 1

Schematic representation of pH, manometric, and impedancometric assemblies used in this study. From left to right: manometric, impedance, and pH catheter.

Figure 2

Air swallowing. Air (high impedance) is propulsed in front of a bolus (low impedance) and moves aborally.

Figure 3

Two different types of belches. (A) The gastric belch is characterised by an increase in impedance that moves in oral direction. (B) A supragastric belch is characterised by an episode with high impedance, the onset of which starts in the proximal channels and moves distally; the end of which is cleared in the opposite direction.

Figure 4

pH, manometric, and impedancometric recordings of a supragastric belch. A decrease in oesophageal pressure (D) precedes the influx of air is followed by a simultaneous increase in pressure (P) in all channels. This increase in pressure is much larger than as seen with a common cavity phenomenon.

Figure 5

pH, manometric, and impedancometric recordings of supragastric belch. Air influx is preceded by a pharyngeal contraction (marked with C) and followed by an simultaneous increase in pressure (P) in all channels.