Total Reflux Research Articles

Hydrophilic modification of packings for water distillation and its mass transfer performance

Water distillation is proved to be an effective method for the recovery of tritium from nuclear power plant drainage. In addition to the geometry and material, the surface wettability of the internals also affects the mass transfer performance of the packings. In this paper, we prepared a superhydrophilic coating on the surface of copper packings by a simple method, to increase the intensity of gas-liquid interface, and thus intensifying the heterogeneous mass transfer process. Scanning electron microscopy, atomic force microscopy, X-ray diffraction and X-ray photoelectron spectroscopy were employed to study the physical and chemical condition changes of the packings surface. Measured by ultraviolet fluorescence imaging technology, the wetted area of the copper wire mesh corrugated packing increased by 58.0 % ∼ 91.2 %. The mass transfer performance for separating H2O-HTO mixture with tritium activity of 12.9 MBq/kg is conducted in the total reflux mode distillation column. With varied measured conditions, the height equivalent of theoretical plate (HETP) drops from 3.5 ∼ 5.8 cm to 1.9 ∼ 2.4 cm after the packing surface modification, which indicates that the mass transfer performance has been sufficiently improved.

The Prevalence of Esophageal Disorders Among Voice Patients With Laryngopharyngeal Reflux—A Retrospective Study

The goal of this study was to determine the prevalence of esophageal disorders among voice patients with intractable laryngopharyngeal reflux (LPR) who have undergone 24 pH impedance and esophageal manometry. A retrospective chart review was performed of patients with LPR-associated dysphonia in the absence of subjective dysphagia who presented between January 1, 2007 and June 30, 2019 and underwent 24 pH impedance and esophageal manometry studies after inadequate response to lifestyle modifications, high dose of Proton Pump Inhibitor (PPIs), H2 blockers, alkaline water, and Gaviscon (GlaxoSmithKline, Warren, NJ, USA). The comorbidities, medications, Strobovideolaryngoscopy findings, 24 pH impedance, and esophageal manometry results were analyzed. The study included 109 patients ages 19 to 80 years old, with a mean age of 51.5 (SD 16.8). About 24.8% of the 109 subjects were found to have peristaltic wave abnormalities indicating esophageal dysmotility (11% with esophageal stasis). Lower esophageal sphincter pressures were normotensive in 56.9% of patients, hypertensive in 24.8%, and hypotensive in 18.4% of patients. In addition, the upper esophageal sphincter pressures were normotensive in 57.8% of patients, hypertensive in 36.7%, and hypotensive in 2.8% of patients. About 12.6% had both lower esophageal sphincter and upper esophageal sphincter dysfunction (hypertensive or hypotensive). The average total reflux events in patients exhibiting dysmotility on manometry 101.81, which was significantly higher compared with the mean total of 61.28 in the group of patients without dysmotility (P= 0.0396). In addition, there was a significantly higher prevalence of total events that were weakly acidic in the group with dysmotility compared with the group without (all patients performed the study on reflux medications, mean of total weakly acidic events 70.2 in dysmotility group vs 44.2 in normal motility group, P= 0.0427).Finally, the average number of total supine reflux events and the total acidic supine events were both significantly higher in the dysmotility group compared with the group without motility problems (P = 0.0199 and P = 0.0213, respectively). Esophageal dysmotility may be a significant cofactor in voice patients with refractory LPR on appropriate reflux medications and lifestyle modifications. Further research is advised.

Postreflux swallow-induced peristaltic wave index from pH-impedance monitoring associates with esophageal body motility and esophageal acid burden.

Postreflux swallow-induced peristaltic wave (PSPW) on pH-impedance monitoring and contraction vigor on high-resolution manometry (HRM) both assess esophageal peristaltic response. We aimed to evaluate relationships between PSPW and esophageal peristalsis on HRM in the context of reflux disease in this multicenter cohort study. pH-impedance and HRM studies performed on patients with persisting reflux symptoms were reviewed from 6 centers (5 in Europe and 1 in US). Total, upright and supine acid exposure time (AET) were evaluated from pH-impedance studies; PSPW index (PSPWI) and mean nocturnal baseline impedance (MNBI) were calculated using standard methodology. Esophageal body contraction vigor was analyzed using distal contractile integral (DCI), and DCI ratio>1 between single swallows and multiple rapid swallows (MRS) defined presence of contraction reserve. Student's t test, ANOVA, and linear regression were utilized to investigate relationships between PSPW, contraction vigor, and contraction reserve. Of 296 patients (52.8±0.8yr, 63% F), median PSPWI was 0.475. Only 24.0% had intact DCI; the remainder had varying degrees of hypomotility. As hypomotility increased, PSPWI and MNBI decreased significantly, while total AET and reflux episodes had an inverse response (P≤.002 for each). MRS data were available in 167 (56.4%), 72.5% had contraction reserve. MRS cohorts with normal PSPWI had significantly lower reflux burden compared to low PSPWI, regardless of presence or absence of contraction reserve (P≤.001). PSPWI correlates with esophageal hypomotility and reflux burden, and complements clinical reflux evaluation. Intact PSPW is more relevant to esophageal reflux clearance than contraction reserve.

