Is the 13C-acetate breath test a valid procedure to analyse gastric emptying in children?

The Evaluation of Gastric Emptying Using the 13 C-Acetate Breath Test in Neurologically Impaired Patients - A Focus on the Stomach Function and Morphology

PURPOSE

We explored factors affecting gastric emptying in neurologically impaired (NI) patients using the 13C-acetate breath test.

METHODS

Twenty-four NI patients were classified by the presence of gastroesophageal reflux disease (GERD), which was treated by fundoplication plus gastrostomy, or the absence of GERD, which was treated by gastrostomy alone, along with gastric malposition involving cascade stomach and organoaxial gastric volvulus (OGV). Gastric emptying parameters (GEPs), which were the emptying half time (T 1/2 , minute), the lag phase time (T lag , minute), and the gastric emptying coefficient (GEC), were measured before and after surgery. We evaluated the relationship between GEPs and GERD, gastric malposition, and surgical intervention. All data were expressed as the median (interquartile range).

RESULTS

The T1/2 and GEC of patients with OGV were significantly worse than in those without OGV before surgery (T1/2 with OGV: 241.3 [154.9, 314.3] vs. T1/2 without OGV: 113.7 [105.2, 151.4], p = 0.01, GEC with OGV: 3.19 [2.46, 3.28] vs. GEC without OGV: 3.65 [3.24, 3.90], p = 0.02). GERD and cascade stomach were not associ ated with GEPs. The GEPs of all NI patients showed no significant difference between before and after surgery. The surgical change in T1/2 (ΔT 1/2 ) in the patients with OGV was significantly lower than in those without OGV (ΔT1/2 with OGV: -47.1 [-142.7, -22.1] vs. ΔT1/2 without OGV: -3.78 [-26.6, 12.0], p = 0.03).

CONCLUSION

Stomach malposition, such as OGV, seems to affect gastric emptying and may be improved by surgi cal intervention.

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

Complications in patients with neurological impairment after gastrostomy

BACKGROUND

Neurological impairment (NI) is responsible for most conditions that require a permanent gastrostomy tube. The present study assessed the occurrence of short- and long-term complications after video-assisted gastrostomy (VAG) in patients with NI.

METHODS

The incidence of short- (<6 months) and long-term (over 2 years) complications of VAG were analyzed in a retrospective study. The differences between the incidence of the complications of VAG according to the age at surgery (≤15 years vs. ≥16 years) were also evaluated. The short- and long-term complications observed were granulation tissue formation, infection requiring antibiotic treatment, skin problems, perigastrostomy leakage, vomiting, accidental tube dislodgement, dumping syndrome, ileus, and peritonitis.

RESULTS

Eighty-two patients were evaluated for short- and long-term complications. The long-term complication rate was significantly lower than the short-term complication rate (P = 0.0026). Onodera's prognostic nutritional index before VAG in patients with long-term complications was significantly lower than in patients without such complications (P = 0.046). The incidence of long-term granulation tissue formation, infection, and vomiting were significantly lower than those of similar short-term complications. Long-term skin problems were associated with short-term skin problems (odds ratio: 18.95; 95% confidence interval: 4.53-92.98; P < 0.001). The number of patients ≥16 years old with short- and long-term skin problems was significantly higher than in patients ≤15 years old (P = 0.0014 and P = 0.0073, respectively).

CONCLUSIONS

The incidence rate of granulation tissue formation and infection after VAG were lower in the long term than in the short term. However, patients ≥16 years old presented with persistent complications.

European guideline on indications, performance and clinical impact of 13 C-breath tests in adult and pediatric patients: An EAGEN, ESNM, and ESPGHAN consensus, supported by EPC

Introduction

¹³C‐breath tests are valuable, noninvasive diagnostic tests that can be widely applied for the assessment of gastroenterological symptoms and diseases. Currently, the potential of these tests is compromised by a lack of standardization regarding performance and interpretation among expert centers.

Methods

This consensus‐based clinical practice guideline defines the clinical indications, performance, and interpretation of ¹³C‐breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 43 experts from 18 European countries. Consensus on individual statements and recommendations was established if ≥ 80% of reviewers agreed and <10% disagreed.

Results

The guideline gives an overview over general methodology of ¹³C‐breath testing and provides recommendations for the use of ¹³C‐breath tests to diagnose Helicobacter pylori infection, measure gastric emptying time, and monitor pancreatic exocrine and liver function in adult and pediatric patients. Other potential applications of ¹³C‐breath testing are summarized briefly. The recommendations specifically detail when and how individual ¹³C‐breath tests should be performed including examples for well‐established test protocols, patient preparation, and reporting of test results.

Conclusion

This clinical practice guideline should improve pan‐European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, this guideline identifies areas of future clinical research involving the use of ¹³C‐breath tests.

Gastric emptying in healthy children using the Spirulina breath test: The impact of gender, body size, and pubertal development

BACKGROUND

There are no pediatric norms for gastric emptying (GE) measured by nuclear scintigraphy. The ¹³ C-labeled, stable isotope GE breath test (GEBT) is a non-radioactive alternative. We aimed to determine normative GEBT ranges in a cohort of healthy children and examine the influence of age, gender, puberty, and body surface area (BSA).

