What is the best method for calculating the optimal position of an esophageal pH probe in children?

In assessment of distal esophageal pH, the sensor of the probe should be placed above the upper border of the lower esophageal sphincter. There are several methods to estimate the distance from the nose where the probe should be fixed according to the patient's height. We studied the accuracy of these methods. Data of patients who underwent esophageal monitoring were collected prospectively. The esophageal pH electrode was set with the aid of fluoroscopy in all cases, considering the location recommended by the current guideline. Esophageal probe position and anthropometric data of each patient were recorded. We compared the actual esophageal pH electrode distance from the nose with that estimated by Nowak's, Strobel's, Staiano-Clouse's, and Moreau's formulae and the Great Ormond Street Hospital (GOSH) table. A total of 98 patients were included, with ages ranging from 2 months to 19 years old. The highest success rate (67%) for all age groups was achieved by Nowak's formula (3.2 + 0.2 × height in cm). Considering only children under 3 years old, the GOSH table reached the highest-yet probably overestimated-fraction of adequate predictions. A corrected Staiano and Clouse's formula (4.28 + 0.191 × height in cm) had a slightly lower success rate than Nowak's due to a poorer performance in younger children. In conclusion, Nowak's formula is the most accurate regardless of age. It can help reduce radiation due to systematic fluoroscopy, as well as the subsequent manipulation of the esophageal probe. However, it still leads to pH sensor misplacements in more than one-third of children. In consequence, a confirmatory X-ray is advisable even after using the formula.

Analyses of the relationship between a 'number of reflux episodes' exceeding 70 and the pH index in neurologically impaired children by evaluating esophageal combined pH-multichannel intraluminal impedance measurements.

BACKGROUND: The present study aimed to evaluate the characteristics associated with a number of reflux episodes (NoRE) of 70 by comparing the clinical and multichannel intraluminal impedance pH measurements (pH/MII) and pH index (pHI) in neurologically impaired (NI) children. PATIENTS AND METHODS: NI children (1-16 years of age) in whom pH/MII had been measured for GERD study were enrolled in this study. All children were divided into NoRE >70 or ≤70 and pHI >4.0 or ≤4.0, >5.0 or ≤5.0 or >7.0 or ≤7.0. In addition, the NI children with pHI >4.0, >5.0 and >7.0 were subdivided into NoRE >70 and ≤70 groups. The clinical and pH/MII measurements were compared between each of the two groups. The cutoff values of pHI and baseline impedance (BI) (Z6) were calculated to discriminate NoRE >70 and ≤70. RESULTS: A total of 61 NI children were enrolled in this study. There was a significant difference in the acid-related parameters, the NoRE (nonacid) and BI between NoRE >70 and ≤70, acid-related parameters and BI between pHI >4.0 and ≤4.0, >5.0 and ≤5.0 and >7.0 and ≤7.0 groups. Furthermore, a significant difference was still observed in the BI between NoRE >70 and ≤70 groups among patients with pHI >4.0, >5.0 or >7.0. The cutoff values of pHI and BI (Z6) for discriminating NoRE >70 and ≤70 were 9.2 and 1049Ω, respectively. CONCLUSION: The present study indicates that NoRE 70 corresponds to GERD in which patients suffer severe acid exposure with pH of around 9% and esophageal mucosal damage with low BI value in NI children.

Correlation of sleep-disordered breathing and laryngopharyngeal reflux: a two-channel triple-sensor pHmetry catheter study.

