The Symptom Index: A Clinically Important Parameter of Ambulatory 24-Hour Esophageal pH Monitoring

Ambulatory 24-h esophageal pH monitoring is an accurate quantitative test of gastroesophageal reflux (GER). However, it does not answer the question: are the patients' symptoms due to GER? We developed a numerical scale to quantify the percent association between symptoms and pH less than 4--the symptom index (SI). In 100 consecutive patients with heartburn or chest pain, the SI for the chief complaint was either high (greater than 75%) or low (less than 25%) in 77% of cases. A similar bimodal distribution was seen when heartburn or chest pain symptoms were individually evaluated. There was a good association between high SI and the presence of GER (97.5%), as well as low SI and a normal 24-h pH study (81.1%). Endoscopy was normal in 89.5% of patients with low SI, but patients with high SI had esophagitis in only 69.7% of cases. The Bernstein test showed a poor association with the SI. Therefore, the SI gives clinically relevant information regarding the role of acid reflux and patient's symptoms. We believe this simple calculated index should be included in the analysis of 24-h esophageal pH studies.     

Esophageal scintigraphy and pH measurement in asthmatic adults suspected of having gastroesophageal reflux

Fifty-five adults with asthma were explored by gastroesophageal scintigraphy (GES) and pH monitoring (3 postprandial hours, 12 nocturnal hours). For their asthma, all patients received theophylline twice a day. Associated digestive symptomatology led to investigations for gastroesophageal reflux (GER). Twelve hours pH monitoring, the reference method, was validated in 13 normal volunteers. During 12 hr pH monitoring, 4 criteria were studied: number of GER, percentage of time at pH 4, number of GER longer than 5 min and longest GER. Acid reflux occurred in 69 p. 100 of cases. Three hours postprandial pH monitoring and GES showed a GER in 40 and 47.5 p. 100 of cases (p greater than 0.05). GES revealed pulmonary aspiration in almost a quarter of asthmatic adults. Detection of a 30 p. cent increment of nocturnal GER by long pH monitoring could explain that results may differ with various techniques. Pulmonary aspiration was more frequent after longer and deeper GER. The mean duration of GER was more than 9 min but it was not significantly different from GER without pulmonary aspiration. GES may be helpful after 12 h pH monitoring because it can prove pulmonary aspiration. Its association with long and intense GER at 12 h pH monitoring suggests definitive surgical treatment of GER in asthmatic patients.     

Therapy Insight: treatment of gastroesophageal reflux in adults with chronic cough

Gastroesophageal reflux (GER) is the second most common cause of chronic cough in immunocompetent patients who are nonsmokers, not on angiotensin-converting-enzyme inhibitors and have normal chest radiographs. Identification of GER in chronic cough patients can be difficult; most patients with GER-related cough have no esophageal symptoms and no esophageal test is adequate to make this diagnosis. Post-hoc analysis of four prospective intervention trials has identified a clinical patient profile that can predict the presence of GER-related cough 91% of the time. Clinical practice guidelines from the American College of Chest Physicians and the British Thoracic Society recommend initiating an initial empiric GER therapy trial, with esophageal testing being reserved for nonresponders. The empiric trial should include conservative measures and PPIs twice daily for 3 months. Selected patients who have dysphagia might benefit from the addition of a prokinetic agent. Esophageal manometry and pH testing with impedance monitoring (if available) should be performed in nonresponders while they are on therapy. It can take more than 50 days for cough to respond to medical GER therapy. Surgical fundoplication might be helpful in very carefully selected patients. Careful evaluation and treatment resolves cough in approximately 80% of patients with GER-related cough.     

