L. Wallin

12-Hour Simultaneous Registration of Acid Reflux and Peristaltic Activity in the Oesophagus

Twelve-hour simultaneous registration of acid gastro-oesophageal reflux and peristaltic activity in the oesophagus was carried out on 30 healthy subjects. The intensity of the acid gastro-oesophageal reflux was determined by automatic integration of the pH variation. Acid gastro-oesophageal reflux to pH less than or equal to 4 occurs in normal subjects within a range of 0--2.4% of the total registration period. The intravariation was measured in 10 investigations on 1 subject, and lay within the intervariation. To maintain the pressure-measuring system intact, 3 ml H2O/h were fed to the proximal and distal pressure catheters, respectively; it has been shown that this small quantity of water has no influence on the pH variation. Peristaltic activity for the entire measuring period was recorded and related to the individual reflex episodes. The total activity was found to be dependent on the level of consciousness, with little activity occurring during sleep. A positive correlation was found between the lowest pH during a reflux episode and the peristaltic activity in the oesophagus (p less than 0.001), between the lowest pH during a reflux episode and the duration of the reflux episode (p less than 0.001), and between the peristaltic activity and the duration of the reflux episode (p less than 0.001). During long-term registration of oesophageal pH it appears that pH less than or equal to 4 is a usable parameter for distinguishing between pathological and non-pathological acid gastro-oesophageal reflux. Sudden falls in pH to below 4 release increased peristalsis in the oesophagus.

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.

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.

Acid Gastro-Oesophageal Reflux and Oesophageal Pressure Activity during Postprandial and Nocturnal Periods: A Study in Subjects with and without Pathologic Acid Gastro-Oesophageal Reflux

The aim of the investigation was to evaluate the relative quantity of acid gastrooesophageal reflux during different time periods in subjects with and without pathologic reflux. Twenty duodenal ulcer patients, 10 with and 10 without pathologic acid gastro-oesophageal reflux, and 26 asymptomatic volunteers were subjected to 12 h of simultaneous monitoring of pH and pressure activity in the oesophagus. The monitoring period was divided into a 3-h postprandial period, a night period of 6 h, and a 3-h period in the morning. The highest reflux frequency and the longest duration of oesophageal acid exposure were found in the postprandial hours (p less than 0.001). Thereafter, all groups had an even reduction in reflux rate. A greater absolute reduction in the duration of oesophageal acid exposure could be measured in patients with pathologic reflux as compared with the other groups (p less than 0.001). In spite of this, both reflux frequency and time with acid in the oesophagus were increased during the night in patients with pathologic reflux (p less than 0.001). Pathologic refluxers had in total 11 times as much reflux as normal subjects, and in addition 37.9% of the reflux took place during the 6 night hours. In contrast, only 5.4% of the reflux recorded in normal subjects occurred during this period. The pressure activity during periods with a normal intraoesophageal pH was reduced in all three groups during the night (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Fourier-analysis of peristaltic pressure variations in the oesophagus during a 12-hour investigation: A study in normal subjects

Long-term measurements have been made of peristaltic pressure variations 8 and 23 cm proximally to the gastro-oesophageal sphincter. The investigation was performed using perfused catheter systems and results of the 12-h measuring period were recorded on tape recorder. The peristaltic pressure variations were frequency analysed using a Fast Fourier Transform analyser. Nineteen normal subjects took part in the study. One subject was tested seven times. The investigation showed that the significant information regarding the pressure variations can be registered by recording systems with an upper frequency limit of at least 2 Hz. The pressure variations were built up more rapidly proximally in the organ than distally. Repeated investigations on a single subject showed that the intravariation lies within the intervariation in the subjects tested.

Gastro-Oesophageal Function in Duodenal Ulcer Patients

An investigation of the gastro-oesophageal region was made in 39 patients with uncomplicated duodenal ulcer (DU). The results were compared with the results from a group of normal volunteers. The DU patients had a lower gastro-oesophageal sphincter pressure (p less than 0.05) and a reduced acid-clearing ability (p less than 0.05). Furthermore, an increased acid gastro-oesophageal reflux (p less than 0.05) and a greater number of reflux episodes lasting longer than usual (p less than 0.05) were demonstrated. There was a positive correlation between low gastro-oesophageal sphincter pressure and acid gastro-oesophageal reflux within the pH intervals 0--3 and 0--4. The peristaltic activity was measured by the number of pressure amplitudes registered in the upper and lower part of the oesophagus; an increase (p less than 0.05) in pressure amplitudes in the lower part was found in the DU patients. When time relationship was used to distinguish between propagating, simultaneous, and reversed peristaltic activity, an increase in reversed peristaltic activity (p less than 0.001) was demonstrated in DU patients. The conclusion is that DU patients have an increased acid gastro-oesophageal reflux, probably as a result of an incompetence in the gastro-oesophageal sphincter barrier, and a reduced acid-clearing ability. The peristaltic activity is increased during the reflux episodes, although this investigation does not determine whether this is due to an increased reflux volume or an insufficient peristaltic activity.

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.