Acid perfusion test and 24-hour esophageal pH monitoring with symptom index. Comparison of tests for esophageal acid sensitivity

Evaluation of esophageal sensation

Dramatic progress has been made over the past decade in the sophistication and availability of equipment to test esophageal motility and sensation. High-resolution esophageal manometry and impedance have moved from the research clinic into clinical practice. Some of the testing is costly and time consuming, and requires extensive experience to perform the testing and properly interpret the results. These sensory studies are valuable in the interpretation of clinical problems, and provide important research information. Clinicians should evaluate the research studies to advance their understanding of the pathophysiology of the esophagus.

Acid-suppressive therapy with esomeprazole for relief of unexplained chest pain in primary care: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

High-quality data regarding the efficacy of acid-suppressive treatment for unexplained chest pain are lacking. The aim of this study was to evaluate the efficacy of esomeprazole in primary-care treatment of patients with unexplained chest pain stratified for frequency of reflux/regurgitation symptoms.

METHODS

Patients with a ≥ 2-week history of unexplained chest pain (unrelated to gastroesophageal reflux) who had at least moderate pain on ≥ 2 of the last 7 days were stratified by heartburn/regurgitation frequency (≤ 1 day/week (stratum 1) vs. ≥ 2 days/week (stratum 2)) and randomized to 4 weeks of double-blind treatment with twice-daily esomeprazole 40 mg or placebo. Chest pain relief during the last 7 days of treatment (≤ 1 day with minimal symptoms assessed daily using a 7-point scale) was analyzed by stratum in keeping with the predetermined analysis plan.

RESULTS

Overall, 599 patients (esomeprazole: 297, placebo: 302) were randomized. In stratum 1, more esomeprazole than placebo recipients achieved chest pain relief (38.7% vs. 25.5%; P=0.018); no between-treatment difference was observed in stratum 2 (27.2% vs. 24.2%; P=0.54). However, esomeprazole was superior to placebo in a post-hoc analysis of the whole study population (combined strata; 33.1% vs. 24.9%; P=0.035).

CONCLUSIONS

A 4-week course of high-dose esomeprazole provided statistically significant relief of unexplained chest pain in primary-care patients who experienced infrequent or no heartburn/regurgitation, but there was no such significant reduction in patients with more frequent reflux symptoms.

Noncardiac chest pain: diagnostic evaluation

Noncardiac chest pain (NCCP) is a common and challenging clinical problem. It is estimated that more than 70 million Americans (23% of the population) suffer from this condition yearly. Patients with NCCP represent a diagnostic dilemma. Their chest pain is often indistinguishable from cardiac pain leading to extensive and expensive evaluations. Once coronary artery disease and other cardiac and pulmonary sources of chest pain are excluded, patients are frequently referred to gastroenterologists to look primarily for esophageal sources of pain. A variety of diagnostic tests are available to the practicing clinician to identify the origin of pain, including ambulatory pH testing, esophageal motility, upper endoscopy, provocative testing and even therapeutic trials.

Visceral sensitivity testing

Visceral hypersensitivity is regarded as an important factor in the pathogenesis of functional gastrointestinal disorders. Assessment of visceral sensitivity has several important aims: increasing the understanding of normal and abnormal visceral sensory mechanisms and participating sensory pathways, serving as diagnostic tool to detect patients with abnormal visceral sensitivity, and evaluating therapeutic interventions directed towards modification of visceral sensitivity. Current stimulation modes in sensitivity tests include mechanical distension by barostat or tensostat, nutrient drink or water load, chemical stimulation, e.g. acid provocation or capsaicin ingestion, electrical, or thermal stimulation. Multimodal probes incorporating several stimulation modes in one device have recently been developed. Assessment of visceral sensation can be based on subjective responses of conscious perception or on objective parameters such as visceromotoric responses or central sensory processing patterns. All methods face the challenge that visceral sensitivity may be influenced by a wide spectrum of different factors, including the test techniques themselves, and improved, preferably non-invasive sensitivity tests with a greater standardisation and a broader applicability are still needed.

Risk factors for non-cardiac chest pain in the community

BACKGROUND

Non-cardiac chest pain is a common and expensive condition. Risk factors for non-cardiac chest pain are poorly understood and lack description in the USA community.

AIM

To explore risk factors and health-seeking behaviour in non-cardiac chest pain in a USA community.

METHODS

Olmsted County, MN subjects who reported at least monthly or severe chest pain in response to a validated questionnaire were compared with controls. All the Mayo Clinic medical records were reviewed; those with cardiac disease or relevant organic conditions were excluded.