METHODS

Healthy children ages 8-18 years completed the [¹³ C]-Spirulina platensis GEBT after an overnight fast. Breath samples were collected at baseline, every 15 min × 1 h, then every 30 min for 4 h total. The ¹³ CO₂ excretion rate was determined by the change in ¹³ CO₂ /¹² CO₂ over time in each breath sample, expressed as kPCD (Percent ¹³ C Dose excreted/min). A mixed model with random time was used for multivariable analysis and outcome fit into a quadratic model.

KEY RESULTS

The 100 subjects completed the test meal within allotted time. Median (IQR) age was 13.5 (11.3-15.5) years; 51% were female. Females had lower ¹³ CO₂ excretion rates (slower GE) than males across time (p < 0.001) while decreased excretion rates correlated with higher BSA (p = 0.015). Gender differences were also noted within pubertal stages with females showing slower GE. Multivariable analysis suggested that pre-pubertal children have faster GE than both peri- and post-pubertal groups (p < 0.0001).

CONCLUSIONS & INFERENCES

Gender, puberty, and BSA influence GE rates in healthy children more than age. Although further data are needed, pubertal stage and hormonal influences may be unique factors to consider when assessing GE in children.

13 C-gastric emptying breath tests: Clinical use in adults and children

¹³ C-gastric emptying breath tests (¹³ C-GEBT) are validated, reliable, and non-invasive tools for measurement of gastric emptying (GE) velocity of solids and liquids without radiation exposure or risk of toxicity. They are recommended and routinely used for clinical purposes in adult as well as pediatric patients and can be readily performed onsite or even at the patient's home. However, the underlying methodology is rather complex and test results can be influenced by dietary factors, physical activity, concurrent diseases, and medication. Moreover, epidemiological factors can influence gastric emptying as well as production and exhalation of ¹³ CO₂ , which is the ultimate metabolic product measured for all ¹³ C-breath tests. Accordingly, in this issue of Neurogastroenterology & Motility, Kovacic et al. report performance of the ¹³ C-Spirulina breath test in a large group of healthy children and show significant effects of gender, pubertal status, and body size on test results. The purpose of this mini-review is to evaluate the clinical use of ¹³ C-GEBT in adults and children, exploring available protocols, analytical methods, and essential prerequisites for test performance, as well as the role of GE measurements in the light of the current discussion on relevance of delayed GE for symptom generation.

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.

Effects of starvation and short-term refeeding on gastric emptying and postprandial blood glucose regulation in adolescent girls with anorexia nervosa

Postprandial glucose is reduced in malnourished patients with anorexia nervosa (AN), but the mechanisms and duration for this remain unclear. We examined blood glucose, gastric emptying, and glucoregulatory hormone changes in malnourished patients with AN and during 2 wk of acute refeeding compared with healthy controls (HCs). Twenty-two female adolescents with AN and 17 age-matched female HCs were assessed after a 4-h fast. Patients were commenced on a refeeding protocol of 2,400 kcal/day. Gastric emptying (¹³C-octanoate breath test), glucose absorption (3-O-methylglucose), blood glucose, plasma glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), insulin, C-peptide, and glucagon responses to a mixed-nutrient test meal were measured on admission and 1 and 2 wk after refeeding. HCs were assessed once. On admission, patients had slower gastric emptying, lower postprandial glucose and insulin, and higher glucagon and GLP-1 than HCs ( P < 0.05). In patients with AN, the rise in glucose (0-30 min) correlated with gastric emptying ( P < 0.05). With refeeding, postprandial glucose and 3-O-methylglucose were higher, gastric emptying faster, and baseline insulin and C-peptide less ( P < 0.05), compared with admission. After 2 wk of refeeding, postprandial glucose remained lower, and glucagon and GLP-1 higher, in patients with AN than HCs ( P < 0.05) without differences in gastric emptying, baseline glucagon, or postprandial insulin. Delayed gastric emptying may underlie reduced postprandial glucose in starved patients with AN; however, postprandial glucose and glucoregulatory hormone changes persist after 2 wk of refeeding despite improved gastric emptying. Future research should explore whether reduced postprandial glucose in AN is related to medical risk by examining associated symptoms alongside continuous glucose monitoring during refeeding.

Severe Delayed Gastric Emptying Induces Non-acid Reflux up to Proximal Esophagus in Neurologically Impaired Patients

Background/Aims

The aim of this study is to investigate the degree of delayed gastric emptying (DGE) and evaluate how the severity of DGE affects gastroesophageal reflux disease (GERD) in neurologically impaired (NI) patients utilizing 24-hour multichannel intraluminal impedance pH measurements (pH/MII) and ¹³C-acetate breath test (¹³C-ABT) analyses.

Methods

¹³C-ABT and pH/MII were conducted in 26 NI patients who were referred to our institution due to suspected GERD. At first, correlation analyses were performed to investigate the correlation between the ¹³C-ABT parameters and the clinical or pH/MII parameters. Thereafter, all patients were divided into 2 groups (DGE and severe DGE [SDGE] group) according to each cut off half emptying time (t_1/2, 90-170 minutes). Each pH/MII parameter was compared between the 2 groups in each set-up cutoff t_1/2.