Pulmonary aspiration shown by scintigraphy in gastroesophageal reflux-related respiratory disease

OBJECTIVES: Gastroesophageal reflux (GER) may underlie respiratory manifestations via vagally mediated airway hyperresponsiveness or microaspiration, and intraesophageal pH monitoring is generally used to identify GER in patients with such manifestations. We aimed to establish the frequency of retrograde pulmonary aspiration in patients with unexplained respiratory manifestations. METHODS: Fifty-one patients with refractory respiratory symptoms (cough, n = 18; pneumonia, n = 14; apnea, n = 8; asthma, n = 7; and laryngitis, n = 4) were prospectively evaluated. They underwent 24-h intraesophageal pH monitoring and gastroesophageal 99Tc scintigraphy with lung scan 18 to 20 h after the test meal. RESULTS: Thirteen of 51 patients (25.5%) had abnormal intraesophageal pH study results (mean reflux index, 11.3%; range, 6.5 to 50%); and in 25 of 51 patients (49%), overnight scintigraphy showed pulmonary aspiration. Nineteen of these 25 patients had entirely normal pH study results, whereas 6 of 13 patients with abnormal pH study results had aspiration. Pulmonary aspiration was demonstrated in all patients with apnea and 61.5% of patients with recurrent pneumonia. Nine of 25 patients (36%) with aspiration had histologic evidence of esophagitis, whereas histologic esophagitis was present in 5 of 13 patients (38.4%) with pathologic GER as shown by intraesophageal pH monitoring. CONCLUSIONS: Pulmonary aspiration as demonstrated by overnight scintigraphy is common in children with unexplained and refractory respiratory manifestations, suggesting that GER could be the underlying cause of these manifestations. Since only a few children with chronic or recurrent respiratory symptoms have a pathologic gastroesophageal acid reflux, a normal intraesophageal pH study result does not rule out GER in these children.     

Esophageal Impedance/pH Monitoring in Pediatric Patients: Preliminary Experience with 50 Cases

This paper describes multiple intraluminal impedance (MII) in 50 children with typical and atypical gastroesophageal reflux (GER) symptoms and discusses the possible clinical significance of objective numeric data provided by MII computed analysis. Patients underwent 24-hr pH/MII monitoring. Reflux parameters were analyzed with relation to age and reported symptoms. Nonacidic MII events occurred as frequently as acidic ones. A Pathologic Bolus Exposure Index associated with a normal pH Reflux Index was detected in 26% of our series. Significant correlations were found regarding acid and bolus clearing times and their ratio. We conclude that the low rate of symptom occurrence in the pediatric population represents a limit on MII evaluation. Our study confirmed that nonacid GER is at least as frequent as acid GER. As MII provides interesting objective data that could be used in clinical practice, we suggest further research to define normal ranges in the pediatric population.     

Chronic hoarseness secondary to gastroesophageal reflux disease: documentation with 24-h ambulatory pH monitoring

Gastroesophageal reflux (GER) has been implicated in otolaryngologic problems, particularly chronic hoarseness that cannot be attributed to other causes. To study this relationship, we used 24-h ambulatory intraesophageal or dual pharyngoesophageal pH monitoring in 33 patients with chronic hoarseness and laryngeal lesions suggestive of acid irritation. Twenty-six of the patients (78.8%) had pH evidence of severe GER, being at least three times greater than the upper limit of normal. In contrast to 19 patients with proven esophagitis, this GER was worse in the upright position. Of 15 patients with both pharyngeal and esophageal probes, three had esophagopharyngeal reflux, and two had atypical unexplained pharyngeal decreases in pH to below 4.0. Less than half of the 33 patients had the typical symptoms of GER, and standard esophageal tests usually yielded normal findings. Occult GER, predominantly in the upright position, appears to be common and severe in patients with chronic hoarseness, who have laryngeal lesions suggestive of GER. The causative mechanisms are not clear. The 24-h esophageal pH monitor is useful in screening this potentially treatable problem.     