RESULTS

Of 2118 eligible subjects, 1524 (72%) returned a questionnaire, 389 subjects (26%) reported any chest pain and 186 (12.2%) at least monthly or severe chest pain. Of these, 62 were excluded for a cardiac diagnosis or another organic cause. Thus, 124 subjects (9.1%, 95% CI: 7.6-10.8%) reported at least monthly or severe non-cardiac chest pain, of which 65 (52.4%) had frequent reflux symptoms. Independent risk factors for non-cardiac chest pain were obesity (OR 3.0, 95% CI: 1.64-5.50), family history of reflux (OR 2.8, 95% CI: 1.73-4.32), previous cigarette use (OR 2.0, 95% CI: 1.27-3.18), aspirin use (OR 1.5, 95% CI: 1.00-2.31) and use of antiarthritis medicines (OR 2.0, 95% CI: 1.27-3.16). Compared with subjects with non-cardiac chest pain and associated gastro-oesophageal reflux symptoms, subjects with non-cardiac chest pain without associated gastro-oesophageal reflux symptoms were less likely to have a family history of reflux, more likely to be younger, and less likely to be obese. Compared with controls, subjects with non-cardiac chest pain without gastro-oesophageal reflux symptoms were younger (OR 0.97, 95% CI: 0.95-0.99), reported higher somatic symptom scores (OR 1.1, 95% CI: 1.08-1.73) and were more likely to be obese (OR 2.6, 95% CI: 1.15-5.93).

CONCLUSIONS

Recurrent or severe non-cardiac chest pain is common in the community. Half of the people with significant non-cardiac chest pain have frequent reflux symptoms, thus, risk factors for non-cardiac chest pain are similar to risk factors for gastro-oesophageal reflux disease. People with non-cardiac chest pain without reflux symptoms have a slightly different risk factor profile.

Gastroesophageal reflux

Gastroesophageal reflux disease (GERD) is the most common disease of the gastrointestinal system. Heartburn, regurgitation, and dysphagia are the most common symptoms of GERD. However, chest pain, chronic cough, laryngitis, hoarseness, and other otolaryngologic manifestation can be the primary manifestations of the disease. Endoscopy, barium studies, and especially pH monitoring and therapeutic trials may help in establishing the diagnosis of GERD. The introduction of H2 antagonists and especially of proton pump inhibitors (PPI) has brought symptomatic relief in most patients. However, surgical procedures, especially laparoscopic fundoplication, are still required in some patients. Barrett's esophagitis is the most common complication of GERD and is associated with a high prevalence of esophageal adenocarcinoma. Whether or not treatment with either PPIs or H2 antagonists can prevent this complication is still under investigation.

The value of ambulatory 24 hr esophageal pH monitoring in clinical practice in patients who were referred with persistent gastroesophageal reflux disease (GERD)-related symptoms while on standard dose anti-reflux medications

To determine the value of pH testing in clinical practice in gastroesophageal reflux disease patients who failed anti-reflux treatment. Patients resistant to standard dose proton pump inhibitor or an H2-blocker underwent pH testing. Randomly selected patients from the proton pump inhibitor failure group underwent the modified acid perfusion test as compared to patients with non-erosive reflux disease. In the proton pump inhibitor failure group (n = 70), 63.8% had a normal pH test as compared to 29% in the H2-blocker group (n = 31) (P = 0.007). Sensory intensity rating and acid perfusion sensitivity score were significantly higher in the non-erosive reflux disease control group than the proton pump inhibitor failure group (P < 0.05). Most patients who continued to be symptomatic on proton pump inhibitor once daily demonstrated a normal pH test and overall lack of increased chemoreceptor sensitivity to acid.

Paroxysmal laryngospasm: a typical but underrecognized supraesophageal manifestation of gastroesophageal reflux?

Thirty-five consecutive adult patients with paroxysmal laryngospasm (LS) and with unimpaired vocal fold mobility were prospectively studied for coexisting gastroesophageal reflux disease (GERD). Nineteen patients reported frequent (>3 episodes a week) LS episodes (FLS patients) and 16 patients reported occasional LS episodes (OLS patients). All patients underwent an extensive otorhinolaryngological (ORL) examination, upper gastrointestinal (GI) endoscopy, ambulatory 24-hr dual-channel esophageal pH monitoring, and esophageal manometry. In addition, a subset of LS patients also underwent ambulatory duodenogastroesophageal reflux (DGER) monitoring. Patients with daily LS used the symptom marker during pH monitoring indicating separate LS episodes. All FLS patients and 14 OLS patients (87%) had a diagnosis of GERD. Only 10 patients (29%) experienced heartburn and/or regurgitation. Compared to OLS patients, FLS patients generally had more severe GERD as indicated by a higher prevalence of a hiatus hernia, higher distal and proximal esophageal acid exposure times, and higher values of DGER. In six FLS patients, 21 LS episodes (91%) occurred simultaneously with acid reflux, indicating a causal association between LS and GER. On antireflux therapy consisting of omeprazole, 20 mg bid, or lansoprazole, 30 mg oid, and lifestyle measures, LS ceased completely in all patients within 6 weeks. The present study not only demonstrates the role of GER in the pathogenesis of LS and the effectiveness of antireflux therapy, but also suggests that LS in adult patients with unimpaired vocal fold mobility might be considered a typical, although most frequently unrecognized, supraesophageal manifestation of GER.