Results

The mean t_1/2 of all patients was 215.5 ± 237.2 minutes and the t_1/2 of 24 (92.3%) patients were > 100 minutes. Significant moderate positive correlations were observed between both t_1/2 and lag phase time and the non-acid reflux related parameters. Furthermore, the patients in the SDGE group demonstrated higher non-acid reflux related parameters than those of the DGE groups when the cutoff was t_1/2 ≥ 140 minutes.

Conclusion

The present study demonstrated that GE with t_1/2 ≥ 140 minutes was related to an increase of non-acid exposure reaching up to the proximal esophagus in NI patients, and indicating that NI patients with SDGE might have a high risk of non-acid GERD.

Does laparoscopy-aided gastrostomy placement improve or worsen gastroesophageal reflux in patients with neurological impairment?

BACKGROUND/PURPOSE

The purpose of this study was to retrospectively investigate whether laparoscopy-aided gastrostomy placement (LGP) improved or worsened gastroesophageal reflux (GER) in neurological impairment (NI) patients.

METHODS

Subjects included 26 NI patients nourished via nasogastric tubes (age, 1-17years; median, 6years). They were divided into groups based on the percentage of time with an esophageal pH <4.0 (reflux index: RI) before LGP: Group 1 (GI, n=13), RI <5.0%; Group II (GH, n=13), RI ≥5.0%. Acid/nonacid reflux episodes (RE) were evaluated using combined pH-multichannel intraluminal impedance (pH-MII) monitoring, and gastric emptying was measured with the C breath test before and after LGP.

RESULTS

RI and number of RE evaluated with pH analyses and number of total/acid distal and proximal bolus RE with pH-MH increased significantly in GI. RI and acid clearance time with pH analyses and number of total bolus RE with pH-MII decreased significantly in GH. Gastric emptying parameters did not change significantly in GI, whereas the half-gastric emptying time and gastric emptying coefficient improved significantly in GH.

CONCLUSION

LGP reduces GER in NI patients with pathological GER by improving gastric emptying, although it has a paradoxical influence on those without pathological GER.

Gastric emptying measurement of liquid nutrients using the (13)C-octanoate breath test in critically ill patients: a comparison with scintigraphy

PURPOSE

Scintigraphy is considered the most accurate technique for the measurement of gastric emptying (GE) but, for patients in the intensive care unit, it is technically demanding, involves radiation and can interfere with care. The (13)C-octanoate breath test ((13)C-OBT) is a simple, non-invasive technique that does not involve radiation exposure.

AIM

To evaluate the performance of the (13)C-OBT in the assessment of GE in critically ill patients.

METHODS

The GE was assessed in 33 mechanically ventilated patients (23 M; 54.3 ± 3.0 yrs; APACHE II: 22.0 ± 1.1). Following test meal administration (100 ml Ensure(®)), concurrent scintigraphic measurement and breath samples ((13)C-OBT) were collected over 4 h. Scintigraphic meal retention was determined and the gastric emptying coefficient (GEC) and half emptying time [t50(BT)] were calculated for the (13)C-OBT. Delayed GE was defined as meal retention >13 % at 180 min.

RESULTS

Delayed GE was identified in 27/33 patients. Meal retention correlated modestly with t50(BT) (r = 0.55-0.66; P < 0.001) and well with GEC (r = -0.63 to -0.74; P < 0.0001). The strength of agreement between the two techniques was highest between GEC and retention at 120 min. The best cut-off GEC for defining delayed GE was 3.25 (AUC = 0.75; 95 % CI = 0.52-0.99; P = 0.05), with 89 % sensitivity and 67 % specificity to detect delayed GE. The GE was delayed in all (23/23) patients with feed intolerance (GRV > 250 ml) on scintigraphy and 91 % (21/23) patients on (13)C-OBT.

CONCLUSION

In critical illness, there was a correlation between (13)C-OBT and gastric scintigraphy, with GEC performing as a better and more sensitive marker of detecting delayed GE than t50. However the relatively wide 95 % confidence intervals suggest that (13)C-OBT is more suitable as a technique to assess GE in a group setting for research studies rather than for individual patients in clinical practice.

Early Effect of Single-dose Sitagliptin Administration on Gastric Emptying: Crossover Study Using the (13)C Breath Test

Background/Aims

The gastrointestinal motility effects of endogenous incretin hormones enhanced by dipeptidyl peptidase-IV (DPP-IV) inhibitors have not yet been sufficiently investigated. The aim of this study was to determine whether single pre-prandial sitagliptin, the DPP-IV inhibitor, administration might have an effect on the rate of liquid gastric emptying using the ¹³C-acetic acid breath test.

Methods

Ten healthy male volunteers participated in this randomized, two-way crossover study. The subjects fasted for overnight and were randomly assigned to receive 50 mg sitagliptin 2 hours before ingestion of the liquid test meal (200 kcal per 200 mL, containing 100 mg ¹³C-acetate) or the test meal alone. Under both conditions, breath samples were collected for 150 minutes following the meal. Liquid gastric emptying was estimated by the values of the following parameters: the time required for 50% emptying of the labeled meal (T_1/2), the analog to the scintigraphy lag time for 10% emptying of the labeled meal (T_lag), the gastric emptying coefficient and the regression-estimated constants (β and κ), calculated by using the ¹³CO₂ breath excretion curve using the conventional formulae. The parameters between the 2 test conditions were compared statistically.