PURPOSE: To investigate the relationship between sleep-disordered breathing with gastroesophageal reflux (GER) and laryngopharyngeal reflux (LPR) using a two-channel triple-sensor pHmetry catheter. METHODS: The study was carried out on a total of 34 people with complaints of snoring, witnessed apnea and daytime sleepiness. 24-h pH monitoring with a two-channel, triple-sensor antimony pH catheter was applied to individuals simultaneously with polysomnography (PSG) on the day they would sleep in the sleep laboratory. Obstructive sleep apnea syndrome (OSAS) severity and reflux grade were compared with each other. Data obtained from PSG and pHmetry results were numerically compared with each other. The relationship between apnea, hypopnea, and arousal periods and reflux episodes was then examined by overlaying pHmetry graphics for each patient. RESULTS: A total of 34 individuals (18 males-52.9% and 16 females-47.1%), age ranging from 27 to 71 years (mean 50.5 ± 11.0) participated in the study. GER was detected in 52.9% and LPR in 85.3% of the patients. In 35.3% of cases, pathologic GER was not observed despite LPR detection. No statistically significant relationship was found between the numerical values of apnea-hypopnea index (AHI) and arousal numbers and reflux parameters of individuals and between OSAS severity and LPR and GER (p > 0.05). There was no statistically significant correlation between respiratory events and reflux episodes with regard to timing (p > 0.05). CONCLUSION: The prevalence of GER and LPR is found to be high in patients with sleep-disordered breathing. There is no significant relationship between OSAS severity and GER and LPR grade or respiratory events and reflux episodes with regard to timing.

Sedation and Afternoon Placement of the 48-Hour Wireless Ambulatory pH Capsule Results in More Reflux on the First Day.

BACKGROUND: A 48-hour wireless capsule results often vary from the first to second day. Previous investigations comparing discrepant acid reflux readings have yielded variable results. In this study we investigated differences in data obtained on day 1 versus day 2, and the effect of time of capsule placement on discrepancies. METHODS: We performed a retrospective cohort study. Patients undergoing a 48-hour wireless capsule study between January 2012 through November 2013 were eligible for inclusion. We collected reflux data for each patient and calculated the proportion of patients in four groups based on abnormal DeMeester score groups (+/+, -/+, +/-, -/-). We placed patients into morning placement or afternoon placement categories and calculated the proportions of patients with various DeMeester score discrepancies. KEY RESULTS: This study evaluated 229 patients. The mean day 1 DeMeester score was 28.38 and the mean day 2 DeMeester score was 23.24 (P<0.0001). The mean day 1 DeMeester score in the morning group was 24.9 and 31.7 in the afternoon group (P<0.05). The mean total DeMeester score in the morning placement group was 23.1 and 30.6 in the afternoon group (P<0.05). Twenty-five percent of afternoon patients had a +day 1/-day 2 DeMeester discordance, whereas only 12% of morning placement patients had this discordance (P=0.26). CONCLUSIONS: Afternoon capsule placement is associated with a significantly increased amount of acid reflux on day 1. Approximately 10% of 48-hour esophageal wireless monitoring studies may falsely overestimate reflux when the capsule is placed in the afternoon. Capsule placement should ideally be performed in the morning.

Safety and Efficacy of Wireless pH Monitoring in Patients Suspected of Gastroesophageal Reflux Disease: A Systematic Review.

INTRODUCTION: The primary aim of this systematic review was to determine the safety, technical efficacy, and effectiveness of 48-hour wireless pH monitoring (WM) for gastroesophageal reflux disease (GERD), compared with no pH monitoring in patients who failed to tolerate a catheter. In the absence of eligible studies, the secondary aim was to determine these performance characteristics for WM relative to catheter-based pH monitoring (CBM) in patients suspected of GERD, who are able to tolerate a catheter. METHODS: A protocol was registered on the PROSPERO database (CRD42013005852) before conducting the systematic review, which included the study selection criteria, and critical appraisal methods. Several key databases were searched to identify eligible comparative studies. RESULTS: Chest pain occurred more often with WM compared with CBM; however, other adverse events were reported less frequently with WM. Technical failures, mostly due to attachment failures and early capsule detachments, were 3 times higher with WM, compared with CBM, [pooled relative risk (from meta-analysis)=3.3; 95% confidence interval, 1.63-6.81; I=0%; P=0.012; k=8). The sensitivity and specificity of WM varied widely, depending on type of analysis, monitoring time, capsule placement, reference standard, and diagnostic threshold. DISCUSSION: WM is usually better tolerated than CBM but has more technical problems. Test accuracy was highly variable between studies; therefore, conclusions could not be drawn regarding the performance of the 2 tests. To make meaningful comparisons between WM and CBM a consensus is needed on the diagnostic threshold for GERD, monitoring time, appropriate capsule positioning, and the reference standard.

