Novel testing of human gastric motor and sensory functions: rationale, methods, and potential applications in clinical practice

Patients with postprandial distress syndrome experience problems with their interoceptive perceptual function to the gastric region, but their heartbeat perception is normal: a case control study

BACKGROUND

Visceral hypersensitivity in functional dyspepsia can be localized or widespread, and there is no simple method of assessment. Measuring interoceptive accuracy at different sites provides an assessment of perceptual hypersensitivity to specific ecological phenomena. The purpose of this study was to characterize visceral hypersensitivity by comparing gastric sensory and cardiac perceptual tests in patients with postprandial distress syndrome and in healthy volunteers.

METHODS

Sixteen patients with postprandial distress syndrome (age = 47.5 ± 17.4, all female) and 16 healthy volunteers (age = 43.3 ± 16.1, all female) participated in the study after a six-hour fast. Each participant answered questionnaires about physical and mental quality of life, depression and anxiety, tendency of alexithymia, and somatosensory amplification. After completing the questionnaire, the participants took the heartbeat tracking task and the five-minute water load test. We performed statistical analysis using the Mann-Whitney U test and Spearman's rank correlation coefficient.

RESULTS

Subjects with postprandial distress syndrome had a lower drinking capacity than healthy volunteers (postprandial distress syndrome = 360.9 ± 170.0 mL, healthy volunteers = 644.1 ± 297 mL, P = 0.009), but there was no significant difference in the heartbeat perception score (postprandial distress syndrome = 0.599 ± 0.175, healthy volunteers = 0.623 ± 0.181, P = 0.647). There was a negative correlation (r = - 0.509, P < 0.05) between drinking capacity and the heartbeat perception score in healthy volunteers, but no correlation in postprandial distress syndrome (r = - 0.156, P = 0.564). Heartbeat perception score did not correlate with psychological measures.

CONCLUSIONS

Compared with healthy volunteers, only the five-minute water load test values were reduced in patients with postprandial distress syndrome, and no difference was observed in the heartbeat tracking task. Combining the 5-minute water load test and the heart rate tracking task revealed a lost cardiac-gastric perceptual relationship in patients with postprandial distress syndrome that was not observed in healthy volunteers, suggesting that there is hypersensitivity in gastric interoceptive perceptual function. Performing sensory examinations at two different sites may be useful in clarifying whether visceral hypersensitivity is localized.

TRIAL REGISTRATION

UMIN000057586. Registered11 March 2023(retrospectively registered).

The new measures of interoceptive accuracy: A systematic review and assessment

Conscious interoception, the perception of internal bodily states, is thought to contribute to fundamental human abilities (e.g., decision-making and emotional regulation). One of its most studied dimensions is interoceptive accuracy: the objective capacity to detect internal bodily signals. In the past few years, several labs across the world have started developing new tasks aimed at overcoming limitations inherent in classical measures of interoceptive accuracy. In this systematic review, we identified these tasks (since 2015) for the cardiac, respiratory, and gastrointestinal domains. For each identified task, we discuss their strengths and weaknesses, and make constructive suggestions for further improvement. In the general discussion, we discuss the (potentially elusive) possibility of reaching high validity in the measurement of interoceptive accuracy. We also point out that interoceptive accuracy may not be the most critical dimension for informing current theories, and we encourage researchers to investigate other dimensions of conscious interoception.

Factors associated with successful weight loss after liraglutide treatment for obesity

AIM

To identify patient factors, including gastrointestinal functions, that are predictive or associated with weight loss in response to once-daily 3 mg liraglutide administered subcutaneously (SQ) or placebo in obesity.

METHODS

One hundred and thirty-six obese adults (87% female) were randomized in a placebo-controlled, 16-week trial of liraglutide, escalated to 3 mg administered SQ daily. Gastrointestinal functions were measured at baseline and 16 weeks: gastric emptying of solids (GET1/2 ); fasting and postprandial gastric volumes; kcal ingested during ad libitum buffet meal and the nutrient drink test. GET1/2 was also measured at 5 weeks. A multiple variable regression model examined variables associated with weight loss of more than 4 kg at 16 weeks. A parsimonious model using backward selection identified the final model.

RESULTS

Weight loss of more than 4 kg at 16 weeks occurred in 71% of liraglutide- and 16% of placebo-treated patients. In all participants combined, parameters univariately associated with a weight loss of more than 4 kg were GET1/2 at 5 and 16 weeks, weight loss at 5 weeks and kcal intake during the buffet meal at 16 weeks. The final parsimonious model (area under the receiver operator characteristics [AUROC] curve = 0.832) identified that factors associated with more than 4-kg weight loss were GET1/2 at 5 weeks (OR = 2.505; 95% CI: 1.57-3.997) per 50 minutes and kcal intake during ad libitum meal at 16 weeks (OR = 0.721; 95% CI: 0.602-0.864) per 100 kcal. Among only the 60 liraglutide-treated subjects, kcal intake at 16 weeks was associated with 4-kg weight loss (AUROC = 0.757).

CONCLUSIONS

Slower GET1/2 and weight loss at 5 weeks predicted a weight loss of more than 4 kg at 16 weeks in all participants. Among liraglutide-treated adults, weight loss of more than 4 kg was associated with ad libitum meal kcal intake at 16 weeks.

The duodenal mucosa associated microbiome, visceral sensory function, immune activation and psychological comorbidities in functional gastrointestinal disorders with and without self-reported non-celiac wheat sensitivity

Frequently, patients with functional gastrointestinal disorders (FGIDs) report intolerance of wheat products. We compared gastrointestinal symptoms, sensory function, psychiatric comorbidities, gut-homing immune cells, and duodenal mucosa-associated microbiome (d-MAM) in FGID patients and controls with and without self-reported wheat sensitivity (SR-NCWS). We recruited 40 FGID patients and 20 controls referred by GPs for treatment. Gastrointestinal/extraintestinal symptoms, visceral sensory function, psychological comorbidities, and SR-NCWS were assessed in a standardized approach. Peripheral gut homing T-cells (CD4⁺α4⁺β7⁺CCR9⁺/CD8⁺α4⁺β7⁺CCR9⁺) were quantified, and the d-MAM was assessed by DNA sequencing for 46 subjects. Factors of bacterial genera were extracted utilizing factor analysis with varimax rotation and factors univariately associated with FGID or SR-NCWS included in a subsequent multivariate analysis of variance to identify statistically independent discriminators. Anxiety scores (p < .05) and increased symptom responses to a nutrient challenge (p < .05) were univariately associated with FGID. Gut homing T-cells were increased in FGID patients with SR-NCWS compared to other groups (p all <0.05). MANOVA revealed that anxiety (p = .03), visceral sensory function (p = 0.007), and a d-MAM factor comprise members of the Alloprevotella, Prevotella, Peptostreptococcus, Leptotrichia, and Veillonella lineages were significantly (p = .001) associated with FGID, while gut homing CD4⁺α4⁺ β7⁺CCR9⁺ T-cells were associated (p = .002) with SR-NCWS. Compared to controls, patients with and without SR-NCWS show that there are shifts in the amplicon sequence variants within specific bacterial genera between the FGID subgroups (particularly Prevotella and Streptococcus) as well as distinct bacterial taxa discriminatory for the two different FGID subtypes. Compared to controls, both FGID patients with and without SR-NCWS have an increased symptom response to a standardized nutrient challenge and increased anxiety scores. The FGID patients with SR-NCWS - as compared to FGID without SR-NCWS (and controls without SR-NCWS) - have increased gut homing T-cells. The d-MAM profiles suggest species and strain-based variations between the two FGID subtypes and in comparison to controls.