Inclusion of supine period in short-duration pH monitoring is essential in diagnosis of gastroesophageal reflux disease

Prolonged esophageal pH monitoring is the most accurate method for detecting abnormal gastroesophageal reflux (GER) in patients with gastroesophageal reflux disease (GERD). However, some investigators have found that short-duration postprandial pH monitoring in the upright position is also useful, while others have failed to find such results. Therefore, we have compared a 6-hr period of pH monitoring (3-hr postprandial period after daytime meal and 3-hr supine period) with a total 24-hr period in detecting abnormal gastroesophageal reflux. Sixty-five patients (44 men, mean age 41.3 years) with GERD and 16 healthy volunteers (11 men, mean age 34.3 years) underwent 24-hr pH monitoring according to a standard protocol. Various reflux parameters during 24-hr pH monitoring were compared with reflux parameters during the 6-hr period. Abnormal GER was detected in 56 patients presenting with typical symptoms of GERD (sensitivity 86.2%). These patients could be further divided into upright (N=18), supine (N=15), and combined (N=23) refluxers, depending on the posture in which abnormal reflux occurred. Esophageal pH monitoring during the 3-hr postprandial upright period showed abnormal reflux in only 35 patients (sensitivity 53.8%;P<0.00005, compared with the 24-hr pH monitoring period). Abnormal GER was identified in 13 of 18 upright, 19 of 23 combined, and only one of 15 supine refluxers, as well as in two of nine patients with normal 24-hr pH-metry. However, inclusion of the 3-hr supine monitoring period in the 3-hr postprandial upright period improved detection of abnormal GER to 78.5% (51 patients;P=NS compared with 24-hr pH monitoring period). This was related mainly to improved detection of abnormal GER in supine refluxers (11 of 15; 73.3%). Esophageal acid exposure time correlated significantly with severity of esophagitis only during the total and supine periods of both the 24- and 6-hr periods and not during the upright period. Esophageal acid clearance correlated significantly with increasing grades of esophagitis for the supine and total periods only. We conclude that 3-hr postprandial pH monitoring, as has been conventionally practiced, is not appropriate in the detection of abnormal GER; inclusion of a supine period in the short-duration pH monitoring schedule increases the detection of pathological reflux. We therefore recommend that a supine period should be included in short-duration pH monitoring schedules. We also found that supine reflux was the most important factor in the development of esophagitis.     

Association of apnea and nonacid gastroesophageal reflux in infants: Investigations with the intraluminal impedance technique

An association of apnea and gastroesophageal reflux (GER) was proposed previously. However, pH metry as the standard diagnostic tool for GER only measures acid reflux (pH < 4). It is difficult to interpret studies in infants with a presumed association between apnea and GER based on pH metry because the buffering effect of feeding may result in predominantly nonacid GER. The aim of this study was to investigate the temporal association of apnea and GER with the pH-independent intraluminal impedance technique (IMP). Infants with recurrent regurgitation or respiratory symptoms suggestive of apnea were investigated simultaneously with IMP, pH monitoring, and polygraphy. IMP patterns, pH, oronasal flow, and chest wall movement were recorded and analyzed. In 22 infants, 364 GER episodes were recorded by IMP. One hundred and sixty five apneas were documented by visual validation of polygraph records. Forty-nine apneas (29.7%) were associated with GER; 11 (22.4%) of these showed acid reflux (pH < 4). A significant correlation between the time spent apneic and GER was found (P < 0.001). There is marked association between apnea and gastroesophageal reflux in infants. Patients potentially at risk cannot be reliably identified by pH metry. Its exclusive use is therefore not suitable for the detection of all GER-associated apneas in infants. The pH-independent intraluminal impedance technique has proven to be a sensitive diagnostic tool for this approach.     

Gastroesophageal reflux and unexplained chronic respiratory disease in infants and children

Thirty-eight children, aged from a few weeks to 7 years, with severe chronic pulmonary disease and without gastrointestinal symptoms, were investigated for gastroesophageal reflux (GER), using prolonged pH probe monitoring and gastroesophageal scintiscanning. All treatments were discontinued before testing. GER was found in 24 patients (63%) (group I) and it was not observed in 14 patients (group II). All patients of group I received antireflux treatment, consisting of cisapride; in 22 of 24 patients, GER was controlled, as indicated by improvement of either pH monitoring or scintiscanning, or both. Eighteen of these 22 (82%) had remission of their pulmonary disease, and only two patients of group II (14%) had spontaneous remission of the respiratory symptoms. We concluded that GER was probably the cause of the respiratory disease in 63% of our patients, since treatment of GER was followed by disappearance of the respiratory complaints in most of them. The combination of gastroesophageal scintiscanning and pH probe study improved the diagnostic accuracy.     

