Nonacid Gastroesophageal Reflux Research Articles

The Real Relevance of Nonacid Reflux in Pediatric Patients.

Gastroesophageal reflux (GER) is one of the most common presenting complaints to pediatric gastroenterologists, and a wide variety of symptoms in children are potentially attributable to typical or atypical GER. While reflux diagnosis and treatment paradigms classically have focused on targeting acid, there is a growing recognition of the prevalence and significance of nonacid GER in both children and adults. This review explores the role of nonacid reflux in pediatric patients, including definitions, associations with symptoms, pathophysiologic mechanisms, and treatment implications.

Подходы к терапии ГЭРБ с учетом разнообразия ее клинических форм

Approximately one third of gastroesophageal reflux disease (GERD) patients are resistant or partially responsive to proton pump inhibitors (PPIs). It is assumed that non-acid reflux is the cause of 15–62% of cases concerning the PPI therapy inefficacy in GERD patients. The review reveals the issues on the prevention and therapy of non-acid GERD types, ways to improve the treatment efficacy. Understanding the patterns of reflux and pathogenetic mechanisms of non-acid GERD types makes it possible to choose the right drugs. For the prevention and treatment of bile reflux, it is necessary to normalize esophageal, gastric and duodenal motility, as well as biliary system function, and prescribe adequate antisecretory and cytoprotective therapy. The basic drugs for the GERD treatment are PPIs. In order to elevate the GERD therapy effect, drugs are used that can enhance the protective factors of the mucous membranes, i.e., cytoprotectors. UDCA drugs are the basis of GERD therapy with a predominance of bile reflux. Prokinetics are used in the treatment of duodenogastroesophageal reflux to normalize the biliary system function, as well as the motor-evacuation function of the stomach and intestines. Heterogeneity of pathogenesis, including the possibility of acid and non-acid gastroesophageal reflux, necessitates GERD differentiated therapy. KEYWORDS: GERD, reflux, prokinetic, gastroprotectors, cytoprotector, proton pump inhibitors. FOR CITATION: Seliverstov P.V., Lazareva Yu.A., Egorov D.V. Methods for GERD therapy according to its clinical form diversity. Russian Medical Inquiry. 2023;7(7):432–438 (in Russ.). DOI: 10.32364/2587-6821-2023-7-7-5.

Squamous Cancer of the Esophagus in Africa: A Causal Pathway Established

Squamous cancer of the esophagus has been endemic in much of East, Central and Southern Africa since the 1940s. Much research has concentrated on attempts to identify major carcinogenic influences, and failure to do so has made it clear that the problem in high incidence areas (HIAs) is not primarily of potent environmental carcinogens, but of population susceptibility. In Africa the association with maize is constant and strong. Research in the last decade has helped to explain that association. Considered along with historical findings there is now enough evidence to establish causal associations of a nutritionally deficient maize diet and use of maize meal with squamous cancer of the esophagus. Evidence is available in a high incidence area of degenerating maize meal resulting in excess production of PGE2, gastric hypochlorhydria and a predominant pattern of non-acid gastroesophageal reflux. This pathway explains the existence of major population susceptibility: a poor maize-based diet provides specific nutritional deficiencies and n-6 fatty acid dominance which cause failure of homeostasis of the arachidonic acid cascade; with this background chemically degenerating maize meal then triggers duodenogastric reflux and non-acid gastro-esophageal reflux; non-acid reflux causes squamous cancer of the esophagus. Within a susceptible population, environmental carcinogens including tobacco increase individual risk. There is sufficient evidence that this is an active pathway, and the dominant pathway to SCCE in high incidence areas in Africa.There is sufficient evidence to justify appropriate preventative measures.