Two years' experience of using the Bravo wireless oesophageal pH monitoring system at a single UK tertiary centre.

AIM: The Bravo wireless pH monitoring system enables oesophageal pH to be monitored in children intolerant to nasal catheters and records measurements over 48 hours. This study aimed to document the minimum child weight that enabled successful capsule placement and any associated complications. We also compared the diagnostic sensitivity of 48 hours versus 24 hours. METHODS: We included 203 consecutive patients (122 male children) with clinically documented or suspected reflux symptoms. The age range was two years to 19 years, and the minimum weight was 9.29 kg. The pH capsule was deployed endoscopically under general anaesthetic. Recordings taken over 24 and 48 hours were compared to determine the frequency of differences and correlations in the reflux index and DeMeester scores. RESULTS: Testing using the detached probe was successful in 190 children (93.6%) with weight as low as 9.29 kg, with no side effects, with failed deployment being the most frequent problem. Clinically different results in the reflux index were found in 16% of the children's day 1 or day 2 readings (p < 0.0001), suggesting the benefit of 48-hour measurements. CONCLUSION: Measuring oesophageal pH with the Bravo wireless pH monitoring system was successful in 93.6% of cases. A 48-hour test improved the detection rate of gastro-oesophageal reflux disease by 16%.

Long-term wireless pH monitoring of the distal esophagus: prolonging the test beyond 48 hours is unnecessary and may be misleading.

Wireless pH monitoring of the esophagus has been widely used to detect GERD for more than a decade. It is generally well tolerated and accepted by patients, but it is still unclear whether prolonging a recording beyond the usual 48 hours can improve the test's diagnostic value. The aim of this study is to examine the diagnostic yield of 96-hour pH monitoring vis-à-vis 24- and 48-hour tests, and to ascertain whether any gain in diagnostic terms was of genuine clinical utility. Patients with suspected GERD underwent 4-day PPI-off wireless pH monitoring of the distal esophagus. The capsule was inserted under endoscopic control, 6 cm above the squamocolumnar junction. Average acid exposure time was calculated after 24, 48, and 96 hours of recording. Ninety-nine patients completed the 96 hour test, and formed the study sample. The wireless test method was used in 42 patients (42.4%) unable to tolerate the traditional pH-monitoring catheter, and in 57 (57.6%) with a previous negative pH study despite symptoms suggestive of GERD. On complete analysis, 47 patients (47.5%) had a pathological test result: 19 patients within the first 24 hours (19.2%, 24 hour group); another 16 after 48 hours (+16.2%, 48 hour group), and a further 12 (+12.1%, 96 hour group) only after 96 hours of monitoring. All 47 patients with an abnormal acid exposure were offered and accepted surgery (10 patients) or medical therapy (37 patients). Clinical follow-up was obtained in all patients with a positive Bravo test result after a median 67 months (IQR: 38-98) using a validated symptom questionnaire. A good outcome after fundoplication or medical therapy was achieved in 73.7% of patients in the 24 hour group, in 62.5% of those in the 48 hour group, and in only 25% of those in the 96 hour group, P = 0.02. Long-term wireless pH monitoring enables an increase in the diagnostic yield over traditional 24- and 48-hour pH studies, but prolonging the test may constitute an unwanted bias and prompt the recruitment of more complex patients, in whom the outcome of surgical or medical therapy may prove less than satisfactory. These findings should be taken into account when establishing the guidelines for assessing GERD with such long-term pH monitoring methods.