Update on pediatric gastroparesis: A review of the published literature and recommendations for future research

BACKGROUND

Due to scarcity of scientific literature on pediatric gastroparesis, there is a need to summarize current evidence and identify areas requiring further research. The aim of this study was to provide an evidence-based review of the available literature on the prevalence, pathogenesis, clinical presentation, diagnosis, treatment, and outcomes of pediatric gastroparesis.

METHODS

A search of the literature was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines with the following databases: PubMed, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, and Web of Science. Two independent reviewers screened abstracts for eligibility.

KEY RESULTS

Our search yielded 1085 original publications, 135 of which met inclusion criteria. Most articles were of retrospective study design. Only 12 randomized controlled trials were identified, all of which were in infants. The prevalence of pediatric gastroparesis is unknown. Gastroparesis may be suspected based on clinical symptoms although these are often non-specific. The 4-hour nuclear scintigraphy scan remains gold standard for diagnosis despite lack of pediatric normative comparison data. Therapeutic approaches include dietary modifications, prokinetic drugs, and postpyloric enteral tube feeds. For refractory cases, intrapyloric botulinum toxin and surgical interventions such as gastric electrical stimulation may be warranted. Most interventions still lack rigorous supportive data.

CONCLUSIONS

Diagnosis and treatment of pediatric gastroparesis are challenging due to paucity of published evidence. Larger and more rigorous clinical trials are necessary to improve outcomes.

Role of Gastric Emptying in Symptoms of Gastroparesis

The symptoms of gastroparesis, such as nausea, vomiting, postprandial fullness, early satiety and abdominal pain, frequently impair the quality of life of the affected individuals. The diagnosis of gastroparesis is made after structural etiologies are ruled out and an assessment of gastric function shows delayed gastric emptying. The role of the delay in gastric emptying in the pathogenesis of symptoms of gastroparesis has been debated, with some studies suggesting an association between delayed gastric emptying and the upper gastrointestinal symptoms, while others do not. The recent literature supports the importance of using reliable methods to assess gastric emptying, as delay in gastric emptying measured on a reliable test (4-h scintigraphy or breath test) is associated with the severity of upper gastrointestinal symptoms. In addition to measuring total gastric emptying, evaluation of regional gastric retention in the proximal and distal stomach and whole gut transit to assess small intestinal and colonic transit may provide additional useful information in patients with more generalized symptoms of gastrointestinal dysmotility.

Clinical measurement of gastrointestinal motility and function: who, when and which test?

Symptoms related to abnormal gastrointestinal motility and function are common. Oropharyngeal and oesophageal dysphagia, heartburn, bloating, abdominal pain and alterations in bowel habits are among the most frequent reasons for seeking medical attention from internists or general practitioners and are also common reasons for referral to gastroenterologists and colorectal surgeons. However, the nonspecific nature of gastrointestinal symptoms, the absence of a definitive diagnosis on routine investigations (such as endoscopy, radiology or blood tests) and the lack of specific treatments make disease management challenging. Advances in technology have driven progress in the understanding of many of these conditions. This Review serves as an introduction to a series of Consensus Statements on the clinical measurements of gastrointestinal motility, function and sensitivity. A structured, evidence-based approach to the initial assessment and empirical treatment of patients presenting with gastrointestinal symptoms is discussed, followed by an outline of the contribution of modern physiological measurement on the management of patients in whom the cause of symptoms has not been identified with other tests. Discussions include the indications for and utility of high-resolution manometry, ambulatory pH-impedance monitoring, gastric emptying studies, breath tests and investigations of anorectal structure and function in day-to-day practice and clinical management.

Gastric accommodation in healthy subjects studied by ultrasound, manometry, and impedancemetry

BACKGROUND

Gastric accommodation to a meal may be important in the pathogenesis of upper gastrointestinal disorders, but has been difficult to investigate in a minimally invasive fashion.

METHODS

We studied gastric and lower esophageal physiology during food intake, combining transabdominal ultrasound, multichannel high-resolution impedance-manometry (HRIM) and a symptom questionnaire. A HRIM catheter was distally positioned at incisura angularis and 300 mL saline with 75 g glucose was ingested. Target variables were recorded for 30 min after fluid intake.

KEY RESULTS

Fifteen healthy subjects' participated (11W/4M, median age 23.8 y) and all accepted the meal with few symptoms. At incisura angularis maximum change in pressure from pre-intake values was -7.4 mmHg after 60 s (P < .0001), rising to pre-intake values within 20 min. The corresponding area increased significantly from pre-intake values of 8.0 cm² to 14.1 cm² shortly after intake (P = .0012), peaked at 5 min and slowly decreased towards 30 min. The corresponding maximum change in stress from pre-intake pressure values was -59.2 mmHg shortly after (P < .0001), reaching pre-intake values within 20 min. Strain rose from 0 shortly before to 0.36 shortly after (P < .0001), peaking at 5 min. At incisura angularis, fullness was positively correlated with area and to strain, while fullness, area, and stress were negatively correlated with pressure.

CONCLUSIONS & INFERENCES

The multimodal method enabled assessment of the gastric accommodation reflex, stress and strain in the stomach. It triggered few symptoms in healthy volunteers. We propose it to be a more physiological replacement of the barostat technique.

The predictive value of hunger score on gastric evacuation after oral intake of carbohydrate solution

BACKGROUND

Surgical patients are asked to fast for a sufficient duration to ensure that the amount of residual liquid in the stomach is within the safe range, thereby reducing the risk of gastric reflux perioperatively. The authors hypothesized that subjective hunger numerical rating scale (NRS) score could also help assess the process of gastric emptying and determine the amount of fluid remaining in the stomach.

METHODS

The current study consisted of healthy volunteers recruited by advertisement and mutual introduction. Participants were asked to rate their subjective hunger feeling every 30 min after oral administration of 8 mL/kg carbohydrate nutrient solution that contained 10% maltodextrin and 2.5% sucrose. Consecutively, the gastric residual fluid was measured by magnetic resonance imagining (MRI). The Spearman's correlation coefficient, the ROC curves and the stepwise regression were used to analyze the predictive value of NRS for the gastric emptying process.

RESULTS

The cohort consisted of 29 healthy volunteers enrolled in this study. The area under ROC curves estimated by the NRS score for the gastric residual volume of 2 mL/kg, 1 mL/kg, and 0.5 mL/kg were AUC2.0 = 0.78, AUC1.0 = 0.76, and AUC0.5 = 0.72, respectively. The correlation coefficient between the NRS score and the residual liquid in the stomach was -0.57 (P < 0.01). The correlation coefficient between the increase of the NRS score and the decrease of gastric liquid residual volume was 0.46 (P < 0.01). The standardized estimate of NRS score for the residual volume was -0.18 (P < 0.01) and the standardized estimate of fasting time was -0.73 (P < 0.01).