Results

No significant differences in the calculated parameters, including T_1/2, T_lag, gastric emptying coefficient or β and κ, were observed between the 2 test conditions.

Conclusions

The present study revealed that single-dose sitagliptin intake had no significant influence on the rate of liquid gastric emptying in asymptomatic volunteers.

Gastric emptying of water in children with severe functional fecal retention

The objective of this study was to evaluate gastric emptying (GE) in pediatric patients with functional constipation. GE delay has been reported in adults with functional constipation. Gastric emptying studies were performed in 22 children with chronic constipation, fecal retention and fecal incontinence, while presenting fecal retention and after resuming regular bowel movements. Patients (18 boys, median age: 10 years; range: 7.2 to 12.7 years) were evaluated in a tertiary pediatric gastroenterology clinic. Gastric half-emptying time of water (reference range: 12 ± 3 min) was measured using a radionuclide technique immediately after first patient evaluation, when they presented fecal impaction (GE₁), and when they achieved regular bowel movements (GE₂), 12 ± 5 weeks after GE₁. At study admission, 21 patients had reported dyspeptic symptoms, which were completely relieved after resuming regular bowel movements. Medians (and interquartile ranges) for GE₁ and GE₂ were not significantly different [27.0 (16) and 27.5 (21) min, respectively (P = 0.10)]. Delayed GE seems to be a common feature among children with chronic constipation and fecal retention. Resuming satisfactory bowel function and improvement in dyspeptic symptoms did not result in normalization of GE data.

Is there a difference in gastric emptying between myotonic dystrophy type 1 patients with and without gastrointestinal symptoms?

Gastrointestinal symptoms are frequent complaints in patients with myotonic dystrophy type 1 (MyD1) and may be associated with reduced gastrointestinal motility caused by smooth muscle dysfunction. Although previous studies have found delayed gastric emptying (GE) in MyD1 patients, the relationship between GE and symptoms has been unclear. We investigated GE in 23 MyD1 patients and 20 healthy volunteers using the 13C-acetate breath test. The MyD1 patients were divided into two groups: those with gastrointestinal symptoms (n = 9) and those without gastrointestinal symptoms (n = 14). The GE function was estimated using the 13C-acetate breath test as half-emptying time (HET) and peak time of the 13C-%-dose-excess curve (T max). GE (HET and T max) was more significantly delayed in patients with MyD1 than in the controls. The GE in MyD1 patients with gastrointestinal symptoms was significantly delayed compared to those without gastrointestinal symptoms. The GE in MyD1 patients with gastrointestinal symptoms was more significantly delayed than in the controls. The GE was significantly delayed in MyD1 patients with gastrointestinal symptoms for >5 years as compared to those with the disease for <5 years, while GE of MyD1 patients without gastrointestinal symptoms did not correlate with the duration of the disease. The GE in MyD1 patients did not correlate with the muscular disability rating scale. These findings suggest that impairment of GE evolves over time and that the progression of delayed GE and skeletal muscle impairment are independent. Smooth muscle impairment may be affected at an earlier stage in MyD1.

Is there a difference in gastric emptying between Parkinson's disease patients under long-term L-dopa therapy with and without motor fluctuations? An analysis using the 13C-acetate breath test

The mechanism underlying the motor fluctuations that develop after long-term L-dopa therapy is not fully known. It has been speculated that malabsorption of L-dopa from the small intestine occurs. It was reported that gastric retention in Parkinson's disease (PD) patients with motor fluctuations is increased as compared with that in PD without fluctuations. Because L-dopa therapy may worsen the symptoms of delayed gastric emptying (GE), it was not clear whether the delayed GE of PD patients with motor fluctuation was affected by L-dopa therapy. We assessed GE in PD patients with and without motor fluctuations. We investigated GE in 40 patients with PD under long-term L-dopa therapy, 20 fluctuators with "delayed-on" and "noon" phenomena, 20 nonfluctuators, and 20 healthy volunteers. GE was examined by the 13C-acetate breath test ((13)CABT) [the half emptying time (HET), the peak time of the (13)C-%-dose-excess curve (T(max))], with expirations collected for 4 h after a test meal and analyzed for (13)CO(2) using an infrared (IR) spectrophotometer. The T(max) of GE as assessed using the (13)C-ABT was significantly delayed in all PD patients as compared with controls (P = 0.002). The HET was significantly delayed in all PD patients as compared with controls (P < 0.001). The T(max) and HET were not significantly delayed in PD patients with motor fluctuations as compared with PD patients without motor fluctuations. These results demonstrated that GE is commonly delayed in PD patients with long-term L-dopa therapy. Delayed GE does not differ between PD patients with and without motor fluctuations. This finding demonstrated that the motor fluctuation in PD may not be influenced by GE.