Sensory testing of the esophagus

Originally, sensory testing of the esophagus included the acid perfusion test and the edrophonium test, which were developed to assess patients with non-cardiac chest pain. In the last 2 decades interest in functional esophageal disorders has increased and thus further understanding of the underlying mechanisms of esophageal pain required development of new sensory testing techniques. Balloon distension using a computerized electronic device, electrical stimulation and impedance planimetry have generated important information about esophageal sensory thresholds for pain in different disease states. Intraluminal ultrasonography has been used to determine the physiologic changes of the muscle wall of the esophagus during perception of typical esophageal symptoms. Central evaluation of patients undergoing esophageal stimulation has recently been introduced to assess cerebral activation in different esophageal disorders. However, many studies using esophageal sensory testing are afflicted with significant design flaws, making interpretation of the results very difficult. This is primarily due to lack of recognition of factors that can modulate esophageal sensation.

Noncardiac chest pain: an Asian view

NCCP is a common condition in Asia. The diagnostic approach of NCCP in Asians is similar to the Western population. GERD is the most common etiology. PPI therapy is an attractive alternative to other invasive diagnostic tests for NCCP and is equally effective for the Asian population.

Lack of association between esophageal acid sensitivity detected by prolonged pH monitoring and Bernstein testing

OBJECTIVES

Heartburn, a common medical symptom, is thought to be the result of acid reflux into the esophagus. Perfusion of the esophagus with exogenous acid (Bernstein test) in susceptible individuals causes heartburn. Temporal correlation between heartburn and pH drop in the esophagus from endogenous acid, as reflected by a positive symptom index (SI), provides further evidence of a correlation between acid in the esophagus and heartburn. We tested the relationship between heartburn and acid in the esophagus by determining the SI and Bernstein test results in the same individual.

METHODS

Ninety-three patients with heartburn underwent 24-h pH monitoring and Bernstein testing. A Bernstein score that included the severity of heartburn and the time of heartburn onset during Bernstein test was calculated. The relationship between SI, Bernstein test, and Bernstein score was determined.

RESULTS

Fifty-eight patients reported symptoms during the prolonged pH recording. A positive SI was detected in 27 patients. Forty-nine patients had a positive Bernstein test. There was no correlation between the patients with a positive SI and positive Bernstein test results. There was no correlation between SI and Bernstein score. A positive Bernstein test within 5 min of acid infusion did not predict heartburn during spontaneous reflux episodes of >/=5 min.

CONCLUSIONS

The lack of association between symptoms induced by acid perfusion of the esophagus compared with symptoms following spontaneous reflux in the same individual suggests that the heartburn following acid perfusion and spontaneous heartburn are induced by different stimuli.

Esophageal dysmotility and acid sensitivity in patients with mitral valve prolapse and chest pain

Mitral valve prolapse (MVP) patients often experience non-cardiac chest pain. The aims of this study were to determine, in patients with non-cardiac chest pain: (i) whether esophageal dysmotility is more common in patients with MVP than in patients without MVP; and (ii) if acid sensitivity is an important cause of the chest pain in MVP patients. Esophageal manometry and acid perfusion testing were performed in 277 consecutive patients with non-cardiac chest pain. Patients with MVP (13 female, one male; mean age 49 years) were more likely (P = 0.01) to have esophageal dysmotility, while acid perfusion was less likely (P < 0.05) to provoke their chest pain, than in patients without MVP. The most common esophageal motor abnormalities detected in patients with and without MVP were diffuse esophageal spasm (prevalence, 57%) and non-specific motor disorder (prevalence, 9%), respectively. This study, the first large prospective series examining possible esophageal sensorimotor correlates of chest pain in MVP patients, demonstrates that in the absence of a cardiac cause for chest pain, a specific esophageal motility disorder should be excluded, rather than assuming the chest pain is likely to be due to acid sensitivity.

