Gastric Emptying Of Liquids Research Articles

362. DELAY IN SOLID GASTRIC EMPTYING IS ASSOCIATED WITH SILENT REGURGITATION EVENTS, PULMONARY MICROASPIRATION AND LARYNGOPHARYNGEAL REFLUX DISEASE

Abstract Background Pulmonary micro-aspiration (PMA) is a feared complication of severe and sometimes silent gastroesophageal reflux disease (GORD). A novel scintigraphic test that shows refluxate contamination of the pharynx, upper and lower airways has recently been developed. This test and multiple observations allowed the development of a hypothesis that prolongation in solid gastric emptying (SGE) may be a more critical than delays in liquid gastric emptying (LGE) in micro-aspiration into the airways. Methods Standard LGE and SGE studies together with the novel microaspiration test were evaluated in paired studies in patients with medially resistant symptoms GORD to measure rates of micro-aspiration after each meal. Either water labelled with 99m Technetium Phytate for the LGE or a labelled egg sandwich for the solid meal was utilised. Major symptoms were noted and the cough and reflux severity index (CSI & RSI) obtained in all patients. Results A total of 131 patients were included in this study (59M/72F). The age range was 21 to 83 years with a mean of 52 years. Patients were in the overweight range for body mass index (BMI), with a mean of 26.8. Major symptoms were of bloating, nausea, belching and dyspepsia as well as cough, throat clearing and globus. Less than 20% complained of heartburn. Results. SGE was abnormal in 92% (Mean 766 min) and LGE was abnormal in 53% (Mean 82 min). PMA was shown in 35% after the SGE and in 71% after the LGE. PMA positive patients were older. SGE and PMA were significantly correlated (p<0.00) but not LGE. The only significant symptom in the PMA group was bloating. RSI was abnormal in 64% and CSI in 46%. Conclusion The majority of patients with PMA do not complain of heartburn. Bloating in patients with severe GORD should raise the possibility of gastroparesis and PMA. Prolonged SGE may be critical in the physiology of atypical reflux and present another treatment goal with addition of pyloroplasty to anti-reflux procedure of choice.

363. REFLUX MICRO-ASPIRATION: WHAT HAVE WE LEARNED

Abstract Background The accurate diagnosis of gastro-oesophageal reflux pulmonary microaspiration has only become possible recently with the introduction of a novel technique of reflux micro-aspiration scintigraphy study combined with single photon emission computed tomography (SPECT) combined with x-ray tomography (CT) in a hybrid instrument. This has allowed the accurate diagnosis of pulmonary and airway contamination with refluxate. Previously only patients with large volume symptomatic reflux aspiration were diagnosed clinically (Mendelson syndrome) or by 2-dimentional barium meal or an older plantar (2 dimensional) technique of scintigraphic aspiration studies. The concept of reflux micro-aspiration has been implicated in multiple pulmonary diseases but without absolute proof from an adequate diagnostic test. Little was known about the natural history, physiology, and response to treatment amongst patients with silent reflux micro-aspiration. The aim of this presentation is to summarise a series of research projects studying the natural history of the disease, common presenting symptoms, pathophysiology and response to treatment. Methods A prospectively populated database of patients referred to a tertiary specialist reflux diagnostic service with atypical and/or treatment resistant reflux was evaluated. The database contained records of consecutive patients including demographic information, presenting symptoms, investigations including imaging, upper gastro-intestinal physiology studies and novel reflux micro-aspiration scintigraphy studies. Treatment details including medical and surgical treatment and post treatment clinical information and investigations. Multiple studies were conducted using the information from the database and findings are summarised in this presentation. Results The novel reflux micro-aspiration scintigraphy with SPECT/CT was compared with other studies (multichannel intraluminal impedance and 24-hour pH monitoring) and was found to be sensitive to reflux occurring outside the oesophagus. Patients with reflux micro-aspiration can present a wide variety of symptoms, commonly a combination of typical symptoms of gastro-oesophageal reflux disease (heartburn and regurgitation) and respiratory symptoms. Reflux micro-aspiration was associated with reduced lower oesophageal sphincter pressure, severe ineffective oesophageal motility (IOM), and pharyngeal contamination with refluxate on reflux scintigraphy. Delayed liquid gastric emptying was not associated with reflux micro-aspiration, however gastroparesis with solids is associated with micro-aspiration. Micro-aspiration was common in patients with giant hiatus hernias and mostly resolved with surgery. Anti-reflux surgery resulted in resolution of aspiration in the majority of patients, however severe IOM was associated with lesser rates of microaspiration resolution. Conclusion Reflux micro-aspiration appears to be a more common manifestation of GORD than previously thought. The work summarised in this presentation discusses the presentation, physiological associations, and treatment of patients with reflux micro-aspiration.