The effects of assisted autogenic drainage, combined or not with bouncing on gastroesophageal reflux in infants

This study aimed to determine the effect of assisted autogenic drainage (AAD) with or without bouncing (BAAD) on both acid and non-acid gastroesophageal reflux (GER) in infants <1year. During a 24-h multichannel intraluminal impedance-pH monitoring (MII-pH), infants were treated with a 20-min intervention of AAD (in supine position) or BAAD (in upright position), 2h postprandial. In this controlled trial with intra-subject design, the number of reflux episodes (REs) was the primary outcome measure. The results during AAD and BAAD were compared to a baseline period before intervention and 20min after intervention. Overall, 50 infants were included in both groups. During AAD a significant decrease of RE's was found compared to baseline (p=0.001). No significant differences were found in the BAAD group compared to baseline (p=0.125). AAD and BAAD do not cause or increase GER in infants under the age of 1year.

Devices for esophageal function testing.

Background and AimsEsophageal function testing is an integral component of the evaluation of refractory GERD and esophageal motility disorders. This review summarizes the current technologies available for esophageal function testing, including the functional luminal imaging probe (FLIP), high-resolution esophageal manometry (HRM), and multichannel intraluminal impedance (MII) and pH monitoring.MethodsWe performed a MEDLINE, PubMed, and MAUDE database literature search to identify pertinent clinical studies through March 2021 using the following key words: esophageal manometry, HRM, esophageal impedance, FLIP, MII, and esophageal pH testing. Technical data were gathered from traditional and web-based publications, proprietary publications, and informal communications with pertinent vendors. The report was drafted, reviewed, and edited by the American Society for Gastrointestinal Endoscopy Technology Committee and approved by the Governing Board of the American Society for Gastrointestinal Endoscopy.ResultsFLIP is a high-resolution impedance planimetry system used for pressure and dimension measurement in the esophagus, pylorus, and anal sphincter. FLIP provides complementary information to HRM for esophageal motility disorders, especially achalasia. The Chicago classification, based on HRM data, is a widely adopted algorithmic scheme used to diagnose esophageal motility disorders. MII detects intraluminal bolus movement and, combined with pH measurement or manometry, provides information on acid and non-acid gastroesophageal reflux and bolus transit in patients with refractory GERD and for preoperative evaluation for anti-reflux procedures.ConclusionsEsophageal function testing techniques (FLIP, HRM, and MII-pH) have diagnostic and prognostic value in the evaluation of esophageal motility disorders and refractory GERD. Newer technologies and classification systems have enabled an increased understanding of these diseases.

Non-acid reflux and sleep apnea: the importance of drug induced sleep endoscopy

BackgroundWe present the first case of a patient with obstructive sleep apnea syndrome (OSA), where drug induced sleep endoscopy was helpful to suspect a non-acid reflux disease and showed an improvement in a swollen epiglottis after treatment. Patient ameliorated significantly his disease only with medical therapy.Case presentationA 54-year-old man without significant anatomical findings with obstructive sleep apnea syndrome and non-acid gastroesophageal reflux disease (GERD) disease whose Apnea- hypopnea index (AHI) was significantly reduced with the intake of 500 mg of sodium alginate twice a day for 6 months. Conventional digestive tests such as esophagoscopy and simple- and double-channel 24-h pH-metry suggested mild GERD. Conventional proton-pump inhibitor treatment with pantoprazole (40 mg daily) was started without any improvement in his sleep. Multichannel intraluminal 24-h impedanciometry indicated the presence of severe pathological GER of gaseous origin. The patient’s AHI decreased from 25.3 at baseline to 8 after treatment with sodium alginate. A drug-induced sleep endoscopy study showed the changes before and after this treatment and was helpful for the diagnosis.ConclusionsThus, medical treatment can be a therapeutic option in some patients with OSA. Multichannel 24-h impedanciometry should be performed when nonacid GERD is suspected.