Diminished mechanosensitivity and chemosensitivity in patients with achalasia

The pathogenesis of achalasia involves the degeneration of enteric and autonomic nervous systems with resultant effects on esophageal motility. The neural degeneration could affect visceral sensation in achalasia. The aim of this study was to examine mechanosensitivity and chemosensitivity in patients with achalasia. Perceptual responses to esophageal distension and acid perfusion were assessed in nine achalasia patients and nine healthy subjects. Mechanosensitivity was evaluated using a barostat with a double-random staircase distension protocol. Responses were graded as follows: 0, no sensation; 1, initial sensation; 2, mild discomfort; 3, moderate discomfort; and 4, pain. Chemosensitivity was graded along a visual analog scale after perfusion of saline and 0.1 N HCl. Barostat pressure-volume relationships were used to report esophageal body compliance. Barostat pressures for initial sensation and mild discomfort were not significantly different for patients and controls. The pressures for moderate discomfort (37.9 +/- 3.5 vs. 25.7 +/- 2.4 mmHg; P < 0.05) and pain (47.8 +/- 2.3 vs. 32.2 +/- 3.5 mmHg; P = 0.002) were significantly higher in achalasics than controls. Seven of the eight achalasia patients never reached pain thresholds at the maximum distension pressure (50 mmHg). Sensation to acid perfusion was significantly lower in achalasics compared with controls (2.2 +/- 1.2 vs. 6.7 +/- 1.7 cm; P < 0.05). Compliance was significantly increased in patients with achalasia compared with controls. We conclude that both mechanosensitivity and chemosensitivity are significantly diminished in achalasia patients compared with controls. Also, initial sensation and pain sensation are differentially affected in achalasics. These findings suggest that neuropathic defects in achalasia may manifest themselves in visceral sensory and motor dysfunction.

Noncardiac chest pain: evaluation and treatment

Noncardiac chest pain is a heterogeneous condition for which diagnosis and treatment are challenging. Research is needed to streamline evaluation to minimize unnecessary invasive testing and costs. Chest pain clinics to assess chest pain patients are popular in the United States and may be of value in reassuring patients and reducing presentation to hospital; however, recently this has been contended [111]. Options for the effective treatment of NCCP are dependent on the risk of an adverse outcome and the cost-effectiveness of the management algorithm that is followed. Most (64%) of those presenting to the emergency department with chest pain are classified as having NCCP [112,113]. GERD is probably the most important cause and application of a test of acid suppression with a high-dose PPI for 1 to 2 weeks seems to be a useful diagnostic tool. In those patients with GERD-related NCCP, short-term and potentially long-term therapy with a PPI (commonly higher than standard dose) is required to alleviate symptoms. Esophageal dysmotility is relatively uncommon in patients with NCCP and evaluation by esophageal manometry might be limited to rule out achalasia. Chest wall syndromes are common but probably often missed. Many patients with NCCP have psychologic or psychiatric abnormalities, as either the cause or an effect of the chest pain, but diagnosis here depends on techniques not applied easily in the acute situation. Pain modulators seem to offer significant improvement in chest pain symptoms for non-GERD-related NCCP. Finally, trials of management strategies to deal with this problem are required urgently, because the earlier discharge of patients with NCCP may exacerbate the problem. Fig. 2 provides a flow chart for diagnosis and treatment of NCCP.

Sustained esophageal contraction: a motor correlate of heartburn symptom

Heartburn occurs in the presence as well as the absence of acid reflux. We searched for a motor correlate of heartburn. Twelve subjects with heartburn were studied with 24-h synchronized pressure, pH, and high-frequency intraluminal ultrasound (HFIUS) imaging of the esophagus. The HFIUS images were analyzed every 2 s for a period of 2 min before and 30 s after the onset of heartburn during 20 acid reflux-positive and 20 acid reflux-negative heartburn episodes. The esophageal muscle thickness was measured as a marker of contraction. Esophageal pressure and HFIUS images were recorded during the Bernstein test in 15 subjects. Sustained esophageal contractions (SECs) were identified during 13 of 20 heartburn episodes associated with acid reflux and 15 of 20 heartburn episodes without acid reflux. SECs were detected during 2 of 40 matched control periods only (P < 0.05). The duration of SECs was 44.9 +/- 26.9 s. The Bernstein test reproduced heartburn symptoms in 8 of 15 subjects. SECs were identified during 6 of 8 (75%) Bernstein-positive and in 1 of 7 (14.3%) Bernstein-negative tests (P = 0.04). We conclude that a SEC precedes both spontaneous and induced heartburn symptoms and may be the cause of heartburn sensation.

Synergy between low-dose ranitidine and antacid in decreasing gastric and oesophageal acidity and relieving meal-induced heartburn

BACKGROUND

The pathophysiology of recurrent postprandial heartburn and the basis for the effectiveness of antacids or low doses of histamine H2-receptor antagonists have not been well studied.