Whole Gut Transit Scintigraphy for the Assessment of Patients with Symptoms of Chronic Constipation

IntroductionWhole gut transit scintigraphy (WGTS) can detect delayed colonic transit (CT), different types of CT delays, and assess upper GI tract transit.AimTo delineate the frequency of different types of CT patterns in patients with chronic constipation (CC), determine the relationship between these CT patterns and upper GI tract transit abnormalities, and assess how symptoms relate to different colonic transit patterns.MethodsRetrospective review of patients who had WGTS for CC. Patients completed a modified PAGI-SYM questionnaire to assess symptoms. Patients ingested a standard solid (Tc-99m egg sandwich)–liquid (In-111 water) meal to assess solid meal gastric emptying (GE), liquid GE, small bowel transit (SBT), and geometric center of colonic activity at 24, 48, and 72h.ResultsOne hundred and eighty six patients underwent WGTS. Main symptoms were constipation (41%), nausea (24%), and bloating (22%). CT assessment showed 32% of patients had normal transit, 31% colonic inertia (CI), 28% functional rectosigmoid obstruction (FRS0), and 9% generalized slow colonic transit (GSCT). GE was delayed in 36%; more commonly in CI and FRSO. SBT was delayed in 19%; more commonly in GSCT and CI. Patients with CI had less bowel movements per week whereas patients with normal CT had more bm/week.ConclusionsIn this series of patients with symptomatic constipation, WGTS assessment showed delayed colonic transit in 68% of patients, with 31% having colonic inertia, 28% a functional rectosigmoid obstruction pattern, and 9% generalized delay in colonic transit. Abnormalities in GE and SBT were present in 36 and 19%. WGTS is helpful to document delayed colonic transit (CT), assess the pattern of the delay in CT, and determine if there are upper GI transit abnormalities.

Effect of lixisenatide on liquid gastric emptying in type 2 diabetes – Implications for the use of GLP-1 receptor agonists before procedures

Gastric emptying of a glucose drink was measured in people with type 2 diabetes given lixisenatide (20 μg/day or placebo) for 8 weeks. Intragastric retention at 240 min (2 (0−11)% vs 48 (3–97)%; P < 0.0001) was much greater with lixisenatide than placebo. Accordingly, lixisenatide may delay liquid gastric emptying markedly.

Scintigraphy of Gastrointestinal Motility: Best Practices in Assessment of Gastric and Bowel Transit in Adults.

Various radiologic examinations and other diagnostic tools exist for evaluating gastrointestinal diseases. When symptoms of gastrointestinal disease persist and no underlying anatomic or structural abnormality is identified, the diagnosis of functional gastrointestinal disorder is frequently applied. Given its physiologic and quantitative nature, scintigraphy often plays a central role in the diagnosis and treatment of patients with suspected functional gastrointestinal disorder. Most frequently, after functional gallbladder disease is excluded, gastric emptying scintigraphy (GES) is considered the next step in evaluating patients with suspected gastric motility disorder who present with upper gastrointestinal symptoms such as dyspepsia or bloating. GES is the standard modality for detecting delayed gastric emptying (gastroparesis) and the less commonly encountered clinical entity, gastric dumping syndrome. Additionally, GES can be used to assess abnormalities of intragastric distribution, suggesting specific disorders such as impaired fundal accommodation or antral dysfunction, as well as to evaluate gastric emptying of liquid. More recently, scintigraphic examinations for evaluating small bowel and large bowel transit have been developed and validated for routine diagnostic use. These can be performed individually or as part of a comprehensive whole-gut transit evaluation. Such scintigraphic examinations are of particular importance because clinical assessment of suspected functional gastrointestinal disorder frequently fails to accurately localize the site of disease, and those patients may have motility disorders involving multiple portions of the gastrointestinal tract. The authors comprehensively review the current practice of gastrointestinal transit scintigraphy, with diseases and best imaging practices illustrated by means of case review. ©RSNA, 2024 See the invited commentary by Maurer and Parkman in this issue.

