Combined impedance-pH Monitoring Research Articles

Reflux scintigraphy in gastro-esophageal reflux disease: a comparison study with 24 hour pH-impedance monitoring

Objective Reflux scintigraphy is often used to diagnose gastro-esophageal reflux disease (GERD). However, the efficacy of this study remains controversial. Our aim was to determine the role of reflux scintigraphy in diagnosing GERD by comparing it to 24 h combined pH-impedance study as the gold standard. Materials and methods Adult patients who presented for investigations of reflux symptoms were prospectively recruited into the study. All patients underwent high resolution esophageal manometry and those with major motor disorders of the esophagus were excluded. Eligible patients immediately underwent reflux scintigraphy following insertion of the pH-impedance catheter. Results Thirty patients were included in the study. Using a total acid exposure time (AET) of >4.2% as the reference for abnormal acid reflux, reflux scintigraphy had a sensitivity and specificity of 62.5 and 68.2%, respectively, in detecting acid reflux. When compared to AET >6%, reflux scintigraphy had a sensitivity and specificity of 66.7 and 62.5%, respectively, and a positive predictive value of 30.8% and a negative predictive value of 88.2%. There were no associations between outcomes of reflux scintigraphy and total AET (p = .46), total (acid or non-acid) reflux events (p = 0.11), proximal AET (p = .33) or the number of proximal reflux episodes (p = .75) on 24 h pH-impedance study. Conclusions Reflux scintigraphy has limited role in diagnosing GERD when compared to 24 h combined pH-impedance monitoring.

The Lyon Consensus: Does It Differ From the Previous Ones?

Gastroesophageal reflux disease (GERD) is a complex disorder with heterogeneous symptoms and a multifaceted pathogenetic basis, which prevent a simple diagnostic algorithm or any categorical classification. Clinical history, questionnaires and response to proton pump inhibitor (PPI) therapy are insufficient tools to make a conclusive diagnosis of GERD and further investigations are frequently required. The Lyon Consensus goes beyond the previous classifications and defines endoscopic and functional parameters able to establish the presence of GERD. Evidences for reflux include high-grade erosive esophagitis, Barrett’s esophagus, and peptic strictures at endoscopy as well as esophageal acid exposure time > 6% on pH-metry or combined pH-impedance monitoring. Even if a normal endoscopy does not exclude GERD, its combination with distal acid exposure time < 4% on off-PPI pH-impedance monitoring provides sufficient evidence refuting this diagnosis. Reflux-symptom association on pH-monitoring provides supportive evidence for reflux-triggered symptoms and may predict a better treatment outcome, when present. Also recommendations to perform pH-impedance “on” or “off” PPI are well depicted. When endoscopy and pH-metry or combined pH-impedance monitoring are inconclusive, adjunctive evidence from biopsy findings (eg, microscopic esophagitis), high-resolution manometry (ie, ineffective esophagogastric barrier and esophageal body hypomotility), and novel impedance metrics, such as mean nocturnal baseline impedance and post-reflux swallow-induced peristaltic wave index, can contribute to better identify patients with GERD. Definition of individual patient phenotype, based on the level of refluxate exposure, mechanism of reflux, efficacy of clearance, underlying anatomy of the esophagogastric junction, and clinical presentation, will lead to manage GERD patients with a tailored approach chosen among different types of therapy.

Issue Highlights

Issue Highlights

Reflux and Belching after Laparoscopic 270 degree Posterior Versus 180 degree Anterior Partial Fundoplication