Nissen fundoplication for gastroesophageal reflux: No deterioration of gastric emptying measured by C-acetate breath test

Aim:

To study the gastric emptying 30 days after laparoscopic Nissen fundoplication (NF) in gastroesophageal reflux.

Materials and Methods:

Three patients were evaluated with ¹³C-acetate breath test (ABT) performed pre and post-NF. The liquid test meal consisted of Racol^™ mixed with ¹³C-acetate.

Results:

In the patient without neurological impairment (NI), the preoperative t_½ex and t lag were 0.900 and 0.510 hours, respectively. The postoperative t_½ex and t lag were 0.959 and 0.586 hours, respectively. In one patient with NI, the preoperative t_½ex and t lag were 1.828 and 1.092 hours, respectively. The postoperative t_½ex and t lag were 2.081 and 1.025 hours, respectively. In the other patient with NI, the preoperative t_½ex and t lag were 2.110 and 0.980 hours, respectively. The postoperative t_½ex and t lag were 1.118 and 0.415 hours, respectively.

Conclusions:

Our findings suggest that ¹³C-ABT parameters did not worsen in any of the children after laparoscopic NF.

Is there a delayed gastric emptying of patients with early-stage, untreated Parkinson's disease? An analysis using the 13C-acetate breath test

During the pre-symptomatic stage of Parkinson's disease (PD), the idiopathic PD related abnormal synuclein immunostaining is confined to the medulla oblongata and olfactory bulb, according to Braak. In the study of the enteric nervous system of PD, it has reported that Lewy bodies were found in the Auerbach's and Meissner's plexuses. These lesions may cause dysfunction of the gastrointestinal tract (GI) as pre-clinical symptoms of PD. However, because L: -dopa therapy itself may worsen the symptoms of the digestive tract function, it is needed to evaluate the gastrointestinal tract function in patients with early-stage, untreated (de novo) PD. In the present study, using the (13)C-acetate breath test ((13)C-ABT), we investigated gastric emptying in 20 untreated, early-stage PD patients and 40 treated, advanced-stage PD patients, and 20 healthy volunteers. Gastric emptying was examined by the (13)C-ABT [the half emptying time (HET), the peak time of the (13)C% dose-excess curve (T (max))]. The T (max) and HET of gastric emptying as assessed using the (13)C-ABT was significantly delayed in untreated, early-stage PD patients as compared to the controls (P < 0.001). The T (max) and HET of gastric emptying were not significantly delayed in untreated, early-stage PD patients as compared to treated, advanced-stage PD patients. The results demonstrated that delay in gastric emptying did not differ between untreated, early-stage and treated, advanced-stage PD patients. Gastric emptying of untreated, early-stage PD is already delayed. Delayed gastric emptying may be one of markers of the pre-clinical stage of PD.

Effects of smoking cessation on gastric emptying in smokers

BACKGROUND

Smoking cessation can lead to changes in appetite and weight gain in some patients; thus, smoking cessation may alter gastrointestinal motility. Effects of smoking cessation on gastric emptying in smokers have not been established.

AIM

This study sought to determine how smoking cessation affects gastric emptying in smokers.

METHODS

Participant group comprised 53 habitual smokers and 12 healthy nonsmokers. Habitual smokers were treated for 2 months with transdermal nicotine patches. Gastric emptying was studied using C acetate breath tests at the beginning of the study, and at 1 week and 9 weeks after cessation of patch use. Maximal CO2 excretion time (Tmax), CO2 excretion half-life (T1/2), and parameters beta and kappa, representing initial and subsequent gastric-emptying phases, respectively, were determined using conventional formulae.

RESULTS

Before smoking cessation, Tmax was reached significantly later in smokers (0.94+/-0.3 h, P=0.014) than in controls (0.89+/-0.1 h). At 1 week after the end of treatment, Tmax was significantly decreased (from 1.05+/-0.32 h to 0.72+/-0.64 h, P=0.003). T1/2 also tended to decrease, but not significantly. Although beta was decreased significantly (from 2.46+/-0.40 to 2.17+/-0.58, P=0.022), kappa was unchanged. However, by 9 weeks after the end of treatment, Tmax (1.28+/-0.69 h) had increased to levels seen before treatment.

CONCLUSIONS

Smoking cessation temporarily accelerates gastric emptying, and decreases in beta suggest that initial-phase gastric emptying accelerates after smoking cessation. The temporary acceleration of gastric emptying after smoking cessation may be involved in the temporary increase in appetite and weight gain seen after smoking cessation.

Impact of rikkunshito, an herbal medicine, on delayed gastric emptying in profoundly handicapped patients

PURPOSE

Rikkunshito is used to treat functional dyspepsia in adults. This study investigated the effects of rikkunshito on delayed gastric emptying in handicapped patients.

METHODS

A retrospective review was performed in nine profoundly handicapped patients (aged 1-19 years). All were diagnosed with delayed gastric emptying based on their half gastric emptying time (T(1/2)) over 90 min. Gastric emptying was evaluated after the ingestion of liquid meals using the (13)C-acetate breath test and the BreathID system. Participants were given rikkunshito [0.3 g/(kg day)] with the aim of accelerating gastric emptying. Parameters related to gastric emptying before and during rikkunshito administration were compared using the Wilcoxon signed-rank test. Data were expressed as the median (range).