Evaluation of reboiler temperature retention time on MEG degradation products at varying MEG concentrations

Mono ethylene glycol (MEG) has been used as a thermodynamic hydrate inhibitor in the gas industry. Due to its high usage, recoverability and environmental impact, MEG is regenerated instead of releasing to the environment. During the regeneration (distillation) process, MEG is exposed to higher temperatures in the reboiler to remove surplus water. When exposed to high temperatures, MEG thermal degradation process can occur due to dissociation to organic acids including glycolic, acetic and formic acids. A batch distillation system was utilised in total reflux mode at different reboiler temperatures retention times for up to 18 h in a span of 3 h and MEG concentrations of 80.8, 70.3, 63.1, 51.0 and 40.2 vol percentage (vol %) with corresponding reboiler testing temperatures of 118.0, 113.2, 108.8, 104.2 and 102.5 °C, respectively. The objective of this experimental work focuses on determining the MEG degradation products i.e. organic acids, accumulation in the MEG regeneration system. The degradation products were analysed using Ion Chromatography (IC) technique at the Curtin Corrosion Centre (CCC) laboratory, Perth, Western Australia.The experimental results indicate that there is an increasing trend of the MEG degradation products at higher boiling point temperatures for higher MEG concentrations in comparison to the lower MEG concentrations. Moreover, organic acids accumulation in the reboiler was evident at longer reboiler retention time durations of 18 h. The findings of this study conclude that it is preferable to operate the reboiler at lower MEG concentrations levels of 40.2 vol % and at reboiler retention time of 3 h to decrease the likelihood of the MEG degradation products. The percentage increase of the total organic acids at 40.2 vol % was found to be 27.7% as compared to 32.6% at 80.8 vol %. This study is beneficial to the oil and gas industry as it proposes the percentage amount of MEG to be used for hydrate inhibition in order to minimize the production of organic acids. High levels of organic acids accumulation in the regenerated lean lowers the efficiency of MEG thermodynamic inhibition performance.

Esophageal Pathophysiologic Changes and Adenocarcinoma After Bariatric Surgery: A Systematic Review and Meta-Analysis.

INTRODUCTION:To assess the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on acid reflux and esophageal motor function and to evaluate the observation of esophageal adenocarcinoma (EAC) after bariatric surgery.METHODS:We searched 5 databases for adults who underwent SG or RYGB and had esophageal pH test and/or esophageal manometry before and after surgery. A separate systemic search of observational studies and a retrospective review at 3 institutions of adults who developed EAC after these surgeries were conducted. Outcomes were changes in manometric and pH parameters and EAC cases after SG and RYGB.RESULTS:A total of 27 nonrandomized studies (SG: 612 patients; RYGB: 470 patients) were included. After SG, lower esophageal sphincter pressure and esophageal body amplitude were decreased and the risk of ineffective esophageal motility was increased. Total and recumbent acid exposure times were increased. After RYGB, an increased risk of ineffective esophageal motility was observed. Total, upright, and recumbent acid exposure times were decreased. The total reflux episodes remained unchanged but with increased nonacid reflux and decreased acid reflux events. Including our largest series, 31 EAC cases have been reported to date after SG and RYGB.DISCUSSION:This systematic review demonstrates increased acid reflux after SG and decreased acid reflux after RYGB. An observed increased nonacid reflux after RYGB might contribute to failure of gastroesophageal reflux disease improvement. This refluxate might be noxious to the esophagus, warranting further studies. RYGB might not entirely preserve esophageal function as previously believed.