BackgroundLaparoscopic 270 degree posterior, or Toupet (LTF), and 180 degree anterior partial fundoplication (LAF) ensure equal reflux control and reduce the risk of gas-related symptoms compared to 360 degree (Nissen) fundoplication. It is unclear which type of partial fundoplication is superior in preventing gas-related side-effects. The aim of this study was to determine differences in effect of LTF and LAF on reflux characteristics and belching patterns. MethodsUpper gastrointestinal endoscopy, esophageal manometry, and 24-h combined pH-impedance monitoring were performed before and 6 months after fundoplication (n = 10, LTF vs. n = 10, LAF). Observed changes after surgery (∆) were compared between the two procedures. ResultsSymptomatic reflux control as well as the reduction in the mean number of acid (∆ − 58.5 vs. − 66.5; P = 0.912), liquid (∆ − 17.0 vs. − 43.5; P = 0.247), and mixed liquid gas reflux episodes (∆ − 38.0 vs. − 40.0; P = 0.579) were comparable following LTF and LAF. There were no differences in the mean number of weakly acidic reflux episodes after LTF and LAF (1.0 (0.8–4) vs. 1.0 (0–3), P = 0.436). The reduction in proximal (P = 1.000), mid-esophageal (P = 0.063), and distal reflux episodes (P = 0.315) was comparable. Both procedures equally reduced the number of gastric belches (P = 0.278) and supragastric belches (P = 0.123), with no significant reduction in the number of air swallows after either procedure (P = 0.278). ConclusionLTF and LAF provide similar reflux control, with a comparable effect on acidic, liquid, and gas reflux. Both procedures equally reduced the number of belches and supragastric belches. This study provides the physiological evidence for the published randomized trials reporting similar symptomatic outcome after both types of partial fundoplication.

Most Patients With Gastroesophageal Reflux Disease Who Failed Proton Pump Inhibitor Therapy Also Have Functional Esophageal Disorders

As many as 45% of patients with gastroesophageal reflux disease (GERD) still have symptoms after receiving once-daily proton pump inhibitor (PPI) therapy. We aimed to compare reflux characteristics and patterns between responders and non-responders to once-daily PPI therapy using combined impedance-pH monitoring. Patients who reported heartburn and/or regurgitation at least twice per week for 3 months while receiving standard-dose PPI therapy were assigned to the PPI failure group (n = 16). Patients who reported a complete resolution of symptoms on once-daily PPIs for at least 4weeks were assigned to the PPI success group (n = 13). We collected demographic data and subjects completed the short-form 36 and the GERD health-related quality of life questionnaires. Patients then underwent upper endoscopy and combined esophageal impedance-pH monitoring while on PPI therapy. Four patients in the PPI success group (31%) and 4 patients in the PPI failure group (25%) had abnormal results from the pH test (P = 1.00). Most of the patients in the PPI failure group (75%) were found to have either functional heartburn or reflux hypersensitivity with GERD. Impedance and pH parameters did not differ significantly between the PPI failure and success group. We found no difference in reflux characteristics between patients with GERD who had successful vs failed once-daily PPI therapy. Most patients in the PPI failure group (75%) hadfunctional esophageal disorders.

Impedance-pH Monitoring for Diagnosis of Reflux Disease: New Perspectives.

Heartburn is the most specific symptom of gastroesophageal reflux disease (GERD). In clinical practice, heartburn relief by a proton pump inhibitor (PPI) trial does suffice to confirm GERD. However, an objective diagnosis of GERD is required before anti-reflux endoscopic or surgical interventions, independently from PPI response. Thus, since normal findings at upper endoscopy are detected in the majority of patients with heartburn, reflux monitoring is often required. When traditional catheter-based or wireless pH tests are used, reflux episodes are conventionally identified by pH drops below 4.0 units. Combined impedance-pH monitoring has the advantage to provide a comprehensive assessment of both physical and chemical properties of refluxate and the distinction between acid and weakly acidic refluxes, both proven to cause heartburn. Unfortunately, the conventional impedance-pH parameters, namely acid exposure time and number of reflux events, are characterized by suboptimal diagnostic sensitivity, and the reliability of symptom-reflux association indexes remains questionable. Therefore, novel impedance parameters, namely the post-reflux swallow-induced peristaltic wave (PSPW) index and the mean nocturnal baseline impedance (MNBI), have recently been proposed in order to achieve a better diagnostic yield. In fact, they proved to be highly accurate in distinguishing reflux-related from reflux-unrelated heartburn, off- as well as on-PPI therapy. Currently, manual review of impedance-pH tracings is needed because of the modest accuracy of available software tools for automated analysis. PSPW index and MNBI are highly applicable and reproducible, and their calculation requires a few additional minutes during the manual review of impedance-pH tracings. So far, we believe that PSPW index and MNBI are ready for prime time and should become part of the standard analysis of impedance-pH tracings for GERD diagnosis in patients with endoscopy-negative heartburn.