CONCLUSIONS

The subjective hunger NRS score can not accurately predict the gastric residual volume, but it can provide a reference for clinicians to judge the gastric emptying process and it should be used as a second check after oral intake of clear fluids before surgery according to the new fasting protocol.

Assessment of Gastric Accommodation in Patients with Functional Dyspepsia by 99mTc-Pertechtenate Single Photon Emission Computed Tomography Imaging: Practical but not Widely Accepted

Objective:

Impaired gastric accommodation is one of the main symptoms in patients with functional dyspepsia. The aim of the present study was to assess gastric accommodation in patients with functional dyspepsia using single photon emission computed tomography (SPECT) imaging.

Methods:

Twenty-four patients with functional dyspepsia and 50 healthy volunteers as control group were enrolled in this study. All participants were given 5 mCi 99mTc-pertechtenate intravenously, served with a low fat meal, and underwent SPECT scanning 20 minutes after the meal.

Results:

Based on the scintigraphic data, gastric volumes were found to be significantly increased after food ingestion in both patient and control groups. We also found that while there was no significant difference between patient and control groups in terms of fasting gastric volumes, postprandial gastric volume was significantly lower in patients as compared to healthy individuals (p<0.05).

Conclusion:

Measuring gastric volume by using SPECT can be a valuable method in the detection of functional dyspepsia and in differentiation of this entity from other organic disorders.

Mechanisms Regulating Insulin Response to Intragastric Glucose in Lean and Non-Diabetic Obese Subjects: A Randomized, Double-Blind, Parallel-Group Trial

Background/Objectives

The changes in blood glucose concentrations that result from an oral glucose challenge are dependent on the rate of gastric emptying, the rate of glucose absorption and the rate of insulin-driven metabolism that include the incretins, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). The rate of insulin-driven metabolism is clearly altered in obese subjects, but it is controversial which of these factors is predominant. We aimed to quantify gastric emptying, plasma insulin, C-peptide, glucagon and glucose responses, as well as incretin hormone secretions in obese subjects and healthy controls during increasing glucose loads.

Subjects/Methods

The study was conducted as a randomized, double-blind, parallel-group trial in a hospital research unit. A total of 12 normal weight (6 men and 6 women) and 12 non-diabetic obese (BMI > 30, 6 men and 6 women) participants took part in the study. Subjects received intragastric loads of 10 g, 25 g and 75 g glucose dissolved in 300 ml tap water.

Results

Main outcome measures were plasma GLP-1 and GIP, plasma glucagon, glucose, insulin, C-peptide and gastric emptying. The primary findings are: i) insulin resistance (P < 0.001) and hyperinsulinemia (P < 0.001); ii) decreased insulin disposal (P < 0.001); iii) trend for reduced GLP-1 responses at 75 g glucose; and iv) increased fasting glucagon levels (P < 0.001) in obese subjects.

Conclusions

It seems that, rather than changes in incretin secretion, fasting hyperglucagonemia and consequent hyperglycemia play a role in reduced disposal of insulin, contributing to hyperinsulinemia and insulin resistance.

Trial Registration

ClinicalTrials.gov NCT01875575

Clinical features and severity of gastric emptying delay in Brazilian patients with gastroparesis

CONTEXT

Gastroparesis is defined by delayed gastric emptying without mechanical obstruction of the gastroduodenal junction, which has been increasingly investigated. Nevertheless, knowledge on the relationships between etiology, symptoms and degree of delayed gastric emptying is limited.

OBJECTIVES

The demographic, clinical and etiological features of Brazilian patients with gastroparesis were studied and the relationships between these findings and the severity of gastric emptying were determined.

METHOD

This is a retrospective study of medical records of 41 patients with symptoms suggestive of gastroparesis admitted between 1998 and 2011, who had evidence of abnormally delayed gastric emptying on abdominal scintigraphy. Cases with idiopathic gastroparesis were compared with those of patients with neurologic disorders or diabetes mellitus, in whom autonomic neuropathy is likely to occur.

RESULTS

The majority of the patients were women (75.6%) with a median age of 41 years and a long-term condition (median: 15 years). Twelve patients (29.3%) had a body mass index of less than 20 kg/m2. The most common presenting symptoms were dyspepsia (53.6%), nausea and vomiting (46.3%), weight loss (41.4%) and abdominal pain (24.3%). Regarding etiology, 16 patients had digestive disorders including idiopathic gastroparesis (n = 12), 12 had postoperative conditions, 11 had diseases of the nervous system, five had diabetes mellitus and in three cases gastroparesis was associated to a variety of conditions. In the majority of patients (65.8%) gastric emptying was severely delayed. There was no association between etiology of gastroparesis, type of presenting symptoms and the degree of delay in gastric emptying. Gastroparesis patients with proven (neurological conditions) or presumed (diabetes) nervous system involvements were significantly younger (P = 0.001), had more recent symptom onset (P = 0:03) and a trend towards more severe gastric empty (P = 0:06). There were no significant differences between this subgroup of patients and that comprising cases of idiopathic gastroparesis regarding any of the variables studied.

CONCLUSIONS

The demographic, clinical and etiological characteristics of Brazilian patients with gastroparesis are quite varied, but there is a predominance of women with long-standing symptoms and marked delay in gastric emptying. The type of presenting symptoms and the degree of delay in gastric emptying do not predict the etiology of gastroparesis. However, severely delayed gastric emptying in younger patients with recent symptom onset should raise the suspicion of impaired neural control of gastro-duodenal motility.

Applying novel nutrient drink to clinical trial of functional dyspepsia

Background/Aims

The drink test has been regarded as a surrogate marker of gastric accommodation. The aims of this study were to develop a novel nutrient drink test (NDT) protocol and investigate its potential for application to a clinical trial of functional dyspepsia (FD).

Methods

A novel NDT was designed, involving drinking 125 mL of nutrient 4 times at 5-minute intervals or until maximal tolerability. Healthy volunteers and patients with FD rated their symptoms every 5 minutes for 20 minutes in a developmental study. Patients with FD were enrolled in an open trial of itopride for 4 weeks. NDT was performed before and after treatment. Improvement of integrative symptoms score during NDT after treatment for more than 50% compared with baseline was defined as responder.

Results

Total aggregate symptom scores, sum of symptom scores measured during NDT, were higher in FD patients (n = 40, 368.1 ± 245.3) than in controls (n = 19, 215.9 ± 171.2) (P = 0.018) in a developmental study. In an open trial of itopride, symptom scores measured during NDT decreased significantly at all time points after treatment in responders (n = 49), whereas did not in non-responders (n = 25). Total aggregate symptom score for NDT correlated significantly with integrative dyspeptic symptom score, sum of 8 symptom scores of NDI questionnaire, at baseline (r = 0.374, P = 0.001) and after treatment (r = 0.480, P < 0.001).