Current management of proton pump inhibitor-refractory gastroesophageal reflux disease

Here we review current concepts in diagnosis and treatment of proton pump inhibitor (PPI)-refractory gastroesophageal reflux disease (PPIGERD) which includes an insufficient response to daily PPI 8-week therapy in combination with pathological gastroesophageal reflux. Patients with PPI-GERD frequently suffer from non-acidic and asymptomatic gastroesophageal reflux. In developed countries, PPI-GERD accounts for 30-40% of all patients receiving PPIs. Diagnosis of PPIGERD is performed by means of clinical anamnesis, esophagogastroscopy and impedance-pH monitoring. PPI-GERD needs to be differentiated with functional heartburn, reflux hypersensitivity and nonerosive reflux disease. Functional heartburn is characterised by reference time with a esophageal pH &lt; 4 and the absence of a link between reflux episodes and GERD symptoms. Reflux hypersensitivity is diagnosed with normal esophageal acid exposure and association of reflux episodes with symptoms of GERD. Nonerosive reflux disease can be diagnosed solely by evaluating pathological acid exposure (pH &lt; 4 for &gt; 6% of the time). Treatment of PPI-GERD includes diet and lifestyle modification to reduce weight in obese patients, optimization of PPI use, and administration of alginate, prokinetics, baclofen and other drugs. Surgical treatment is also widely used and provide good results.

Laparoscopic Posterior Partial Fundoplication for Gastroesophageal Reflux Disease.

Gastroesophageal reflux disease (GERD) is a common condition that greatly impacts quality of life. Management options include medical and surgical therapies. Nonoperative management typically relies on longitudinal use of acid-suppressive medications such as proton pump inhibitors, which is associated with a significant financial burden and an increasing number of recognized side effects. The surgical management of GERD is focused on correction of the lower esophageal sphincter dysfunction by means of a fundoplication, thus limiting acid and nonacid gastroesophageal reflux. Multiple techniques have been described, including use of complete (360°) fundoplication or partial fundoplication in either an anterior (180°) or posterior (220-270°) position. Recent studies have shown that the total and the partial fundoplications are similarly effective in controlling GERD. A partial fundoplication may also be advantageous when treating patients with GERD and poor esophageal motility. This article focuses on the posterior partial (modified Toupet) fundoplication, with attention to the key elements of the preoperative workup, appropriate patient selection, and important technical steps that are associated with the best outcomes.

A New, Noninvasive Accelerometric Method for Diagnosing Acid andNon-Acid Gastroesophageal Reflux in Premature Infants: Proof of Concept.

Non-acid reflux is common in premature neonates. Current methods of diagnosing gastroesophageal reflux (GER) such as pH probes, multichannel impedance monitoring, X-rays, or endoscopy are either invasive or unable to diagnose non-acid reflux. Passage of a naso-esophageal tube is uncomfortable. Imaging studies are of short duration and may miss reflux entirely. Herein, we present proof of concept of a noninvasive accelerometric device that detects acid and non-acid reflux in premature infants. An accelerometer was taped over the subxiphoid process in patients suspected of having GER who were already scheduled for pH probe or multichannel impedance monitoring. The largest cohort was preterm infants, but term infants and toddlers were also studied. Low-frequency subaudible signals were obtained on a digital recorder (sampling rate 200 Hz) signals. Fast Fourier transforms graphically displayed the frequency and amplitude of signals. Data were then resampled at a rate of 60 Hz to create a spectrogram with a focused range of 0-30 Hz representing reflux-associated events. Proof of concept was attained through successful comparison with results from concurrent pH probes, multichannel impedance recordings, and ultrasound studies. We have thus validated accelerometry as a noninvasive method for assessing both acid and non-acid GER. The noninvasiveness of this diagnostic modality allows for repeated testing to assess the efficacy of anti-reflux medications, even when patients remain on antacids. This technology allows for more rational management of patients with GER and represents a major advance in the diagnosis and treatment of GER.