Clinical Utility of Bronchoalveolar Lavage Pepsin in Diagnosis of Gastroesophageal Reflux among Wheezy Infants.

Background. There is no gold standard test for diagnosis of gastroesophageal reflux disease (GERD) associated infantile wheezing. Objectives. To evaluate the value of bronchoalveolar lavage (BAL) pepsin assay in diagnosis of GERD in wheezy infants. Methods. Fifty-two wheezy infants were evaluated for GERD using esophageal combined impedance-pH (MII-pH) monitoring, esophagogastroduodenoscopy with esophageal biopsies, and BAL pepsin. Tracheobronchial aspirates from 10 healthy infants planned for surgery without history of respiratory problems were examined for pepsin. Results. Wheezy infants with silent reflux and wheezy infants with typical GERD symptoms but normal MII-pH had significantly higher BAL pepsin compared to healthy control (45.3 ± 8.6 and 42.8 ± 8 versus 29 ± 2.6, P < 0.0001 and P = 0.011, resp.). BAL pepsin had sensitivity (61.7%, 72 %, and 70%) and specificity (55.5%, 52.9%, and 53%) to diagnose GERD associated infantile wheeze compared to abnormal MII-pH, reflux esophagitis, and lipid laden macrophage index, respectively. Conclusion. A stepwise approach for assessment of GERD in wheezy infants is advised. In those with silent reflux, a trial of antireflux therapy is warranted with no need for further pepsin assay. But when combined MII-pH is negative despite the presence of typical GERD symptoms, pepsin assay will be needed to rule out GERD related aspiration.

Mo1119 Detection of Reflux Mechanisms in PPI Non-Responder Patients: Post Prandial High Resolution Impedance Manometry (HRIM) Study

Background: In the last decade combined impedance-pH monitoring has become the gold standard for the detection of reflux episodes with several studies demonstrating its increased diagnostic yield in gastro-esophageal reflux disease (GERD). This is mainly due to the capability of impedance-pH to correlate symptoms to both acid and non-acid reflux episodes. However, despite its large use in clinical practice, limited data about its clinical usefulness for the management of GERD patients are present. AimM mean age 49; 14 ERD, 22 NERD and 12 NARD) reporting at least 3 symptoms during the impedance-pH monitoring were included. Fundoplication had a similar effect in all groups, as shown in the Figure. At 1 year, esophageal AET and number of total, acid and non-acid refluxes significantly decreased after surgery (in all cases, p<0.01), whereas mean lower esophageal pressure increased (p<0.05). The percentage of patients with resolved or markedly improved typical symptoms at 12 months after surgery was similar among the groups (ERD 93% vs. NERD 82% vs NARD 83%, p=ns). Quality of life similarly improved in all groups (p=ns). Finally, the percentage of failure or adverse events did not differ among the groups (ERD 21% vs. NERD 23% vs NARD 17%, p=ns). Conclusion: Our data show that laparoscopic fundoplication was a safe and effective procedure in relieving typical reflux symptoms in patients with NARD as well as in patients with ERD and NERD, thus markedly improving their quality of life. Therefore, impedance-pH monitoring facilitated a more focused therapeutical approach to patients with PPI-resistant GERD.

Mo1117 Patients With Non-Acid Reflux Disease and Those With Erosive and Non-Erosive Reflux Disease Have Similar Response to Anti-Reflux Surgical Therapy

