Relationship Between Gastroesophageal Reflux and Symptoms in Patients Referred for Ambulatory pH Monitoring

Gastroesophageal reflux disease: clinical, endoscopic, and intraluminal esophageal pH monitoring evaluation

One hundred and twenty-two patients with gastroesophageal reflux disease were studied (90 with and 32 without esophagitis) with the objective of analyzing possible differences between those with and without esophagitis. Evaluation consisted of clinical interview, endoscopy of the high digestive tract, esophageal manometry, and pH monitoring. There was no significant difference between the groups in age, sex, or symptoms. The incidence of hiatal hernia was greater in the group with esophagitis. Although the frequency of motor changes was similar, the type of anomaly was different. The reflux pattern was very similar in both groups. Therefore, the concept of reflux disease, esophagitis, and pathological reflux still needs a broader definition for greater diagnostic precision and for comparing the results of different studies on the subject. Normal reflux (confirmed using pH esophageal monitoring) in 12.2% of patients with esophagitis suggests that other factors are implicated in the etiology of the disease besides those measured using this examination.

Laparoscopic antireflux surgery in the treatment of the acid-sensitive oesophagus

BACKGROUND

Approximately 10 per cent of patients referred for 24-h oesophageal pH tests with symptoms suggestive of gastro-oesophageal reflux disease will have a normal endoscopic examination and normal distal oesophageal acid exposure times, but a clear temporal correlation between their symptoms and episodes of acid reflux. These patients have an 'acid-sensitive oesophagus', which forms part of the spectrum of reflux-related conditions. Their response to antireflux surgery has not been reported previously. This study represents a prospective cohort analysis of a clearly defined group of patients with acid-sensitive oesophagus who have undergone laparoscopic antireflux surgery.

METHODS

Nineteen patients (nine male and ten female; median age 32 years) underwent laparoscopic antireflux surgery for acid-sensitive oesophagus. All had had an incomplete response to medical therapy.

RESULTS

Eighteen of 19 patients were graded Visick I or II at 6 months after operation; all 16 patients followed for 1 year were graded Visick I or II. There were significant falls in DeMeester symptom score (4.0 versus 0.5; P < 0.001), symptom events (20 versus none; P < 0.001), number of reflux episodes (17 versus two; P < 0.001) and overall acid exposure times (1.2 versus 0.3 per cent; P < 0.001) after operation.

CONCLUSION

Laparoscopic antireflux surgery is a valid and effective treatment for patients with an acid-sensitive oesophagus. Presented in poster form to the British Society of Gastroenterology, Birmingham, March 2000 and the American Gastroenterological Association, San Diego, May 2000

Endoscopy-negative reflux disease

The majority of patients with symptoms of gastro-oesophageal reflux have no endoscopic evidence of oesophagitis. There has been remarkably little systematic gathering of information about this group of patients. It is commonly believed that they have a mild form of reflux disease, with low levels of dysfunction that usually respond to simple therapeutic measures. Emerging data from recent studies indicate that this is not the case. Endoscopy-negative patients have symptom severities comparable to those with erosive disease, and which significantly impair their quality of life. The limited data available on the pathophysiology of endoscopy-negative reflux disease suggest that, in the majority of patients, it is as much a disease of excessive gastro-oesophageal reflux as it is in patients with oesophageal lesions. The same principles that apply to successful treatment in patients with oesophagitis also hold true for patients with endoscopy-negative disease.

Diagnostic evaluation in gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) describes the clinical manifestations of reflux of gastric contents and the associated symptoms and patterns of tissue injury. Although its exact prevalence is difficult to determine, there is no doubt the GERD is the most common esophageal disease and probably among the most prevalent conditions seen in the primary care setting. GERD has a wide clinical spectrum, making the diagnostic evaluation challenging and complicated at times. Confirmatory test are rarely needed in patients with typical symptoms of heartburn or regurgitation who have a good clinical response to GERD therapy. This article describes the diagnostic tests necessary for some cases of GERD.

Exclusion of the meal period improves the clinical reliability of esophageal pH monitoring

Meal period exclusion from 24-h pH testing allows better separation between controls and patients with gastroesophageal reflux disease. We reviewed the results of 24-h pH studies of 350 patients with reflux symptoms. They were divided into two groups based on the 95th percentile of the total percentage of time when pH was < 4 for healthy persons in our laboratory. Thus group A consisted of 212 patients with symptoms and normal acid exposure and group B consisted of 138 patients with symptoms and abnormal acid exposure. The change in upright reflux excluding the meal period was calculated for each patient. Meal period exclusion resulted in opposite effects for the two groups of patients, with a change in median upright reflux of -0.6% for group A and +0.5% for group B (p < 0.0001). After meal exclusion, five patients were reclassified as having reflux, with four (80%) of these responding to antireflux therapy. Nine other patients were recategorized as not having reflux after meal exclusion. Only one of seven patients (14%) for whom data were available responded to treatment (two patients were lost to follow-up). We recommend meal period exclusion from pH analysis because it improves the clinical reliability of esophageal pH monitoring.

Managing the patient with atypical chest pain

Since angina and heartburn can feel the same, excluding cardiac disease may be the first order of business. That done, clinical findings and laboratory tests can help identify the esophageal disturbance. Gastric acid reflux, motility disorders, and visceral nerve hypersensitivity--alone or in combination--can cause chest pain, and each may call for a different pharmacologic regimen.