Interference with daily activities and major adverse events during esophageal pH monitoring with bravo wireless capsule versus conventional intranasal catheter: a systematic review of randomized controlled trials.

For three decades, ambulatory 24-hour intranasal pH monitoring has been the established gold standard for detecting acid reflux in patients with refractory gastroesophageal reflux disease. However, device-associated adverse events and unpleasant experiences, reported by patients during pH monitoring have led to the invention of more convenient pH monitors such as Bravo wireless capsule. To compare the interference with daily activities and major adverse events during pH monitoring with Bravo wireless capsule (Bravo) versus conventional intranasal catheter (catheter), PubMed, Cochrane Library, Clinical Trials.gov, and Google Scholar were searched up to March 20, 2015. Only randomized controlled trials in adult patients that compared the interference with routine daily activities and adverse events between Bravo and catheter pH monitors were included. After screening 574 articles, three unique studies with 167 patients met our inclusion criteria. The average age of patients enrolled in these studies was 51 years. Interference with normal daily activities was more in the catheter than Bravo group: 75 ± 5 versus 92 ± 2, P < 0.001 (Andrews et al, findings were reported as100 mm, mean visual analogue scale (VAS) ± standard error of the mean, 100 = completely normal); Wong et al. (mean ± standard error of the mean): 1.3 ± 0.2 versus 0.32 ± 0.1, P = 0.001 and Wenner et al. using 10 cm median VAS (Interquartile range),10 been the worst is 5.7 (2.3-8.0) compared to 0.7 (0.2-3.4), P < 0.0001, respectively. Overall adverse events were more in the catheter group than Bravo (39 ± 4 vs. 26 ± 4, P = 0.012 for Andrews et al. (100 been the worst) and 5.1 (2.0-6.6) vs. 2.1 (0.5-4.6), P < 0.001 for Wenner et al.). No overall adverse events recorded for Wong et al. Most patients in catheter group complained of nasal and throat symptoms. Significantly, runny nose in 24 out of 25 patients (96%) catheter versus 13 out of 25 (52%) Bravo, P = 0.001 and nose pain 15 out 25 (60%) versus 8 out of 25 patients (32%), P = 0.047, respectively for Wong et al. Andrews and Wenner et al also showed profound nasal discomforts in catheter group compared to Bravo (39 ± 3 vs. 10 ± 3, P < 0.001 and 6.5 (1.5-8.0) versus 0.2 (0.0-1.9), P < 0.0001, respectively. Throat symptoms reported in Wong et al. were mainly throat discomfort in catheter group 23 out of 25 patients (92%) versus Bravo 12 out of 25 (48%), P = 0.001 and throat pain catheter (12 out of 25 patients (48%) vs. Bravo 4 out of 25 (16%)), P = 0.032. This trend was also observed in Andrews et al. with profound throat discomfort in the catheter group 43 ± 4 compared to Bravo 19 ± 4, P < 0.001. Majority of the patients randomized to Bravo group reportedly perceived chest pain higher than those in catheter group; 9 out of 25 patients (36%) versus 2 out of 25 (8%), P = 0.037 in Wong et al. 29 ± 4 versus 14 ± 3, P = 0.001 for Andrews et al., 2.4 (0.3-5.9) versus 1.1 (0.3-2.9), P = 0.084 in Wenner et al. respectively (though not statistically significant). Bravo wireless capsule pH monitor interfered less with daily activities and adverse events were minimal compared to conventional intranasal catheter.

Accuracy of the Air Flow Sphincter Locator system in identifying the lower esophageal sphincter for placement of pH catheters.

