Intraluminal Impedance Monitoring Research Articles

Mean nocturnal baseline impedance: Influencing factors and diagnostic value in gastroesophageal reflux disease.

At present, there are few studies related to mean nocturnal baseline impedance (MNBI), esophageal dynamic reflux monitoring, high-resolution esophageal manometry (HRM) parameter indexes, and its diagnostic value in gastroesophageal reflux disease (GERD). To analyze the factors influencing MNBI and examine the diagnostic value of MNBI in GERD. A retrospective analysis on 434 patients with typical reflux symptoms who underwent gastroscopy, 24-hour multichannel intraluminal impedance and pH monitoring (MII/pH) and HRM. They were divided into the conclusive evidence group (103 cases), borderline evidence group (229 cases), and exclusion evidence group (102 cases) according to the level of diagnostic evidence of GERD based on the Lyon Consensus. We analyzed the differences in MNBI, esophagitis grade, MII/pH and HRM index among the groups; the correlation between MNBI and the above indexes and its influence on MNBI; and to evaluate the diagnostic value of MNBI in GERD. There were significant differences in MNBI, Acid Exposure Time (AET) 4%, DeMeester score, and total reflux episodes among the three groups (P< 0.001). EGJ contractile integral (EGJ-CI) of the conclusive evidence group and the borderline evidence group was significantly lower than that in the exclusion evidence group (P< 0.001). MNBI was significantly and negatively correlated with age, BMI, AET 4%, DeMeester score, total reflux episodes, EGJ classification, esophageal motility abnormalities, and esophagitis grade (all P< 0.05), and significantly and positively correlated with EGJ-CI (P< 0.001). Age, BMI, AET 4%, EGJ classification, EGJ-CI, and esophagitis grade had significant effects on MNBI (P< 0.05); MNBI was used to diagnose GERD with a diagnostic cutoff of 2061 Ω, and AUC was 0.792 (sensitivity 74.9%, specificity 67.4%); MNBI was used to diagnose exclusion evidence group with a diagnostic cutoff of 2432 Ω, AUC was 0.774 (sensitivity 67.6%, specificity 72%). AET, EGJ-CI, and esophagitis grade are the most important influence factors of MNBI. MNBI has good diagnostic value in identifying conclusive GERD.

Bronchoalveolar lavage cytology in children with chronic unexplained cough and severely neurologically impaired children.

We aimed to compare the cellular composition of bronchoalveolar lavage (BAL) fluids in children with chronic unexplained cough (group 1) and severely neurologically impaired children with chronic or recurrent respiratory problems (group 2) with the BAL cytology of children without pulmonary or systemic diseases (group 3). Bronchoscopy with BAL fluid analysis was performed in all subjects. Children with respiratory symptoms underwent 24-hour multichannel intraluminal impedance monitoring. A significant difference was found between the groups in the total number of cells in BAL fluid cytology (191 [range, 24-12,747], 747 [range, 53-13,000], and 105 [range, 41-233] cells/μL, P = .015), in the percentage of neutrophils (21.2 [SD = 32.4], 49.4 [SD = 36.6], and 3.6 [SD = 2.4], P < .001), and in the percentage of lipid-laden macrophages (10.3 [SD = 11.4], 13.7 [SD = 15.8] and 0.44 [SD = 1.0], P < .001). The BAL fluid cytology provides useful data for determining the cause of chronic unexplained cough and chronic or recurrent respiratory problems in severely neurologically impaired children.

Executing and facilitating the successful combined multichannel intraluminal impedance and pH monitoring study

Executing and facilitating the successful combined multichannel intraluminal impedance and pH monitoring study

Assessment of Esophageal Motility Disorders in Patients With Refractory Gastroesophageal Reflux Disease