Conclusions

Our novel NDT can quantify dyspeptic symptoms and reflected therapeutic effects of itopride treatment in a clinical trial of FD patients. This NDT can be used as an effective parameter in clinical trials or drug development programs for assessing effects of novel therapies on postprandial symptoms.

Gastroparesis: from concepts to management

While the symptoms of gastroparesis are common, an accurate diagnosis is based on a combination of those symptoms with a documented delay in gastric emptying. Typical symptoms include nausea, vomiting, early satiety, postprandial fullness, bloating, and abdominal discomfort. Patients with gastroparesis face many diagnostic and therapeutic challenges. The most common origins of gastroparesis are idiopathic causes and diabetes mellitus. The increased use of certain medications in medicine today, including opiates and drugs with anticholinergic properties, can alter gastrointestinal functions and mimic symptoms of gastroparesis. Accordingly, alternative explanations for symptoms and altered gastrointestinal function need to be considered. Numerous clinical sequelae, including weight loss and severe protein-calorie malnutrition, may be seen in advanced stages of gastroparesis. This article provides an overview of gut sensorimotor function to help the reader better understand the clinical presentation of patients with dyspepsia and those who may have accompanying delayed gastric emptying that meets criteria for gastroparesis. Techniques available for diagnosing motor dysfunction and the principles of gastroparesis management are reviewed. Nutrition recommendations and a review of pharmacologic agents, nonpharmacologic techniques, and novel treatment modalities are provided.

Sensitivity and specificity of hypnosis effects on gastric myoelectrical activity

Objectives

The effects of hypnosis on physiological (gastrointestinal) functions are incompletely understood, and it is unknown whether they are hypnosis-specific and gut-specific, or simply unspecific effects of relaxation.

Design

Sixty-two healthy female volunteers were randomly assigned to either a single session of hypnotic suggestion of ingesting an appetizing meal and an unappetizing meal, or to relax and concentrate on having an appetizing or unappetizing meal, while the electrogastrogram (EGG) was recorded. At the end of the session, participants drank water until they felt full, in order to detect EGG-signal changes after ingestion of a true gastric load. During both conditions participants reported their subjective well-being, hunger and disgust at several time points.

Results

Imagining eating food induced subjective feelings of hunger and disgust as well as changes in the EGG similar to, but more pronounced than those seen with a real gastric water load during both hypnosis and relaxation conditions. These effects were more pronounced when imagining an appetizing meal than with an unappetizing meal. There was no significant difference between the hypnosis and relaxation conditions.

Conclusion

Imagination with and without hypnosis exhibits similar changes in subjective and objective measures in response to imagining an appetizing and an unappetizing food, indicating high sensitivity but low specificity.

Measurement of gastric emptying time of solids in healthy subjects using scintigraphic method: a revised technique

The gastric emptying half time (GET) of solid food in 24 healthy volunteers (11M/13F) was evaluated using a revised technique and a gamma camera scan. Within 20 min and after 8 h of fasting, each volunteer ate two pieces of toast with a two-egg-omelette that was mixed with 18.5 MBq (99m)Tc-labelled phytate. The raw data were analysed in the MATLAB program to establish the gastric intestine tract (GI tract) biokinetic model. The GI tract model defines the metabolic mechanism with reference to five compartments, which are stomach, body fluid, small intestine (SI), upper large intestine and lower large intestine, according to the ICRP-30 report. The model was expressed using four simultaneous time-dependent differential equations. The gastric emptying half-time and T(1/2eff)(SI) of males were 62.6±15.4 and 149.8±204.1 min, respectively, and those of females were 98.8±16.3 and 131.6±38.4 min.

A placebo-controlled trial of an oral capsaicin load in patients with functional dyspepsia

BACKGROUND

The pathophysiology of functional dyspepsia is poorly understood. Visceral hypersensitivity may play a key role. We studied a previously validated test to assess chemical hypersensitivity in functional dyspepsia by applying an oral capsaicin load.

METHODS

A total of 116 outpatients with upper gastrointestinal (GI) symptoms participated in this double-blind, placebo-controlled trial of which 73 patients received a final diagnosis of functional dyspepsia. Patients swallowed a capsule containing 0.75 mg capsaicin or placebo. A graded questionnaire evaluated the severity of nine upper GI symptoms before and after capsule ingestion and an aggregate symptom score was calculated. A final score of >9 was considered as a positive test.

KEY RESULTS

In functional dyspepsia, median perception scores were 10.8 (interquartile range: 4.5-18.8) after ingestion of capsaicin and 0.5 (0.0-2.5) after placebo (P < 0.001). Thirty-seven functional dyspepsia patients (54%) had a positive test after capsaicin ingestion, whereas only four (11%) patients with upper GI symptoms but without functional dyspepsia were capsaicin positive [median perception score: 1.5 (0.0-5.0)]. After placebo, symptom scores were low and not significantly different among patient groups (P > 0.05). Clinical characteristics, age, and gender distribution was similar in capsaicin positive and capsaicin negative functional dyspepsia patients (P > 0.05). The value of patient blinding was good.

CONCLUSIONS & INFERENCES

Half of functional dyspepsia patients had chemical hypersensitivity, determined with an oral capsaicin load. Placebo response was negligible. The results of the capsaicin test were not associated with specific dyspepsia symptoms or Rome subgroups.

Long-term Ultrasonographic Follow-up Study of Gastric Motility in Patients with Functional Dyspepsia

Although patients with functional dyspepsia complain of epigastric symptoms, the relation between these symptoms and gastric motility remains controversial. There are few reports on the clinical course of functional dyspepsia, including changes in gastric motility, observed over a considerably long period. We conducted a study to examine association between changes in symptoms and changes in ultrasonographically evaluated gastric motility over a long-term follow-up period in patients with functional dyspepsia. Forty patients (18 men, 22 women; mean age, 53.7 years) with functional dyspepsia were followed up by medical interview, physical examination, endoscopy, and ultrasonography for gastric motility. Follow-up ranged from 1.0 to 7.8 years (mean, 3.0 years). Ultrasonographic evaluation of gastric motility included gastric emptying rate and antral contractions. During the follow-up period, patients were treated with proton pump inhibitors, H2-blockers, or prokinetics. Symptoms improved in 21 patients (group A), but symptoms persisted or worsened in 19 patients (group B). There were no significant differences in clinical characteristics between the two groups. Gastric motility improved in group A but not in group B. In conclusion, improved gastric motility appears to correspond to and may explain improved symptoms in some patients with functional dyspepsia.

Characterization of a reproducible gastric pain model using oral capsaicin titration in healthy volunteers

BACKGROUND

  Sensory sensitization is one of the main pathophysiological hypotheses in functional gastrointestinal disorders (FGIDs). As sensitization may affect various sensory modalities, we aimed to develop a reproducible gastric pain model utilizing polymodal pathways for use in functional and other pain disorders.

METHODS

In this double-blind, cross-over study 42 healthy subjects swallowed one capsule containing either capsaicin 0.5mg or nocebo every 15min until moderate pain (intensity >30 on 100mm visual analogue scale) was attained for at least 5min. Pain was rated every minute. Capsaicin titration was repeated thrice for reliability calculation.