The Air Flow Sphincter Locator (AFSL) is marketed as an alternative method to manometry for localizing the lower esophageal sphincter (LES) for pH probe placement. Such a system is desirable due to the additional time, cost, and discomfort associated with dual nasal intubation, but its accuracy has never been assessed. To assess the accuracy of the AFSL in localizing the LES. Fifty consecutive outpatients presenting for pH and manometry studies were included. The upper border of the LES was determined using HRM and the AFSL by two technicians independently. LES locations measured by technicians using AFSL versus manometry, as well as the manometrically determined LES locations by technicians versus MDs were compared. Differences in LES locations determined by HRM as read by MDs versus technicians were small; none were >3 cm, and 92% were within 2 cm. Comparison between LES locations determined by technicians using HRM versus the AFSL revealed that 52% had a difference of 2-3cm and 32% had a difference of >3 cm. Hiatal hernia was associated with a difference in LES location of >3 cm. Excluding patients with hiatal hernia, nonetheless, still produced a >3 cm difference in 24% of studies. Prior reports have suggested that a difference greater than +/-3 cm in pH probe placement is considered unacceptable for clinical studies. Based on our study, the AFSL placed the LES outside of this range in 32% of patients, and may be particularly inaccurate in the setting of a hiatal hernia. This suggests that the device may not be an acceptable alternative to manometry in determining LES location for pH probe placement.

Continuous 48-Hour Wireless Esophageal pH Monitoring in Children: Comparison Between Days 1 and 2.

AIM: Comparison of days 1 and 2 to each other and to the total recording of 48 hours in continuous 48-hour wireless esophageal pH monitoring in children. METHODS: A retrospective study of 105 patients who underwent 48-hour pH monitoring (Bravo) studies between January 1992 and June 2010 was performed. Reflux variables were compared between days 1 and 2. RESULTS: A total of 58 (55.2%) patients were men. The number of reflux episodes, number of long reflux >5 minutes, duration of the longest reflux (minutes), time pH <4 (minutes), fraction time pH <4 supine (%), fraction time pH <4 upright (%), reflux index, and DeMeester score did not differ between days 1 and 2. CONCLUSIONS: No effect of anesthesia was observed on the gastroesophageal reflux parameters on children.

Implementation of objective activity monitoring to supplement the interpretation of ambulatory esophageal PH investigations.

Conventional catheter-based systems used for ambulatory esophageal pH monitoring have been reported to affect patient behavior. As physical activity has been associated with gastroesophageal reflux disease (GERD), there is a risk that abnormal behavior will degrade the value of this diagnostic investigation and consequent management strategies. The aim of this study was to quantify the effect of conventional pH monitoring on behavior and to investigate the temporal association between activity and reflux. A total of 20 patients listed for 24 hours pH monitoring underwent activity monitoring using a lightweight ear-worn accelerometer (e-AR sensor, Imperial College London) 2 days prior to, and during their investigation. PH was measured and recorded using a conventional nasogastric catheter and waist-worn receiver. Daily activity levels, including subject-specific activity intensity quartiles, were calculated and compared. Physical activity was added to the standard pH output to supplement interpretation. Average patient activity levels decreased by 26.5% during pH monitoring (range -4.5 to 51.0%, P = 0.036). High-intensity activity decreased by 24.4% (range -4.0 to 75.6%, P = 0.036), and restful activity increased on average by 34% although this failed to reach statistical significance (-24.0 to 289.2%, P = 0.161). Some patients exhibited consistent associations between bouts of activity and acidic episodes. The results of this study support the previously reported reduction in activity during ambulatory esophageal pH monitoring, with the added reliability of objective data. In the absence of more pervasive pH monitoring systems (e.g. wireless), quantifying activity changes in the setting of activity-induced reflux might guide the physicians' interpretation of patient DeMeester scores resulting in more appropriate management of GERD.

Esophageal pH Monitoring in Children: A Simple Mathematical Formula for pH Probe Positioning.

Correct pH probe placement is vital for the precision of esophageal pH monitoring. This study aimed at finding the optimal formula for placement of pH probe in the locus proposed by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition European Pediatric Impedance Working Group, that is, 2 vertebrae above the diaphragm. An analysis of data regarding 353 children ages 0-18 years in whom the position of the pH sensor was determined radiographically revealed that a mathematical formula (3.2 + 0.2 × body length or height, centimeter) could guide the probe to within 1/12 of thoracic spine length of the desired location in 71.7% of all of the patients.