There is insufficient data about esophageal body dysmotility in patients with refractory gastroesophageal reflux disease (RGERD) and inadequate response to proton pump inhibitors (PPIs) treatment. This study aimed to assess esophageal motility disorder and reflux parameters among these patients by high-resolution manometry (HRM) and intraluminal impedance and pH (MII‐pH) monitoring after stopping PPI therapy. A retrospective study was conducted among 100 RGERD patients admitted to Taleghani Hospital (Tehran, Iran) for one year. More than half of them were males (55%). Their mean age was 47.10±6.92, and 50% of patients had ineffective esophageal motility (IEM). Middle, distal, and proximal esophageal pressure (MEP, DEP, and PEP), lower esophageal sphincter (LES) basal pressure (LESP), integrated relaxation pressure (IRP), distal contractile integral (DCI), large breaks, upper esophageal sphincter basal pressure (UESP), and LES length (LESL) in IEM patients were significantly lower than the patients with normal esophageal motility (P&lt;0.001). Furthermore, there were more patients in the IEM group with long-term and abnormal weakly acid reflux compared with the non-IEM group (P&lt;0.05). It seems that the evaluation of reflux parameters and esophageal motility could lead to additional insights into the pathophysiological mechanisms of RGERD. Nevertheless, further studies are suggested to evaluate the effects of esophageal motility disorders among RGERD patients.

Difference in meal-related esophageal intraluminal impedance change between gastroesophageal reflux disease and functional disorders

Objectives Gastroesophageal reflux disease (GERD) has overlapping symptoms with functional disorders such as functional heart burn. Twenty-four-hour pH with impedance monitoring is useful for differentiation. The intraluminal impedance change with meal in distal esophagus is not investigated. Methods We performed a retrospective investigation of clinical files, 24-hour pH with intraluminal impedance monitoring in patients with GERD and functional disorders. The post-reflux swallow induced peristaltic wave (PSPW) index as well as the impedance in distal esophagus before the first meal and 30 min and 60 min after the meal were measured and analyzed. Results A significant decrease of intraluminal impedance in distal esophagus was noted at 30 min (ΔI 30min −301.5 [747.5] Ω, p = 0.018) and recovered at 60 min (ΔI 60min −194.6 [766.0] Ω, p = 0.126) after meals in GERD patients. On the other hand, there was no significant change of impedance in patients with functional disorders. There were positive correlations between ΔI 30min and PSPW index (correlation = 0.232, p = 0.038). Comparing GERD to functional disorders, the best cut-off value for ΔI 30min was –212Ω with 74.4% sensitivity and 60.5% specificity. Conclusions The intraluminal impedance in distal esophagus was lowered after meals in GERD patients other than functional disorders. This impedance change was correlated with PSPW index and could help differentiate GERD from functional disorders.

The diagnostic value of pepsin concentration in saliva for laryngopharyngeal reflux disease.

To explore the diagnostic efficacy of pepsin concentration in saliva for laryngopharyngeal reflux (LPR) disease. In this study, we recruited 40 participants with abnormal sensation of throat into the study who visited our hospital from March 2020 to December 2020. The 24h multichannel intraluminal impedance and pH monitoring (24h MII-pH), reflux symptom index (RSI) and reflux finding score (RFS), pepsin concentration in saliva were collected. The Cohen's kappa test and receiver-operating characteristic (ROC) curves were performed to determine and compare the sensitivity and specificity of five diagnostic methods: RSI; RFS, pepsin concentration, RSI + RFS, RSI + RFS + pepsin concentration. The area under the curve (AUC) of RSI, RFS, pepsin concentration, RSI + RFS, RSI + RFS + pepsin concentration were 0.767, 0.733, 0.870, 0.750,0.867, respectively. That is, the pepsin concentration has maximum AUC (the cutoff point is 219.47 (ng/mL); the sensitivity and 1-specificity is 0.300, 0.933, respectively.). The positive predictive value was 90.3% (28/31), and the negative predictive value was 77.8% (7/9). The Cohen's kappa coefficients of the five diagnostic subgroups were: RSI 0.486 (95% CI 0.207-0.764, P = 0.001); RFS 0.333 (95% CI 0.021-0.644, P = 0.032); RSI + RFS: 0.517 (95% CI 0.205-0.829, P = 0.001); pepsin concentration: 0.699 (95% CI 0.379-0.931, P = 0.001); RSI + RFS + pepsin concentration: 0.500 (95% CI 0.181-0.819, P < 0.001). The pepsin concentration has the maximum AUC area and highest consistency with the 24h MII-pH. Therefore, it has certain value in the screening and diagnosis of diseases related to LPR disease.