Gastric emptying during and following resolution of moderate diabetic ketoacidosis in type 1 diabetes: a case series

IntroductionTo use the ‘gold standard’ technique of scintigraphy to quantify gastric emptying (GE) as soon as practicable during an admission with diabetic ketoacidosis (DKA) and following its resolution at least...

Normative Data of Liquid Gastric Emptying and Small-bowel Transit: A Prospective Cross-sectional Study.

The primary objective was to establish the reference values for liquid gastric emptying and small bowel. The secondary objectives encompassed comparing the anterior view and geometric mean methods, assessing gender differences, and exploring potential correlations with age. Thirty-five consecutive healthy participants (28 females and 7 males) with a mean age of 42 ± 11 years (median, 42; range, 23-65) underwent liquid gastric emptying scintigraphy at five intervals (0, 0.5, 1, 2, and 4 h), with optional additional imaging at 24 h. Liquid gastric emptying was evaluated using percent retention and half-time (T1/2). Small-bowel transit was assessed using the index of small-bowel transit (ISBT), calculated as the ratio of terminal ileal reservoir counts to total abdominal counts at 4 h. Reference values were established based on percentiles or mean and standard deviation (SD). Rapid small-bowel transit was determined through visual inspection. Statistical analysis involved paired Samples t-test or Wilcoxon signed-rank test for comparing imaging methods, independent Samples t-test or Mann-Whitney U-test for gender comparison, and Spearman's rank correlation for assessing age-related associations. A 2-tailed P < 0.05 indicated significance. Rapid liquid gastric emptying based on the geometric mean method was defined as percent retention <8% at 30 min, while delayed emptying as percent retention >33%, >20%, and >4% at 1, 2, and 4 h, respectively. The reference range of T1/2 of gastric emptying was 10-60 min. The reference value for small-bowel transit using the geometric mean method was established as ISBT >30% at 4 h, while rapid small-bowel transit was defined as the first visualization of activity in the cecum-ascending colon within 1 h. Parameters for liquid gastric emptying and small-bowel transit were notably higher in the anterior view method compared to the geometric mean method (P ≤ 0.019), except for percent retention at 2 h (P = 0.510). Nevertheless, the obtained reference values, whether based on percentiles or mean and SD, showed no notable variance between the two methods to warrant clinical significance. Gender did not display an impact on liquid gastric emptying or small-bowel transit in either method (P ≥ 0.173), and age demonstrated no significant moderate or strong correlations (Spearman's ρ ≤ 0.397). The study determined reference values for liquid gastric emptying and small-bowel transit through a standard gastric emptying scintigraphy protocol, avoiding additional complex procedures or extended imaging sessions. The established normative data can apply to individuals of both genders aged ≥18 years. While advocating the geometric mean method as the primary choice, the study acknowledges that in busy centers handling multiple studies with limited resources and a single-head gamma camera catering to multiple studies, the anterior view method remains a feasible alternative.

Comparison of gastric emptying before and after treatment for subclinical hypothyroidism