24-h multichannel intraluminal impedance-pH monitoring may be an inadequate test for detecting gastroesophageal reflux in patients with mixed typical and atypical symptoms.

BACKGROUND: The detection of gastroesophageal reflux (GERD) via pH testing is the key component of the evaluation of patients considered for antireflux surgery. Two common pH testing systems exist, a multichannel, intraluminal impedance-pH monitoring (MII-pH) catheter, and wireless (Bravo(®)) capsule; however, discrepancies between the two systems exist. In patients with atypical symptoms, MII-pH catheter is often used preferentially. We aimed to elucidate the magnitude of this discrepancy and to assess the diagnostic value of MII-pH and the Bravo wireless capsule in a population of patients with mixed respiratory and typical symptoms. METHODS: The study population consisted of 66 patients tested with MII-pH and Bravo pH testing within 90 days between July 2009 and 2013. All patients presented with laryngo-pharyngo-respiratory (LPR) symptoms. Patient demographics, symptomatology, manometric and endoscopic findings, and pH monitoring parameters were analyzed. Patients were divided into four comparison groups: both pH tests positive, MII-pH negative/Bravo positive, MII-pH positive/Bravo negative, and both pH tests negative. RESULTS: Nearly half of the patients (44%) had discordant pH test results. Of these, 90% (26/29) had a negative MII-pH but positive Bravo study. In this group, the difference in the DeMeester score was large, a median of 29.3. These patients had a higher BMI (28.5 vs. 26.1, p = 0.0357), were more likely to complain of heartburn (50 vs. 23%, p = 0.0110), to have a hiatal hernia, (85 vs. 53%, p = 0.0075) and a structurally defective lower esophageal sphincter (LES, 85 vs. 58%, p = 0.0208). CONCLUSIONS: In patients with LPR symptoms, we found a high prevalence of discordant esophageal pH results, most commonly a negative MII-pH catheter and positive Bravo. As these patients exhibited characteristics consistent with GERD (heartburn, defective LES, hiatal hernia), the Bravo results are likely true. A 24-h MII-pH catheter study may be inadequate to diagnose GERD in this patient population.

Clinical value of wireless pH-monitoring of gastro-esophageal reflux in children before and after proton pump inhibitors.

BACKGROUND: Wireless pH-monitoring is an accurate method for diagnosing adults with gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the use of the Bravo capsule on children investigated for GERD in terms of safety, tolerability and feasibility before and after administration of proton pump inhibitors. METHODS: A Bravo capsule was inserted during upper endoscopy under general anaesthesia or deep sedation with propofol. 48-hour pH-metry was performed in 106 children (50 males, 56 females) at the median age of 11 years (range 17 months-18 years). On the second day of investigation, proton pump inhibitor (PPI) was given at a mean dose of 1.6 mg/kg (SD ±0.6 mg). The definition of GERD was set to a reflux index (RI) of ≥5% and DeMeester score (DMS) ≥14.7. RESULTS: Application of the capsule was successful in 103 of the 106 children (97.2%) and interpretable in 99 of these 103 (96.1%). 49 of the children with interpretable results (49.5%) had GERD according to RI, while 51 (56.7%) had GERD according to DMS. After PPI was given on day 2, RI decreased from a median of 4.9% (range 0.3-63.4%) to 2.2% (0-58.0%), while DMS decreased from a median of 17.6 (range 2.2-207.6) to 8.2 (0.3-178.6), respectively (p < 0.0001). No severe adverse events were reported. CONCLUSION: Wireless pH-metry is a safe and tolerable method when investigating children for GERD. PPI given on the second day of assessment provides additional information on response to treatment suggesting that pH-metry preferably should be extended to 48 hours.

Wireless 'mini' multichannel intraluminal impedance-pH: what is the optimal design of a miniature wireless device?

