Steen Boesby

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

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 greater than 0.10); the coefficient of variation was 0.18 for both techniques. The pharyngo-oesophageal sphincter pressure was measured 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 less than 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 less than 0.05). The observed rise in sphincter pressure may be explained as a response acting to prevent gastro-oesophageal reflux from entering the pharynx.

Relationship between Gastro-Oesophageal Acid Reflux, Basal Gastro-Oesophageal Sphincter Pressure, and Gastric Acid Secretion

Twelve-hour continuous pH-recording at the distal end of the oesophagus and measurement of basal gastro-oesophageal sphincter pressure with perfused catheters were carried out in 108 subjects. Fasting gastric secretion, basal secretion, and maximal acid secretion after subcutaneous injection of 6 microgram pentagastrin/kg bodyweight were determined additionally in some of the subjects. There was a significant inverse correlation between the results of continuous pH-recording and basal gastro-oesophageal sphincter pressure, which confirms the relationship between low sphincter pressure and gastro-oesophageal acid reflux. Furthermore, there was a significant direct correlation between the results of continuous pH-recording and the volume of basal secretion and the basal acid output. These findings emphasize the significance of gastric acid secretion for the results of continuous pH-recording. As reflux-preventive surgery may elicit alterations in the variables of acid secretion, the results of continuous pH-recording do not allow conclusions to be drawn with regard to the effectiveness of a surgically established gastro-oesophageal barrier.

Effect of Cisapride on the Gastro-Oesophageal Function in Normal Human Subjects

The aim of this study was to investigate oesophageal peristalsis and gastro-oesophageal function in normal subjects after 4 days of cisapride 10 mg p.o. 3 times/day and 10 mg 1.5 h before the investigation. The study was carried out in a double-blind cross-over design with coded cisapride or placebo tablets. Basal sphincter pressure increased after cisapride (p less than 0.002). The peristaltic pressure amplitude in the oesophageal body as well as the duration and velocity of the peristaltic pressure wave were measured after wet swallows. No changes were found. Intragastric pH was unchanged after cisapride. No effect was found on the result of a standard acid clearing test. Plasma concentration of cisapride did not correlate with any of the other variables. Oral cisapride increases fasting gastro-oesophageal sphincter pressure, but does not influence oesophageal peristalsis, acid clearing or intragastric pH in normal subjects.

Oesophageal Peristalsis in Normal Subjects: Influence of pH and Volume during Imitated Gastro-oesophageal Reflux

Acid gastro-oesphageal reflux in normal human subjects is followed by oesphageal peristalsis. The aim of the present study was to investigate the influence of pH and volume during imitated reflux on oesophageal peristalsis. Fluid volumes of 2.5, 5, 10, and 15 ml (pH 1.0, 4.0, or 7.0) were instilled randomly in the lower end of the oesophagus in eight healthy subjects. Further, repeated instillations were carried out in one subject. Oesophageal pressures were measured 5, 10, and 15 cm oral to the gastro-oesophageal sphincter and in the pharynx, and pH 5 cm oral to the sphincter. Peristalsis confined to the oesophagus was found to be related to the volume of the instilled fluid, whereas pharynx-mediated peristalsis seemed to be related to the acidity of the fluid. It is concluded that peristalsis after imitated gastro-oesophageal reflux is influenced by both the volume and the acidity of the instilled fluid. Volume seems to initiate a local clearing mechanism, whereas low pH initiates pharynx-mediated peristalsis.

Gastro-Oesophageal Sphincter Pressure, Motility and Acid Clearing: A Study of Hiatus Hernia Patients and Normal Subjects, and of the Effect of a Modified Belsey MK IV Repair on the Results of the Manometric and Acid-Clearing Tests

Basal gastro-oesophageal sphincter pressure was recorded in 68 patients with symptomatic, radiologically verified sliding hiatus hernia, and in 37 healthy subjects. The diameter of the probe was 2.5 mm, and the flow rate 0.5 ml/min. Mean sphincter pressure was lower in patients (6 mm Hg) than in normal subjects (15 mm Hg). In 32 per cent of the patients sphincter pressure was within normal range (8-24 mm Hg), whereas in 68 per cent it was lower than in the normal subjects. There seemed to be no relationship between sphincter pressure and severity of symptoms. Oesophageal acid clearing was investigated in 57 of the patients and in 26 of the normal subjects. Normal subjects clear the bolus of acid in an average of 10 swallows (range 4-16). In patients the incidence of prolonged clearing was greater, but the acid-clearing ability did not seem to be related to the degree of severity of the symptoms. A manometric study was made of 45 patients and an acid-clearing study made of 40 patients, before and 3 months after a modified Belsey MK IV repair for hiatal hernia. Mean postoperative sphincter pressure was higher (10 mm Hg) than the preoperative mean (6 mm Hg), but was still lower than the normal mean. Significant changes in acid-clearing ability could not be demonstrated. The results are inconclusive with regard to the importance of oesophageal motility disturbances for the symptomatology and acid-clearing ability. Thirty-seven out of 45 patients became free of symptoms, and the rest - except 1 (relapse of hernia) - improved.