Geographic Disparities in Clinical Characteristics of Duodenitis–Proximal Jejunitis in Horses in the United States

Duodenitis–proximal jejunitis (DPJ) is an idiopathic and potentially fatal disease of horses characterized by abdominal pain, proximal intestinal inflammation, and subsequent gastric and small intestinal fluid accumulation. Although this disease is known to be costly and life threatening in the equine industry, the severity of clinical signs can vary widely, and an exact etiology has yet to be elucidated. This study looked to identify differences in clinical parameters of horses with DPJ between geographic regions in an effort to corroborate anecdotal reports and support theories of differing etiologies. Case records were compared from veterinary academic referral hospitals in three different geographic locations in the United States to determine if significant differences in clinical, clinicopathologic, and prognostic characteristics exist among horses with DPJ. Clinical measurements on presentation that were significantly different between regions included heart rate, peritoneal total protein, albumin, anion gap, aspartate aminotransferase, gamma-glutamyl transferase, sodium, chloride, potassium, and creatinine. Duration of hospitalization and maximum body temperature while hospitalized were also different between regions. There were no significant differences in peritoneal cell count, total white blood cell count, neutrophil count, band neutrophils, calcium, total plasma protein, temperature on presentation, duration of reflux, total reflux volume, or age between hospitals. The mortality rates between hospitals were not significantly different. Increased severity of clinical signs and biochemical abnormalities were identified in the Southeastern United States hospital compared with the Northeastern and Western hospitals. A prospective, multicenter case–control study could identify risk factors contributing toward regional differences in this disease in the future.

Modeling and Simulation of Flow and Uranium Isotopes Separation in Gas Centrifuges Using Implicit Coupled Density-Based Solver in OpenFOAM

The performance of a gas centrifuge that is used for isotopes separation is dependent on the gas flow inside it. In this study, for modeling the UF6 gas flow, an Implicit Coupled Density-Based (ICDB) solver, was developed in OpenFOAM. To validate the ICDB solver, the gas flow within the rotor in total reflux state was compared with the analytical solution obtained by Onsager model and the numerical solution obtained by the Fluent software. The results showed that the ICDB solver had acceptable accuracy and validity. Also the computational efficiency of Roe, AUSM (Advection Upstream Splitting Method) and AUSM+ up schemes were compared. The results showed AUSM+ up scheme is efficient. Then, the uranium isotopes separation in a gas centrifuge was simulated. It was revealed that all gas flow characteristics including velocity, pressure, temperature and axial mass flux, as well as uranium isotope separation parameters including separation power and separation coefficients could well be predicted.

Greenhouse gas emissions reduction by process intensification: Reactive distillation column with side decanter

Direct hydration of cyclohexene to produce cyclohexanol is the industrial process with a lower raw material cost but with a quite expensive process. Large energy consumption is consequence of large cyclohexene recycle related with its unfavourable chemical equilibrium. This study corroborates that the Asahi process is a good candidate for intensification avoiding the cyclohexene recycle. Rigorous simulation shows that a single reactive distillation column, with a side decanter, operated at total reflux, allows overcoming the chemical equilibrium limitations as the product is continuously collected by the column bottoms and the heat of reaction is directly used to separate the product by distillation. The novel process is studied and compared to the classical Asahi process. An energy comparison with the available processes proposed in the literature is performed. Therefore, achieving more energy-efficient processes leads to lowering their environmental impact, thus decreasing the carbon dioxide emissions. Applying the proposed methodology for cyclohexanol production, more than 67,000 t CO2/y emissions can be avoided compared to the nowadays used classical process, thus the potential savings applying process intensification to the chemical industry are very large and worth further investigation.

Flag on the play, delay of game

AbstractMany process safety systems are aimed at attaining and maintaining normal operation. How to maintain a safe process during abnormal operation is more difficult to assess. Initiating events that could cause abnormal operation are varied and they are easily overlooked or discarded as highly improbable. There is a netherworld when operations are suspended or the process is on hold. Hold can be a distillation unit that is placed on total reflux or a reactive process where the process is not at reaction conditions; perhaps reactant additions have been suspended. The assumption is that the process remains at a static condition until we want it to resume. The proverb, “Time and tide waits for no man” should have also included chemical reactions. While some upset causes are not preventable, they can be anticipated and plans developed to safely manage the process until normal operation can resume. Maintenance activities are also prone to increased risk due to delayed or suspended operations. All of these situations have warning signs that can be recognized, but only if an effort is made to assess the situation and develop plans to safely manage the process through the delay.