METHODS

The selected subjects (n=26) had heartburn more than four times a week for at least 2 months, which was responsive to antacids. Gastric pH and oesophageal pH were measured for 1 h before, during, and 4.5 h after ingestion of a meal over 0.5 h. Heartburn severity was assessed at 15-min intervals beginning at the end of the meal. Each subject randomly received placebo, 75 mg ranitidine, 420 mg calcium carbonate, and ranitidine plus calcium carbonate. Values for pH were converted to acid concentration (mM) and integrated acidity was calculated from the cumulative, time-weighted means of the acid concentrations for every second of the postprandial recording period.

RESULTS

There was a close temporal relationship between heartburn and oesophageal acidity. Most oesophageal acid exposure occurred over a 90-min period that began approximately 45 min after the end of the meal. During this period the gastric acid concentration was less than 5% of maximal. Ranitidine significantly decreased gastric but not oesophageal acidity, whilst antacid significantly decreased oesophageal but not gastric acidity. Ranitidine plus antacid significantly decreased both gastric and oesophageal acidity. Antacid alone and ranitidine plus antacid significantly decreased heartburn severity.

CONCLUSIONS

Determining integrated gastric and oesophageal acidity provides novel information regarding the pathophysiology of meal-induced heartburn as well as the actions of low-dose ranitidine and antacid. For subjects with meal-induced heartburn, treatment with low-dose ranitidine plus antacid is particularly effective in decreasing gastric and oesophageal acidity as well as heartburn severity.

The role of acid and duodenal gastroesophageal reflux in symptomatic GERD

OBJECTIVE

Mixed reflux of acid and duodenal contents frequently occurs in patients with gastroesophageal reflux disease (GERD). The aim of this study was to establish the contribution of acid and duodenal gastroesophageal reflux (DGER) to symptoms in patients with presumed GERD.

METHODS

A total of 72 patients (37 women), mean age 45 yr (+/-2 yr), underwent 24-h ambulatory pH and Bilitec monitoring. Patients pressed a marker button when experiencing typical symptoms. For each symptom episode, minimal pH and maximal bilirubin optical density in a 2- or 4-min interval were calculated. For each patient, the symptom index (SI) and symptom-association probability for acid and for bile reflux were determined.

RESULTS

A total of 544 symptom episodes were identified. Using a 2-min interval, 28% were associated with acid reflux, 9% with DGER, and 12% with mixed reflux. No significant difference was found when a 4-min interval was used. A positive SI for acid reflux was present in 21% of the patients and for DGER in 14%. All patients with a positive SI for DGER had also a positive SI for acid reflux. A positive symptom-association probability for acid reflux was present in 22% of the patients, for DGER in 7% of the patients, and for mixed reflux in 10% of the patients.

CONCLUSIONS

Symptom episodes in patients with presumed GERD are more related to acid reflux than to DGER. DGER does not play a major role in producing typical esophageal symptoms.

A critical approach to noncardiac chest pain: pathophysiology, diagnosis, and treatment

Approximately 30% of coronary angiograms performed in this country are negative for significant coronary artery disease. These patients are classified as having noncardiac or unexplained chest pain (UCP). Despite the good overall prognosis, this condition has significant morbidity and costs. The pathophysiology of this condition is likely caused by overlapping cardiac, esophageal, and psychiatric abnormalities with visceral hyperalgesia playing a central role. Gastroenterologists are often consulted in the evaluation of these patients because esophageal disorders are among the most common conditions associated with UCP. However, clinical symptoms are unreliable in differentiating between esophageal and cardiac causes of UCP. Gastroesophageal reflux disease, not esophageal motility disorders, is the most common esophageal disorder present in patients with UCP. The most useful diagnostic test in the evaluation of UCP is 24-h pH monitoring. An initial empiric trial of high-dose acid suppression is the most cost-effective intervention in the management of these patients. A clinical algorithm is suggested for the evaluation and treatment of UCP.

Diagnosis of reflux disease

There are numerous tests for which a diagnostic value in the context of gastro-oesophageal reflux disease has been claimed. Some of these tests (e.g. the acid perfusion test) have become obsolete after the advent of 24-hour oesophageal pH monitoring. With the latter test not only can excessive reflux be identified, but also, and more importantly, a temporal relationship can be demonstrated between a patient's symptoms and reflux episodes. Radiographical examination of the oesophagus has largely been replaced by endoscopy, although the use of the former test is still indicated in certain circumstances (e.g. in the differentiation of sliding from para-oesophageal hiatus hernia). In clinical practice, the so-called proton pump inhibitor test has gained considerable popularity. Despite several studies on the specificity and sensitivity of this test, its value has not yet been established with sufficient accuracy. Conventional manometric evaluation of lower oesophageal sphincter pressure has been over-emphasized as a diagnostic test in gastro-oesophageal reflux disease.