Catheter-based methods for multichannel intraluminal impedance-pH monitoring are invasive and uncomfortable. The current alternative is a wireless system that clips to the esophageal mucosa, but which only measures pH. A shorter two-site wireless sensor that detects impedance and pH, and can be clipped to the esophagus, would be desirable. This study compares sensor positions and separations to determine the optimal configuration of a two-site wireless sensor. Records of 20 patients (10 on and 10 off proton pump inhibitor) who had ambulatory reflux testing with a multichannel intraluminal impedance-pH system (Sandhill Scientific Inc., Highlands Ranch, CO, USA) with six impedance and two pH sensors were reviewed. An investigator was blinded to four combinations of impedance channels plus pH. He read a 3-hour postprandial section from each of the combinations (total of 80 studies) and marked reflux episodes. Results were compared with his own interpretation of the full tracing. Two hundred and two total reflux episodes were analyzed, 113 acid (pH < 4) and 89 nonacid (pH > 4). Mean and median numbers of total reflux episodes were calculated. In the full study, the interpreter detected a mean of 10 reflux episodes per study. In the 5 cm and 7 cm, 3 cm and 7 cm, and 3 cm and 5 cm studies, the interpreter found a mean of 8.1, 11.1, and 9.8 reflux episodes per study, respectively. One-way analysis of variance yielded a P-value of 0.43. The trend of these preliminary findings suggests that the 3 cm and 5 cm site is the most sensitive and the 5 cm and 7 cm is the least, with the 3 cm and 7 cm site perhaps as the preferred location. The lack of a significant difference, at the very least, suggests that any of the 'mini' locations could be used. The small number of observations could have resulted in a Type II statistical error.

Can multichannel intraluminal pH-impedance monitoring be limited to 3 hours? Comparison between ambulatory 24-hour and post-prandial 3-hour recording.

Esophageal multichannel intraluminal pH-impedance recording (MII) is now a valid technique for determining the acidic, liquid, gas or mixed nature of gastroesophageal reflux episodes. However, some recordings may stop prematurely due to technical reasons or poor patient tolerance of the probe. Therefore, we questioned whether analysis of post-prandial 3-hour recording could predict the results obtained in ambulatory 24-hour recording. Fifty patients with symptoms of gastroesophageal reflux disease were investigated. For each patient, post-prandial 3-hour MII was recorded after a test meal, then followed by ambulatory 21-hour MII. Correlation between the total number of liquid reflux events in the 3-hour and 24-hour recordings was elevated (R=0.71; P<0.001), with better correlation for acid (R=0.80; P<0.001) and weak acid reflux (R=0.56; P<0.001) than non-acid reflux (R=0.44; P<0.01). Sensitivity and specificity of 3-hour recording in detecting elevated liquid reflux over 24 hours (id>75reflux/24 h) were 49% and 100%, respectively, for 8 or less liquid/mixed reflux events per 3 hours, and 78% and 88%, respectively for 15 or more liquid/mixed reflux events per 3 hours. The sensitivity and specificity of symptom association probability (SAP) calculated over 3 hours were 56% and 91%, respectively. In conclusion, we identified relevant indicators on the 3-hour post-prandial recording likely to give accurate prediction of absence or presence of gastroesophageal reflux disease from 24-hour MII recording.

[The diagnostic impact and limitations of 24 hour pH monitoring with multichannel intraluminal impedance]. / Znaczenie diagnostyczne i ograniczenia 24 godzinnej pH-metrii przelyku z impedancja.