RESULTS

Emesis and hematemesis were relieved with rikkunshito administration in four symptomatic patients. The T(1/2) and T(lag) decreased significantly during rikkunshito administration from 115 min (94-167 min) to 107 min (64-66 min; p = 0.02), and from 60 min (42-90 min) to 47 min (29-59 min; p = 0.03), respectively. The gastric emptying coefficient did not show a significant change [3.1 (2.8-3.8) vs. 3.2 (2.6-4.0), p = 0.15)] with rikkunshito treatment.

CONCLUSION

The administration of rikkunshito resulted in symptomatic relief and improved gastric emptying in profoundly handicapped patients with delayed gastric emptying.

Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

OBJECTIVE

To develop a North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) international consensus on the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

METHODS

An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which developed these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies. The committee convened in face-to-face meetings 3 times. Consensus was achieved for all recommendations through nominal group technique, a structured, quantitative method. Articles were evaluated using the Oxford Centre for Evidence-based Medicine Levels of Evidence. Using the Oxford Grades of Recommendation, the quality of evidence of each of the recommendations made by the committee was determined and is summarized in appendices.

RESULTS

More than 600 articles were reviewed for this work. The document provides evidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

CONCLUSIONS

This document is intended to be used in daily practice for the development of future clinical practice guidelines and as a basis for clinical trials.

(13)C-phenylalanine breath test correlates with liver fibrosis in postoperative biliary atresia

BACKGROUND

Values derived from the (13)C-phenylalanine breath test (PBT) may serve as an index for liver fibrosis and clinically predictive readings for liver diseases in adults. In the present study the PBT was conducted in postoperative biliary atresia (BA) children to evaluate phenylalanine metabolism in the liver, and the results based on biochemical data, especially the index on liver fibrosis, were compared with PBT findings.

METHODS

Hepatofunctional evaluations were conducted in 10 postoperative BA children with moderate (group B; n = 4) and severe (group A; n = 6) liver dysfunction, and the PBT results were compared with those of 13 normal healthy children (group C). Subjects were orally given single-bolus (13)C-phenylalanine at 3.5 mg/kg (maximum dosing: 100 mg) in the morning. Time-related exhaled gas was periodically collected until 120 min after dosing. The (13)CO(2) levels were monitored with gas chromatography-mass spectrometry before and after administration, and the (13)C excretion rate, (13)C cumulative excretion and time of maximum (13)C excretion rate were monitored accordingly.

RESULTS

Total bile acid, hyaluronic acid, type IV collagen 7S, total bilirubin or albumin and the PBT findings were significantly correlated. The PBT findings in group A were significantly lower those of group B, indicating that phenylalanine metabolism was markedly attenuated in the former.

CONCLUSION

The PBT values correlated well with liver fibrosis in postoperative BA children. Because PBT is a non-invasive approach, results from this method may serve as a useful and reliable index for post-surgical monitoring of children operated on for liver fibrosis.

Reliability of the ICRP'S dose coefficients for members of the public: IV. basis of the human alimentary tract model and uncertainties in model predictions

The biokinetic and dosimetric model of the gastrointestinal (GI) tract applied in current documents of the International Commission on Radiological Protection (ICRP) was developed in the mid-1960s. The model was based on features of a reference adult male and was first used by the ICRP in Publication 30, Limits for Intakes of Radionuclides by Workers (Part 1, 1979). In the late 1990s an ICRP task group was appointed to develop a biokinetic and dosimetric model of the alimentary tract that reflects updated information and addresses current needs in radiation protection. The new age-specific and gender-specific model, called the Human Alimentary Tract Model (HATM), has been completed and will replace the GI model of Publication 30 in upcoming ICRP documents. This paper discusses the basis for the structure and parameter values of the HATM, summarises the uncertainties associated with selected features and types of predictions of the HATM and examines the sensitivity of dose estimates to these uncertainties for selected radionuclides. Emphasis is on generic biokinetic features of the HATM, particularly transit times through the lumen of the alimentary tract, but key dosimetric features of the model are outlined, and the sensitivity of tissue dose estimates to uncertainties in dosimetric as well as biokinetic features of the HATM are examined for selected radionuclides.

Validity of 13C octanoic acid breath test for measurement of solid meal gastric emptying time in children

BACKGROUND/PURPOSE

It is important to establish a physiologic range of gastric emptying (GE) in children. Gastric emptying time measured with (99)Tc-labeled solid meal (GE(Tc)) is the gold standard. Large-scale studies with GE(Tc) are ideal but not feasible because of radiation exposure. The (13)C-labeled octanoic acid breath test (GE(13C)) does not involve radiation and is suitable for large studies. The aim of this study was to validate GE(13C) with GE(Tc) and to explore whether GE(13C) could be used to establish a physiologic range of GE in children.

METHOD

Twenty-five healthy children underwent simultaneous GE(Tc) and GE(13C) using a standardized solid test meal. The time taken for the stomach to empty half its content (T(1/2)(13C)) and solid lag phase (lag(13C)) for GE(13C) were computed from the fractional excretion of (13)C in expired air. T(1/2)(13C) and lag(13C) were compared with corresponding values obtained by GE(Tc).