Aetiology of Oesophageal Cancer in Africa - A Review of Historical and Current Evidence

There is no current agreement on the cause of squamous cancer of the oesophagus in Africa, a major cause of morbidity and mortality in East and Southern Africa. The remarkable history is reviewed together with all recent evidence using a literature search.&#x0D; &#x0D; There are consistent and continuing associations with maize and with tobacco. Changes of type of maize, patterns of consumption and processing occurred around 1930, and a rapid rise of oesophageal cancer dated from that time. &#x0D; &#x0D; Tobacco has a worldwide association with cancer of the oesophagus, but there is a substantial minority of non-users in high incidence areas. Other carcinogens have come under suspicion, but there is evidence against any of these acting as the principal carcinogenic influence in Africa. Recent studies in Japan and in South Africa have shown an association between non-acid gastro-oesophageal reflux and squamous cancer of the oesophagus.&#x0D; &#x0D; There is no credible candidate for principal oesophageal carcinogen in Africa. There is good reason to look again at milled maize: its deficiencies, contaminations, and degenerative processes. Associations between diet, non-acid reflux and squamous cancer of the oesophagus merit further study.

DOZ047.60: Evaluation of gastroesophageal reflux in children born with esophageal atresia using pH and impedance monitoring

Abstract Aim of the Study The ESPHGAN-NASPGHAN guideline (Krishnan, 2016) recommends routine prescription of proton pump inhibitors in the first year of life after esophageal atresia (EA) repair, and to monitor gastroesophageal reflux (GER) using pH-impedance (pH-MII) monitoring and/or endoscopy at time of discontinuation and during long term follow up of these patients. This study aimed to evaluate acid and non-acid GER in infants and school-aged children with EA using pH-MII monitoring. Methods Children born with EA between 2011–2017, who underwent a 24-hour pH-MII study during infancy (≤18 months) or at 8 years old as part of a standardized longitudinal follow-up program, were included. Exclusion criteria were: isolated tracheoesophageal fistula, esophageal replacement therapy, tube feeding and monitoring &lt; 18 hours. Anti-acid therapy was discontinued before pH-MII measurement. Data was collected on reflux index (RI; exposure to pH &lt; 4 in %, &gt;7% considered abnormal), retrograde bolus movements (RBM) and bolus clearance time (BCT). Automatically detected RBM were manually reviewed and modified/deleted if necessary. Results We included 57 children (51% male, 2% isolated EA, 44% thoracoscopic repair): 24 infants (median age 0.6 years) and 33 school-aged children (median age 8.2 years). In infants, median RI was 2.6% (abnormal in n = 2), median RBM was 61 (62% non-acid, 58% mixed) and median of the mean BCT was 11 seconds. In school-aged children, median RI was 0.3% (abnormal in n = 4), median RBM was 21 (64% non-acid, 75% mixed) and median of the mean BCT was 13 seconds. Of the automatically detected 3,313 RBM, 1,292 were manually deleted from the tracings: 52% of non-acid RBM and 8% of acid RBM (mainly misinterpreted swallows or one event recognized as several events). Conclusions Most children with EA off medication have a normal RI, yet experience a significant number of non-acid RBM. After manual revision of the tracings a high percentage of RBM was deleted. Our data show that automated impedance analysis software needs refinement for use in infants and children with EA, and question the need for standard anti-acid therapy in these patients.

Esophageal Impedance-pH Monitoring and Pharyngeal pH Monitoring in the Diagnosis of Extraesophageal Reflux in Children.

Various clinical symptoms are attributed to extraesophageal reflux disease (EERD). Multichannel intraluminal impedance-pH monitoring (MII-pH) is considered to correlate symptoms with acid and nonacid gastroesophageal reflux (GER) events. Pharyngeal pH monitoring (Dx-pH) is considered to correlate the decrease in the pH level in the oropharynx with reported symptoms and to diagnose supraesophageal reflux. We aimed to assess the correlation between acid reflux episodes recorded by Dx-pH and GER detected via MII-pH in children with suspected EERD. The study enrolled 23 consecutive children (15 boys and 8 girls; median age 8.25 [range 3-16.5] years) with suspected EERD. MII-pH and Dx-pH were conducted concurrently in all patients. A total of 1228 reflux episodes were recorded by MII-pH. With the antimonic sensor placed inside the impedance probe, 1272 pH-only reflux episodes were recorded. Of these, 977 (76.81%) were associated with a retrograde bolus transit. Regarding GER, 630 full-column episodes extended to the most proximal pair of impedance sensors; 500 (83.33%) demonstrated an acidic character. The following acid reflux numbers were determined by the Dx-pH system: for pH < 4, n = 126; pH < 4.5, n = 136; pH < 5, n = 167; and pH < 5.5, n = 304, and for a decrease in pH > 10% relative to the baseline, n = 324. There was no significant correlation between the number of pharyngeal reflux episodes detected by Dx-pH and that of GERs identified by MII-pH. The proportion of oropharyngeal pH events that were temporally related to a GER episode increased with the extended pH criteria. The highest proportion was observed for a pH decrease of ≥10% from the baseline and did not exceed 5.2%. The application of the extended pH criteria in the Dx-pH system resulted in an increase in the number of diagnosed laryngopharyngeal refluxes; most were not temporally associated with GER episodes confirmed by MII-pH. Thus, the efficacy of the exclusive application of Dx-pH for supraesophageal gastric reflux diagnosis is uncertain.

