pH probe positioning for 24-hour pH-metry by manometry or pH step-up

OBJECTIVES: Before pH measurement, manometry is recommended for precise pH probe positioning. We investigated whether the pH probe could be positioned accurately by the pH difference between the oesophagus and the stomach (pH step-up). METHODS: Dual-channel 24-h pH-metry with probes positioned 5 cm above either the manometrically determined upper lower oesophageal sphincter margin or the pH step-up was performed in healthy volunteers and reflux patients. To determine the pH step-up, the pH probe was pulled back from the stomach until a sudden rise to pH greater than four occurred. Probe position, reflux episodes and the fraction of the time pH was less than four were compared using the Wilcoxon test for difference and the Hodges-Lehman estimate inclusive confidence interval for equivalence. The pH step-up method was evaluated further during proton pump inhibitor therapy and after drug discontinuation. RESULTS: The pH probe was positioned 2 cm and 1 cm closer to the stomach by the pH step-up method in the volunteers and reflux patients, respectively. A small increase in upright reflux episodes but not in supine reflux episodes was registered by the probe positioned by pH step-up. No significant differences in the fraction of the time pH was less than four were obtained between the two probes. The Hodges-Lehman calculation proved equivalence for both methods of probe positioning for 24-h pH-metry. During proton pump inhibitor therapy, no pH step-up was detectable in three volunteers and in one patient. On the first day after discontinuing therapy, the pH step-up method yielded clear-cut results again. CONCLUSION: The pH probe for diagnostic 24-h pH-metry and, with some limitations, also for 24-h pH-metry for therapy control, can be positioned accurately by the pH step-up method.     

Functional relationships between cricopharyngeal sphincter and oesophageal body in response to graded intraluminal distension.

Responses of the cricopharyngeal sphincter to graded intraluminal distension were studied in order to determine its response threshold and to define the functional relationship between the sphincter and oesophageal body. Nine normal subjects underwent manometric study using a multilumen tube with an attached inflatable balloon sited 10 cm below the sphincter. Sphincteric and oesophageal motor responses to six graded balloon inflations were recorded in each subject. The sphincter responded to distension with increasing rise in pressure, from a median value of 42.5 mmHg at lowest levels of distension to 95 mmHg at maximal tolerated distension. Non-swallow related contractile activity was stimulated in the oesophageal body proximal to the distension and increased in quantity as inflation progressed. Distal propagation of this secondary activity was progressively inhibited with increasing distension. These interrelated changes thus show the normal upper oesophageal clearance responses to intraluminal distension. It is suggested that their more widespread application, in addition to standard manometric techniques, might provide a more rational evaluation of those patients suspected to have impaired oesophageal clearance, but in whom standard manometry is non-diagnostic.     

24-hour oesophageal two-level pH monitoring in healthy children and adolescents

Two-level pH recording in the oesophagus was performed for 24 h in 28 healthy schoolchildren between 9.3 and 17.3 years of age, to obtain reference values for reflux studies. The pH probes were placed 5 and 15 cm above the lower oesophageal sphincter by means of the manometric technique. A standardized acid-free diet was given on the day of recording. A drop in pH to 4.0 or below was regarded as reflux. The normal upper limit of total reflux time was 1.0% at the lower oesophageal level. Mean reflux time was about three times shorter at the upper level than at the lower, which indicates the importance of exact positioning of the pH probe.     

The LES Locator: Accurate Placement of an Electrode for 24-Hour pH Measurement with a Combined Solid State Pressure Transducer

Twenty-four-hour esophageal pH monitoring is the gold standard for diagnosing gastroesophageal reflux disease. A possible limitation to the widespread use of this test is that manometry is required for accurate placement of the pH electrode 5 cm above the lower esophageal sphincter. We compared the accuracy of a single solid state pressure transducer, combined with a pH electrode, in determining the proximal border of the lower esophageal sphincter (LES) with the values obtained from stationary manometry in 40 patients referred to our laboratory for 24-h pH studies. Not only was there a strong correlation (r = 0.9) between LES values obtained by the two techniques, but none of the values obtained by the single solid state transducer were outside the clinically accepted range of greater than +/- 3 cm. The presence of a hiatal hernia or low sphincter pressure did not affect these measurements. The larger probe was tolerated somewhat less well (p = 0.02) than a standard antimony electrode during the prolonged pH studies. In conclusion, a single solid state pressure transducer on a pH probe with the help of a LES locator accurately identifies the proximal border of the LES. Therefore, stationary esophageal manometry is no longer needed prior to 24-h pH monitoring, potentially making this important clinical tool available to a wider variety of clinicians at all levels of the health care system, in investigating gastroesophageal reflux and its protean clinical presentations.     