Aim: The aim of this study was to evaluate the effect of levothyroxine treatment on dyspeptic symptoms and gastric emptying time in patients with subclinical hypothyroidism. Materials and Methods: Liquid gastric emptying scintigraphy was performed to detect the presence of gastroparesis in patients with dyspeptic complaints who were followed up with a diagnosis of subclinical hypothyroidism in the thyroid outpatient clinic. Those with specific hypothyroidism symptoms during their follow-up were treated with low dose (25 mg) levothyroxine for at least 6 months. Liquid gastric emptying scintigraphy test was performed again after treatment for those who continued to have dyspeptic complaints. Patients whose gastric emptying time was calculated using a liquid gastric emptying scintigraphy test before and after levothyroxine treatment were retrospectively examined. For testing, 18.5-37 MBq (0.5-1 mCi) 99m-TC nanocolloid was added to 300 ml of water. Late images were acquired at 30 minutes and one hour. The time activity curve was obtained. Results: Gastric emptying was normal in 13 (23.6%) patients in the liquid gastric emptying scintigraphy test performed before treatment. After treatment, gastric emptying half-time was normalized in 34 (81%) of 42 (76.4%) patients with a long gastric emptying half-time before treatment. In total, 47 patients had normal gastric emptying half-time values after treatment, and gastric emptying half-time was calculated to be long in 8 patients (14.5%). Conclusion: In our study, gastric emptying time was prolonged in 76.4% of patients with subclinical hypothyroidism, and in 81% of these patients, gastric emptying time was calculated within normal limits after LT4 treatment. Detection of prolongation of gastric emptying time due to the presence of gastroparesis in subclinical hypothyroidism cases followed up without treatment may be a guide in the prescription of treatment.

Evaluation of Dyspepsia with Optimal and Suboptimal Gastric Emptying Tests in Patients with Euthyroid Goiter.

The presence of gastroparesis in patients with dyspepsia can be evaluated by gastric emptying scintigraphy. We aimed to evaluate gastroparesis with optimal solid gastric emptying scintigraphy and suboptimal liquid gastric emptying scintigraphy in euthyroid goiter patients with dyspepsia. We included 67 patients diagnosed with euthyroid goiter with dyspepsia complaints. The patients did not use any medication and did not have any other chronic diseases. Solid and liquid gastric emptying scintigraphy was performed on all patients. In our retrospective study; the images were reevaluated. The region of interest was plotted on the area compatible with the stomach and timeactivity curves were obtained. The correlation of solid and liquid gastric emptying test results was evaluated. Twelve (18%) of the patients were male and the mean age of the patients was 64 (49-75). There is a correlation between solid and liquid gastric emptying scintigraphy (p< 0.0005, r: 0.0880). Solid gastric emptying time was prolonged in 27 patients (40%). Liquid gastric emptying was prolonged in 23 patients (34%). Solid gastric emptying was also prolonged in all patients with prolonged liquid gastric emptying. According to the results of the optimal gastric emptying test performed with radio-labeled solid food. The rate of gastroparesis was low in our patient group with dyspepsia complaints. However, there is a correlation between the optimal test and suboptimal gastric emptying test results in our patient group. Liquid gastric emptying scintigraphy may be preferred in specific patient groups in case of suspected gastroparesis because of its easy application and short duration.

Liquid and solid gastric emptying and correlation with clinical characteristics in pediatric patients with dyspepsia.

There is limited data on gastric emptying in dyspeptic children. We aimed to determine solid and liquid emptying rates in dyspeptic children and correlate with clinical characteristics. Charts of dyspeptic children undergoing 4-hour dual-phase gastric scintigraphy were reviewed for demographics, symptoms, and comorbidities. In 1078 dyspeptic patients (65% females, median age 13 years) vomiting (55%), nausea (53%), and abdominal pain (52%) were the most common symptoms. The most common comorbidities were mental health (32%), neurologic (27%), and hypermobility spectrum disorders (20%). Solid and liquid emptying rates were aligned in 61.23%. Delayed solid with normal liquid emptying were noted in 2.5%, compared to delayed liquid with normal solid emptying in 26.16%. Abdominal pain had a trend for association with delayed or normal solid emptying (p = 0.06). Nausea was mostly reported with normal solid emptying (p < 0.0001) and underreported in patients <12 years with vomiting (29%). Abnormal solid emptying (rapid and delayed) was noted more frequently in children with mental health disorders (p = 0.027). Rapid liquid emptying was more common in children with genetic disorders (p = 0.032). Over half of children with dyspepsia had delayed liquid gastric emptying, and one quarter had delayed liquid with normal solid emptying. Dual-phase gastric emptying studies may help target therapy in dyspeptic children. Nausea is not a reliable symptom for dyspepsia in younger children. Given the significant association of abnormal gastric emptying in children with mental health disorders, we recommend screening and treating children with dyspepsia.