Multichannel Intraluminal Impedance and pH Monitoring are Complementary Methods in the Diagnosis of Gastroesophageal Reflux Disease in Children.

Gastroesophageal reflux is considered to be a disease when reflux of gastric contents causes troublesome symptoms in infants and children. The aim of this study was to compare the diagnostic value of the multichannel intraluminal impedance monitoring and only pH monitoring in the diagnosis of gastroesophageal reflux disease in infants and children. This prospective cross-sectional study consisted of pediatric patients aged between 1 month and 18 years old with symptoms suggestive of gastroesophageal reflux disease. Patients were divided into 2 groups as younger than 24 months (group 1) and older than 24 months (group 2). Twentyfour hours multichannel intraluminal impedance-pH monitoring was performed on the patients. This study included 50 pediatric patients. The mean age of the patients was 5.35 ± 4.92 years. In group 1, total reflux events were fewer than group 2 (P = .03) by pH monitoring. In group 1, the number of non-acid reflux events was higher than in group 2 and in group 2, the number of acidic reflux events was higher than group 1 (P = .04). Reflux was detected by multichannel intraluminal impedance-pH monitoring in 13 (40%) of 32 patients who were assessed as negative by pH monitoring. It was concluded that more reliable results were obtained when the 2 methods were used together in this study.

NORMAL VALUES OF ESOPHAGEAL 24-HOUR IMPEDANCE-PH AMBULATORY IN AN ARGENTINE COHORT OF HEALTHY VOLUNTEERS.

There are no data of reference values on 24-hour multichannel intraluminal impedance and pH (pH-MII) monitoring in Argentinian populations. Our aim was to obtain the normal values of pH-MII variables among healthy asymptomatic volunteers in a metropolitan Health Care Center of Argentina, and to compare them with data already published from other regions around the world. A cross-sectional study was undertaken in a tertiary referral center in Buenos Aires. We enrolled healthy subjects and asked them to undergo esophageal pH-MII 24hours monitoring. pH-MII variables were recorded and described. Median reflux events was 20.5 (25-75%, 95%) interquartile range: (14-46, 50) and proximal reflux episodes was 2.5 (0-10, 11). Sixty percent were acid reflux episodes: 12 (5-29, 38), representing a relatively low value when compared to those reported in European, American and Chinese populations. Our study shows the first reference of normal values of gastroesophageal reflux in an Argentinian population. We found a total number of reflux events and a total number of proximal reflux events lower than what was reported until this date by other authors.

24-HOUR ESOPHAGEAL MULTICHANNEL PH-IMPEDANCE MONITORING IN THE DIAGNOSIS OF GASTROESOPHAGEAL REFLUX DISEASE (CLINICAL CASES)

Background. Gastroesophageal reflux disease (GERD) is an urgent problem of modern gastroenterology as well as the most common pathology of the upper gastrointestinal tract; it is a chronic disease that significantly reduces the patient's quality of life, increases the risk of developing Barrett's esophagus and esophageal adenocarcinoma. Objective. To assess the potentials of multichannel intraluminal pH impedance monitoring in the diagnosis of esophageal diseases. Material and methods. In 3 patients with clinical and endoscopic signs of GERD esophageal multichannel intraluminal pH-impedance monitoring was performed using the diagnostic equipment Digitrapper pH-Z from Given Imaging (USA). Results. 24-hour esophageal pH monitoring enabled to verify the diagnosis of GERD, to reveal a hypersensitive esophagus and manifestations of nocturnal acid breakthrough. Conclusions. Multichannel intraluminal pH-impedance monitoring is the "gold standard" for the diagnosis of esophageal diseases; it significantly expands opportunities of gastroenterologists in the treatment of GERD.

Prevalence of Gastro-esophageal Reflux Disease in Suspected Laryngo- pharingeal Reflux Unresponsive to Proton-pump Inhibitors.