KEY RESULTS

Moderate pain in the upper abdomen was successfully achieved in 38 of 42 subjects (90%) with capsaicin titration and in one of 42 (2%) with nocebo. The median dosage required to induce moderate pain for at least 5min was two capsules (interquartile range 1-3) and the median gastric pain intensity was 47 (41-53). The median duration of moderate pain was 8min (5-12). Moderate pain was successfully reproduced with capsaicin in all subjects on study days 2 and 3, with an excellent Cronbach reliability coefficient of >0.8.

CONCLUSIONS & INFERENCES

Standardized gastric pain can be conveniently achieved in a majority of healthy subjects using a simple oral capsaicin titration, with minimal adverse events. The between-test reproducibility is high and nocebo responses are negligible. This technique stimulating a multimodal physiological pathway will be useful in the investigation of sensory changes in FGIDs, including functional dyspepsia.

Management of diabetic gastroparesis

Symptoms suggestive of gastroparesis occur in 5% to 12% of patients with diabetes. Such a complication can affect both prognosis and management of the diabetes; therefore, practicing clinicians are challenged by the complex management of such cases. Gastroparesis is a disorder characterized by a delay in gastric emptying after a meal in the absence of a mechanical gastric outlet obstruction. This article is an evidence-based overview of current management strategies for diabetic gastroparesis. The cardinal symptoms of diabetic gastroparesis are nausea and vomiting. Gastroesophageal scintiscanning at 15-minute intervals for 4 hours after food intake is considered the gold standard for measuring gastric emptying. Retention of more than 10% of the meal after 4 hours is considered an abnormal result, for which a multidisciplinary management approach is required. Treatment should be tailored according to the severity of gastroparesis, and 25% to 68% of symptoms are controlled by prokinetic agents. Commonly prescribed prokinetics include metoclopramide, domperidone, and erythromycin. In addition, gastric electrical stimulation has been shown to improve symptoms, reduce hospitalizations, reduce the need for nutritional support, and improve quality of life in several open-label studies.

Altered GI motility in critically Ill patients: current understanding of pathophysiology, clinical impact, and diagnostic approach

Gastrointestinal (GI) motility disturbances are common in critically ill patients. GI tract dysmotility has been linked to increased permeability of intestinal mucosa and bacterial translocation, contributing to systemic inflammatory response syndrome, sepsis, and multiple organ dysfunction syndrome. A key issue in providing nutrition to critically ill patients is intolerance of enteral feeding as a result of impaired GI motility. Remarkable progress has been made in the understanding of the regulation of GI motility in critical illness. Predominant motility abnormalities seen in ICU patients include antral hypomotility, delayed gastric emptying, and reduced migrating motor complexes. The diagnosis of motility disturbances can be challenging to establish in critically ill patients. The available tests used for detection of abnormal motility have major limitations in the ICU setting. Recognition of the type and site of intestinal motility disorder is important to guide the therapy and improve the outcome.

Association between clinical manifestations of complicated and uncomplicated peptic ulcer and visceral sensory dysfunction

BACKGROUND AND AIMS

Peptic ulcer disease (PUD) usually manifests as either dyspepsia or less commonly with complications such as bleeding. Patients with bleeding ulcers are often asymptomatic until the bleeding occurs. A lack of dyspeptic symptoms might be explained by impaired visceral sensory function. The aim of this study was to assess symptom profiles and compare visceral sensory thresholds in patients with bleeding peptic ulcer (BPU) and uncomplicated PUD.

METHODS

A total of 30 patients with BPU, 25 with uncomplicated PUD and 32 healthy controls (HC) without dyspeptic symptoms were recruited. In ulcer patients after at least 8 weeks of ulcer treatment and an 8-hr fast, visceral sensitivity was tested using a standardized nutrient challenge with an enteral feeding solution. Five key symptoms (fullness, abdominal pain, retrosternal/abdominal burning, nausea, and regurgitation) were assessed using visual analog scales (0-100).

RESULTS

Twenty-five of the 30 (83%, 95% confidence interval 65-94%) patients with BPU had no dyspeptic symptoms compared with none of the 25 uncomplicated PUD patients. Patients with BPU and HC had significantly lower symptom responses (BPU 127.6 +/- 24.6, HC 89.8 +/- 13.9) to the nutrient challenge than uncomplicated PUD patients (338.4 +/- 56.2, P < 0.0001). Patients with dyspeptic symptoms (30/55) had significantly higher symptom responses (327.3 +/- 47.8) than the 25/55 patients without symptoms (98.9 +/- 23.4, P < 0.0001).

CONCLUSION

Most patients with BPU present without dyspeptic symptoms. Even after healing of the ulcer, patients with uncomplicated PUD have a significantly augmented symptom response to a standardized nutrient challenge compared to patients with complicated ulcers and HC. Differences in the processing of upper gastrointestinal visceral afferents may play a major role in the clinical presentation (complicated vs uncomplicated) of PUD.

Gastrointestinal targets of appetite regulation in humans

The aim of this paper is to describe and discuss relevant aspects of the assessment of physiological functions - and related biomarkers - implicated in the regulation of appetite in humans. A short introduction provides the background and the present state of biomarker research as related to satiety and appetite. The main focus of the paper is on the gastrointestinal tract and its functions and biomarkers related to appetite for which sufficient data are available in human studies. The first section describes how gastric emptying, stomach distension and gut motility influence appetite; the second part describes how selected gastrointestinal peptides are involved in the control of satiety and appetite (ghrelin, cholecystokinin, glucagon-like peptide, peptide tyrosin-tyrosin) and can be used as potential biomarkers. For both sections, methodological aspects (adequacy, accuracy and limitation of the methods) are described. The last section focuses on new developments in techniques and methods for the assessment of physiological targets involved in appetite regulation (including brain imaging, interesting new experimental approaches, targets and markers). The conclusion estimates the relevance of selected biomarkers as representative markers of appetite regulation, in view of the current state of the art.

Diabetes mellitus and gastric emptying: questions and issues in clinical practice

It is long known that both type 1 and type 2 diabetes can be associated with changes in gastric emptying; a number of publications have linked diabetes to delayed gastric emptying of variable severity and often with poor relationship to gastrointestinal symptomatology. In contrast, more recent studies have reported accelerated gastric emptying when adjusted for glucose concentration in patients with diabetes, indicating a reciprocal relationship between gastric emptying and ambient glucose concentrations. This review proposes that gastroparesis or gastroparesis diabeticorum, a severe condition characterized by a significant impairment of gastric emptying accompanied by severe nausea, vomiting, and malnutrition, is often overdiagnosed and not well contrasted with delays in gastric emptying. The article offers a clinically relevant definition of gastroparesis that should help differentiate this rare condition from (often asymptomatic) delays in gastric emptying. The fact that delayed gastric emptying can also be observed in non-diabetic individuals under experimental conditions in which hyperglycaemia is artificially induced suggests that a delay in gastric emptying rate when blood glucose concentrations are high is actually an appropriate physiological response to hyperglycaemia, slowing further increases in blood glucose. The article discusses the strengths and weaknesses of various methodologies for assessing gastric emptying, especially with respect to the diabetes population, and reviews newer diabetes therapies that decelerate the rate of gastric emptying. These therapies may be a beneficial tool in managing postprandial hyperglycaemia because they attenuate rapid surges in glucose concentrations by slowing the delivery of meal-derived glucose.

