Multichannel Intraluminal Impedance pH-metry Research Articles

Gastroesophageal reflux disease and salivary pepsin in patients with heterotopic gastric mucosa in the upper esophagus.

Heterotopic gastric mucosa in the upper esophagus (HGMUE) is reported to be related to gastroesophageal reflux disease (GERD). This study investigated the prevalence of GERD and the use of salivary pepsin to diagnose gastroesophageal reflux, especially proximal reflux, in HGMUE patients. One hundred and fifty-three HGMUE patients and 50 healthy volunteers were studied. All subjects took a reflux symptom index questionnaire (RSI); underwent endoscopy, barium esophagogram, high-resolution manometry (HRM), and 24-hour multichannel intraluminal impedance-pH-metry (MII-pH); and salivary pepsin test. Ninety-five (62.1%) HGMUE patients but no control subjects were diagnosed with GERD. The salivary pepsin concentration, RSI score, DeMeester score, acid exposure time (AET), total reflux episodes, proximal acidic reflux episodes, and proximal weakly acidic reflux episodes were significantly higher in the HGMUE group than in the control group (P < 0.05). The salivary pepsin test showed a sensitivity of 85.9% and specificity of 56.9% for diagnosing GERD using the optimal cut-off value of 75ng/mL. One hundred and seven (69.9%) and 46 (30.1%) HGMUE patients were categorized as pepsin (+) and pepsin (-), respectively when 75ng/mL was used as a cut-off value. Male sex, RSI, AET, and proximal acid reflux episodes were positive predictive factors for the occurrence of pepsin (+) in HGMUE patients. GERD, especially GERD with proximal acid reflux and related symptoms, was common in HGMUE patients. The salivary pepsin test could be an additional useful test for testing reflux in HGMUE patients, but it will not replace the MII-pH.

Validation of Peptest™ in Patients with Gastro-Esophageal Reflux Disease and Laryngopharyngeal Reflux Undergoing Impedance Testing

Pepsin in the gastric refluxate is a marker for a prior reflux event and rapid detection might be achieved using the Peptest™, an in vitro diagnostic medical device. The aim of this study was to validate the use of Peptest™ to reliably diagnose reflux in patients with gastro-esophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) disease diagnosed with multichannel intraluminal impedance/ pHmetry (MII-pH). 20 reflux patients were recruited of whom 10 had classical GERD and 10 had LPR. All patients underwent MII-pH and provided expectorated saliva samples when a MII-pH reflux event was observed, or reflux symptoms were experienced, and all were tested for the presence of pepsin using the Peptest™. Pepsin was detected in 31 out of 45 samples (68.9%). At least 1 positive pepsin result was seen in 16 patients (80%) and this was the same, irrespective of the GERD or LPR diagnosis. Peptest™ had a positive predictive value of 69% to detect MII-pH reflux events. Peptest™ is a good first-line diagnostic procedure to use in reflux sufferers to confirm the presence of reflux.

Nasal high-frequency oscillatory ventilation inhibits gastroesophageal reflux in the neonatal period

Nasal high-frequency oscillatory ventilation (nHFOV) in neonates is increasingly considered due to enhanced alveolar ventilation, absence of patient-ventilator asynchrony and lessened ventilator-induced lung injury. Although any type of non-invasive respiratory support can lead to gastric distension via esophageal air passage and thus promote gastroesophageal refluxes (GERs), we have shown that nasal continuous positive airway pressure (CPAP; 6 cmH2O) and intermittent positive pressure ventilation (15/4 cmH2O) conversely inhibit GERs in lambs. The current objective was to test the hypothesis that nHFOV also inhibits GERs compared to spontaneous ventilation without respiratory support. Eight lambs underwent five hours of polysomnographic and esophageal multichannel intraluminal impedance pHmetry recordings to assess GERs and air passage into the esophagus, with and without nHFOV (mean airway pressure = 8 cmH2O, oscillation frequency = 8 Hz, amplitude ≈ 20 cmH2O and I:E = 1:2). Results revealed that GERs were decreased with nHFOV (p = .03), despite an increase in gas-containing swallows (p = .01). In conclusion, similarly to nasal CPAP and intermittent positive pressure ventilation, nHFOV inhibits GERs in newborn lambs.