Laryngopharyngeal Reflux (LPR) may be part of Gastroesophageal Reflux Disease (GERD). However, sometimes suspected LPR seems refractory to Proton Pump Inhibitors (PPI), questioning therefore the GERD diagnosis. Our aim was to evaluate the real-life prevalence of GERD in patients with a recent laryngoscopic diagnosis of LPR, and unresponsive to PPI. We also assessed whether other causes than GERD could explain the laryngoscopic findings in those patients. We retrospectively analyzed patients with the diagnosis of LPR, and unresponsive to PPI. Those patients must have been investigated by: upper gastrointestinal endoscopy with biopsies; multichannel intraluminal impedance and pH monitoring (MII-pH); X-ray of the chest and/or of the paranasal sinuses; hormonal thyroid assessment; prick tests to assess food and/or inhalants and pollen allergy. We enrolled 28 patients (18, 64.3%, males and 10, 35.7%, females; median, IQR age 39.4, 21-75 yrs). Endoscopic hiatal hernia was found in 9/28 (32.1%) patients; the MII-pH analysis showed abnormality in 2/28 (7.14%) patients (both having also GERD symptoms); Chest X-ray found chest diseases in 2/28 (7.14%) patients and X-rays of the paranasal sinuses found sinusitis in 1/28 (3.6%); 2/28 (7.14%) patients had hyperthyroidism; food and/or inhalants and pollen allergy was found in 9 (32.1%) patients. In 12/28 (42.9%) patients, any of the investigated diseases was found. This study found that the real prevalence of GERD in patients with a recent laryngoscopic diagnosis of LPR, and unresponsive to PPI, is low. Moreover, more than 40% of them did not show any of the investigated diseases in real life.

Esophageal Nocturnal Baseline Impedance and Post-reflux Swallow-induced Peristaltic Wave Index in Identifying Proton Pump Inhibitor-refractory Non-erosive Reflux Disease.

Background/AimsEsophageal mean nocturnal baseline impedance (MNBI) levels and post-reflux swallow-induced peristaltic wave (PSPW) index could increase the diagnostic value of 24-hour multichannel intraluminal impedance and pH monitoring in patients with gastroesophageal reflux disease. This study aims to compare the MNBI and PSPW index in patients with no evidence of erosive reflux disease.MethodsImpedance-pH monitoring tracings from 70 patients, 50 with non-erosive reflux disease (NERD) and 20 with functional heartburn (FH), were reviewed. According to proton pump inhibitors (PPI) treatment response, NERD patients were divided into NERD/PPI responders and NERD/PPI nonresponders. MNBI, PSPW index, and intercellular spaces were measured and compared among each group.ResultsMNBI values and PSPW index were lower in NERD patients than in FH (P < 0.01 and P < 0.05, respectively). MNBI positively correlated with PSPW index (r = 0.525, P < 0.001). NERD/PPI responders had lower MNBI values and PSPW index compared to NERD/PPI nonresponders (both P < 0.01). MNBI and PSPW index distinguished NERD from FH patients with an area under the curve of 0.914 and 0.677, respectively. Wider intercellular space could be identified in patients with NERD (P < 0.01).ConclusionMNBI and PSPW index may differentiate NERD from FH patients and relate to PPI treatment efficacy in patients with NERD.

A narrative review of gastroesophageal reflux in the pediatric patient.

Gastroesophageal reflux (GER) is the retrograde passage of gastric contents into the esophagus. It is a physiologic condition that is common in neonates, typically resolves spontaneously, and does not result in clinically significant complications. When pathologic, gastroesophageal reflux disease (GERD) can cause numerous complications including persistent emesis, failure to thrive, aspiration, and respiratory symptoms. While a diagnosis can often be made from a thorough history and physical, some patients may require further testing. In general, many clinicians will reserve extensive investigation such as multiple intraluminal impedance and pH monitoring for patients with a confounding clinical picture or relative contraindications to medical or surgical management. Whereas most pediatric GER resolves spontaneously, medical management including lifestyle changes, changes to feeds, and the use of H2-antagonists and/or proton pump inhibitors (PPIs) can be utilized to alleviate symptoms. Surgical treatment is reserved for patients who are refractory to medical management or have suffered significant complications as a consequence of GER. In this article we seek to provide a concise but detailed review of recent updates in the understanding, work up and management of GER in the pediatric patient. A summary of new technologies used in the diagnostic and therapeutic arms of this disease are included.

Simultaneous Evaluation of Laryngopharyngeal Reflux and Swallowing Function Using Hypopharyngeal Multichannel Intraluminal Impedance Measurements in Neurologically Impaired Patients.