24-H pharyngeal pH monitoring in healthy volunteers: a normative study

BACKGROUND: Gastropharyngeal reflux has been associated with disorders of the upper and lower airways. It may be shown by pharyngeal pH-metry, but reports on normality in healthy volunteers are scarce. No definite consensus has been reached considering the upper limit of normality (ULN). The aim of the present study was therefore to quantify the occurrence of pharyngeal acid exposure (pH < 4) in healthy volunteers and, further, to examine its relation to acid exposure of the oesophagus and oesophageal motility and its occurrence in relation to age, sex, and body position. METHODS: Forty healthy volunteers underwent ambulatory 24-h pH-metry, using antimony electrodes positioned 2 cm above the upper oesophageal sphincter and 5 cm above the lower oesophageal sphincter on the basis of manometry. Technical artefacts were excluded before calculation of all results. RESULTS: Gastropharyngeal reflux occurred in most healthy volunteers without any significant relation to age, sex, or body weight. Pharyngeal acid reflux occurred mainly in the upright position. The ULN for pharyngeal acid exposure time was assessed to 0.9% (0.2% after exclusion of mealtimes). The ULN for the number of acid events in the pharynx was 18 (6.1). The corresponding ULNs for the oesophagus were 7% and 84. CONCLUSION: Gastropharyngeal reflux may be effectively monitored by ambulatory pH-metry. The present study provides reference limits, a prerequisite for evaluating the pathophysiologic importance of the phenomenon.     

Determination of pH turning point with pH mapping of the gastroesophageal junction: an alternative technique to orientate esophageal pH monitoring

Manometric location of the lower esophageal sphincter (LES) has been mandatory before esophageal pH monitoring, despite costs and discomfort related with esophageal manometry. The aims of the study were: (i) to map the pH of the gastroesophageal junction (GEJ) to determine a pH turning point (PTP) and its relation with LES; and (ii) to test the feasibility of this technique to orientate esophageal pH monitoring. We studied 310 adult patients who underwent esophageal manometry and pH monitoring off acid‐suppressive therapy. GEJ pH mapping was carried out by step‐pulling the pH sensor from 5 cm below to 5 cm above LES, and a PTP was determined when pH changed from below to above 4, in centimeters from the nostril. Thirty‐six patients referred only for pH monitoring were studied with pH sensor placed at 5 cm above the PTP. Out of 310 patients, a PTP was found in 293 (94.5%): inside LES in 86.3%, into the stomach in 8.2% and in the esophageal body in 5.5% of patients. The median distance between PTP and place where pH sensor monitored reflux was 8 cm. Among 36 patients who performed pH monitoring without LES manometry, there was no gastric monitoring during reflux testing. In adult patients investigated off acid suppressive therapy, GEJ pH mapping with reflux monitoring 5 cm above the PTP can be an alternative technique to perform esophageal pH monitoring when LES manometry is not available. Additional studies are needed before the widespread use of GEJ pH mapping in the clinical practice.     