Background: In the last decade combined impedance-pH monitoring has become the gold standard for the detection of reflux episodes with several studies demonstrating its increased diagnostic yield in gastro-esophageal reflux disease (GERD). This is mainly due to the capability of impedance-pH to correlate symptoms to both acid and non-acid reflux episodes. However, despite its large use in clinical practice, limited data about its clinical usefulness for the management of GERD patients are present. AimM mean age 49; 14 ERD, 22 NERD and 12 NARD) reporting at least 3 symptoms during the impedance-pH monitoring were included. Fundoplication had a similar effect in all groups, as shown in the Figure. At 1 year, esophageal AET and number of total, acid and non-acid refluxes significantly decreased after surgery (in all cases, p<0.01), whereas mean lower esophageal pressure increased (p<0.05). The percentage of patients with resolved or markedly improved typical symptoms at 12 months after surgery was similar among the groups (ERD 93% vs. NERD 82% vs NARD 83%, p=ns). Quality of life similarly improved in all groups (p=ns). Finally, the percentage of failure or adverse events did not differ among the groups (ERD 21% vs. NERD 23% vs NARD 17%, p=ns). Conclusion: Our data show that laparoscopic fundoplication was a safe and effective procedure in relieving typical reflux symptoms in patients with NARD as well as in patients with ERD and NERD, thus markedly improving their quality of life. Therefore, impedance-pH monitoring facilitated a more focused therapeutical approach to patients with PPI-resistant GERD.

Chronic Cough and Reflux: An Ongoing Conundrum Possibly Elucidated by Combined pH Impedance Monitoring

Chronic Cough and Reflux: An Ongoing Conundrum Possibly Elucidated by Combined pH Impedance Monitoring

Principles of combined esophageal impedance-PH monitoring in children: indications, benefits and limitations

The standard test for suspected gastroesophageal reflux is pH monitoring. However, the majority of gastroesophageal reflux episodes in infants and children are nonacidic (pH &gt; 4) and extraesophageal symptoms apparently can be caused by both acidic (pH &lt; 4) and nonacidic reflux. In order to overcome these aspects, a new technique has been developed and placed under scrutiny in the past twenty years: multichannel intraluminal impedance. Combined with standard pH recording, it provides more information than simple pH measurement because it allows the study of non-acid reflux and the temporal association between symptoms and nonacid reflux. Data can be analyzed for bolus composition (gas, fluid, solid) and reflux height, duration, and clearance. Although normal values for the pediatric population are not yet available, combined multichannel intraluminal impedance and pH measurement has the potential to become the new “gold standard” for gastroesophageal reflux testing.

Evaluation of gastroesophageal reflux after laparoscopic cholecystectomy using combined impedance-pH monitoring.

Postoperative gastroesophageal reflux (GER) is one of the causes of post-cholecystectomy syndrome (PCS). Reports studying the effect of cholecystectomy on GER show conflicting results and only a few studies have used the more sensitive technique of combined impedance-pH monitoring. This study aimed to study the effect of laparoscopic cholestectomy on GER (acid/non-acid reflux) using impedance-pH monitoring. Sixty three consecutive patients of symptomatic cholelithiasis were evaluated. All patients underwent esophageal mannometry and 24-hour impedance-pH monitoring pre- and postoperatively. Frequency scale for the symptoms of GERD (FSSG) scoring was also done in each patient pre- and postoperatively. Out of sixty three patients, four developed symptoms of reflux postoperatively as detected by FSSG scoring. However, no significant changes were observed in lower esophageal sphincter (LES) characteristics, acid and non-acid reflux characteristics, total number of reflux episodes, or in the physical character of the refluxate following laparoscopic cholecystectomy. Significant decrease in the proximal acid reflux episodes was observed. The chemical characteristics (acid or non-acid reflux) as well as physical properties (liquid, gas or mixed) of reflux episodes remain unaffected following laparoscopic cholecystectomy. Cholecystectomy itself doesn't increases GER.

Combined pH-impedance monitoring and high-resolution manometry of Japanese patients treated with proton-pump inhibitors for persistent symptoms of non-erosive reflux disease