Selected interventions in nuclear medicine: gastrointestinal motor functions

The measurement of gastrointestinal functions by the use of scintigraphy is established in clinical practice and research. The most commonly used test is the gastric-emptying test, which is acknowledged as the gold standard to measure gastric motility and is conducted according to a consensus statement from the national nuclear medicine and motility societies. Other techniques are somewhat more esoteric (eg, measurement of gastric accommodation with single-photon emission computed tomography) or the scintigraphic approach is not the acknowledged gold standard (eg, colonic transit, rectoanal angle, and emptying, esophageal transit). The performance characteristics of many of the scintigraphic measurements have been published and the pros and cons established in the literature. Pharmacologic interventions may also be used during scintigraphy to aid in diagnosis and treatment. Gastrointestinal scintigraphy is an integral and important component of the assessment of gastrointestinal function.

Visceral sensitivity testing

Visceral hypersensitivity is regarded as an important factor in the pathogenesis of functional gastrointestinal disorders. Assessment of visceral sensitivity has several important aims: increasing the understanding of normal and abnormal visceral sensory mechanisms and participating sensory pathways, serving as diagnostic tool to detect patients with abnormal visceral sensitivity, and evaluating therapeutic interventions directed towards modification of visceral sensitivity. Current stimulation modes in sensitivity tests include mechanical distension by barostat or tensostat, nutrient drink or water load, chemical stimulation, e.g. acid provocation or capsaicin ingestion, electrical, or thermal stimulation. Multimodal probes incorporating several stimulation modes in one device have recently been developed. Assessment of visceral sensation can be based on subjective responses of conscious perception or on objective parameters such as visceromotoric responses or central sensory processing patterns. All methods face the challenge that visceral sensitivity may be influenced by a wide spectrum of different factors, including the test techniques themselves, and improved, preferably non-invasive sensitivity tests with a greater standardisation and a broader applicability are still needed.

Methods for the assessment of gastric emptying in critically ill, enterally fed adults

Critically ill patients may experience delayed gastric emptying. Patients receiving enteral feeding are monitored closely to detect a delay of gastric emptying, assess feeding tolerance, and prevent aspiration pneumonia. The most common practice for assessing gastric emptying is to measure the aspirated gastric residual volume; however, this is an unreliable method that lacks standardization, fails to differentiate normal digestive secretions from enteral formula, and results in unnecessary interruptions of enteral nutrition. The aim of this review is to identify an alternative method to assess gastric emptying, which should be reliable, sensitive, harmless, feasible, and inexpensive. Several techniques are discussed: scintigraphy, paracetamol absorption test, breath tests, refractometry, ultrasound, and gastric impedance monitoring. Refractometry seems to be the most appropriate tool for the regular assessment of enteral nutrition; however, standardization and validation of this method are needed before it can be routinely used to monitor critically ill patients receiving enteral nutrition.

Tests of gastric neuromuscular function

Tests of gastric neuromuscular function are used to evaluate patients with symptoms referable to the upper digestive tract. These symptoms can be associated with alterations in the rates of gastric emptying, impaired accommodation, heightened gastric sensation, or alterations in gastric myoelectrical function and contractility. Management of gastric neuromuscular disorders requires an understanding of pathophysiology and treatment options as well as the appropriate use and interpretation of diagnostic tests. These tests include measures of gastric emptying; contractility; electrical activity; regional gastric motility of the fundus, antrum, and pylorus; and tests of sensation and compliance. Tests are also being developed to improve our understanding of the afferent sensory pathways from the stomach to the central nervous system that mediate gastric sensation in health and gastric disorders. This article reviews tests of gastric function and provides a basic description of the tests, the methodologies behind them, descriptions of the physiology that they assess, and their clinical utility.

Normal values for the satiety drinking test in healthy children between 5 and 15 years

In adults, a slow caloric drinking test has been proposed as a non-invasive tool to estimate gastric accommodation and to quantify meal-induced symptoms in functional dyspepsia (FD). The same test has been proposed for paediatric FD, but normal values are only available for adolescents and adults. The aim of the study was (i) to establish normal values for the satiety drinking test in young children and (ii) to study the influence of demographic factors. In all, 59 healthy children [27 girls; age range 5-16 years, body mass index (BMI) 17.4 +/- 2.5 kg m(-2)] were studied in the morning after an overnight fast. They drank a liquid nutrient meal (1.5 kcal mL(-1)) from beakers that were filled by a peristaltic pump filled at a rate of 15 mL min(-1) with. For every 5 min, satiety was scored on a graphic rating scale grade 0-5 (1 = threshold, 5 = maximum), until a score of 5 was reached. Values are given as mean +/- SEM and compared by t-test; correlation analysis was performed using Spearman rank test. All children performed the test as indicated except for one 5 years old who stopped prematurely for dislike of the taste. The endpoint was reached at 360 +/- 23 mL (540 +/- 34 kcal), and was age-dependent (Spearman r = 0.28, P = 0.03). No correlation was found between the maximum volume ingested and gender, weight, height or BMI. Age-dependent normal ranges were determined for ages 5-16 at 3-year intervals, and were found to increase with age. We established feasibility of and normal values for a non-invasive satiety drinking test in children with an age range of 5-15 years. This tool can now be used in the assessment of paediatric FD and eating disorders.

Pathophysiology and management of gastroparesis

Gastroparesis is characterized by upper gastrointestinal symptoms associated with delayed gastric emptying, without mechanical obstruction. However, symptoms do not correlate well with the magnitude of delay in gastric emptying. Diabetes mellitus and surgery are the most common causes, although more than 30% of cases are idiopathic. Coordination of insulin action with nutrient delivery is important in diabetics, as postprandial blood glucose levels and gastric emptying are interdependent, and gastroparesis probably represents a major cause of poor glycemic control. Scintigraphy is the gold standard for measuring gastric emptying. Current treatment mainly involves the use of prokinetic drugs. Pyloric botulinum toxin injection and gastric electrical stimulation require more evidence from controlled studies before their use can be recommended. Surgical options remain inadequately studied.

Gastroparesis: Current diagnostic challenges and management considerations

Gastroparesis refers to abnormal gastric motility characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common etiologies include diabetes, post-surgical and idiopathic. The most common symptoms are nausea, vomiting and epigastric pain. Gastroparesis is estimated to affect 4% of the population and symptomatology may range from little effect on daily activity to severe disability and frequent hospitalizations. The gold standard of diagnosis is solid meal gastric scintigraphy. Treatment is multimodal and includes dietary modification, prokinetic and anti-emetic medications, and surgical interventions. New advances in drug therapy, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. In this comprehensive review, we discuss gastroparesis with emphasis on the latest developments; from the perspective of the practicing clinician.