24-H Pharyngeal pH Monitoring in Healthy Volunteers: A Normative Study

Background: Gastropharyngeal reflux has been associated with disorders of the upper and lower airways. It may be shown by pharyngeal pH-metry, but reports on normality in healthy volunteers are scarce. No definite consensus has been reached considering the upper limit of normality (ULN). The aim of the present study was therefore to quantify the occurrence of pharyngeal acid exposure (pH &lt; 4) in healthy volunteers and, further, to examine its relation to acid exposure of the oesophagus and oesophageal motility and its occurrence in relation to age, sex, and body position. Methods: Forty healthy volunteers underwent ambulatory 24-h pH-metry, using antimony electrodes positioned 2 cm above the upper oesophageal sphincter and 5 cm above the lower oesophageal sphincter on the basis of manometry. Technical artefacts were excluded before calculation of all results. Results: Gastropharyngeal reflux occurred in most healthy volunteers without any significant relation to age, sex, or body weight. Pharyngeal acid reflux occurred mainly in the upright position. The ULN for pharyngeal acid exposure time was assessed to 0.9% (0.2% after exclusion of mealtimes). The ULN for the number of acid events in the pharynx was 18 (6.1). The corresponding ULNs for the oesophagus were 7% and 84. Conclusion: Gastropharyngeal reflux may be effectively monitored by ambulatory pH-metry. The present study provides reference limits, a prerequisite for evaluating the pathophysiologic importance of the phenomenon.     

Determinants of oesophageal 'alkaline' pH environment in controls and patients with gastro-oesophageal reflux disease.

The determinants of the oesophageal alkaline pH environment are poorly understood. Saliva (pH 6.4-7.8) may be a major contributor, although some argue the importance of refluxed alkaline duodenal contents. Acid and alkaline reflux parameters were studied over 2 days in 30 subjects (control, oesophagitis and Barrett's patients; 10 each) using glass pH electrodes. In phase 1, one pH electrode was placed 1 cm below the upper oesophageal sphincter to assess the influence of saliva and the other 5 cm above the lower oesophageal sphincter. Phase 2 was identical except that one pH probe was 5 cm below the lower oesophageal sphincter to record duodenogastric reflux. Patient groups spent, on average, 50 fold more time during the upright and supine periods at acidic pH than controls. Saliva was responsible for the percentage of time the pH > 7 and contributed significantly to the percentage of time the pH > 6 in both the proximal and distal oesophagus of control subjects, as shown by an absence of pH > 7 and a significant (p < 0.001) fourfold decrease in pH > 6 during sleep. A similar pattern was seen in the proximal oesophagus of both reflux groups. The reflux and Barrett's patients, however did not show a significant decrease in the percentage of time the pH > 6 at night in the distal oesophagus suggesting a relative increase in 'alkaline' exposure from another source. This was not because of duodenogastric reflux as the corresponding pH rises in the fundus of the stomach were non-existent. Although this was not studied specifically, it is believed to be a protective meachanism, the result of alkaline secretion produced by submucosal oesophageal glands.     

Accurate placement of the esophageal pH electrode for 24-hour pH monitoring using a combined pH/manometry probe

OBJECTIVE: Accurate placement of a pH electrode requires manometric localization of the lower esophageal sphincter (LES). Combined manometry/pH devices using water-perfused tubes attached to pH catheters and the use of an electronic "LES locator" have been reported. We investigated whether accurate placement of pH probes can be achieved using such a probe, and whether this may reduce the need for the performance of the usual stepwise pull-back manometry. METHODS: Thirty consecutive patients (15 men, 15 women; median age, 56 yr; interquartile range, 42-68 yr) referred for manometry and pH testing were included in the study. The localization of the LES was determined with standard esophageal manometry. After that, a second 3-mm pH electrode with an internal perfusion port was passed into the stomach. Using this catheter, a single stepwise pull-through manometry was performed and the LES position was noted. LES location, mean pressure, and length obtained with standard manometry were compared to data from the combined pH/manometry catheter. Additionally the time necessary to perform each of the procedures was noted and the patient's discomfort caused by the catheter was evaluated using a standardized questionnaire. RESULTS: The LES location with the pH/manometry probe was proximal to that with standard manometry in 19 patients (63%), the same in nine patients (30%), and distal in two patients (7%). The differences were <2 cm in 29 of 30 (97%) patients. The LES location with the pH/manometry probe required a median of 6.5 min (interquartile range: 3.5-8.5 min) versus a median of 21.5 min (interquartile range: 14.5-26.5 min) for standard manometry (p < 0.0001). In addition, LES evaluation using the combined pH/manometry probe provided accurate data on the resting pressure, as well as overall and intraabdominal length of the LES. All patients tolerated the combination probe better than the standard manometry probe (p < 0.001). CONCLUSIONS: Placement of the esophageal electrode for 24-h esophageal pH monitoring using a combined pH/manometry probe is accurate. The technique is simple, time-saving, and convenient for the patients. Because it is possible to accurately evaluate the LES using this technique, it may even replace conventional manometry before pH probe placement.     