Erythromycin and Reflux Events in Premature Neonates: A Randomized Clinical Trial.

Gastroesophageal reflux disease (GERD) in premature neonates may manifest as apnea, bradycardia, growth failure, aspiration, or feeding intolerance. Erythromycin ethylsuccinate (EES), is often used as a pro-kinetic in the management of GERD, despite lack of evidence or safety from randomized controlled trials. We sought to study the efficacy of enteral EES at a dose of 50 mg · kg · day in decreasing the frequency of gastroesophageal reflux events as determined by pH-multichannel intraluminal impedance (pH-MII) monitoring. In a randomized, double-blind, placebo-controlled trial, eligible premature neonates with clinical signs of GERD underwent 24-hour pH-MII monitoring. If >5 reflux events were identified on pH-MII, then subjects were randomized to receive either EES or placebo. Repeat 24-hour pH-MII was performed on day 7 of study treatment and compared to initial pH-MII. Forty-three premature neonates were enrolled. Of those, 31 neonates were randomized, 15 to EES and 16 to placebo with a median (IQR) pretreatment total reflux events per 24 hours of 23 (16-40) and 29 (12-40), respectively. Day 7 total events per 24 hours decreased by 4 events in the EES group to 19 (15-33) and by 10 events in the placebo group to 19 (11-26) (P = 0.09). There were no differences in pretreatment and day 7 acidic and nonacidic reflux, proximal reflux, total or percent reflux time, median or longest bolus clearance time, or nurse-reported apnea events between groups. Enteral EES did not decrease reflux events on 24-hour pH-MII at the dose studied. Therefore, it may be ineffective in the treatment of GERD in premature neonates.

Twenty-four-hour oesophageal pH studies in rural Eastern Cape Province, South Africa.

Recent studies in rural Eastern Cape Province, South Africa, have shown an increased number of non-acid gastro-oesophageal reflux events, an increase in baseline gastric pH compared with other published series, and evidence suggestive of duodenogastric reflux. There are no published data on oesophageal pH in this community or in Africa. To ascertain whether oesophageal pH in this rural community is within normal limits. We carried out 24-hour oesophageal pH/impedance studies on 91 participants. Analysis was carried out using computer software to determine 24-hour percentage times of oesophageal pH above 4, 5, 6, 7 and 8. Oesophageal pH during each episode of non-acid reflux was also recorded. Participants were from Canzibe in rural Eastern Cape. Of the studies, 72 were satisfactory and showed 24-hour percentage times with an oesophageal pH &gt;6 of 69.3/35.12/51.16 (upright/supine/total); percentage times with a pH &gt;7 were 12.66/3.44/8.86 and those with a pH &gt;8 were 0.48/0.21/0.37. These results are within the range of other published series. Of episodes of non-acid reflux, 90.2% were associated with an oesophageal pH of 4 - 7. Baseline oesophageal pH is not significantly affected by the increased numbers of non-acid gastro-oesophageal reflux events reported in this community. If there is a pathogenic effect of non-acid reflux in the Eastern Cape, it does not appear to be mediated through raised oesophageal pH.