Data on acid and non-acid reflux patterns and esophageal function in Japanese patients with non-erosive reflux disease (NERD) are limited. The aim of this study was to use combined multichannel intraluminal impedance pH monitoring (MII-pH) and high-resolution manometry (HRM) to investigate the characteristics of Japanese patients who were treated with a "double-dose" (20 mg) of rabeprazol (a proton-pump inhibitor; PPI) for persistent symptoms of NERD. Twenty-five patients who complained of typical gastroesophageal reflux disease symptoms, which had occurred more than twice a week despite treatment with rabeprazol, were enrolled in the study. All patients underwent upper endoscopy, esophageal HRM, and 24-h MII-pH monitoring while double-dose PPI therapy was continued. Twelve (48.0%) of the patients had a positive symptom index (SI) with 234 recorded symptoms, 127 (54.3%) of which were related to reflux episodes. Of those with reflux episodes, 29 (22.8%) were related to acid reflux, while 98 (77.2%) were the result of a weaker acidic reflux. In acid reflux and in mixed (liquid-gas) reflux, the proximal esophageal region was involved to a significantly greater degree (P<0.002 and P=0.005, respectively) than the distal region. In liquid reflux, there was no difference between the distal and proximal regions. HRM showed that proximal motility parameters were significantly more defective than in those of healthy volunteers. MII-pH monitoring indicated that weakly acidic reflux and mixed refluxate in the proximal esophagus is the major cause of persistent symptoms in patients with NERD who are being treated with PPI. HRM showed that proximal esophageal dysfunction might be a key condition that facilitates reflux.

How Useful the Combined Impedance-pH Monitoring Is for Evaluation of Refractory Reflux Symptoms?

TO THE EDITOR: I read with great interest the paper entitled Yield of combined impedance-pH monitoring for refractory reflux symptoms in clinical by Karamanolis et al,1 which was published in April 2011 issue of Journal of Neurogastroenterology and Motility. Esophageal impedance pH monitoring allows detection of reflux of any composition (liquid or gas) and pH (acid, weakly acid or non-acid). Many prevalence studies have suggested the relationship between weakly acid or non-acid reflux and residual symptoms in patients suspected to have gastroesophageal reflux disease (GERD).2,3 Prof. Karamanolis evaluated the yield of impedance pH monitoring in patients with persistent GERD symptoms on proton pump inhibitor (PPI) therapy. With symptom index analysis, 20.5% of patients showed symptoms receiving a diagnosis that could not have been achieved with pH testing alone. Fifty-two percent of patients reporting symptoms during the impedance-pH monitoring had no reflux-symptom association (non-GERD). Heartburn was the most prevalent symptom associated with acid reflux, whereas regurgitation and ear, nose and throat (ENT) symptoms were associated with non-acid reflux. These results were similar to a Multicenter MII-pH studies in patients with PPI refractory symptoms in which suggested that approximately one third of patients to have weakly acid or nonacid reflux.2,3 The problem of MII-pH on PPI therapy may be the limited number of reflux event associated with symptoms. Fifty-two percent (37/71) patients did not report any symptoms during the impedance pH study. In my opinion, the limitation of the study, as the authors had mentioned in the text, was that the patients' groups were inhomogeneous regarding medication use and predominant symptoms. It could have an influence on the diagnostic sensitivity and clinical impact of esophageal impedance pH monitoring. In those who fail on PPI once a day, there are 2 major potential therapeutic strategies that are utilized in clinical practice - switching to another PPI or doubling the dose of the same PPI. Doubling the PPI dose is by far the most common therapeutic strategy used by practicing physicians. In this study, 59% of patients were refractory to single dose of PPI. In those patients the MII-pH may be the next step after doubling the PPI dose in the diagnostic algorithm. In addition, to obtain the therapeutic response, patients reporting extraesophageal manifestation usually require more than the standard dose of PPI.4 The second question is about the role of impedance in patients with atypical symptoms while on PPI. As many experts have indicated, those in whom GERD is more likely (typical symptoms) should be considered for impedance pH testing while on therapy because testing in those patients is more likely to reveal ongoing reflux (either acid or nonacid) despite the medication. In contrast, patients in whom GERD is less likely (atypical presentation) may be best served by pH monitoring while off medication.5 A negative test in those patients while off therapy directs the diagnostic work up toward other causes, and it enables cessation of unnecessary PPI therapy. Choosing patients based on their clinical presentation may be helpful. ENT symptoms are widely accepted as it is unlikely to be related with acid. Therefore, in those patients, impedance pH monitoring while off medication could give more clinical information. Further studies with large cases are needed to solve the limitations of the present study and to evaluate to whom clinical impact of impedance pH would be more.