Gastroesophageal pH step-up inaccurately locates proximal border of lower esophageal sphincter

Limiting the widespread use of 24-hr pH monitoring is the necessity of manometrically placing the pH probe 5 cm above the proximal lower esophageal sphincter (LES) border. Therefore, we prospectively compared LES localization by gastroesophageal pH step-up with manometry in 71 patients and 14 asymptomatic volunteers. The gastroesophageal pH step-up significantly correlated with the proximal LES border in patients (r=0.53, P<0.0001) and volunteers (r=0.91, P<0.0001). Based on previously published criteria, the pH step-up value was considered acceptably accurate if it was within ±3 cm (6 cm total span) of the manometrically determined proximal LES border. In 58% of patients and 29% of volunteers the pH step-up occurred outside this accuracy range. Esophagitis (P=0.015) and abnormal reflux parameters (P=0.002) were variables contributing to this error. Subsequent analysis found that the pH step-up overestimated the proximal LES border and occurred at the midportion of the sphincter. The pH step-up still inaccurately located the mid LES in 34% of patients. Therefore, manometry should remain the standard for accurate LES localization prior to placing the pH probe.     

Prospective evaluation of 24 hour ambulatory pH metry in Belsey Mark IV antireflux surgery.

This study evaluated the effect of the 270 degrees Belsey Mark IV fundoplication on 24 hour ambulatory pH metry variables. Thirty seven patients with confirmed gastro-oesophageal reflux disease who had a Belsey Mark IV antireflux procedure were evaluated preoperatively and three to six months postoperatively including endoscopy, lower oesophageal sphincter manometry, and 24 hour ambulatory pH metry. In 30 of 37 patients the Belsey Mark IV fundoplication was judged successful based on symptom relief and healing of oesophagitis. In these 30 patients percentage reflux for total, upright, and supine time (median and range) decreased significantly (p < 0.001) from 10.0% (2.7-35.3%), 10.8% (3.2-39.9%), and 6.7 (0.0-33.0%) respectively to 0.5% (0.0-7.4%), 0.6% (0.0-13.7%), and 0.1% (0.0-4.9%) after operation. This decrease in reflux time resulted predominantly from a significant (p < 0.001) reduction in the number of reflux episodes from 98 (23-231) to 14 (0-82) postoperatively. Normalisation of total reflux time (upper limit of normal for time with pH below 4:4%) was found in 89% and normalisation of total and upright and supine reflux in 64% of successfully operated patients with confirmed abnormal acid reflux before operation. A successful antireflux procedure was associated with significant (p < 0.001) increases in lower oesophageal sphincter pressure from 7.8 (0.6) mm Hg to 14.5 (0.7) mm Hg mean (SEM). In seven patients with a failed antireflux operation basal lower oesophageal sphincter pressure did not change significant;y (preoperative value 5.7 (1.3) mm Hg; postoperative value 7.8 (0.8) mm Hg). In these patients reflux time did not decrease after the operation and remained in the abnormal range in all patients. It is concluded that a successful, in contrast with a failed, Belsey Mark IV fundoplication is associated with significant decreases in total, upright, and supine reflux time. Normalisation of pH metry variables is not a prerequisite for successful antireflux surgery. A surgery. A successful 270 degree Belsey Mark IV fundoplication was associated with a significant increase in basal lower oesophageal sphincter pressure, in contrast with the failure group. Restoration of a sufficient lower oesophageal sphincter barrier is an important aim in antireflux surgery.     