Gastroesophageal reflux disease (GERD) is a result of reflux of gastric contents into the esophagus. Gastroscopy is often the first examination performed in GERD diagnosis. Some patients have macroscopic lesions, namely erosions, in the esophagus above the cardia of stomach. It enables to diagnose gastroesophageal reflux disease. However, many patients have no macroscopic lesions of the esophageal mucosa in endoscopy. That is why 24-hour pH monitoring with multichannel intraluminal impedance is the gold standard in diagnosis establishing of GERD and make feasible to distinguish acid, weakly acid and nonacid reflux and its correlation with reported symptoms. Impedance-pH is used to establish diagnosis of GERD, in patient qualification to anti-reflux surgery, to find the cause of not efficient reflux disease treatment as well as the cause of extra-esophageal symptoms of reflux disease. During impedance-pH test catheter connected with the recorder is placed in patient's esophagus. Recorded data is analyzed with the computer program. The examination is safe, the only complication that can occur is nasal bleeding, which can be a result of mucosa damage caused while catheter implementation. Nowadays disposable catheters are used, that excludes the risk of catheter related infection. On the basis of pH-impedance results it is possible to divide patients into 3 groups: patients with functional heartburn, patients with esophageal hypersensitivity and abnormal esophageal acid exposure. This classification is very helpful in the choice of treatment - antireflux surgery, proton pump inhibitor or prokinetic therapy.

Batteryless implantable dual-sensor capsule for esophageal reflux monitoring.

BACKGROUND: Chronic GERD affects approximately 15% of adults in the United States and is one of the most prevalent clinical conditions involving the GI tract. The commercial tools for monitoring GERD include multichannel intraluminal impedance (MII) probes and pH-sensing capsules. However, MII probes cause discomfort, which alters patients' regular activities, whereas the pH-sensing capsule lacks the ability to detect weak or nonacid episodes, misses reflux episodes with similar pH values, and has a limited sampling rate and battery life. OBJECTIVE: To develop and test an implantable batteryless dual-sensor capsule that can be used to diagnose and monitor GERD. DESIGN: The implanted capsule is wirelessly powered by an external device. Simulated reflux episodes were created in 3 live porcine models. Impedance and pH data were continuously measured and recorded. INTERVENTION: The implant capsule was placed in the esophagus along with a commercial pH-sensing capsule for comparison. MAIN OUTCOME MEASUREMENTS: Precise impedance and pH readouts were obtained and compared with those from a commercial pH-sensing capsule. RESULTS: The wireless energy supplied by the external unit was strong enough to power the implant. The pH sensor accurately measured pH levels and the impedance sensor precisely located the reflux episodes. LIMITATION: Simulated reflux events in a pig model. CONCLUSION: Our wireless sensors are reliable in operation and provide accurate assessment of simulated reflux episodes. The entire device can potentially be used to diagnose and monitor GERD.

Clinical utility and tolerability of JSPH-1 wireless esophageal pH monitoring system.

BACKGROUND: Wireless esophageal pH monitoring system is an important approach for diagnosis of gastroesophageal reflux disease (GERD), the aim of this study is to test the tolerability and utility of the first wireless esophageal pH monitoring system made in China, and evaluate whether it is feasible for clinical application to diagnose GERD. METHODS: Thirty patients from Department of Gastroenterology of The First Affiliated Hospital of Chongqing Medical University who were suspected GERD underwent JSPH-1 pH capsule. The capsule was placed 5 cm proximal to the squamocolumnar junction (SCJ) by endoscopic determination, the data was recorded consecutively for 48 hours. Then all pH data was downloaded to a computer for analysis. The discomforts reported by patients were recorded. RESULTS: 30 patients were placed JSPH-1 pH capsule successfully and completed 24-hour data recording, 29 patients completed 48-hour data recording. One patient complained of chest pain and required endoscopic removal. No complications and interference of daily activities were reported during data monitoring or follow-up period. 48-hour pH monitoring detected 15 patients of abnormal acid exposure, on day1 detected 9 patients, the difference had statistical significance (P<0.01). Positive symptom index (SI) was identified in 3 patients with normal pH data in both 24-hours. In total, 48-hour monitoring increased diagnosis of GERD in 9 patients. CONCLUSION: 48-hour esophageal pH monitoring with JSPH-1 wireless pH monitoring system is safe, well tolerated and effective. It can be feasible for clinical application to diagnose GERD.