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.

24-h Multichannel Intraluminal Impedance PH-metry 1Year After Laparocopic Sleeve Gastrectomy: an Objective Assessment of Gastroesophageal Reflux Disease.

It is not yet clear if laparoscopic sleeve gastrectomy (LSG) causes newly onset gastroesophageal reflux (GERD) or worsens already existing GERD. This is due to the absence of prospective studies using objective assessment measures of GERD such as pH monitoring. Our study aims at assessing GERD 1-year post-LSG procedure for obesity. Twelve asymptomatic obese patients were studied prospectively by using 24-h multichannel intraluminal impedance-pHmetry (MIIpH) pre- and 12months post-LSG. Of patients' 1-year post-LSG, 83.33% of patients' suffer from GERD (either newly onset or worsening of already existing) as indicated by abnormal DeMeester score. Mean DeMeester score 1-year post LSG was 47, almost 2.5 times higher than the preoperative score (p=0.072). The percentage of total time with pH lower than four was statistically significant higher postoperatively (13.27% vs 3.87%, p=0.048). This study is one of the few assessing GERD post-LSG by using 24-h MIIpH. The majority of patients suffer from GERD 12months postoperatively, implying that close postoperative monitor for GERD with the use of pH testing and upper gastrointestinal endoscopy in order to early diagnose GERD and identify possible mucosal injury and also a prophylactic proton pump inhibitor use may be of great importance.

Laryngopharyngeal Reflux in Children with Chronic Otitis Media with Effusion.

Background/AimsTo evaluate the characteristic properties of laryngopharyngeal reflux (LPR) and gastroesophageal reflux (GER) in children with otitis media with effusion (OME) using 24-hour multichannel intraluminal impedance combined with dual-probe (pharyngeal and esophageal) pH-metry.MethodsChildren aged 7–10 years of age with OME underwent 24-hour multichannel intraluminal impedance pH-metry. The upper pH sensor was situated 1 cm above the upper esophageal sphincter, and the lower pH sensor was placed 3–5 cm above the lower esophageal sphincter. Parents were asked to complete the gastroesophageal reflux assessment of symptoms in a pediatrics questionnaire.ResultsTwenty-eight children were enrolled; LPR was detected in 19 (67.9%) children. The criteria of the LPR diagnosis was the presence of at least one supraesophageal episode with a pH < 5.0 and a change in the pH value measured from the initial level at the upper sensor of > 0.2. In total, 64 episodes were observed. Assessment of all LPR episodes showed the presence of 246 episodes in the entire study. A considerable predominance of weakly acidic episodes (87.8%) was noted; there were 6.5% acidic episodes, and weakly alkaline episodes reached 5.7%. Pathological GER was noted in 10 (35.7%) subjects. Acid GER was detected in 8 children, 2 of whom demonstrated non-acidic reflux. In the LPR-negative patients, no pathological GER was confirmed with the exception of a single case of non-acidic reflux.ConclusionsLPR was frequently noted in the group of children with OME, and it might be an important risk factor in this common disease.

Inhibitory Effect of Nasal Intermittent Positive Pressure Ventilation on Gastroesophageal Reflux.