Reproducibility of long-term ambulatory esophageal combined pH/manometry

Long-term ambulatory esophageal manometry is used increasingly, but normal values and data on the reproducibility of the method are not available. Thus, studies were conducted using paired 24-hour recordings, separated by 1-4 weeks, in 24 healthy volunteers (aged 19-50). Computerized analysis of each two-channel pressure recording (5 and 15 cm above lower esophageal sphincter) determined mean contraction amplitude, duration, area under the curve, contractility and propagation velocity, and the proportion of propagated contractions during day and night periods. A combined glass pH electrode (5 cm above lower esophageal sphincter) was used to register acid reflux. Visual analysis of the 24-hour contractility patterns showed marked intraindividual reproducibility but, although most subjects showed similar meal-associated increases and sleep-associated decreases in contraction frequency and amplitude, considerable interindividual variation was observed. This was confirmed by comparing the variation between subjects in the first and second recordings with the variation between recordings in the same subject; for all pH and manometry variables, the coefficient of variation was two to three times greater between subjects than between recordings in the same subject. The recordings were highly reproducible within subjects (nighttime contraction duration, P less than 0.05; all other variables, P less than 0.01). Thus, computerized ambulatory pH manometry is reproducible and because healthy volunteers have a characteristic individual pattern of esophageal motility, the method is perfectly suitable for repeated-measure design physiological and pharmacological studies. However, generally applicable normal values are difficult to define.     

Is ineffective oesophageal motility associated with reflux oesophagitis?

OBJECTIVE: To evaluate the association between ineffective oesophageal motility and reflux oesophagitis controlling for hiatal hernia, hypotensive lower oesophageal sphincter and male sex in patients with gastro-oesophageal reflux disease. METHODS: A total of 387 patients with reflux disease (mean age, 46 years, 42% men) were consecutively selected from a database. All patients underwent upper endoscopy, oesophageal manometry and 24 h oesophageal pH-metry in accordance with a standardized protocol. Reflux disease was confirmed either by endoscopy (oesophagitis grade I-IV according to Savary-Miller) or by pH-metry (increased acid exposure). Hiatal hernia was diagnosed endoscopically, whereas ineffective oesophageal motility and hypotensive lower oesophageal sphincter were characterized during manometry testing. The association between ineffective oesophageal motility and reflux oesophagitis was assessed by logistic regression analysis. RESULTS: A total of 166 patients with oesophagitis (mean age 45 years, 49% men) and 221 without oesophagitis (mean age 46 years, 37% men) were present. Prevalences of ineffective oesophageal motility, hiatal hernia, hypotensive lower oesophageal sphincter and male sex were significantly higher in patients with oesophagitis compared with those without oesophagitis (P<0.05). Ineffective oesophageal motility was independently associated with oesophagitis after multivariate logistic regression analysis (odds ratio=1.68; 95% confidence interval=1.04-2.70). CONCLUSION: Ineffective oesophageal motility is associated with reflux oesophagitis, independently of hiatal hernia, hypotensive lower oesophageal sphincter and male sex.     

Ambulatory 24-Hour Pharyngeal pH Monitoring in Healthy Korean Volunteers

Pharyngeal pH monitoring is the standard diagnostic approach for laryngopharyngeal reflux (LPR). However, the normal values for Asian populations are still unknown. We evaluated the results of ambulatory 24-h pharyngeal pH monitoring in healthy volunteers to determine the normal reference values in the Korean population. Thirty healthy subjects underwent ambulatory 24-h pharyngeal pH monitoring with glass electrodes positioned 1 cm above the upper esophageal sphincter and 5 cm above the lower esophageal sphincter, based on esophageal manometry after upper gastrointestinal endoscopy. LPR occurred in about one half of the healthy volunteers without any significant association with age, gender and body mass index. Pharyngeal acid reflux occurred mainly in the upright position. At the 95th and 90th percentile, after the exclusion of mealtimes, the upper limits of normal (ULN) for pharyngeal acid exposure were 0.41% and 0.18%. The ULNs for the number of pharyngeal acid events were 12.8 and 5.0. The corresponding ULNs for the esophagus were 5.1% and 3.8% and 62.7 and 32.6. The findings of this study help establish the reference standards for LPR in Korean patients.     