Comparison between manual and automated techniques for assessment of data from dynamic antral scintigraphy

OBJECTIVE

This work aimed at determining whether data from dynamic antral scintigraphy (DAS) yielded by a simple, manual technique are as accurate as those generated by a conventional automated technique (fast Fourier transform) for assessing gastric contractility.

METHODS

Seventy-one stretches (4 min) of "activity versus time" curves obtained by DAS from 10 healthy volunteers and 11 functional dyspepsia patients, after ingesting a liquid meal (320 ml, 437 kcal) labeled with technetium-99m (99mTc)-phytate, were independently analyzed by manual and automated techniques.

RESULTS

Data obtained by both techniques for the frequency of antral contractions were similar. Contraction amplitude determined by the manual technique was significantly higher than that estimated by the automated method, in both patients and controls. The contraction frequency 30 min post-meal was significantly lower in patients than in controls, which was correctly shown by both techniques.

CONCLUSIONS

A manual technique using ordinary resources of the gamma camera workstation, despite yielding higher figures for the amplitude of gastric contractions, is as accurate as the conventional automated technique of DAS analysis. These findings may favor a more intensive use of DAS coupled to gastric emptying studies, which would provide a more comprehensive assessment of gastric motor function in disease.

Disintegration of solid foods in human stomach

Knowledge of the disintegration of solid foods in human stomach is essential to assess the bioavailability of nutrients in the gastrointestinal (GI) tract. A comprehensive review of food gastric digestion, focusing on disintegration of solid foods, is presented. Most of the research reviewed in this paper is contained in the medical, pharmaceutical, food, and nutritional literature. Stomach physiology is briefly introduced, including composition and rheological properties of gastric contents, stomach wall motility in fed/fasted states, and hydrodynamic and mechanical forces that act on the ingested food. In vivo and in vitro methods used for studying food and drug digestion in GI are summarized. Stomach emptying rate, which controls the rate of absorption of nutrients, is highly related to the disintegration of foods. This topic is highlighted with focus on the important mechanisms and the influence of chemical and physical properties of foods. Future research in this area is identified to increase our fundamental understanding of the food digestion process in the stomach as related to the food composition, material properties such as texture and microstructure, and chemical characteristics. This information is necessary to develop new guidelines for seeking innovative processing methods to manufacture foods specifically targeted for health.

Effects of mitemcinal (GM-611), an orally active erythromycin-derived prokinetic agent, on delayed gastric emptying and postprandial glucose in a new minipig model of diabetes

AIMS

This study was conducted to evaluate the suitability of a new minipig model for investigating aspects of diabetes such as delayed gastric emptying and glucose metabolism abnormalities, and to test the effects of mitemcinal (GM-611), an orally active erythromycin-derived motilin receptor agonist, on gastric emptying and postprandial glucose in normal and diabetic minipigs.

METHODS AND RESULTS

Intravenous injection of 300 mg/kg streptozotocin (STZ) to 5-week-old minipigs induced moderate hyperglycemia (about 200 mg/dl) for >80 weeks without insulin treatment. Decreased insulin production (P<.05), increased area under the glucose curve (P<.05), and slower glucose disappearance (P<.05) were demonstrated, and there was no severe inhibition of body weight gain, liver failure, or renal failure. Gastric emptying was significantly delayed in diabetic minipigs (P<.05) at 80 weeks, but not at 40 weeks, post-STZ. Oral administration of mitemcinal (5 mg/kg) at 80 weeks accelerated gastric emptying and induced a similar postprandial glucose profile in normal and diabetic minipigs with delayed gastric emptying.

CONCLUSIONS

The new diabetic minipig model showed suitability for investigating diabetes, gastric emptying, and plasma glucose excursions. Since delayed gastric emptying and irregular plasma glucose excursions are characteristic of diabetic gastroparesis, the accelerating and regulating effects of mitemcinal on this model add to the existing evidence that mitemcinal is likely to be useful for treating diabetic gastroparesis.

Review article: gastroparesis

BACKGROUND

Gastroparesis is a chronic disorder caused by stomach pump failure and characterized by profound nausea, vomiting and epigastric pain. Most often, the cause is unapparent and of the known associations, diabetes is the most common. Diagnosis is usually made using an isotope-labelled test meal. Treatment is incremental and includes education, dietary support, prokinetic and antiemetic agents. There are novel approaches including gastric neurostimulation.

AIM

To review current concepts of gastric motor function, aetiology, investigation and treatment of gastroparesis.

METHODS

A systematic web-based review of the literature was undertaken using a lexicon of terms associated with gastroparesis.

RESULTS

There are few controlled studies of this condition. Little is known about causation or underlying nerve, muscle or pacemaker pathology. Idiopathic gastroparesis occurs most commonly in women and gastric emptying is often abnormal in diabetes. Isotopic gastric scintigraphy remains the gold standard investigation, but alternative tests are being developed. Treatment is multimodal and includes education, and nutritional support. There are no adequately powered controlled trials to support a particular drug regimen. In intractable gastroparesis, gastric neurostimulation appears to offer benefit.

CONCLUSION

Despite a significant progress in the past decade, further controlled trials are required into the therapeutic options available for treating this intriguing condition.

Effects of oral mitemcinal (GM-611), erythromycin, EM-574 and cisapride on gastric emptying in conscious rhesus monkeys

We assessed and compared the effects of oral mitemcinal (an orally active, erythromycin-derived motilin-receptor agonist; Code name: GM-611), erythromycin, EM-574 and cisapride on gastric emptying in conscious Rhesus monkeys using the acetaminophen method. Mitemcinal and erythromycin induced significant, dose-dependent increases in indices of gastric emptying, but mitemcinal required a much lower dose for the same effect. Cisapride induced a bell-shaped dose response, and EM-574, a potent erythromycin derivative and originally developed as an enteric coated formulation, had little effect when it was given orally uncoated. Since our previous study showed that response to motilin is similar in Rhesus monkeys and humans, these results suggest that oral mitemcinal may be effective for the treatment of symptoms in human disorders related to delayed gastric emptying (e.g., functional dyspepsia and gastroparesis). Combined with the results of other studies, these results suggest that mitemcinal may be able to replace the withdrawn drug, cisapride, as the drug of choice for treating delayed gastric emptying.

Dyspepsia in childhood and adolescence: insights and treatment considerations

Functional dyspepsia (FD) is common in children, with as many as 80% of those being evaluated for chronic abdominal pain reporting symptoms of epigastric discomfort, nausea, or fullness. It is known that patients with persistent complaints have increased comorbidities such as depression and anxiety. The interaction with psychopathologic variables has been found to mediate the association between upper abdominal pain and gastric hypersensitivity. These observations suggest that abnormal central nervous system processing of gastric stimuli may be a relevant pathophysiologic mechanism in FD. Despite increased understanding, no specific therapy has emerged; however, recent nonpharmacological-based options such as hypnosis may be effective. Novel approaches, including dietary manipulation and use of nutraceuticals such as ginger and Iberogast (Medical Futures Inc., Ontario, Canada), may also be considered.