Non-acid gastro-oesophageal reflux is associated with squamous cell carcinoma of the oesophagus

IntroductionSquamous cell carcinoma of the oesophagus is a common cancer among South Africans. Due to the absence of effective screening and surveillance programme for early detection and late presentation, squamous...

Acid and nonacid gastroesophageal reflux after single anastomosis gastric bypass. An objective assessment using 24-hour multichannel intraluminal impedance-pH metry

BackgroundSingle anastomosis gastric bypass (SaGB) was introduced in 2001 as an alternative to “loop” gastric bypass. It was considered as a procedure that would eliminate alkaline reflux and associated esophagitis. ObjectivesExisting evidence about the postoperative incidence of gastroesophageal reflux (GERD) after SaGB is based on studies using symptom questionnaires. The aim of our study was to evaluate GERD 12 months after SaGB by using 24-hour multichannel intraluminal impedance pH metry (24-h MIIpH). SettingSurgical department of a university hospital MethodsMorbidly obese candidates for SaGB underwent 24-hour MIIpH prior and 12 months after their bariatric procedure. ResultsThere were 11 patients included in this prospective study. Results of 24-hour MIIpH revealed that DeMeester score (40.48 versus 24.16, P = .339) had an increasing trend 12 months after SaGB. Acid reflux episodes decreased, whereas nonacid reflux episodes increased postoperatively, both in proximal and distal esophagus. Total median bolus clearance time and acid clearance time increased. De novo GERD developed in 2 patients (28.6%) and worsening of already existing GERD developed in all patients with preoperative evidence of GERD. ConclusionThe use of symptom questionnaires to assess postoperative GERD after SaGB may not accurately depict the real image. Twenty-four–hour MIIpH in 12 months after SaGB revealed an increase of total number of nonacid reflux episodes and a decrease of total number of acid reflux episodes, with longer duration of each acid reflux episode. Close postoperative follow-up with reflux testing and possibly endoscopy could eliminate the risk of complicated GERD.

Differentiation therapy for non-acidic gastroesophageal reflux disease

To investigate the clinical and pathogenetic features of the non-acidic types of gastroesophageal reflux disease (GERD) and to evaluate the impact of combined therapy versus monotherapy on the course of this disease. The investigation enrolled 62 patients with non-acidic GERD. The follow-up period was 6 weeks. The patients were divided into 2 groups: 1) weakly acidic gastroesophageal refluxes (GER); 2) weakly alkaline GER. Then each group was distributed, thus making up 4 groups: 1) 19 patients with weakly acidic GER who received monotherapy with rabeprazole 20 mg/day; 2) 21 patients with weakly acidic GER had combined therapy with rabeprazole 20 mg and itopride; 3) 8 patients with weakly alkaline GER who received ursodeoxycholic acid (UDCA) monotherapy; and 4) 14 patients with weakly alkaline GER who had combined therapy with UDCA and itopride, The clinical symptoms of the disease, the endoscopic pattern of the upper gastrointestinal tract (GIT) mucosa, histological changes in the esophageal and gastric mucosa, and the results of 24-hour impedance pH monitoring were assessed over time. During differentiation therapy, the majority of patients reported positive clinical changes and an improved or unchanged endoscopic pattern. Assessment of impedance pH monitoring results revealed decreases in the overall number of GERs, the presence of a bolus in the esophagus, and the number of proximal refluxes. These changes were noted not only in patients taking proton pump inhibitors (PPIs), but also in those treated with UDCA monotherapy or combined PPI and prokinetic therapy. A differentiated approach to non-acidic GER treatment contributes to its efficiency. Adding the prokinetic itomed (itopride hydrochloride) to PPI therapy in a patient with weakly acidic GER enhances the efficiency of treatment, by positively affecting upper GIT motility. The mainstay of therapy for GERD with a predominance of weakly alkaline refluxes is UDCA, the combination of the latter and the prokinetic can exert a more pronounced effect on the clinical and endoscopic pattern and upper GIT motility.

Reflux monitoring in children.