Chronic aspiration without gastroesophageal reflux as a cause of chronic respiratory symptoms in neurologically normal infants

OBJECTIVE: To describe 13 neurologically normal infants with chronic respiratory symptoms who had swallowing dysfunction with silent chronic aspiration without gastroesophageal reflux (GER) as the cause of their respiratory symptoms. BACKGROUND: Infants with neurologic disorders and infants with GER are known to have chronic respiratory symptoms. Isolated swallowing dysfunction and aspiration without GER in neurologically normal infants have not been widely reported. DESIGN: Retrospective chart review. SETTING: A tertiary pulmonary-care center at a children's hospital. PATIENTS: One hundred twelve otherwise healthy infants referred for respiratory symptoms who underwent esophageal pH studies and videofluoroscopic swallow studies (VSSs). METHODS: The records of infants referred between January 1997 and December 1999 to the Department of Pediatric Pulmonology who underwent 24-h esophageal pH monitoring and VSS as part of an evaluation for recurrent stridor and/or wheezing were reviewed. Significant GER was diagnosed if the percentage of time with esophageal pH < 4 was > 6%. Infants included in the study presented with recurrent respiratory symptoms, were born at term, were neurologically normal, had normal results of esophageal pH studies, but had abnormal results of VSSs (n = 13). RESULTS: All 13 infants presented with a variety of recurrent respiratory symptoms including wheezing and intermittent stridor. Ten of 13 infants had spitting and/or choking episodes with feeding. The mean (+/- SD) age at the onset of symptoms was 2.0 +/- 1.6 months, and the mean age at VSS was 5.9 +/- 3.4 months. All 13 infants had normal results of 24-h esophageal pH studies but had abnormal results for VSSs. All infants had evidence of swallowing dysfunction and direct silent aspiration of liquids with thin consistency. Six infants also were aspirating liquids with thick and/or semi-thick consistencies. None of the infants had evidence of structural anomalies on esophagograms. Nine infants were treated with thickened food, and in four infants oral feedings were stopped. Three of these infants required nasojejunal feeding, and one infant required gastrostomy tube feeding. VSSs were repeated every 3 months. In all infants, swallowing dysfunction resolved within 3 to 9 months. All infants tolerated the resumption of oral feeding. Videofluoroscopic documentation of the resolution of aspiration was followed by the resolution of respiratory symptoms in all infants. CONCLUSION: There is a subgroup of otherwise healthy infants, presenting with wheeze and/or stridor, who have isolated swallowing dysfunction and silent aspiration as the cause of their respiratory symptoms.     

Gastro-oesophageal reflux disease and respiratory disease

Abstract An epidemiological survey showed that respiratory symptoms with gastro-oesophageal reflux (GER) were twice as high as those without GER symptoms. In 46 cases of unknown chronic cough or asthma, 67% had positive oesophageal pH monitoring. Of 34 patients with snoring and reflux symptoms, 16 (47.1%) were confirmed as positive for obstructive sleep apnoea (OSA) and GER. Anti-reflux therapy significantly improved both GER and OSA.     