Long-Term Outcomes of Pylorus-Preserving Gastrectomy for Early Gastric Cancer.

In the short term, pylorus-preserving gastrectomy (PPG) has been reported to have advantages over distal gastrectomy (DG) with regard to postprandial symptoms and dumping syndrome. We aimed to evaluate the quality of life after PPG for early gastric cancer in the long term in comparison to that after DG. Twenty-six patients who underwent gastrectomy (11 PPG, 15 DG) for early gastric cancer at Osaka University Hospital participated and were followed for more than 4years. Body weight changes, nutritional status, dual-phase scintigraphy findings, endoscopic survey results, and questionnaire responses after gastrectomy were examined. There were significantly lower ratios of weight changes in PPG than in DG, 5years after surgery. There were no differences in the clinicopathological characteristics, nutritional parameters, questionnaire responses, and endoscopic findings between the two groups. Based on gastric scintigraphy, although the gastric emptying of liquids showed similar curves in the two groups, gastric emptying of solids was significantly slower in the PPG group than in the DG group (P = .039). PPG had advantages with regard to long-term outcomes over DG in terms of weight maintenance and the prevention of rapid gastric emptying. PPG might be efficient in patients with early gastric cancer.

Effect of blenderized tube feeds on gastric emptying: A retrospective cohort study.

Blenderized tube feeds (blends) are associated with lower hospital admissions and reduced gastroesophageal symptoms, but their high viscosity may theoretically prolong gastric emptying. Our objective was to compare differences in gastric emptying with blends vs with formula. We retrospectively identified individuals 6 months to 20 years with enteral tubes who underwent 1-h liquid gastric emptying scintigraphy from 1998 to 2020 at Boston Children's Hospital. Examinations were excluded if a postpyloric tube was present, tracer was administered orally or with diet differing from habitual, habitual diet was indeterminable, imaging was terminated early, or >50% of input counts emptied during bolus administration. Emptying was classified as delayed if gastric residual at 1 h was ≥60% of ingested dose. Eighteen examinations (15 individuals) were performed with blends and 35 examinations (32 individuals) with formula. Although percentage of residual at 1 h was significantly higher in patients receiving blends compared with formula (54 ± 17 vs 40 ± 25, P = 0.04), the number of patients with delayed gastric emptying did not differ (39% vs 29%, respectively, P = 0.54). Type of diet, feed volume or concurrent medications did not predict delayed gastric emptying. Children with blends received higher bolus volumes (106 ± 55 vs 66 ± 59 ml; P = 0.02), and this significantly predicted percentage of residual (β = 0.14; P = 0.01). The proportion of patients with delayed gastric emptying was similar in children receiving blends and formula. Although the mean percentage of gastric residual was higher with blends, this may be explained by higher bolus volumes administered. This preliminary work suggests that blends compare favorably to formula.

Comparison of Gastric Emptying Time after the Ingestion of Whisky with Isocalorically Adjusted Glucose Solution.

Previous studies have shown that the liquid gastric emptying mainly depended on energy content, regardless of compositional differences. But the gastric emptying of alcoholic beverages remains unclear. Therefore, we performed the present study to compare gastric emptying times between whisky mixed with water and glucose solution with uniform energy contents and volumes. As a crossover study, 10 healthy male volunteers ingested one of 3 test solutions with a uniform volume of 150 ml, i.e., whisky with water-containing whisky 30 ml (67 kcal), sugar water containing glucose 16.8 g (67 kcal), and water (0 kcal), and the gastric emptying time of each beverage was then assessed by ultrasound measurements of the gastric antral cross-sectional area. The gastric emptying pattern of whisky with water was faster than that of isocaloric sugar water, but slower than that of water. Each antral cross-sectional area 20, 30, and 40 min after the ingestion of sugar water was significantly larger than that of whisky with water. Antral cross-sectional areas 10 and 20 min after the ingestion of water were significantly smaller than those of whisky with water. In conclusion, the gastric emptying time of whisky would be faster than that of isocaloric glucose solution and slower than that of water. Unlike the other beverages, the gastric emptying time of alcohol drinks does not purely depend on the energy content because alcohol itself has no calorie before absorption. This study is registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000034443).