The omeprazole test is as sensitive as 24-h oesophageal pH monitoring in diagnosing gastro-oesophageal reflux disease in symptomatic patients with erosive oesophagitis

BACKGROUND

Ambulatory 24-h oesophageal pH monitoring and a short course of high dose omeprazole can be used as diagnostic modalities for GERD. However, comparative studies of the diagnostic accuracy and reliability of both strategies have not been performed.

AIM

To compare the omeprazole test to ambulatory 24-h oesophageal pH monitoring in diagnosing GERD in symptomatic patients using endoscopically proven erosive oesophagitis as a gold standard.

METHODS

Patients with heartburn underwent an upper endoscopy. Only those with erosive oesophagitis were included in the study. Subsequently, patients underwent ambulatory 24-h oesophageal pH monitoring and an 'omeprazole test.' Daily symptoms were recorded during the first week (baseline) and repeated during the second week on therapy (omeprazole 40 mg in the morning and 20 mg in the evening).

RESULTS

Thirty-five patients were included in the study. The omeprazole test was significantly more sensitive in diagnosing GERD than total acid contact time on 24-h oesophageal pH monitoring (83% vs. 60%; P < 0.03). However, the sensitivity of the pH test increased to 80% after adding patients with a positive symptom index, and patients with abnormal acid exposure in the supine or erect positions despite normal total acid contact time. Patients with a normal pH test were significantly younger (49 +/- 2.6 years) than those with abnormal test (59 +/- 1.8; P=0.002).

CONCLUSIONS

In this study an omeprazole test was at least as sensitive as ambulatory 24-h oesophageal pH monitoring in diagnosing GERD in patients with erosive oesophagitis.

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.

Acceptability of a paste formulation and efficacy of high dose omeprazole in healing gastric ulcers in horses maintained in race training

Gastric ulceration has been found to occur in 80-90% of Thoroughbreds in active race training. Previously, variable success has been reported using mucosal surface protectants and H2 receptor antagonist. Omeprazole, a substituted benzimidazole, has been shown to inhibit gastric acid secretion in both man and animals. Fourteen horses, in active race training and with endoscopic evidence of moderated to severe gastric ulceration were divided into 2 groups: Group 1 (7 horses) were given placebo paste orally once daily for 28 days; Group 2 (7 horses) received 1.54 g active omeprazole in the placebo once daily for 28 days. Logs detailing administration and acceptability of the paste, and the horse's feeding and training regime were maintained by the trainer of each horse. Endoscopic examination of the stomach occurred at the beginning of the trial, and at 13-17 days and 27-31 days following commencement of the trial. Those horses that were free of ulceration on Days 27-31 were reexamined on Days 35-49. Acceptability of the paste, whether with or without active omeprazole, was deemed excellent in all horses except on one occasion, when one horse swallowed the paste following initial mild reluctance. Of the horses given the placebo (Group 1), 3 were withdrawn after the 13-17 day endoscopic examination: 1 horse to be given a H2 receptor antagonist, 1 horse was removed from training due to aryepiglottic entrapment and 1 horse had a greater than 10% fall in bodyweight from the start of the trial. Of the horses given active omeprazole (Group 2), one horses was relocated to another race track following the 13-17 day endoscopic examination. For the horses given placebo (Group 1), there was no change in the severity of ulceration. In contrast, the severity of ulceration in the horses given active omeprazole was significantly reduced at 13-17 days and 27-31 days. In 2 Group 2 horses, ulcers that had been completely eliminated subsequently returned when reexamined at 35-49 days. The results of this study suggest that omeprazole, employing a once daily dosing schedule, is effective at reducing the severity or eliminating gastric ulcers in Thoroughbreds in active race training.

Recognizing atypical manifestations of GERD. Asthma, chest pain, and otolaryngologic disorders may be due to reflux

The presence of common symptoms, such as heartburn and regurgitation, usually make the diagnosis of gastroesophageal reflux disease (GERD) fairly straightforward. However, extraesophageal symptoms of GERD, such as asthma, noncardiac chest pain, and hoarseness, are often not recognized and therefore are poorly managed. This article sheds light on the atypical manifestations of GERD as well as current approaches to diagnosis and treatment.

Is functional dyspepsia largely explained by gastro-oesophageal reflux disease?