支气管哮喘患者与胃食管返流的症状相关性

目的　探讨胃食管返流 (GER)与成人中、重度支气管哮喘的症状相关性 ,了解 2 4h食管pH监测对哮喘合并GER的诊断价值及抗返流治疗对合并GER的哮喘患者症状的影响。方法　对 2 6例常规治疗后仍有顽固性咳嗽等症状的成人哮喘患者进行 2 4h食管pH监测 ,严格记录监测期间患者出现的各种症状 ,每小时记录 1次呼气峰流速 (PEF)。筛选出适当病例分组抗返流治疗并观察疗效。结果　 2 6例中有 15例DeMeester总积分≥ 14 72 ,2例虽DeMeester总积分 <14 72 ,但咳嗽与返流的症状相关概率 (SAP)≥ 95 % ,共筛选出 17例。将 17例患者随机分为治疗组 (9例 )和对照组 (8例 )。经抗返流治疗后 ,治疗组咳嗽、胸闷和胸骨后烧灼感等症状均较对照组有明显改善 ,2 4hPEF波动率治疗前 [(3 8± 8) % ]、后 [(16± 3 ) % ]比较差异有显著性 (P <0 0 5 )。结论　 (1)中、重度支气管哮喘患者具有较高的GER发生率 (5 8% )。 (2 ) 2 4h食管pH监测有助于了解哮喘患者的症状与GER的相关性。 (3 )对于有GER并与哮喘症状密切相关的患者 ,抗返流治疗可显著地改善其症状及PEF波动率     

Esophageal pH-impedance monitoring in children: position paper on indications,methodology and interpretation by the SIGENP working group

Multichannel intraluminal impedance pH (MII-pH) monitoring currently represents the gold standard diagnostic technique for the detection of gastro-esophageal reflux (GER), since it allows to quantify and characterize all reflux events and their possible relation with symptoms. Over the last ten years, thanks to its strengths and along with the publication of several clinical studies, its worldwide use has gradually increased, particularly in infants and children. Nevertheless, factors such as the limited pediatric reference values and limited therapeutic options still weaken its current clinical impact. Through an up-to-date review of the available scientific evidence, our aim was to produce a position paper on behalf of the working group on neurogastroenterology and acid-related disorders of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) on MII-pH monitoring technique, indications and interpretation in pediatric age, in order to standardise its use and to help clinicians in the diagnostic approach to children with GER symptoms.     

Gastroesophageal reflux symptoms not responding to proton pump inhibitor: GERD,NERD, NARD,esophageal hypersensitivity or dyspepsia?

Gastroesophageal reflux (GER) is a common gastrointestinal process that can generate symptoms of heartburn and chest pain. Proton pump inhibitors (PPIs) are the gold standard for the treatment of GER; however, a substantial group of GER patients fail to respond to PPIs. In the past, it was believed that acid reflux into the esophagus causes all, or at least the majority, of symptoms attributed to GER, with both erosive esophagitis and nonerosive outcomes. However, with modern testing techniques it has been shown that, in addition to acid reflux, the reflux of nonacid gastric and duodenal contents into the esophagus may also induce GER symptoms. It remains unknown how weakly acidic or alkaline refluxate with a pH similar to a normal diet induces GER symptoms. Esophageal hypersensitivity or functional dyspepsia with superimposed heartburn may be other mechanisms of symptom generation, often completely unrelated to GER. Detailed studies investigating the pathophysiology of esophageal hypersensitivity are not conclusive, and definitions of the various disease states may overlap and are often confusing. The authors aim to clarify the pathophysiology, definition, diagnostic techniques and medical treatment of patients with heartburn symptoms who fail PPI therapy.     

Is the questionnaire for the assessment of gastroesophageal reflux useful for diabetic patients?

OBJECTIVE: It has been suggested that the questionnaire reported by Carlsson et al. has high sensitivity in diagnosing gastroesophageal reflux disease (GERD) and is considered to be one of the most useful diagnostic tools for GERD. The aim of the present study was to evaluate the ability of the questionnaire to identify gastroesophageal reflux (GER) diagnosed by 24-h pH monitoring in diabetic patients. MATERIAL AND METHODS: Fifty-three patients with type 2 diabetes were enrolled in the present study. GER was monitored by means of an antimony electrode. Patients completed the questionnaires immediately before undergoing pH monitoring. RESULTS: Diabetic patients were found to have few symptoms, and the average score on the questionnaire was extremely low. No significant difference in scores on the questionnaire was observed between patients with and those without GER. CONCLUSIONS: The questionnaire was shown not to be useful for diagnosing GER as a complication in diabetic patients. We, therefore, should not diagnose GER as a complication in diabetes mellitus on the basis of the questionnaire.     