Transpyloric propagation and liquid gastric emptying in children with foregut dysmotility.

Gastric emptying (GE) requires precise antropyloroduodenal coordination for effective transpyloric flow, the mechanisms of which are still unclear. We aimed to correlate gastric antral function assessed by antroduodenal manometry (ADM) with GE scintigraphy (GES) for liquid feeds in children with suspected gastrointestinal dysmotility. Children who underwent both ADM and GES over a five-year period were reviewed. ADM tracings were re-analyzed to assess antral frequency, amplitude, and motility index (MI) pre-prandially and postprandially. Transpyloric propagation (TPP) was defined as antegrade propagated antral activity preceding duodenal phase III of the migrating motor complex (MMC). TPP was defined as "poor" if occurring in <50% of all presented duodenal phases III. For GES, regions of interest over the whole stomach, fundus, and antrum were drawn to calculate GE half-time (GE-T1/2 ) and retention rate (RR) in each region at 1 and 2h. Forty-seven children (median age: 7.0years) were included. Twenty-two had PIPO, 14 functional GI disorders, and 11gastroparesis. Children with poor TPP had longer GE-T1/2 (113.0 vs 66.5min, p=0.028), higher RR of the whole stomach and fundus at 1h (79.5% vs 63.5%, p=0.038; 60.0% vs 41.0%, p=0.022, respectively) and 2h (51.0% vs 10.5%, p=0.005; 36.0% vs 6.5%, p=0.004, respectively). The pre-prandial antral amplitude of contractions inversely correlated with GE-T1/2 , RR of the whole stomach, and fundus at 2h. TPP during phase III of the MMC correlated with gastric emptying of liquid and its assessment on ADM might predict abnormalities in postprandial gastric function.

A Physiologically Based Pharmacokinetic Model for Studying the Biowaiver Risk of Biopharmaceutics Classification System Class I Drugs With Rapid Elimination: Dexketoprofen Trometamol Case Study.

Biowaiver based on the biopharmaceutics classification system (BCS) has been widely used in the global market for the approval of new generic drug products to avoid unnecessary in vivo bioequivalence (BE) studies. However, it is reported that three out of four formulations of dexketoprofen trometamol (DEX) tablets (BCS class I drug) failed the first BE study. The aim of this study was to determine whether the current biowaiver standard is reasonable for DEX. Thus, we successfully established a physiologically based pharmacokinetic (PBPK) model for DEX and examined the effects of dissolution, permeability, and gastric emptying time on DEX absorption under BCS-based biowaiver conditions using sensitivity analyses. Parameter sensitivity analysis showed that the dissolution rate in pH 1.2 media, permeability, and liquid gastric emptying time were sensitive parameters of Cmax. Therefore, gastric emptying variation was introduced into the PBPK model, and virtual BE studys were conducted on original research formulation and the formulation of the boundary dissolution rate (f2 = 50) prescribed by the biowaiver guideline. The virtual BE results showed dissolution rate changes within the biowaiver range will not cause high non-BE ratio, indicate waive of DEX generic drugs would not lead the risk of Cmax when generic products satisfy the requirements of biowaiver guideline. However, the effect of excipients on gastric emptying as a sensitive factor needs to be further studied when the rapid elimination of BCS class I drug is biowaived.

Gastroparesis in systemic sclerosis: a detailed analysis using whole-gut scintigraphy.