Gastric stasis occurs in spontaneous, visually induced, and interictal migraine

OBJECTIVE

To evaluate and compare gastric motility and emptying during spontaneous migraine to previous observations from induced migraine.

BACKGROUND

We have previously demonstrated a delay in gastric emptying both during the interictal period and during an induced migraine. A limitation noted in these studies was whether there are differences gastrointestinally during a visually induced migraine compared to spontaneous migraines. To address this, 9 additional studies have been performed to ascertain if there is a similar delay during spontaneous migraine

METHODS

Gastric scintigraphy using a standard meal was performed in 3 subjects during 3 periods: spontaneous migraine, induced migraine, and interictal period.

RESULTS

On average, the time to half emptying was delayed during spontaneous migraine (124 minutes), during induced migraine (182 minutes), and during the interictal period migraine (243 minutes) compared to normative values established at our center (112 minutes). On average, similar gastric slowing was seen in all 3 groups when the percentage of nuclear material remaining in the stomach at 2 hours was measured.

CONCLUSIONS

This study provides additional evidence of gastric stasis in migraineurs interictally during induced and spontaneous migraine.

13C-acetic acid is more sensitive than 13C-octanoic acid for evaluating gastric emptying of liquid enteral nutrient formula by breath test in conscious rats

Breath test using 13C-labeled compound has been used as a convenient method to evaluate gastric emptying. 13C-Labeled acetic acid or octanoic acid has been used in clinic. However, there is few report comparing two compounds. This study aimed to compare 13C-acetic acid and 13C-octanoic acid in newly-constituted breath test for monitoring gastric emptying in conscious rats. After fasting, rats were orally administered Racol (liquid enteral nutrient formula) containing 13C-labeled compound (same molar of 13C-acetic acid or 13C-octanoic acid) and housed in a chamber. The expired air in the chamber was collected in a breath-sampling bag using a tube and aspiration pump. The level of 13CO2 in the expired air was measured using an infrared spectrometer at appropriate intervals for 120 min. Expired 13CO2 air from 13C-acetic acid changed at significantly higher levels than that from 13C-octanoic acid. Cmax and AUC120 min values of expired 13CO2 from 13C-acetic acid were significantly higher than those from 13C-octanoic acid, but Tmax was not different between them. These results show that 13C-acetic acid is more sensitive for monitoring gastric emptying than 13C-octanoic acid in liquid test meal although both acids clearly monitored gastric emptying.

Intersubject and intrasubject variability of gastric volumes in response to isocaloric liquid meals in functional dyspepsia and health

Gastric emptying (GE) has a considerable variability, but data on reproducibility of gastric volume measurements are sparse. We aimed to study the reproducibility of postprandial gastric volume responses and GE using magnetic resonance imaging (MRI) in healthy controls (HC) and patients with functional dyspepsia (FD). Eight HC and eight FD patients underwent a MRI study on two occasions. MR images were acquired in seated position before and up to 120 min after liquid meal administration (200 mL, 300 kcal). Fasting (V0), initial postprandial stomach volumes (V1), volume changes (V1 - V0) and meal emptying half-times (T 1/2) were determined. Intersubject and intrasubject coefficients of variation (CV(inter), CV(intra)) and Pearson's correlation coefficients (r) were calculated. T 1/2 on both occasions were (mean +/- SD) 113 +/- 28 and 121 +/- 30 min in HC (ns) and 127 +/- 31 and 128 +/- 37 min in FD (ns), respectively. In HC, CV(inter), CV(intra), r were 31%, 23%, 0.49 for V0; 13%, 7%, 0.68 for V1; 10%, 4%, 0.71 for V1 - V0 and 25%, 7%, 0.90 for T 1/2. In FD these parameters were for V0: 42%, 41%, -0.06; for V1: 18%, 10%, 0.40; for V1 - V0: 20%, 14%, 0.74 and for T 1/2: 26%, 10%, 0.84. The stomach accommodates to a given meal volume, resulting in similar and reproducible postprandial volumes within- and between-subjects. MRI provides reproducible measurements of gastric volume responses in health and disease.

[Diagnostic and therapeutic approach to patients with gastroparesis]

Gastroparesis is a chronic alteration of gastric motility characterized by symptoms suggestive of mechanical obstruction and delayed gastric emptying in the absence of obstruction. Gastroparesis can be idiopathic or attributable to neuropathy or myopathy as in diabetes mellitus and scleroderma or can occur after vagotomy. Diagnosis is based on symptoms (nausea, vomiting, abdominal distension and early satiety), physical examination (capotement) and on complementary investigations, the procedure of choice being isotope gastric emptying tests. Treatment depends on the clinical repercussions. In most patients, gastroparesis can be controlled by prokinetic drugs, dietary measures, exclusion of drugs that alter gastric emptying, and exhaustive control of blood glucose levels. In patients with severe gastroparesis, hospital nutritional measures (intravenous and/or enteral), gastric decompression and intravenous antiemetic and prokinetic agents are required. Aggressive nutritional therapies (parenteral or enteral nasojejunal nutrition), intrapyloric injection of botulinum toxin, implantation of a gastric stimulation device, or gastrectomy should only be used in patients unresponsive to conservative treatment or if there is selective alteration of gastric motility.

The impact of admission diagnosis on gastric emptying in critically ill patients

Introduction

Disturbed gastric emptying (GE) occurs commonly in critically ill patients. Admission diagnoses are believed to influence the incidence of delayed GE and subsequent feed intolerance. Although patients with burns and head injury are considered to be at greater risk, the true incidence has not been determined by examination of patient groups of sufficient number. This study aimed to evaluate the impact of admission diagnosis on GE in critically ill patients.

Methods

A retrospective review of patient demographics, diagnosis, intensive care unit (ICU) admission details, GE, and enteral feeding was performed on an unselected cohort of 132 mechanically ventilated patients (94 males, 38 females; age 54 ± 1.2 years; admission Acute Physiology and Chronic Health Evaluation II [APACHE II] score of 22 ± 1) who had undergone GE assessment by ¹³C-octanoic acid breath test. Delayed GE was defined as GE coefficient (GEC) of less than 3.20 and/or gastric half-emptying time (t50) of more than 140 minutes.

Results

Overall, 60% of the patients had delayed GE and a mean GEC of 2.9 ± 0.1 and t50 of 163 ± 7 minutes. On univariate analysis, GE correlated significantly with older age, higher admission APACHE II scores, longer length of stay in ICU prior to GE measurement, higher respiratory rate, higher FiO₂ (fraction of inspired oxygen), and higher serum creatinine. After these factors were controlled for, there was a modest relationship between admission diagnosis and GE (r = 0.48; P = 0.02). The highest occurrence of delayed GE was observed in patients with head injuries, burns, multi-system trauma, and sepsis. Delayed GE was least common in patients with myocardial injury and non-gastrointestinal post-operative respiratory failure. Patients with delayed GE received fewer feeds and stayed longer in ICU and hospital compared to those with normal GE.

Conclusion

Admission diagnosis has a modest impact on GE in critically ill patients, even after controlling for factors such as age, illness severity, and medication, which are known to influence this function.