RESULT

Correlation coefficient between T(1/2)(13C) and T(1/2)(Tc) was 0.69 (P < .01; r = 0.92 if 3 outliers were omitted). Correlation coefficient between lag(13C) and lag(Tc) was 0.39 (P < .05). There was good agreement between the methods by the Bland Altman method.

CONCLUSION

There is good agreement between GE(13C) and GE(Tc). GE(13C) can be safely used to establish the reference range of GE in healthy children.

Variability of the 13C-acetate breath test for gastric emptying of liquids in healthy children

PURPOSE

Scintigraphy is considered as the "gold standard" for measuring gastric emptying (GE). The C-acetate breath test (C-ABT) offers an attractive alternative to measure GE of liquids as it is nonradioactive. The aim of this study was to assess the variability of the C-ABT for GE of liquids in healthy children using nondispersive infrared spectrometry (NDIRS).

METHODS

The C-ABT was repeated at least 2 times in 21 healthy children (6 girls and 15 boys), aged between 6.2 and 16.4 years, 2 to 7 days apart. After an overnight fast, a standardized milk drink, labeled with 50 or 100 mg C-acetate according to weight, was administered. Breath samples were taken before feeding, at 5-minute intervals for the first 40 minutes and at 10-minute intervals for the following 140 minutes after feeding. Breath samples were analyzed using NDIRS, and C recovery was used to calculate values for gastric half-emptying time (t1/2), time of peak C exhalation, or gastric lag phase (tlag) and gastric emptying coefficient (GEC). Intraindividual variabilities of the parameters t1/2, tlag, and GEC were expressed as coefficient of intrasubject variation (CV).

RESULTS

The median CV of t1/2 was 8.3% (CV range, 1.6%-16.2%; t1/2 interindividual range, 65-112 minutes; and t1/2 intraindividual range, 4-33 minutes). The median CV of tlag was 16.6% (CV range, 2.0%-26.6%; tlag interindividual range, 31-76 minutes; and tlag intraindividual range, 1-35 minutes). The median CV of GEC was 4.3% (CV range, 0.8%-15.7%; GEC interindividual range, 3.81-4.89; GEC intraindividual range, 0.08-1.31). The CVs of t1/2, tlag, and GEC were independent of age, sex, weight, height, and measured values of t1/2, tlag, and GEC.

CONCLUSIONS

The C-ABT using NDIRS is an easy, noninvasive, and nonradioactive procedure with a large intraindividual variation for measuring GE of liquids in healthy children, but comparable to the variation reported with other techniques.

Measurement of hepatic phenylalanine metabolism in children using the [13C]-phenylalanine breath test and gas chromatography–mass spectrometry

The essential amino acid, phenylalanine (PA), is known to be metabolized mainly in the liver of human adults. Because the liver is still in the developmental phase, the PA-related metabolic events in infants remain unsolved. In this study, evaluations of development in hepatic PA metabolism in 37 children and 16 adults were attempted using the (13)C -PA breath test (PBT). The subjects were categorized into four groups according to their ages in years and months: 2 years and 0 month to 3 years and 5 months (group I; n = 12); 3 years and 6 months to 4 years and 11 months (group II, n = 12); 5 years and 0 month to 6 years and 11 months (group III, n = 13); and healthy adults (group IV; n = 16). Changes in CO(2) level of exhaled gas at various time intervals after oral administration of (13)C -PA were monitored using gas chromatography-mass spectrometry to derive the (13)C excretion rate, cumulative excretion curve and time maximum [(13)C excretion rate (T(MAX)). In the present investigation involving children, significant increases of maximum(13)C excretion rate and cumulative excretion at 120 min after administration were established in group III. Furthermore, differences in PBT were not established between groups III and IV. The index for first-pass effect, T(MAX), did not change with time. From the above findings, the (13)C excretion rate increased with time although hepatic PA metabolism in infants remained underdeveloped, and children at the age of 5-7 years manifested PA metabolism similar to that of adults.

Gastric motility after laparoscopically assisted distal gastrectomy, with or without preservation of the pylorus, for early gastric cancer, as assessed by digital dynamic x-ray imaging

This study aimed to evaluate the usefulness of digital x-ray imaging for measuring gastric motility in patients subjected to laparoscopically assisted distal gastrectomy without preservation of the pylorus (LADG) or laparoscopically assisted pylorus-preserving gastrectomy (LAPPG) for early gastric cancer. Between April 1998 and February 2002, 52 patients with preoperative stage IA gastric cancer underwent laparoscopically assisted distal gastrectomy, with 26 receiving LADG for tumors in the lower third of the stomach and 26 receiving LAPPG for tumors in the middle third of the stomach. The gastric emptying ratio at 15 min after the ingestion of the test meal was 61.8% +/- 28.0% for LADG and 42.9% +/- 18.0% for LAPPG ( p < 0.01). The motility index was 2.65% +/- 2.54% for LADG and 8.13% +/- 2.46% for LAPPG ( p < 0.001). In conclusion, LAPPG results in better motility than LADG for patients with early gastric cancer arising in the middle third of the stomach.