Background/AimsThis study aims to evaluate the presence of laryngopharyngeal reflux (LPR) and to investigate the use of hypopharyngeal baseline impedance (BI) for assessing swallowing dysfunction and gastroesophageal reflux disease (GERD) using hypopharyngeal multichannel intraluminal impedance and pH (HMII-pH) monitoring in neurologically impaired patients (NIPs).MethodsThe study population in this retrospective study comprised 20 NIPs (mean age, 36.1 ± 15.0 years; age range, 13-64 years) who underwent multichannel intraluminal impedance and pH (MII-pH), HMII-pH, and laryngoscopy using the Hyodo scoring method from December 2016 to April 2019. The MII-pH and HMM-pH parameters were compared in the NIPs, whereas hypopharyngeal BI values were compared between NIPs with ≥ 5 and < 5 in Hyodo scores. Correlations between the hypopharyngeal BI values and the Hyodo score were analyzed using Spearman’s correlation coefficient. A receiver operator characteristic curve was created to determine the optimum cut-off of hypopharyngeal BI value to discriminate SD.ResultsThree NIPs were diagnosed with pathological LPR and GERD by the HMII-pH monitoring. No significant differences in parameters were observed between MII-pH and HMII-pH monitoring. The correlation analysis demonstrated a significant negative correlation between the hypopharyngeal BI values and Hyodo scores. The optimal cutoff value for hypopharyngeal BI was 1552 Ω.ConclusionsThis study demonstrated the usefulness of HMII-pH monitoring in identifying NIP with pathological LPR. Considering the difficulties in performing examinations in NIPs, HMII-pH monitoring may be a potentially useful technique for the simultaneous evaluation of swallowing dysfunction, LPR, and GERD in NIP.

Multichannel impedance monitoring for distinguishing nonerosive reflux esophagitis with minor changes on endoscopy in children.

Objectives:There are reports describing the relationship between baseline impedance level and esophageal mucosal integrity at endoscopy, such as erosive and nonerosive reflux esophagitis. However, many children with symptoms of gastroesophageal reflux disease have normal findings or minor changes on esophagogastroduodenoscopy. We aimed to examine whether modest changes at esophagogastroduodenoscopy can be evaluated and correlated with esophageal multichannel intraluminal impedance monitoring.Methods:Patients (ages 0–17 years) with upper gastrointestinal symptoms who underwent combined esophagogastroduodenoscopy and multichannel intraluminal impedance monitoring at the Women’s and Children’s Hospital, Adelaide, Australia, between 2014 and 2016 were retrospectively studied and the following data were collected and used for analysis: demographics, multichannel intraluminal impedance data, included baseline impedance. Endoscopic findings were classified by modified Los Angeles grading, Los Angeles N as normal, Los Angeles M as with minimal change such as the erythema, pale mucosa, or friability of the mucosa following biopsy. Patients on proton pump inhibitor were excluded.Results:Seventy patients (43 boys; 61%) were enrolled with a mean age of 7.9 years (range 10 months to 17 years). Fifty-one patients (72.9%) were allocated to Los Angeles N, while Los Angeles M was evident in 19 patients (27.1%). Statistically significant differences were observed in the following parameters: frequency of acid and nonacid reflux and baseline impedance in channels 5 and 6. The median values of the data were 18.3 episodes, 16.0 episodes, 2461.0 Ω, 2446.0 Ω in Los Angeles N, 36.0 episodes, 31.0 episodes, 2033.0 Ω, 2009.0 Ω in Los Angeles M, respectively.Conclusion:Lower baseline impedance is helpful in predicting minimal endoscopic changes in the lower esophagus. A higher frequency of acid and nonacid reflux episodes was also predictive of minimal endoscopic change in the lower esophagus.

Esophageal Involvement and Determinants of Perception of Esophageal Symptoms Among South Koreans With Systemic Sclerosis.