Gastroparesis is a common complication of SSc. We sought to determine the degree of overlap between gastroparesis and dysmotility in other areas of the gut, correlate our findings with gastrointestinal (GI) symptoms, and examine associations between gastroparesis and SSc features. Whole-gut scintigraphy was performed on SSc patients who were enrolled in the Johns Hopkins Scleroderma Cohort, for whom detailed longitudinal clinical and serologic data are collected. A subset of patients completed the University of California Los Angeles Scleroderma Clinical Trial Consortium Gastrointestinal Tract Instrument 2.0 (UCLA GIT 2.0) to quantify their GI symptoms. We examined associations between the presence and severity of gastroparesis, GI symptoms, and SSc clinical features. Ninety-seven SSc patients with and without GI symptoms underwent whole-gut scintigraphy and completed the gastric emptying study. Of the 97, 34 (35%) met criteria for gastroparesis. Of the measures assessed, delayed liquid emptying captured more patients with delayed gastric transit than delayed solid emptying (74% vs 55%), and percentage liquid emptying correlated best with GIT Reflux (ρ = -0.33, P = 0.01) and Distension (ρ = -0.30, P = 0.03) scores. Of 33 patients with gastroparesis, 30 (91%) had abnormal transit in other areas of the GI tract. Higher anti-centromere protein B (CENP-B) titres correlated with slower gastric emptying (ρ = -0.26, P = 0.03), but no specific clinical features of SSc were associated with gastroparesis. Gastric emptying of liquids when given alongside solids may be more sensitive and provide a more clinically relevant measure of gastroparesis in SSc than solid gastric emptying or liquid gastric emptying alone. SSc patients with gastroparesis frequently have dysmotility in other areas of the GI tract, underscoring the need for whole-gut scintigraphy to evaluate the entire gut.

Baseline predictive factors for foregut and hindgut response to long-term gastric electrical stimulation using augmented energy.

Gastric electrical stimulation (GES) has been recommended for drug refractory patients with gastroparesis, but no clear baseline predictors of symptom response exist. We hypothesized that long-term predictors to GES for foregut and hindgut symptoms exist, particularly when using augmented energies. We evaluated 307 patients at baseline, 1week post temporary GES, and one year after permanent GES. Baseline measures included upper and lower symptoms by patient-reported outcomes (PRO), solid and liquid gastric emptying (GET), cutaneous, mucosal, and serosal electrophysiology (EGG, m/s EG), BMI, and response to temporary stimulation. Foregut and hindgut PRO symptoms were analyzed for 12-month patient outcomes. All patients utilized a standardized energy algorithm with the majority of patients receiving medium energy at 12months. Patients were categorized based on change in average GI symptom scores at the time of permanent GES compared to baseline using a 10% decrease over time as the cutoff between improvers versus non-improvers. By permanent GES implant, average foregut and hindgut GI symptom scores reduced 42% in improved patients (n=199) and increased 27% in non-improved patients (n=108). Low BMI, baseline infrequent urination score, mucosal EG ratio, and proximal mucosal EG low-resolution amplitude remained significant factors for improvement status. GES, for patients responding positively, improved both upper/foregut and lower/hindgut symptoms with most patients utilizing higher than nominal energies. Low baseline BMI and the presence of infrequent urination along with baseline gastric electrophysiology may help identify those patients with the best response to GES/bio-electric neuromodulation.

UnderstandingIn VivoDissolution of Immediate Release (IR) Solid Oral Drug Products Containing Weak Acid BCS Class 2 (BCS Class 2a) Drugs.

In vivo drug dissolution kinetics of BCS Class 2a IR solid oral drug products remains largely unknown. An understanding to what extent the solubility influences in vivo dissolution is needed to design appropriate in vitro dissolution methods. In this study, nonsteroidal anti-inflammatory drugs (NSAIDs) are used to investigate the in vivo dissolution of BCS Class 2a drugs based on numerical deconvolution analyses. The PK data were obtained from published literature or drug applications submitted to the FDA. It has been hypothesized that the in vivo drug dissolution rate would likely correlate to the solubility of NSAIDs in the media at gastrointestinal pH. Our findings show a short lag time of absorption (Tlag), comparable to the liquid gastric emptying time and independent of the solubility and formulation. In Vivo drug dissolution of NSAIDs was generally rapid and complete within the regular drug residence time in the small intestine while multi-phase absorption was observed in some subjects for all the NSAIDs. The comparisons of in vivo drug dissolution rate, which was characterized by in vivo dissolution half-life (Thalf), indicate that solubility has a minimal impact on in vivo drug dissolution rate for NSAIDs. Gastric emptying regulated by migrating motor complex (MMC) under fasted state most likely governs drug dissolution and absorption of NSAIDs. For BCS Class 2a IR solid oral drug products, large variability of gastric emptying and MMC as well as the strong driving force of intestinal absorption probably outweigh the impact of solubility on drug in vivo dissolution.