An ambulant porcine model of acid reflux used to evaluate endoscopic gastroplasty

BACKGROUND: There is a lack of suitable models for testing of therapeutic procedures for gastro-oesophageal reflux disease. Endoscopic sewing methods might allow the development of a new less invasive surgical approach to treatment of gastrointestinal disorders. AIMS: To develop an animal model of gastro-oesophageal reflux for testing the efficacy of a new antireflux procedure, endoscopic gastroplasty, performed at flexible endoscopy without laparotomy or laparoscopy. METHODS: At endoscopy a pH sensitive radiotelemetry capsule was sewn to the oesophageal wall, 5 cm above the lower oesophageal sphincter, in six large white pigs. Ambulant pH recordings (48-96 hours; total 447 hours) were obtained. The median distal oesophageal pH was 6.8 (range 6.4-7.3); pH was less than 4 for 9.3% of the time. After one week, endoscopic gastroplasty was performed by placing sutures below the gastro-oesophageal junction, forming a neo-oesophagus of 1-2 cm in length. Postoperative manometry and pH recordings (24-96 hours; total 344 hours) were carried out. RESULTS: Following gastroplasty, the median sphincter pressure increased significantly from 3 to 6 mm Hg and in length from 3 to 3.75 cm. The median time pH was less than 4 decreased significantly from 9.3% to 0.2%. CONCLUSIONS: These are the first long term measurements of oesophageal pH in ambulant pigs. The finding of spontaneous reflux suggested a model for studying treatments of reflux. Endoscopic gastroplasty increased sphincter pressure and length and decreased acid reflux.     

The effect of hiatus hernia on gastro-oesophageal junction pressure

BACKGROUND: Hiatus hernia and lower oesophageal sphincter hypotension are often viewed as opposing hypotheses for gastro-oesophageal junction incompetence. AIMS: To examine the interaction between hiatus hernia and lower oesophageal sphincter hypotension. METHODS: In seven normal subjects and seven patients with hiatus hernia, the squamocolumnar junction and intragastric margin of the gastro-oesophageal junction were marked with endoscopically placed clips. Axial and radial characteristics of the gastro-oesophageal junction high pressure zone were mapped relative to the hiatus and clips during concurrent fluoroscopy and manometry. Responses to inspiration and abdominal compression were also analysed. RESULTS: In normal individuals the squamocolumnar junction was 0.5 cm below the hiatus and the gastro-oesophageal junction high pressure zone extended 1.1 cm distal to that. In those with hiatus hernia, the gastro-oesophageal junction high pressure zone had two discrete segments, one proximal to the squamocolumnar junction and one distal, attributable to the extrinsic compression within the hiatal canal. Inspiration and abdominal compression mainly augmented the distal one. Simulation of hernia reduction by algebraically summing the proximal segment pressures with the hiatal canal pressures restored normal maximal pressure, radial asymmetry, and dynamic responses of the gastro-oesophageal junction. CONCLUSIONS: Hiatus hernia reduces lower oesophageal sphincter pressure and alters its dynamic responsiveness by spatially separating pressure components derived from the intrinsic lower oesophageal sphincter and the extrinsic compression of the oesophagus within the hiatal canal.     

Monitoring of upper oesophageal sphincter pressure in children.

In children technical limitations of upper oesophageal sphincter manometry have restricted investigation to the pull through technique under sedation. In this study we have used an adapted sleeve manometric technique for upper oesophageal sphincter monitoring in unsedated children and determined the influence of the state of arousal on upper oesophageal sphincter pressure. Twenty six children aged 3 to 42 months (median 17.5 months), who were referred for evaluation of oesophageal motor function, were studied with dual sleeve manometric assemblies which monitored upper and lower oesophageal sphincter pressures simultaneously. Pharyngeal, oesophageal body, and gastric pressures were also monitored with seven perfused side holes. Recordings were made for four hours after a meal and were technically successful in 24 children. The child's state of arousal was scored every 12th minute as follows: (A) resting, eyes closed, (B) resting, eyes open, (C) moving but comfortable, (D) restless and uncomfortable, (E) crying. In 67% of the 12 minute samples the children showed good adaptation to the procedure (arousal states A to C). There was a highly significant difference in upper oesophageal sphincter pressure between each of the arousal states (p less than 0.0001), being lowest in category A at (mean (SD) 18.1 (10.3) mmHg and highest in category D 55.7 (13.2) mm Hg. Abrupt changes in the state of arousal were associated with equally abrupt changes in upper oesophageal sphincter pressure. The state of arousal of unsedated children has an important influence on upper oesophageal sphincter pressure. It is essential that this factor is controlled for in any studies of upper oesophageal sphincter tone in children. The sleeve technique is capable of monitoring upper oesophageal sphincter motility for prolonged periods in unsedated children.     