Oesophageal peristalsis. A simple system for the recording of oesophageal peristalsis, and the influence of bolus volume on peak peristaltic pressure amplitude.

Peak oesophageal peristaltic pressure amplitude was recorded in 8 healthy subjects at points 5 and 15 cm proximal to the gastro-oesophageal sphincter, by using an in situ tip-transducer simultaneously with a continuous flush (Intraflo) perfused catheter system with external pressure transducer. Dry swallows and wet swallows of 2.5, 5 and 10ml, respectively, were made in random succession. In all cases the pressures recorded by either system correlated well. In all cases the peristaltic pressure amplitude was significantly higher after the wet swallows. The catheter and flow system used in this study is simple and makes recording of peristaltic pressures independent of the shape of the in situ transducer, and its therefore well suited for measuring the amplitude of oesophageal contractions.

Gastrointestinal Dysfunction in a Community Sample of Subjects with Symptoms of Irritable Bowel Syndrome

Background/Aim: Irritable bowel syndrome (IBS) affects about 15–20% of the population of the Western countries. Traditionally, IBS has been an exclusion diagnosis, but recently definitions have emerged from population-based research. The aim of this population-based study was to evaluate any association between gastrointestinal pathophysiology and IBS in subjects with symptoms of IBS compared to subjects with no abdominal complaints. Methods: From a random sample of 2,656 participants, subjects with IBS (32) together with subjects without abdominal complaints (26), were invited for further evaluation. IBS was defined as more than weekly experience of abdominal pain and distension, and in addition either borborygmia or altering stool consistency. The diagnostic work-up consisted of gastroscopy, manometry and 23-hour pH and pressure recordings of the oesophagus, lactose tolerance test, barium enema, measurement of colonic transit time, and rectoscopy. Results: Compared to the group without abdominal complaints significantly more subjects with IBS had spasms of the colon (OR = 10.2 (1.2–87.3)), and abnormal contractions of the oesophagus at manometry (OR = 9.1 (1.1–78.2)). Furthermore, there was a non-significant tendency towards spasms at 23-hour pH and pressure recordings (OR = 3.58 (0.4–35.2)), and more discomfort at lactose tolerance test (OR = 5.8 (0.6–51.3)) in persons with IBS compared to subjects without abdominal complaints. Conclusion: The results of this population-based study indicate that signs of gastrointestinal dysmotility and hyperperception are more prevalent in subjects with IBS than in subjects without abdominal complaints.

Intraluminal oesophageal manometry. Influence of pressure probe diameter.

The influence of the pressure-probe diameter on the values of gastro-oesophageal sphincter pressure, pharyngo-oesophageal sphincter pressure, and peak peristaltic pressure in the oesophageal body was investigated in eight healthy subjects. A low-compliance perfused pressure-measuring unit was used for the recordings. Three different probes were made with external diameters of 1.5 mm, 3.5 mm, and 4.5 mm. Sphincter pressures were measured in the resting state, and peristaltic pressures were measured during wet swallows. The pressure in the sphincter regions was found to depend on the diameter of the probe, whereas the peak peristaltic pressure amplitudes were independent of the probes used. The need for standardization of manometry equipment is emphasized.

Effect of Domperidone on Gastro-Oesophageal Function in Normal Human Subjects

The aim of the study was to investigate gastro-oesophageal function in normal volunteers after oral administration of domperidone as a single dose (20 mg). The study was designed as a double-blind cross-over investigation. Ten healthy men (aged 27-50 years; median, 30) joined the study. Oesophageal function tests were performed, starting 1.5 h after intake of domperidone or placebo. Gastro-oesophageal sphincter pressure was measured with a perfused catheter system and a continuous pull-through technique. No changes in sphincter pressure were found. Peristaltic pressure amplitude in the body of the oesophagus and the duration and velocity of peristalsis were measured after wet swallows (bolus 5 ml of water). No changes were found. Intragastric pH did not change significantly after domperidone. No effect of domperidone on the results of a standard acid-clearing test could be found. Plasma concentrations of domperidone did not correlate with any of the other variables. In conclusion, domperidone given orally in a dose that has been shown to accelerate gastric emptying does not influence gastro-oesophageal sphincter pressure or peristaltic activity in the normal oesophagus.

Gastric acid secretion in patients with symptomatic hiatus hernia and effect of a modified Belsey MK IV repair on gastric acid secretion.

Fasting, basal, and pentagastrin-stimulated (6 microgram/kg body weight) gastric acid secretion was assessed in 53 patients with radiologically verified sliding hiatus hernia without stricture formation. There was no difference in the acid secretory variables between patients with heartburn and those with heartburn and pain. A study of the acid secretory variables in 34 patients before and 3 months after a modified Belsey MK IV repair for symptomatic hiatus hernia showed that after the repair the pH of basal secretion had risen, and that the volume of basal secretion as well as basal and peak acid output had been reduced. These changes must probably be ascribed to an unintentional vagotomy during the operation. It is concluded that in the evaluation of a surgically established barrier against gastro-oesophageal reflux in terms of oesophageal pH, changes in gastric acid secretion should be taken into consideration.