Functional dyspepsia is a chronic disorder of unknown aetiology. The lack of endoscopic abnormalities in patients with this disorder has led many physicians to believe that gastro-oesophageal reflux disease may be responsible for most symptoms. Our group has addressed this issue, by pathophysiological studies in a large cohort of Dundee patients with persistent dyspeptic symptoms. Peptic ulcer and gallstones were excluded in all patients by appropriate tests. Ambulatory pH monitoring showed oesophageal acid reflux that lay above the conventional diagnostic threshold in approximately 20% of patients. This subset was diagnosed as having gastro-oesophageal reflux disease. In the remainder, moderate or severe reflux-like symptoms were reported by approximately 44% patients, who were categorized as reflux-like functional dyspepsia. Reflux symptoms were mild or absent in 36% patients, who were categorized as non-reflux-like dyspepsia. While oesophageal pH profiles lay within the conventional normal range in both of these functional dyspepsia subgroups, patients with reflux-like functional dyspepsia had significantly greater acid exposure values, including total oesophageal acid exposure time, percentage time at a pH of less than 4.0, DeMeester scores and pain reflux event correlation. Hence patients with reflux-like functional dyspepsia have oesophageal acid exposure that lies below the diagnostic threshold for gastro-oesophageal reflux disease but exceeds that of patients with non-reflux dyspepsia. The high pain/reflux event correlation in reflux-like functional dyspepsia suggests that subthreshold oesophageal acid exposure may be associated with troublesome reflux symptoms.

Esophageal manifestations of rheumatic disorders

This study was performed to review information on functional and anatomic esophageal manifestations in patients with rheumatic disorders and to outline their pathogenesis, diagnosis, and treatment in light of the current medical, endoscopic, and surgical advances. A MEDLINE search of English-language articles published between 1985 and 1995, reviews of the bibliographies of textbooks, and a manual search of the reference lists of relevant articles formed the data sources, all combined with our own clinical experience. Primary research and review articles addressing the pathogenesis, diagnosis, treatment, prognosis, and complications of esophageal disease occurring in a rheumatic context were selected, with emphasis on recently developed medical, endoscopic, and surgical methods for diagnosis and management. Study design and quality were assessed, with particular attention paid to methods and aims. Relevant data on frequency, clinical presentation, and relationship to underlying rheumatic disorder, prognosis, and clinical management were analyzed. Esophageal manifestations are common in patients with rheumatic diseases and range in nature and severity from functional myopathic or neuropathic esophageal dysmotility to extrinsic lumenal compression and esophageal mucosal damage from gastroesophageal acid reflux or opportunistic infection. The primary symptoms of heartburn, dysphagia, odynophagia, chest pain, and bleeding may be directly related to the underlying rheumatic disease or may be the unwanted effects of therapy with nonsteroidal antiinflammatory drugs, immunosuppressants, or disease-modifying agents. Easily over-looked in the context of a multisystemic disease, these esophageal symptoms may be amenable to simple treatments, but frequently require a thorough assessment by modern, sophisticated diagnostic tools. In many instances, functional and structural involvement of the esophagus in patients with rheumatic disorders requires a high index of suspicion for an early diagnosis, correct assessment, intensive surveillance, and aggressive therapy to avoid end-organ damage and decline in quality of life. Significant recent advances in the understanding of esophageal pathophysiology, the development of diagnostic techniques, progress in diagnostic and therapeutic endoscopy, and minimally invasive surgery allow early detection and effective long-term therapy for esophageal dysfunction associated with rheumatic diseases.

Typical and atypical presentations of gastroesophageal reflux disease. The role of esophageal testing in diagnosis and management

Gastroesophageal reflux disease (GERD) is a common disease with many typical and atypical forms of presentation. In the classic presentations of GERD with heartburn and regurgitation, esophageal testing, except for endoscopy, is only required for poorly responding patients or prior to surgical therapy. The atypical presentations of GERD, including chest pain, asthma, and ear, nose, and throat complaints, frequently are not associated with heartburn or regurgitation. Esophageal testing, particularly 24-hour pH monitoring is key to making the diagnosis and ensuring adequate acid suppression.

The diagnosis and management of gastroesophageal reflux disease

GERD is a common clinical problem. Generally, its clinical presentation and management are straightforward. Greater awareness of the numerous extraesophageal manifestations of the disease aids patients and physicians in appropriate recognition and treatment. Medical therapy is effective in the majority of cases but often requires long-term medication for acceptable symptom control. A small, but significant proportion of patients presents with or develops complications of GERD, most importantly Barrett's esophagus. Although the logistics of long-term surveillance of persons with Barrett's esophagus is unclear, the association of this metaplastic change with esophageal adenocarcinoma underscores the importance of regular follow-up.

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.