Non-invasive intermittent positive pressure ventilation can lead to esophageal insufflations and in turn to gastric distension. The fact that the latter induces transient relaxation of the lower esophageal sphincter implies that it may increase gastroesophageal refluxes. We previously reported that nasal Pressure Support Ventilation (nPSV), contrary to nasal Neurally-Adjusted Ventilatory Assist (nNAVA), triggers active inspiratory laryngeal closure. This suggests that esophageal insufflations are more frequent in nPSV than in nNAVA. The objectives of the present study were to test the hypotheses that: i) gastroesophageal refluxes are increased during nPSV compared to both control condition and nNAVA; ii) esophageal insufflations occur more frequently during nPSV than nNAVA. Polysomnographic recordings and esophageal multichannel intraluminal impedance pHmetry were performed in nine chronically instrumented newborn lambs to study gastroesophageal refluxes, esophageal insufflations, states of alertness, laryngeal closure and respiration. Recordings were repeated without sedation in control condition, nPSV (15/4 cmH2O) and nNAVA (~ 15/4 cmH2O). The number of gastroesophageal refluxes recorded over six hours, expressed as median (interquartile range), decreased during both nPSV (1 (0, 3)) and nNAVA [1 (0, 3)] compared to control condition (5 (3, 10)), (p < 0.05). Meanwhile, the esophageal insufflation index did not differ between nPSV (40 (11, 61) h-1) and nNAVA (10 (9, 56) h-1) (p = 0.8). In conclusion, nPSV and nNAVA similarly inhibit gastroesophageal refluxes in healthy newborn lambs at pressures that do not lead to gastric distension. In addition, the occurrence of esophageal insufflations is not significantly different between nPSV and nNAVA. The strong inhibitory effect of nIPPV on gastroesophageal refluxes appears identical to that reported with nasal continuous positive airway pressure.

"Normal Values of 24H Multichannel Intraluminal Impedance pH-Metry in a Greek Obese Population Based on Montreal Definition of Gerd".

Although several studies reporting normal values of 24h multichannel intraluminal impedance pH (MIIpH) have been published, none of them has ever studied obese individuals. The purpose of this study is to determine overall frequency and duration of reflux episodes (acid and non-acid, supine-upright, post and preprandial) in obese asymptomatic volunteers. Obese volunteers were enlisted during their preoperative evaluation for bariatric surgery. Volunteers had no gastroesophageal reflux disease (GERD) symptoms and no evidence of esophageal mucosal injury on endoscopy. Participants underwent a 24h MIIpH. In this prospective observational study, data of 22 obese individuals were analyzed. Mean age was 41.9 years and mean BMI was 47.1 kg/m(2). Mean total reflux episodes was 55.6 and 95th percentile was 99.7. Mean percentage of total time with pH <4 was 2.59 % and 95th percentile was 8.57 %. Mean percentage of bolus exposure was 1.84 % with 95th percentile being 4.47 %. Postprandial acid reflux episodes were statistical significant more frequent in comparison to preprandial acid reflux episodes (19.41 vs. 15, p = 0.008). Mean acid clearance duration was 3.6 times higher than median bolus clearance duration (56.05 and 15.55 s, respectively, p = 0.868). Our study is the first to provide normal values of 24h MIIpH of asymptomatic obese. Normal values of 24h MIIpH of obese asymptomatic individuals differ from the reported normal values of non-obese healthy individuals; having more reflux episodes and equal or slightly higher median bolus exposure and acid clearance. Our results imply that new cut-off values should be employed in order to define GERD in obese individuals.

Results of Multichannel Intraluminal Impedance pH Metry in Symptomathic Children with Normal pH Metry Findings

A retrospective study was performed to evaluate the results of multichannel intraluminal impedance (MII) pH metry in symptomatic children with normal pH monitoring (PM) findings. Children who have reflux index (RI) less than 4% in PM and recurrent symptoms were included. All children underwent MII. Children who received antireflux treatment with normal PM findings were excluded from the study. MII results were evaluated for RI, content of reflux (acid, weak acid, and alkaline) number and type of impedance events, esophageal bolus clearance time and proximal extent of reflux (PER). Eight patients (age range: 5-13 years) were included to the study. The male female ratio was 5:3. The recurrent symptoms were related with gastrointestinal (n = 5) and upper respiratory system (n = 3). One of the patients was operated for esophageal atresia and one was followed for corrosive esophageal disease. Four of the patients had RI higher than 4% in MII. Patients with normal RI in MII, had weak acid reflux (n: 1), alkaline reflux (n = 1) and no reflux (n = 2). When number of impedance events evaluated, four patients had abnormal reflux episodes (70 or more reflux episodes). Impedance event recordings were correlated in 75% of PM findings. The content of impedance events were mixed and gas in nature. Prolonged esophageal clearance time and PER were detected in patients with chest pain and operated esophageal atresia. MII can be considered as a superior diagnostic tool to detect weak acid and alkaline reflux in patients who had recurrent symptoms with normal PM studies. MII also provides information about bolus clearance time and extent of reflux.