Laryngeal signs and pH-multichannel intraluminal impedance in infants and children: The missing ring: LPR and MII-pH in children

Objectiveto investigate the reliability of laryngeal reflux finding score (RFS) and symptom index (RSI) in assessing gastroesophageal reflux (GER) in children and infants. Methodspatients with laryngeal or respiratory symptoms, who underwent laryngoscopy and esophageal pH-impedance (MII-pH) were recruited. RSI and RFS were correlated to MII-pH results. A RSI>13, RFS>7, acid exposure index>7%, total reflux episodes>100/24 h in infants or>70/24 h in children, or a positive symptom index or association probability, were considered pathological. Analysis considering age (</>12 months) was performed. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of the laryngeal scores were calculated. Results197 children (median 53 months, 61 infants) were enrolled. MII-pH was pathological in 5/10 patients with RFS>7, and in 17/31 with RSI>13. RFS>7 had 3.9% sensitivity, 93% specificity, a PPV of 50 and a NPV of 34 in predicting GER disease. RFS was inversely associated to weakly acidic and proximal GER. RSI>13 had 13% sensitivity, 83% specificity, and a PPV and NPV similar to RFS. RSI was significantly associated with the number of acid reflux episodes, and, in infants, with bolus exposure index. ConclusionsRSI and RFS aren't accurate in predicting GER in infants and children. Acid reflux relates to laryngeal symptoms, but neither acid, nor proximal and weakly acidic GER relate to laryngeal alterations.

Quantification of Reflux Velocity by Duplex Ultrasound in Superficial and Deep Venous Insufficiency and its Correlation in the Assessment of the Clinical Stage of Chronic Venous Insufficiency

OBJECTIVE: This study aimed to determine the correlation between ultrasound-derived parameters of chronic venous insufficiency (CVI) and the clinical stage of disease. METHODS: This was a cross-sectional study conducted in a tertiary hospital and included all adult patients who underwent venous duplex ultrasound of the lower extremities with reflux of the superficial and/or deep venous system. The following parameters were measured: vein diameter, reflux duration, peak systolic velocity (PSV), mean diastolic velocity (MDV) and total reflux volume (TRV). Spearman’s Rank-Order coefficient was used to determine the correlation between ultrasound parameters versus the clinical stage of CVI (C0-C6). RESULTS: There was a weak but statistically significant correlation between clinical stage and MDV in the right peroneal (r=0.240), left femoral (r=0.175) and left popliteal (r=0.192); between clinical stage and PSV in the right peroneal vein (r=0.194); and between clinical stage and TRV in the right peroneal (r=0.186), left great saphenous (r=0.167), left femoral (r=0.194) and left popliteal veins (r=0.201). CONCLUSION: There is a statistically significant correlation between the clinical stage of CVI and MDV, PSV and TRV, although the correlations are weak. KEYWORDS: Duplex-derived parameters, chronic venous insufficiency

Study on optimization and performance of biological enhanced activated sludge process for pharmaceutical wastewater treatment

Simulated pharmaceutical wastewater was treated by moving bed biofilm reactor (MBBR) and total reflux sludge reactor process (STR) system. By cultivating specific bacterial groups, optimizing reactor process parameters, and comparatively analyzing the pollutant removal efficiency under stable operating conditions of the system, the treatment efficiency of the two systems under the combined impact load of organic pollutants on the target pollutants indole and naphthalene was studied. The optimal operation parameters of reactors: hydraulic retention time (HRT) was 8 h, aeration was 0.12 m3/h. The effect was better in 25 ± 1 °C than that in 20 ± 2 °C. During stable operation, the average removal rate of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N) of the MBBR system was significantly higher than that of STR, and the two kinds of target pollutants concentration in water was lower than the detection limit. In the combined impact test of organic pollutants, the dominant bacterial group obtained by domestication had a high degradation ability, so the combined impact of indole and naphthalene had little effect on the two reactors. But in the fourth stage, the residual naphthalene concentration in the STR system effluent exceeded the target value. Therefore, the MBBR process has a stronger treatment effect on pharmaceutical wastewater than the STR system during the stable period and the impact load stage.

Model Discrimination for Multicomponent Distillation – A Geometrical Approach for Total Reflux

AbstractWhile rate‐based models are available in commercial flowsheet simulation tools, packed distillation columns are still mostly designed based on the equilibrium stage model in combination with HETP values. In order to discriminate between both types of models in a simple way, this article proposes an algorithmic test, based on a geometric criterion for total reflux operation. Substantial differences are illustrated especially for wide‐boiling mixtures, while component‐specific mass transfer rates either increase or reduce the deviation. The derived results are validated by dedicated experiments.