Background/AimsOur study aims to characterize esophageal motor function; evaluate the relationships among esophagogastroduodenoscopy (EGD), high-resolution manometry (HRM), and 24-hour esophageal multichannel intraluminal impedance monitoring combined with pH-metry (MII-pH); and elucidate the determinants of esophageal symptom perception in South Koreans with systemic sclerosis (SSc).MethodsWe reviewed prospectively collected HRM (n = 46), EGD (n = 41), and MII-pH (n = 37) data from 46 consecutive patients with SSc (42 females; mean age 50.1 years) who underwent esophageal tests between June 2013 and September 2018.ResultsThe most common HRM diagnosis was normal (39.1%), followed by ineffective esophageal motility (23.9%) and absent contractility (21.7%). Erosive esophagitis was observed in 12.2% of total SSc patients, with a higher frequency in patients with absent contractility than those with normal motility (44.5% vs 0.0%, P = 0.01). Pathologic acid exposure was observed in 6 patients (20.0%) and positive symptom association in 18 patients (60.0%) in MII-pH tests of symptomatic patients. The proportion of SSc patients with esophageal symptoms not explained by reflux or mucosal or motor esophageal abnormalities was 33.0%.ConclusionsEsophageal involvement among South Koreans with SSc was characterized by heterogeneous motility patterns, with a higher prevalence of normal motility and lower prevalence of erosive esophagitis. Reflux hypersensitivity or functional heartburn might be partly attributed to the perception of esophageal symptoms in SSc patients who have neither gastroesophageal reflux disease nor esophageal dysmotility.

A single-center retrospective analysis of 46 children with aerophagia

To study the clinical features of aerophagia in children. A retrospective analysis was performed on the medical data of 46 children with aerophagia who were diagnosed and treated in Children's Hospital Affiliated to Nanjing Medical University from October 2011 to September 2019. Among these 46 children, 15 (33%) had Tourette syndrome. Abdominal distension was the most common symptom and was observed in 45 children (98%). The 24-hour esophageal multichannel intraluminal impedance monitoring showed a mean number of 341 times of air swallowing and a mean number of 212 times of gas reflux, and 95% of gas refluxes occurred in the upright body position. Compared with those without Tourette syndrome, the children with Tourette syndrome had a significantly higher incidence rate of air swallowing symptoms (67% vs 6%, P<0.001), but there were no significant differences in other symptoms and the results of 24-hour esophageal impedance. Dietary adjustment, psycho-behavioral therapy, and drug intervention significantly improved the scores of clinical symptoms and quality of life, among which psycho-behavioral therapy was an important intervention measure. Some children with aerophagia may have Tourette syndrome, and such children are more likely to have air swallowing symptoms. Psycho-behavioral therapy is one of the most important treatment methods, and children with aerophagia tend to have a good prognosis after treatment.

Multichannel Intraluminal Impedance and pH Monitoring: A Step Towards Pediatric Reference Values.

Background/AimsCombined multichannel intraluminal impedance and pH monitoring (MII/pH) is considered the most accurate test to detect gastroesophageal reflux (GER), however lacking reference values. We aim to determine reference values for the pediatric population and to correlate these values with age and postprandial/fasting period.MethodsWe evaluated MII/pH traces from patients (newborns, infants, and children) admitted to 3 Italian hospitals and who underwent MII/pH for suspected GER disease. Patients with MII/pH traces that showed significant symptom-reflux associations and/or a pathological reflux index (> 6% for newborns and infants, > 3% for children) were excluded. Traces were analysed in their entirety, and in the postprandial period (first hour after a meal) and the fasting period (the following hours before the next meal) separately.ResultsA total of 195 patients (46 newborns, 83 infants, and 66 children) were included. Age positively correlated with frequency of acidic GER events (r = 0.37, P < 0.05) and negatively associated with weakly acidic GER events (r = 0.46, P < 0.05).ConclusionsThis study describes the distribution of MII/pH values in a pediatric population with normally acidic GER exposure and no significant association between GER events and symptoms. These MII/pH values may be used as reference values in clinical practice for a corrected GER disease diagnosis in the pediatric population.