Significantly Reduced Acid Detection at 10 Centimeters Compared to 5 Centimeters above Lower Esophageal Sphincter in Patients with Acid Reflux

Ambulatory pH monitoring of the esophagus is carried out by positioning a pH sensor 5 cm above the lower esophageal sphincter (LES). There are several techniques to locate the LES, and each method has a different margin of error. This work used dual pH sensors to monitor simultaneously at two different levels (5 and 10 cm above the LES) in order to establish the possible magnitude of error that could arise from inaccurate placement of a pH probe. Thirty-four patients with symptoms of gastroesophageal reflux (GER) were studied. They were grouped as 20 patients with pathological reflux (GER group) and 14 patients with physiological reflux, based on a reflux score derived by Johnson and DeMeester for distal esophageal pH monitoring. When the reflux scores were compared, the difference between the two monitoring levels was statistically significant in the GER group ( p < 0.001) but not in the physiological reflux group ( p = 0.09). In the GER group, the difference in the Johnson and DeMeester score accounted for a change in clinical diagnosis in nine of the 20 patients if the pH probe was placed at 10 cm above the upper margin of LES. Proximal reflux episodes (10 cm above LES) were preceded by distal reflux episodes (5 cm above LES) in 97% (878/901) of cases. Accurate probe placement is essential in the diagnosis of GER.     

Severity of acid gastroesophageal reflux assessed by pH metry: Is it associated with respiratory disease?

About 50% of children with chronic respiratory diseases (RD) have "silent" gastroesophageal reflux (GER). Our purpose was to evaluate the possibility that RD in patients with GER reflects the presence of more severe acid reflux. We compared the severity of parameters from pH studies in children with chronic RD and "silent" GER, to children with signs of symptomatic gastrointestinal (GI) GER with and without RD. This study included 236 children (aged 1 month to 15 years) with abnormal 24-hr pH monitoring among 718 patients studied for suspected diagnosis of GER. Patients were divided into three groups. Group 1 consisted of children with chronic RD but without any GI symptoms of GER. Group 2 was comprised of children with symptomatic GI presentation of GER such as regurgitation, vomiting, heartburn, and failure to thrive, but without any signs or symptoms of RD. Group 3 included children with prevalent RD and concomitant signs of symptomatic GER. Patients with predominant GI manifestations (group 2) had a significantly higher fraction of time with pH <4 (P < 0.01), total time value of pH <4 (P < 0.05), and longest episode with pH <4 (P < 0.05). Esophageal clearance was significantly longer in group 1 patients than in the other two groups (P < 0.05). Patients with mixed disease (group 3) were similar to patients in group 2. Patients with GI symptoms had significantly worse scores for all parameters evaluated except esophageal clearance score, compared to patients without GI symptoms. Longer esophageal clearance was the only parameter associated with respiratory signs in patients with respiratory symptoms compared to those without. In conclusion, the presence of RD in pediatric patients with silent GER is related to longer esophageal clearance, but is not related to severity of reflux.     