How Useful the Combined Impedance-pH Monitoring Is for Evaluation of Refractory Reflux Symptoms?: Author's Reply

TO THE EDITOR: We would like to appreciate the interest shown on our study by Dr. Cho.1 Our response to her queries is as follows: (1) We do agree that doubling the proton pump inhibitor (PPI) dose could be the most appropriate therapeutic strategy for gastroesophageal reflux disease (GERD) patients who are refractory to single dose of PPI before performing a pH-impedance measurement. However, previous studies challenged this approach and showed the majority of patients with persistent GERD symptoms on single PPI dose to experience symptoms continuously on even higher doses of PPIs.2,3 Our results showed that even though patients on standard PPI dose continued to report more symptoms during the study, the PPI dose seemed to have no impact on the symptom index analysis.4 This finding could imply that increase of the PPI dose should not be the solution in patients with refractory GERD like symptoms and that other causes (ie, functional heartburn and hypersensitive esophagus) could explain the origin of symptoms. Moreover, in every day clinical practice, escalation of the dose is sometimes problematic. In our study, the majority of our population was referred by others and the low rate of double dose PPI usage reflects the absence of reimbursement for PPIs above the standard dose in Greece. (2) We also agree that in GERD patients with atypical symptoms, pH-impedance monitoring is better to be performed while they are off medication. As we had mentioned in the article, our patient population was inhomogeneous. Many patients reported both typical and atypical symptoms, whereas others reported only atypical symptoms. It is clear that this practice influenced the sensitivity and clinical impact of pH-impedance monitoring. Choosing the most prevalent symptom could be a better surrogate index. However, it is widely accepted that the majority of patients report more than one symptom. Large population-based studies have shown presence of ENT and pulmonary symptoms among patients with reflux symptoms.5,6 As pH-impedance monitoring is a new technique that tries to find its position in the everyday clinical practice, further studies are needed to evaluate its clinical impact and usefulness.

Nocturnal Gastroesophageal Reflux: Assessment and Clinical Implications

Nocturnal Gastroesophageal Reflux: Assessment and Clinical Implications

Yield of Combined Impedance-pH Monitoring for Refractory Reflux Symptoms in Clinical Practice

Background/AimsIn patients with gastroesophageal reflux disease, persistent symptoms on proton pump inhibitor (PPI) therapy may be due to residual acid or non-acid reflux. Combined impedance-pH has been suggested to be superior to pH alone in the management of refractory patients to PPI. The utility of implementation of this technique in every day clinical practice is still unknown. The aim of this study was to investigate the outcomes of patients studied with combined impedance-pH and to evaluate the yield of additional impedance monitoring over pH alone in patients with persistent gastroesophageal reflux disease symptoms.MethodsSeventy-one patients (31 men; mean age, 49.1 ± 15.5 years) on PPI therapy underwent combined impedance-pH for persistent typical (76%) or atypical (49%) symptoms.ResultsDuring impedance-pH study, 44 (62%) patients reported symptoms. A positive symptom index (SI) was found in 21 (48%) patients: 8 (18.2%) had a positive SI for acid reflux, 9 (20.5%) for non-acid reflux and 4 (9.1%) for mixed reflux. Addition of impedance allowed association between reflux and symptoms in 20.5% of patients who would have been missed by pH study alone. Heartburn was the most prevalent symptom associated with acid reflux, whereas regurgitation and ear, nose and throat symptoms were associated with non-acid reflux.ConclusionsThe use of combined impedance-pH monitoring substantially increased the diagnostic yield compared to pH alone. With SI analysis, 20.5% of patients received a diagnosis that could not have been achieved with pH testing alone.

Pathological bolus exposure plays a significant role in eliciting non‐cardiac chest pain