Three-dimensional semiquantitative analysis of gastric emptying SPECT.

We used dynamic single-photon emission computed tomography (D-SPECT) to overcome the interference of the planar dynamic imaging due to the overlap of internal organs, thus more accurate physiological function can be obtained. 3D printed gastric phantom was used to simulate gastric emptying (GE). First, the planar dynamic liquid GE procedure was used and served as the reference value; second, D-SPECT followed by repeated liquid GE procedures with three gamma cameras were used. The emptying flow rate of the gastric phantom simulated three flow rates of liquid, semisolid and solid. Third, we simulated the intestinal activity that interfered with the residual value obtained by 2D dynamic imaging, which was compared with D-SPECT. Then, we brought the 3D VOI data into the postprocessing program to obtain the residual activity curve and residual percentage. The residual amount obtained in the phantom at 60th minutes in the first stage is 14.57%; the residual amount of liquid emptying are Siemens: 3.33%, GE: 15.06%, PHILIPS: 1.12%; residual amount for semisolid are Siemens: 47.36%, GE: 54.25%, PHILIPS: 51.57%; residual amount for solids are Siemens: 63.98%, GE: 66.88%, PHILIPS: 63.76%. All values are within the normal range. Then, we simulated the intestinal activity that interfered with the residual value obtained by 2D dynamic imaging: 75-90 min: 10.42, 19.48, 19.51 and 11.02%; however, the residual values obtained with 3D SPECT VOI data: 75-90 min: 1.42, 1.41, 1.35 and 1.02%. These results show that the emptying data errors caused by intestinal overlap can be effectively corrected (P = 0.017). D-SPECT imaging can overcome the interference in the semiquantitative data of residual GE caused in 2D mode.

S1396 Glycosylated Hemoglobin Relation With Gastric Emptying Study in Gastroparesis

Introduction: Gastroparesis is a debilitating disorder which includes several upper abdominal symptoms and documented slow gastric emptying (AJG 2013; 108:18). Past studies have shown heterogenous results of correlations between the glycemic control and the gastric emptying study. We aim to study the association of glycosylated hemoglobin (HbA1c) with gastric emptying. Methods: We performed retrospective review of the patients diagnosed with diabetic gastroparesis between September 30th, 2009 and January 31st, 2020. The 99mTc sulfur labeled food study was used to diagnose gastroparesis. Gastric emptying of < 90% for solids at 240 minutes and < 95% for liquids at 60 minutes were identified as delayed gastric emptying. We examined the relationship of HbA1c levels with the rate of gastric emptying examined by various gastric emptying test. The cohort was further divided into HbA1c levels < 7% (good diabetes control), 7-9% (fair diabetes control) and >9% (poor diabetes control). Results: There were 129 patients (mean age 51.1 ± 14.2 years, 61.8% female, 64.1% white) with diabetic gastroparesis. The mean HbA1c level was 8.3 ± 2.2 %. We observed that the HbA1c levels were not associated with level of gastric emptying with either solid (r=-0.12, p=0.28) or liquid study (r=-0.15, p=0.17). The mean gastric emptying was 74.3 ± 20.9% for solids and 67.9 ± 23.6 % for liquids with good glycemic control, 70.8 ± 20.1 % for solids and 52.3 ± 31.1 % for liquids in patients with fair diabetes control and 64.4 ± 26.7 % for solids and 52.9 ± 31 % for liquids in the patients with poorly controlled diabetes mellitus. The level of glycemic control did not predict the percentage of solid gastric emptying (p=0.29) whereas there was trend towards inverse relation with liquids (p=0.09). Conclusion: There is no correlation between the HbA1c levels and gastric emptying time. The level of diabetes mellitus control does not predict the severity of gastroparesis at the time of diagnosis.Figure 1.: A. Correlation of HbA1c levels with liquid gastric emptying at 60 minutes, B. Correlation of HbA1c levels with solid gastric emptying at 240 minutes, C. Glycemic control category and gastric emptying studies (240 min solid and 60 min liquid).Table 1.: Patients’ characteristic and comparison of diabetic gastroparesis with diabetic non-gastroparesis.