Nonpropulsive Esophageal Contractions and Gastroesophageal Reflux

Nonpropulsive esophageal contractions radiologically described as tertiary contractions or "corkscrew" esophagus suggest the presence of an underlying motility disorder and may lead to impaired acid clearance. The goals of this study were to determine the prevalence and role of gastroesophageal reflux (GER) in patients with tertiary contractions. Thirty-five consecutive patients with spontaneous, repetitive, nonpropulsive esophageal contractions noted on esophagography were studied with endoscopy, infusion esophageal manometry, and 24-h ambulatory pH monitoring. All patients had esophageal symptoms, mainly dysphagia, heartburn, and chest pain, but only three were found to have esophagitis by endoscopy and biopsy. Nineteen patients had repetitive, nonlumen-obliterating, nonperistaltic (tertiary) contractions, six had corkscrew esophagus, and 10 had forceful, lumen-obliterating simultaneous contractions (rosary bead esophagus). Twenty patients (58%) had GER by pH criteria with mean values: % time pH less than 4, 40.9; %upright pH less than 4, 41; %supine pH less than 4, 44.3%; number of episodes with greater than 5 min of pH less than 4, 12. Esophageal motility revealed "nutcracker" esophagus in eight, low LESP in two, and nonspecific esophageal motility disorder in 10. Symptoms or severity of nonperistaltic contractions did not correlate with GER. Radiologically demonstrable free reflux or the presence of heartburn did not predict GER. We conclude that 1) GER occurs in up to 58% of patients with nonpropulsive (tertiary) esophageal contractions on esophagography, and may play a role in the induction of abnormal peristaltic activity of the esophageal body; 2) GER is usually not associated with endoscopic evidence of esophagitis or characteristic symptoms, and is recognized by 24-h pH monitoring. We speculate that detection and treatment of GER may improve the symptomatic management of patients with nonpropulsive esophageal contractions.     

pH fluctuations versus reflux episodes in patients with gastroesophageal reflux disease: their optimal thresholds and significance in diagnosis.

In physiological and pathological conditions, pH monitoring in the esophagus shows small variations as well as more pronounced deflections. However, only the latter are traditionally taken into account in 24-hour pH monitoring analysis. The present study was designed to establish optimal thresholds of pH fluctuations versus reflux episodes in separating physiological and pathological gastroesophageal reflux (GER) and to evaluate their significance in the diagnosis. Twenty-four-hour intraesophageal pH monitoring and endoscopy were performed in 62 patients with GER symptoms and in 42 healthy controls. The results showed that the percentages of the time with pH fluctuations in patients with and without esophagitis and in healthy controls were, on average, 12.65, 9.5 and 2.76% in 24 h, respectively, and the respective percentages of the time with reflux episodes in the same groups in 24 h were, on average, 3.12, 2.04 and 0.18%, respectively. Using a receiver-operating-characteristic curve analysis, less than 6.7% of the time with pH fluctuations and less than 0.1% of the time with reflux episodes were defined as the combined thresholds for physiological versus pathological reflux. The sensitivity of the combined thresholds for the detection of GER patients with and without esophagitis was 96.7 and 90%, respectively, and their specificity for the diagnosis of patients with abnormal GER was 100%. It is concluded that pH fluctuations and reflux episodes, when evaluated together, are more useful for classifying patients with GER and their combined thresholds yield higher diagnostic accuracy in assessing patients with gastroesophageal disease.     

Gastric Bile Monitoring: an In Vivo and In Vitro Study of Bilitec Reliability

Background: It has been claimed that the combination of bile and hydrochloride acid (HCl) has a noxious effect on intestinal mucosa. The aim was to study the reliability of the Bilitec 2001 method in monitoring the presence of bile in repeated tests and at different pH and water dilutions. Methods: 24-h esophageal pH and gastric Bilitec monitoring were performed twice with an interval of 6 weeks in 23 patients with symptomatic gastroesophageal reflux (GER). In vitro tests of pH and Bilitec recordings were performed with different mixtures of bile, HCl and water. Results: Gastric bile was present in 37% of the recording time, 28% during day time and 47% during nights. No significant difference was found between the two test occasions. The maximum bile concentration in the stomach was significantly lower in patients with severe pathological GER than in those with normal GER. When concentrated bile was diluted with the same volume of HCl, the pH level fell below 4. The maximum absorption limit with Bilitec in concentrated bile was gradually reduced with decreasing pH. The Bilitec technique recorded the presence of bile even at a pH of 1.4, but not if the bile was diluted with water at a ratio of 1:100 or more. Conclusions: Bilitec gastric recordings show the same clinical result when repeated under standardized conditions. The Bilitec technique is not reliable for monitoring the amount and concentration of bile in the stomach. Bile reflux cannot be monitored with the pH recording technique.