Pathological bolus exposure is defined in the present study as cases in which all reflux percentage times are above 1.4% of the total reflux number, as revealed by impedance-pH monitoring. The role of pathological bolus exposure in the pathogenesis of non-cardiac chest pain (NCCP) is poorly known. We aimed to classify and characterize NCCP using combined impedance-pH monitoring. Seventy-five consecutive patients with NCCP were prospectively enrolled from January 2006 to October 2008. All the patients underwent upper endoscopy, esophageal manometry, and 24-h multichannel intraluminal impedance (MII)-pH metering. Sixteen patients (21.3%) had esophageal erosion upon endoscopy. Upon esophageal manometry, 37 patients (49.3%) had esophageal dysmotility. When the patients were classified based on MII-pH metering, 16 (21.3%) showed pathological acid exposure, and 40 (53.3%) showed pathological bolus exposure. The DeMeester score of patients with pathological acid exposure was higher than that of patients with pathological bolus exposure (P = 0.002). There was no significant difference in age, sex, typical esophageal symptoms, presence of esophageal erosion, esophageal dysmotility, improvement with proton pump inhibitor medication, symptom index ≥ 50%, percentage of time clearance pH below 4 ≥ 4%, and all reflux time ≥ 1.4% in the fasting period between the two groups. When the patients were divided into gastroesophageal reflux disease (GERD)-related NCCP and non-GERD-related NCCP groups based on MII-pH metering and upper endoscopy, there was no difference between the two groups. Combined impedance-pH monitoring improves the detection and characterization of NCCP. This study suggests that pathological bolus exposure plays a major role in eliciting NCCP.

The prevalence of non-acidic reflux and its relation with heartburn symptoms in patients with gastroesophageal reflux disease

Objective To investigate the prevalence of non-acidic reflux in patients with gastroesophageal reflux disease and its correlation extent with heartburn symptom by 24-hour combined multichannel intraluminal impedance-pH (MII-pH) monitoring. Methods Consecutive patients with chief complain of heartburn in gastrointestinal specialty clinic were enrolled. Patients were divided into erosive esophagitis (EE) group, non-erosive reflux disease (NERD) group after upper gastrointestinal endoscope, further diagnosed with 24-hour combined MII-pH monitoring and rabeprazole test. The MII-pH parameters were compared in these two groups. Results 36 cases of EE and 62 of NERD were enrolled. There was significant difference in acidic reflux frequency and acidic reflux time percentage between these two groups (P=0. 001 and 0. 002). The frequency of non-acidic reflux in EE and NERD groups was 37.3% (663/1777) and 44.3% (1220/2754) respectively (x2 =21. 723,P = 0. 000). The percentage of heartburn symptom positive index in patients with acidic reflux, non-acidic reflux , and total reflux in EE group was 36.1 % (13/36), 19.4 % (7/36) and 55.6%(20/36) respectively, while in NERD group was 27. 4% (17/62), 6.4 % (4/62) and 33.8% (21/62).Conclusion The percentage of non-acidic reflux in EE and NERD groups was 37.3% and 44.3%respectively, and the non-acidic reflux was highly related to heartburn symptom. Key words: Gastroesophageal reflux disease; Erosive esophagitis; Non-erosive reflux disease; Esophageal combined multichannel intraluminal impedance monitoring

Characteristics of Symptomatic Reflux Episodes in Patients with Non-Erosive Reflux Disease Who Have a Positive Symptom Index on Proton Pump Inhibitor Therapy

Background and Aim: The reason that some reflux episodes evoke symptoms is poorly understood, therefore the aim of this study is to assess the determinants of reflux perception in patients with non-erosive reflux disease (NERD) on proton pump inhibitor (PPI) therapy. Methods: Ten NERD patients with persistent symptoms, despite double-dose PPI therapy, were included in this study. All patients had a positive symptom index (SI), which was determined by ambulatory 24-hour combined impedance-pH monitoring. Reflux episodes were identified and classified as acid, weakly acidic or weakly alkaline reflux and were considered symptomatic if patients recorded a symptom within 5 min after a reflux episode. Results: A total of 954 liquid reflux episodes were detected, including 135 (14.2%) acid, 782 (82.0%) weakly acidic, and 37 (3.9%) weakly alkaline. Overall, 59 (6.2%) reflux episodes were symptomatic and the majority (88.1%) of symptomatic reflux episodes were weakly acidic reflux. When reflux episodes were confined to the distal esophagus, there were very few reflux symptoms. Proximal reflux is significantly more likely to be associated with reflux symptoms, irrespective of the acidity of the refluxate or the duration of proximal reflux episodes. Conclusions: In NERD patients who have a positive SI on double-dose PPI therapy, the high proximal extent of refluxate is a major factor associated with reflux perception.