Comparison of oesophageal function in patients with acid and non-acid reflux

Background: Decreased oesophageal motility has been described in patients with GastroOesophageal Reflux Disease (GORD); however it is not clear if this impairment is consequence or cause of increased acid exposure. It is known that non-acid reflux causes symptoms. Non-acid reflux may contain pancreatic enzymes and bile that can also be injurious to the oesophageal motility. Therefore the aim of the present study was to investigate the oesophageal motility of patients with symptomatic reflux that is attributed predominately to non-acid reflux and to compare them with patients with symptomatic acid reflux. Patients and methods: Forty-seven symptomatic patients (age: 43(18 – 73)years; male 18; female: 29) were referred for 24h MII-pH and oesophageal motility testing with suspected GORD or who were refractory to double dose PPI treatment. Each patient underwent upper gastrointestinal endoscopy. Water perfusion oesophageal manometry and combined multichannel intraluminal impedance pH-metry were performed in each person after overnight fasting. Non-acid refluxers were defined by having positive symptom correlation predominantly due to non-acid reflux events with positive Symptom Association Probability (SAP) or positive Symptom Index (SI) without positive acid reflux indices of abnormal % time pH< 4, or positive DeMeester score. Acid refluxers were defined by either having positive reflux indices and/or predominately positive symptom correlation with positive SAP or positive SI with acid reflux events. Results: Forty-five per cent (21/47) patients had non-acid reflux and 55% (26/47) were acid refluxers. Oesophagitis was seen in 7 of the 26 acid refluxers but none in the non-acid refluxer group. Only 1 patient out of 21 of non-acid refluxers, whereas 42% (11/26) of the acid refluxers were diagnosed as having ineffective oesophageal motility, notwithstanding that there were no significant differences between the two groups with respect to peristalsis, lower oesophageal pressures, duration of relaxation, complete bolus transit, distal oesophageal amplitude and velocity. Conclusions: Oesophageal motility of patients with non-acid reflux is predominately normal, while ineffective oesophageal motility is frequently diagnosed in acid reflux. This information on oesophageal function in these patients may be useful when evaluating persistent symptoms and selecting treatment, especially antireflux surgery.

Objective outcomes of extra-esophageal symptoms following laparoscopic total fundoplication by means of combined multichannel intraluminal impedance pH-metry before and after surgery

Identifying and treating patients with extra-esophageal symptoms is a challenge. When the patient is unable to control his symptoms with pharmacological therapy alone, anti-reflux surgery may be indicated. This study aims to evaluate the outcomes of total fundoplication in the resolution of extra-esophageal manifestations and verify changes in 24-h MII-pH monitoring before and after surgery. From October 2005 to October 2010, patients who reported respiratory symptoms, possibly related to GERD, have been sent to our Institute. All patients were practiced ambulatory 24-h MII-pH before and after surgery. Thirty-five patients selected for the antireflux surgery have undergone all the same surgical procedures. Data were collected prospectively at 6 and 12 months after laparoscopic fundoplication. After laparoscopic fundoplication, the total percentage of exposure time with esophageal pH < 4, and both in upright and supine position was very low. A statistically significant difference (p < 0.05) was found in the number of detected refluxes at MII and detected refluxes at MII 15-cm segment in pre and post-operative period. Symptom relief was obtained in all patients. Laparoscopic fundoplication is a safe and effective procedure to protect from refractory GERD and extra-esophageal symptoms, when evaluated with a thorough pre-operative selection.