Recently, multichannel intraluminal impedance (MII) monitoring was added to the repertoire of tests to evaluate the (patho)physiology of gastroesophageal reflux (GER) in children. Its advantage above the sole monitoring of the esophageal pH lies in the ability of the detection of both acid and nonacid GER and to discern between liquid and gas GER. Currently, combined 24h pH-MII monitoring is recommended for evaluation of gastro-esophageal reflux disease (GERD) and its relation to symptoms in infants and children, despite the lack of reference values in these age groups. There is new evidence in the current issue of this Journal supporting the role of pH-MII monitoring for the evaluation of children presenting with gastrointestinal symptoms suggestive of GERD and the prediction of the presence of reflux esophagitis. However, several issues should be taken into account when performing pH-MII clinically.

Is the Routine Use of Impedance Analysis for the Diagnosis of Gastro-Esophageal Reflux Disease More Expensive than Conventional pH Monitoring? Cost Analysis of Two Procedures.

Conventional 24-h pH monitoring is the gold standard for the diagnosis of non-erosive, non-acidic gastro-esophageal reflux disease. Multichannel Intraluminal Impedance (MII) analysis markedly improves diagnostic accuracy of non-erosive, non-acidic gastro-esophageal reflux disease. However, MII catheters are more expensive than standard catheters. This study aimed to determine the rates of acid or non-acid reflux and by making a retrospective projection, to predict the costs of two algorithms. We retrospectively reviewed the medical data of 102 patients who presented to our hospital with suspected non-erosive GERD and underwent 24h impedance/pH-monitoring. Demographic characteristics, Demeester scores, number of reflux episodes, and results of impedance analysis were recorded. According to these data, cost was calculated either for the scenario in which impedance measurement was performed solely or following a negative conventional pH monitoring. Thirty-seven of all 102 patients (36.3%) had a Demeester score greater than 14.7. These patients were assigned as group 1 (acid reflux). The impedance analysis of the remaining 65 patients detected 34 patients (33.3%) to have more than 50 reflux episodes over a period of 24h and assigned as Group 2, and 31 patients (30.4%) had no reflux (group 3). The cost of the single- step algorithm using MII catheter was calculated as $15,300, while the total cost of two-step scenario would have been predicted as $16,890. Our study showed that an initial conventional pH monitoring can make the diagnosis of GERD in only one third of the patients with suspected non-erosive GERD. In nearly two-thirds of patients, however, repeated procedures and use of impedance catheters are needed. It is clear that this algorithm has certain drawbacks with regard to cost, patient comfort, and workforce loss.

Are Infants with Bronchopulmonary Dysplasia Prone to Gastroesophageal Reflux? A Prospective Observational Study with Esophageal pH-Impedance Monitoring

To perform an observational cohort study with esophageal pH-multichannel intraluminal impedance (pH-MII) monitoring in symptomatic preterm infants with and without bronchopulmonary dysplasia (BPD). We prospectively studied 46 infants born ≤32 weeks gestational age: 12 infants with BPD and 34 infants without BPD. Each patient had symptoms consistent with gastroesophageal reflux and had 24-hour pH-MII, which were compared between BPD and non-BPD by univariate analysis and quantile regression analysis. Demographic and clinical characteristics were similar between infants with and without BPD, except for fluid administration (145 vs 163 mL/kg/d, P = .003), length of stay (92 vs 69 days, P = .019), and time to achieve complete oral feeding (76 vs 51 days, P = .013). The analysis of 1104 hours of pH-MII tracings demonstrated that infants with BPD compared with infants without BPD had increased numbers of pH-only events (median number 21 vs 9) and a higher symptom sensitivity index for pH-only events (9% vs 4.9%); the number and characteristics of acid, weakly acid, nonacid and gas gastroesophageal reflux events, acid exposure, esophageal clearance, and recorded symptoms did not significantly differ between the 2 groups. The increased number of (and sensitivity for) pH-only events among infants with BPD may be explained by several factors, including lower milk intake, impaired esophageal motility, and a peculiar autonomic nervous system response pattern.