Measuring gastric emptying of semisolids in children using the 13C-acetate breath test: a validation study

BACKGROUND AND AIM

Radioscintigraphy is the gold standard for evaluation of gastric emptying in children, but requires exposure to ionising radiation. Therefore, the aim of the study was to validate the non-radioactive 13C-acetate breath test in children in comparison to radioscintigraphy as reference method.

PATIENTS

Twenty-nine children with dyspeptic or respiratory symptoms were tested for gastric emptying disorders simultaneously performing the 13C-acetate breath test and radioscintigraphy.

METHODS

A semisolid oatmeal was doubly labelled with 150 mg 13C-acetate and 50 MBq 99mTechnetium. Breath samples were collected every 5-10 min for 4 h. After mass spectrometrical 13C-analysis, curve fitting of the 13C-cumulative recovery to the modified power exponential function Y = m(1 - e(-kt) calculated the half emptying times of the breath test (t 1/2 (breath)). Scintigraphic image acquisition began immediately after the ingestion of the 99mTechnetium-labelled testmeal at a rate of one frame every 60 s for 1 h.

RESULTS

Six children showed delayed gastric emptying in scintigraphy (t 1/2(scinti) > 60 min). All these children had prolonged half emptying times t 1/2 (breath) in the 13C-acetate breath test. Using a cut-off t 1/2(breath) > 90 min, the 13C-acetate breath test had a sensitivity of 100% and a specificity of 85%. Scintigraphic and breath test half emptying times were linearly correlated (Y = 0.80x + 47.68, r = 0.76, P < 0.00001).

CONCLUSIONS

The 13C-acetate breath test proves to be a reliable, non-radioactive alternative for measuring gastric emptying in children.

Gastric function measurements in drug development

The function of the stomach includes initiation of digestion by exocrine secretions such as acid and pepsin, which are under the control of the endocrine secretion of hormones that also coordinate intestinal motility. The stomach also stores and mechanically disrupts ingested food. Various techniques have been developed to assess gastric physiology, the most important of which is assessment of acid secretion, as well as gastric motility and gastric emptying. The influence of drugs on gastric function and the effect of gastric secretion and mechanical actions on the bioavailability of novel compounds are of critical importance in drug development and hence to clinical pharmacologists. The control of acid secretion is essential in the treatment of peptic ulcer disease as well as gastrooesophageal reflux disease (GORD); pH-metry can be used to determine the necessary dose of an acid suppressant to heal mucosal damage. Disturbed gastric myoelectric activity leading to gastroparesis can cause delayed gastric emptying, often found in patients with diabetes mellitus. Electrogastrography (EGG) may be used to evaluate the influence of prokinetics and other drugs on this condition and aid in determining effective therapy.

Esophagogastric dissociation versus fundoplication: Which is best for severely neurologically impaired children?

PURPOSE

Neurologically impaired children (NIC) often have swallowing difficulties, severe gastroesophageal reflux, recurrent respiratory infections, and malnutrition. Bianchi proposed esophagogastric dissociation (EGD) as an alternative to fundoplication and gastrostomy. The authors compared these 2 approaches.

METHODS

Twenty-nine consecutive symptomatic NIC refractory to medical therapy were enrolled in a prospective study and divided into 2 groups: A (n = 12), NIC who underwent fundoplication and gastrostomy; B (n = 14), NIC who underwent EGD. Three were excluded because of previous fundoplication. Anthropometric (percentage of the 50th percentile/age of healthy children) and biochemical parameters, respiratory infections per year, hospitalization (days per year), feeding time (minutes), and "quality of life" (parental psychological questionnaire, range 0 to 60), were analyzed (t test and Mann-Whitney test) preoperatively and 1 year postoperatively. Complications were recorded.

RESULTS

Compared with group A, group B presented a statistically significant increase of all anthropometric and nearly all biochemical parameters with a statistical difference in terms of respiratory infections, hospital stay, feeding time, and psychological questionnaire. In group A, 2 bowel obstructions, 1 tight fundoplication, 1 dumping syndrome, and 3 failures of fundoplication occurred. Group B presented 1 anastomotic stricture, 1 paraesophageal hernia, and 1 bowel obstruction.

CONCLUSIONS

Compared with fundoplication and gastrostomy, EGD offered better nutritional rehabilitation, reduction in respiratory infections, and improved quality of life. EGD can be rightfully chosen as a primary procedure.

Gastric emptying of liquid meals measured noninvasively in humans with [13C]acetate breath test

The aim of the present study was to develop a breath test to measure liquid gastric emptying rates that would be without radiation exposure and applicable to field testing. Four different test meals were investigated: a glucose meal, an amino acid meal, a fat meal, and a mixed meal (Ensure). The test meals were labeled with two markers, [13C]acetate and PEG-4000 (polyethylene glycol 4000). Gastric emptying rates were measured simultaneously by both breath test and the double-indicator technique in eight healthy male subjects. The appearance of 13CO2 in the breath closely reflected gastric emptying of the four test meals as measured by the double-indicator technique. It is concluded that the [13C]acetate breath test is a reliable, noninvasive test to measure gastric emptying rates of liquid test meals.