P156 Understanding the associations and impact of severe gastrointestinal involvement in systemic sclerosis: a structured approach

Abstract Background Gastrointestinal (GI) involvement in systemic sclerosis (SSc) has a profound negative impact on patients’ quality of life. However, due to the diversity in manifestations of SSc-associated GI disease, this impact has proven difficult to quantify and to associate with other clinical and demographic features, to identify those most at risk of severe disease. Methods Between September and December 2018, consecutive SSc patients attending a specialist scleroderma clinic completed the UCLA Scleroderma Clinical Trial Consortium Gastrointestinal Tract 2.0 (UCLA SCTC GIT 2.0) questionnaire. Total score and separate domain scores (reflux, distention/bloating, diarrhoea, soilage, constipation, social functioning and emotional wellbeing) were calculated. Domain scores range between 0 and 3, with higher scores indicating greater severity. Associations between mean scores and demographic or clinical characteristics were analysed using Wilcoxon rank-sum test. Results In total, 224 SSc patients fully completed the UCLA SCTC GIT 2.0. Eighty-three percent were female, mean age was 58.2 years and mean disease duration was 14.3 years. Diffuse cutaneous systemic sclerosis (dcSSc) was present in 37.1%, and 22.3% had an overlap syndrome. The most common autoantibodies were anti-centromere (ACA) in 38.0%, anti-topoisomerase I (ATA) in 20.1%, anti-RNA polymerase in 11.2% and anti-U3RNP in 4.5% of patients. For the cohort, the total GIT score was 0.62±0.57 (mean±SD), correlating strongly with visual analogue scale self-reported impact of GI disease (Pearson’s r = 0.72, p &amp;lt; 0.001). Distribution of total and domain scores is summarised in Table 1. We found no association between demographic or clinical characteristics and total GIT score, reflux, distention/bloating, diarrhoea and social functioning. Constipation was most common among ATA + (score 0.69, p = 0.080 v ATA-) and least common among ARA+ subjects (score 0.25, p = 0.014 v ARA-). Soilage was more common in limited cutaneous SSc (score 0.56 v 0.29 in dcSSc, p = 0.048) and ACA+ subjects (score 0.67 v 0.33 in ACA-, p = 0.008). ACA+ patients also had worse emotional wellbeing (score 0.70 v 0.52 in ACA-, p = 0.014). Emotional wellbeing was more severely affected in females (score 0.62 v 0.43 in males, p = 0.078). Conclusion We found that moderate to severe GI disease affects nearly half of all subjects with SSc, which significantly contributes to disease-related morbidity. Disclosures F. Ahmed None. S.I. Nihtyanova None. S. Chatzinikolaou None. V.H. Ong None. C.D. Murray None. C.P. Denton None.

Prolonging gavage feeds for reduction of gastroesophageal reflux in infants.

To determine if prolonging gavage feedings in infants for ≥60 min is associated with decreased gastroesophageal reflux (GER) compared with bolus feeding using multiple-channel intraluminal impedance with pH probe (MII-pH). Retrospective analysis of infants who underwent MII-pH between October 2009 and July 2018 and received gavage feedings. Infants were divided into two groups: bolus (<30 min) or prolonged (≥60 min). Symptoms, number of reflux events and percent time pH < 4 was compared. Fifty-eight infants underwent evaluation. Thirty-one (54%) received bolus gavage feedings and 27 (46%) received prolonged feedings. Groups differed in postmenstrual age. Total reflux episodes were significantly lower with prolonged feeding (median 19 vs. 28 episodes, p = 0.015), with no difference in acid exposure time. There was no significant difference in GER symptoms between the two groups. Prolongation of gavage feedings was associated with decreased total numbers of GER events without reduction in GER symptoms.

A water distillation detritiation facility and its performance test

Water distillation is an effective method for detritiation of drainage from a nuclear power plant, and for the volume reduction of tritiated water from the cooling and safety systems of a nuclear fusion reactor. The height equivalent of theoretical plate (HETP) value is usually required for the conceptual column design to determine the height of the packing layer. A H2O-HTO water distillation engineering detritiation facility is established in Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics. Distillation in a total reflux mode for H2O-HTO with tritium activity of 13.5 MBq/kg has been performed in the column with 12 m height of packing layer and 261 mm inner diameter to measure the value of HETP for phosphor bronze bilayer gauze corrugated structured packing. When the column is operated at overhead pressure of 7 kPa and reflux rate of 25.0 kg/h, the pressure drop of the total column is just 2.0 kPa. The HETP value of the structured packing is 160 mm.