A dose-ranging study of ranitidine and its effect on intragastric and intra-oesophageal acidity in subjects with gastro-oesophageal reflux disease

METHODS

This randomized, double-blind, single-centre, crossover study was designed to assess the effects of three regimens of ranitidine (150 mg b.d., 300 mg b.d. and 300 mg q.d.s.) and placebo on intra-oesophageal and intragastric pH in subjects with gastro-oesophageal reflux disease (GERD). Twenty-six subjects were screened, and 9 were evaluable by the admission criteria. These 9 subjects received each of the regimens for 72 h, and a wash-out period of at least 48 h followed each dosing period. Standard meals and beverages were provided.

RESULTS

With increasing doses of ranitidine, 24-h intragastric mean H+ and integrated H+ fell, and the percentage of the time the pH was equal to or greater than 4 (% time pH > or = 4) rose: the minimum effective dose for these effects was ranitidine 300 mg daily. With increasing doses of ranitidine there was also a progressive decline in mean 24-h intra-oesophageal H+ and integrated H+, and increasing % time pH > or = 4. The minimal effective dose was 300 mg daily for intra-oesophageal mean H+ and integrated H+, and 600 mg for % time pH > or = 4. The minimal effective dose to decrease the number of reflex episodes was 1200 mg ranitidine. For the daytime upright position, a dose effect of increasing ranitidine was also seen, with minimal effective ranitidine doses of 300 mg for a decrease in mean H+, and 1200 mg for % time pH > or = 4.

CONCLUSION

If these higher doses of ranitidine are confirmed to be more effective than the standard 150 mg b.d. regimen for the treatment of patients with gastro-oesophageal reflux disease, then the mechanism of this action probably relates to the lower exposure of the oesophageal mucosa to acid.

Predictive value of symptom profiles in patients with suspected oesophageal dysmotility

The main aim of the study was to determine prospectively, in patients referred for oesophageal manometry, whether certain combinations of oesophageal symptoms are more likely than others to predict the presence of oesophageal dysmotility or a positive response to acid perfusion testing. In 524 consecutive patients, presenting predominantly with (non-cardiac) chest pain (n = 277), dysphagia (n = 186), or heartburn (n = 61), a standardized symptom assessment was completed before oesophageal manometry and acid perfusion testing. Half the patients in each group reported additional ('secondary') oesophageal symptoms as well as the predominant symptom. Oesophageal dysmotility was categorized in accordance with standard manometric criteria for achalasia, diffuse oesophageal spasm, nutcracker oesophagus, hypertensive lower oesophageal sphincter, or non-specific oesophageal motility disorder. In the predominant chest pain group, the prevalence of abnormal manometry was 33%; in the presence of secondary symptoms, especially dysphagia rather than heartburn, however, the prevalence was significantly (p < 0.01) increased. Also in the predominant chest pain group the prevalence of positive acid perfusion testing (44%) was significantly greater (p < 0.05) in those with than in those without secondary symptoms. In the predominant dysphagia group, the prevalence of abnormal manometry was higher than in the other two groups (56%; p < 0.001) but was not affected by the presence or absence of secondary symptoms; this latter finding was also true for the predominant heartburn group. The distribution of specific manometric disorders in any group was not related to the presence or type of secondary symptoms, although a combination of dysphagia and chest pain discriminated achalasia from other manometric disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastroesophageal reflux: diagnosis and management

The pathologic potential of chronic esophagitis cannot be overemphasized. Persistent reflux causing cycles of mucosal damage followed by healing may eventually lead to end-stage disease, with development of peptic stricture. The most effective drugs available are those that inhibit acid production. Drugs that will enhance lower esophageal function are still in the future.

Gastroesophageal reflux disease as a cause of chest pain

Patients with recurrent chest pain free of significant coronary artery disease account for 10% to 30% of patients undergoing coronary angiography. Recent studies suggest that gastroesophageal reflux disease may be very common in these patients. The cause of this chest pain seems to be related primarily to an acid-sensitive mucosa regardless of the presence of esophagitis. Unfortunately, a careful history will not distinguish chest pain arising from a cardiac versus an esophageal source. Therefore, all patients must undergo a thorough cardiac evaluation before assuming that acid reflux is the cause of their complaints. Initial gastroenterology evaluation will usually include upper GI endoscopy or barium studies, possibly with acid perfusion (Bernstein) testing, or both. However, the more sensitive and specific test for acid-related disease is prolonged esophageal pH monitoring. This study quantifies the amount of acid reflux but, more importantly, identifies the relationship between chest pain and acid reflux episodes. Patients should be studied in the outpatient setting with emphasis placed on performing activities that replicate their chest pain. Although we presume that acid-induced chest pain responds as well as heartburn to vigorous antireflux regimens, there are few studies to address this issue. Nevertheless, I have had great success in treating these patients with either high-dose H2 blockers or omeprazole therapy.