Reflux related symptoms in patients with normal oesophageal exposure to acid

Several studies, using pH monitoring with event markers, have identified patients with normal oesophageal exposure to acid despite an apparent relation between symptoms and reflux episodes. In this series of 771 consecutive patients referred for 24 hour oesophageal pH monitoring, a probability calculation was used to evaluate the relation between symptoms and reflux episodes. Oesophageal exposure to acid was normal in 462 of 771 recordings (59.9%); despite this, 70.8% (327 of 462) of these patients used at least once the event marker. In 96 patients (12.5% of total patients) with normal oesophageal exposure to acid, there was a statistically significant association between symptoms and reflux episodes. The symptom cluster of such patients was similar to that usually seen in patients with gastro-oesophageal reflux disease, but symptoms like belching, bloating, and nausea were common thus overlapping with the symptom pattern of functional dyspepsia. In these patients both the duration and the minimum pH of reflux episodes (either symptom related or asymptomatic) were significantly shorter and higher, respectively, when compared with those of patients with gastro-oesophageal reflux disease. These results are consistent with the idea that oesophageal hypersensitivity to acid is the underlying pathophysiological feature of this syndrome.

Lowered oesophageal sensory thresholds in patients with symptomatic but not excess gastro-oesophageal reflux: evidence for a spectrum of visceral sensitivity in GORD

Some patients undergoing ambulatory oesophageal pH monitoring to investigate symptoms suggestive of gastro-oesophageal reflux disease (GORD) are found to have oesophageal acid exposure within the physiological range but show a close correlation between their symptoms and individual reflux episodes. It is suggested that these patients might exhibit enhanced oesophageal sensation, akin to the heightened perception of both physiological and provocative stimuli in the gut that has been described in patients with functional gastrointestinal disorders. This study tested the hypothesis by measuring the sensory thresholds for oesophageal balloon distension and discomfort in 20 patients with symptoms of GORD, in whom ambulatory pH monitoring had shown normal acid exposure times, but in whom the symptom index for reflux events was 50% or greater, and compared these with 15 healthy volunteer controls, and with control groups with confirmed excess reflux. The study group showed lower thresholds both for initial perception of oesophageal distension, and for discomfort, compared with healthy controls (median ml (range)); 7.5 (2-19) v 12 (6-30) (p = 0.002) and 10 (5-20) v 16 (8-30) (p < 0.0001), respectively. Sensory thresholds in the study group were also significantly lower than in patients with excess reflux, and than patients with Barrett's oesophagus, who also exhibited significantly higher sensory thresholds than healthy controls. No differences in sensory thresholds for somatic nerve stimulation were found between the study group and health controls. The results show a spectrum of visceral sensitivity in GORD, with enhanced oesophageal sensation in patients with symptomatic but not excess gastro-oesophageal reflux, suggesting that their symptoms result from a heightened perception of normal reflux events.

Clinical characteristics and natural history of symptomatic but not excess gastroesophageal reflux

Esophageal pH monitoring in patients with gastroesophageal reflux symptoms identifies some who have normal esophageal acid exposure but nevertheless a convincing correlation between symptoms and those reflux events that do occur. These patients may exhibit enhanced sensory perception of physiological reflux. Little is known about the natural history of reflux symptoms in this group, which in our experience comprises up to 6% of those referred for diagnostic pH monitoring. We have therefore followed up by postal questionnaire 70 patients whose initial pH study had demonstrated normal acid exposure but a symptom index > or = 50% and 58 patients found to have excess reflux, for a median of 4.4 and 6.5 years, respectively. The presenting character and frequency of symptoms and endoscopic and manometric findings were similar in the two groups. At review overall symptom frequency had improved (P < 0.01) for both groups similarly. However, 87% of those with normal acid exposure and 79% of those with excess reflux remained symptomatic, 53% and 47%, respectively, recording their symptoms to be the same or worse than at original presentation, despite over 60% in each group continuing to take regular medication. Only six patients in each group were asymptomatic and receiving no therapy at the time of review. The results demonstrate that patients with symptomatic but not excess gastroesophageal reflux constitute a significant clinical problem. Both the persistence of their symptoms and their requirement for therapy are similar to that observed in "genuine" refluxers.

Effect of famotidine on oesophageal sensitivity in gastro-oesophageal reflux disease

Gastric acid suppression could improve heartburn by healing oesophagitis or by reduction of oesophageal sensitivity to acid. To independently assess changes in oesophageal sensitivity, it would be necessary to study patients with reflux disease but no oesophagitis. The aim of this study was to investigate the effect of acid suppression on oesophageal sensitivity and to assess the time course of any measured effect. Twenty seven patients were recruited, of whom 25 completed the study (14 men and 11 women, mean (SD) age 50 (15) years). All had classic symptoms of gastro-oesophageal reflux but normal results of upper gastrointestinal endoscopy and oesophageal mucosal histological tests. Each had abnormal 24 hour pH studies and a positive acid perfusion tests. Subjects were assigned double blind to placebo (n = 11) or famotidine 40 mg twice daily (n = 14) for four weeks. Acid perfusion tests were carried out at 0, 4, 5, and 8 weeks and time to heartburn recorded. Time to heartburn (mean (SEM)) was 124 (78) seconds in the famotidine and 187 (154) in the placebo group at week 0 (NS). Compared with baseline, significant increases in time to heartburn was found with famotidine at weeks 4 (383 (102), p < 0.01) and 5 (344 (92), p < 0.01) but not week 8 (336 (90) seconds). No significant effects were found with placebo (219 (41), 146 (23), and 144 (25) seconds for weeks 4, 5, and 8). Heartburn symptom score decreased significantly with famotidine (mean scores 3.6, 1.9, 2.1, and 2.6 at weeks 0, 4, 5, and 8 (p=0.001)) and showed a significant negative correlation with time to heartburn (r(s)=-0.60; p<0.0001). It is concluded that oesophageal sensitivity to acid is reduced by famotidine independent of and effect on oesophagitis; the effect wanes one to four weeks after the end of treatment and correlates with change in heartburn score.