Novel representation of vapour-liquid equilibrium curves for multicomponent systems: design of total reflux distillation columns

McCabe Thiele diagrams were developed as a graphical tool for designing binary distillation columns. In this article, the method to construct McCabe Thiele diagrams for multicomponent systems is presented, illustrating specifically at total reflux for ideal and nonideal systems. Firstly, a variety of examples were used to depict the novel representation of the vapour-liquid equilibrium (VLE) in two-dimensional space (2D) as contours of VLE for the generation of the x–y diagram. Once the contours of VLE are represented in 2D various design scenarios can be investigated using the generated plot. Hence the proposed graphical method retains the authenticity, simplicity and versatility of the binary McCabe Thiele method. Through examples, it is shown that the depiction of the contours of VLE is a powerful visual tool to identify the type of separation (difficult or simple separation), azeotropes and tangent pinch points. Thereafter, the procedure for calculating the number of stages is presented at total reflux for ideal and nonideal ternary systems to determine the minimum number of stages required. Several simulations for an acetone, benzene and chloroform system were generated using Aspen Plus™ to validate the proposed graphical method. Lastly, it was shown that the proposed graphical method correlated more closely to rigorous simulation than traditional methods.

The Clinical Effect of Domperidone on Reflux Gastritis

The present clinical study observed the effect of domperidone on reflux gastritis. In this study, 200 patients with reflux gastritis were divided into the control group accepting routine drug therapy and the research group accepting domperidone treatment, each group contained 100 patients. The overall treatment efficiency, clinical symptom score before and after treatment and bile reflux monitoring indicators 24 h after treatment were compared between the two groups. On comparing the overall treatment efficiency of patients in both groups, the results showed that the research group was 96.00 % and the control group was 80.00 %. The score of clinical symptoms of the two groups of patients showed that the degree of improvement in the research group was significantly better than that in the control group after treatment, p<0.05. By comparing the monitoring indexes of bile reflux 24 h after treatment between the two groups, the research group had significant advantages in terms of the percent total reflux time, the number of refluxes and the number of refluxes lasting for more than 5 min. The application of domperidone in the treatment of reflux gastritis can significantly improve the therapeutic effect, improve the clinical symptoms and promote the recovery of patients as soon as possible.

Efficiency Estimation of Tray Columns Based on Flow Profiles and Vapor–Liquid Equilibrium Characteristics of Binary Mixtures

A new systematic approach for estimating the section and column efficiencies based on flow profiles and vapor-liquid equilibrium (VLE) characteristics of binary mixtures exclusively for each tray is proposed. A novel iterative technique for approximating the slope of the VLE curve and the tray efficiency is also developed. For demonstrating the predictive capabilities of the new approach, two case studies are formulated in this work - one with a theoretical column processing selected binary mixtures at total reflux, and the other involving an industrial column whose performance data is acquired from the literature. An in-depth analysis of theoretical column study reveals the superiority of the new approach over the most applied method. In the case study of industrial column, the new approach predicts the section efficiency accurately, unlike the efficiency underestimation from the most applied method. Such an approach would allow a priori calculation of the section and column efficiencies in the tray and ...

GER characteristics after fundoplication in children with aerodigestive disorders

PurposeThe purpose of this study was to determine GER characteristics after Nissen fundoplication in children with aerodigestive disorders using pH-impedance technology. MethodsIn this cross-sectional study, the institutional database of Cincinnati Children's Hospital Medical Center was reviewed to identify patients ages below 21 years who had a Nissen fundoplication and underwent esophageal pH-impedance (pH-MII) monitoring over a nine-year period. All reflux-related metrics were modeled as a Poisson random variable as a function of time since fundoplication. ResultsA total of 242 patients were included in the study. The range for time since surgery was 1–192 months. Median total reflux events were 8.5 episodes per 24 h, median acidic reflux events were 0, and median proximal reflux event was 2. There was no significant trend towards increasing reflux episodes over time. ConclusionsChildren had a low number of reflux events after a fundoplication, as measured by pH-impedance, and there was no statistically significant increase observed in the number of reflux events over time. Despite most patients having a functional fundoplication with minimal reflux events throughout the entire age range, up to 58% of our cohort was still on a proton pump inhibitor.