Perioperative gastroesophageal regurgitation in patients with elevated abdominal pressure with nasogastric tubes? A simulation model based on esophageal multichannel intraluminal impedance and pH monitoring

Increased abdominal pressure is common in obese patients and predisposes them to gastroesophageal regurgitation (GER). To drain GER and prevent aspiration, nasogastric (NG) tubes are frequently inserted in obese patients undergoing general anesthesia. However, whether gastric drainage actually decreases the occurrence of GER remains to be elucidated. In this study, increased abdominal pressure was simulated with laparoscopic pneumoperitoneum and Trendelenburg (LPT) positioning, while the retained NG tube was replaced by a pre-inserted esophageal multichannel intraluminal and pH (MII-pH) monitoring. Fifteen patients undergoing elective gynecologic laparoscopy were enrolled in this study. Thirteen patients (86%) developed GER while in the LPT position. With the high occurrence of GER, pre-inserted NG tubes under general anesthesia are not likely to be protective in obese patients.

The Ameliorating Effect of Switching to Vonoprazan: A Novel Potassium-Competitive Acid Blocker in Patients with Proton Pump Inhibitor Refractory Non-Erosive Reflux Disease

Introduction: Weakly acidic reflux has been reported to be the major cause of symptoms in patients with proton pump inhibitor (PPI)-refractory nonerosive reflux disease (NERD) undergoing PPI treatment. We previously reported that reflux at pH 4–5 was the main factor that induced symptoms in such patients. The present study aimed to elucidate the symptom-ameliorating effect of vonoprazan (VPZ) by evaluating the change in the pH value of the refluxate using multichannel intraluminal impedance and pH (MII-pH) monitoring. Methods: We retrospectively evaluated the records of MII-pH monitoring in 29 symptom index (SI) and/or symptom association probability (SAP)-positive patients with PPI-refractory NERD. After switching to VPZ 20 mg/day, we performed MII-pH monitoring again. We assessed the change in the score of the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), the pH value of the refluxate, and the percent times of intragastric pH <4 or <5 before and after switching. We divided the patients into the following 2 groups according to the FSSG score after switching: effective and noneffective groups. Results: Among of the 29 SI/SAP-positive patients, 16 underwent switching to VPZ. Furthermore, of these 16 patients, 10 underwent MII-pH monitoring again after switching. The FSSG score decreased, the pH value of the refluxate increased, and the percent times of intragastric pH <4 or <5 reduced after switching when compared with the findings before switching. In the effective group, both the proportion of reflux at pH <4 and that of reflux at pH 4–5 decreased while taking VPZ when compared with the findings while taking double-dose PPI. In the noneffective group, the proportion of reflux at pH <4 decreased but that of reflux at pH 4–5 increased and that of reflux at pH <5 did not change overall while taking VPZ. In addition, the percent times of intragastric pH <5 values were low in the effective group. Conclusion: Symptom suppression appears to be inadequate in patients with persistent reflux at pH 4–5 even with VPZ 20 mg/day. Strong acid suppressive therapy with VPZ to increase the pH value of the refluxate to ≥5 is useful for symptom improvement.

Reflux characteristics in patients with gastroesophageal reflux-related chronic cough complicated by laryngopharyngeal reflux.

This study aimed to investigate the reflux characteristics in patients with gastroesophageal reflux-related chronic cough (GERC) complicated by laryngopharyngeal reflux (LPR). Patients with chronic cough were recruited. Reflux symptom index (RSI) scoring, cough symptom scoring, assessment of capsaicin cough sensitivity, and multichannel intraluminal impedance and pH monitoring (MII-pH) were performed. RSI score in GERC patients was significantly higher than that in patients with atopic cough (AC), cough variant asthma, eosinophilic bronchitis (EB), and upper airway cough syndrome (UACS) (P<0.05). The RSI score in non-acid GERC patients was significantly higher than that in acid GERC patients (P=0.003). The cut-off value of the RSI score was defined as 19 during diagnosis of non-acid GERC. In the RSI ≥19 group, there was more proximal reflux and more significant gas and non-acid reflux, and the efficacy of a combined use of baclofen or gabapentin was better than that of the RSI <19 group (P<0.05). The efficacy of proton pump inhibitor (PPI) at a routine dosage together with prokinetic agents in the RSI <19 group was better than that in the RSI ≥19 group (P=0.009). LPR overlaps with GERC in part. GERC patients with higher RSI scores may present more proximal reflux, non-acid reflux, and gas reflux, and get better efficacy with neuromodulators (gabapentin or baclofen) used as an add-on therapy.