Studies of the oesophageal clearance responses to intraluminal acid.

Contraction of the upper oesophageal sphincter combined with secondary peristalsis clears the oesophagus of refluxed gastric contents and protects the trachea, but the nature of these reflex stimuli remains controversial. Secondary peristaltic and sphincteric responses were measured during intraluminal infusion of 0.1 N hydrochloric acid and equiosmolar saline solutions in seven normal volunteers. Responses to a single volume infused at varying sites in the oesophagus and to progressively increasing volumes of test solution were measured. In addition oesophageal responses to similar degrees of distension induced by inflation of an intraluminal balloon were also recorded. The sphincteric responses to both stimuli were similar, decreasing in value with distance from the sphincter from values of 70 (68-85) mmHg (median (range] for HCl; and 70 (55-85) mmHg for NaCl at 5 cm below the sphincter to 40 (30-60) mmHg for both HCl and NaCl at 20 cm. As the volume of the solution infused into the proximal oesophagus was increased, the sphincter pressure also rose from a median basal value of 30 (25-50) mmHg to 40 (30-50) mmHg for HCl and NaCl after 1 ml, while after 7 ml infusion, the responses were greater, 65 (45-85) mmHg for HCl, and 60 (45-80) mmHg for NaCl. In the more distal oesophagus, responses were qualitatively similar but quantitatively smaller than proximally, being 30 (25-40) mmHg for HCl and 30 (25-50) mmHg for NaCl following 1 ml and 45 (40-55) mmHg for HCl and NaCl after 7 ml. Secondary peristalsis was also induced equally by both solutions and varied with volumes infused and site of infusion in a manner similar to the sphincter responses. After a 7 ml/min acid infusion 14 (1- 40) secondary contractions/three min were recorded at 5 cm and eight (2 - 18)/three min were recorded at 20 cm. Values for saline were similar, 13 (1- 38)/three min at 5 cm and eight (4 - 25)/three min at 20 cm. Oesophageal distension by a balloon positioned 10 cm below the sphincter induced identical clearance responses to those seen after similar volumes of either acid or saline infused at the same site. These results suggest that the principal stimulus for upper oesophageal clearance is intraluminal distension and do not support the idea that the oesophagus is pH sensitive.     

Oesophageal motility and lower oesophageal sphincter competence in progressive systemic sclerosis and localized scleroderma

Oesophageal motility and lower oesophageal sphincter (LOS) competence were investigated in 13 patients with progressive systemic sclerosis (PSS) and in 16 patients with localized scleroderma (LS) by means of oesophageal manometry and 24-h pH monitoring of the distal oesophagus. Results were compared with those of a control group consisting of asymptomatic volunteers. Marked abnormalities in oesophageal motility and in acid exposure in the distal oesophagus were observed in PSS patients only. The mean resting pressure of the LOS was 10.1 +/- 1.5 mmHg in PSS, 21.4 +/- 1.1 mmHg in LS, and 23.8 +/- 2.0 mmHg in asymptomatic controls. Overall sphincter length was 24.1 +/- 3.4 mm in PSS, 31.1 +/- 1.6 mm in LS, and 39.0 +/- 2.0 mm in the control group. Spincter abdominal length was 12.1 +/- 2 mm, 15.4 +/- 1 mm, and 25.0 +/- 1 mm, respectively. The amplitude and duration of oesophageal waves were markedly reduced at 5, 10, and 15 cm above the LOS in PSS patients, with only the upper part of their gullet being spared. An abnormal acid exposure in the distal oesophagus was observed in 84.6% of PSS patients, whereas only 18.2% (2 of 11) of pH-tested LS patients had an abnormal 24-h pH test. These data show that a marked oesophageal involvement is present only in the systemic form of scleroderma. Oesophageal tests may be useful for a circumstantial diagnosis whenever the diagnosis of PSS is uncertain; however, their use does not seem to be justified as routine in patients with LS.