Gastric emptying in children: unusual patterns detected by scintigraphy

A single-center experience of using milk scintigraphy in 251 pediatric patients: A retrospective study

To report our experience with milk gastroesophageal scintigraphy and the management of gastroesophageal reflux (GER) in children. In 251 pediatric patients we recorded age, underlying disease, central nervous system (CNS) disorders, and GER management. GER management was classified based on treatment plans: grade 0, non-pharmacological treatment; grade 1, non-pharmacological but using a nasogastric tube; grade 2, pharmacological treatment; grade 3, transpyloric feeding; and grade 4, Nissen fundoplication surgery. Patients were included in classified groups with (grades 2, 3, and 4) and without (grades 0 and 1) GER treatment. We evaluated the GER height (classified based on the height of GER, grade 0; no GER, 1; GER in the lower esophagus, 2; GER in the upper esophagus), GER duration in the lower and upper esophagus, presence or absence of massive GER amounts in the lower and upper esophagus, and gastric emptying time. We compared milk scintigraphy results and patient characteristics between groups with (grades 2, 3, and 4) and without (grades 0 and 1) GER treatment. We treated 121 patients for GER. CNS disorders (presence/absence: 46/74 with vs 21/110 without treatment, P < .001). The GER height grade (1.7 ± 0.5 [range, 0-2] with vs 1.5 ± 0.7 [range, 0-2] without treatment, P = .002), massive GER amount (present/absent: 21/99 with vs 9/122 without treatment, P = .011), and duration of GER (seconds) (324.5 ± 508.3 [range, 0-1800] vs 125.0 ± 291.9 [range, 0-1750], P < .001) in the upper esophageal half differed significantly. Similarly massive GER amount (present/absent: 54/66 with vs 34/97 without treatment, P = .002) and GER duration (621.3 ± 601.0 [range, 0-1800] vs 349.8 ± 452.4 [range, 0-1800], P < .001) in the lower esophageal half differed significantly. Additionally, CNS disorders, age, and massive GER in the upper esophageal half differed significantly among grades 2 and 4 in treated patients (P < .05, P < .001, P < .05, respectively). Milk scintigraphy is useful for deciding whether GER treatment is indicated. However, the treatment plan needs to be decided based on each patient's condition.

The impact of gastrointestinal dysmotility on the aerodigestive microbiome of pediatric lung transplant recipients

BACKGROUND

Delayed gastric emptying has been associated with increased graft rejection, although the mechanism of this association is not known. This study aims to investigate the interrelationship between delays in gastrointestinal motility and the diversity and composition of gastric, oropharyngeal, and lung microbiomes in pediatric lung transplant recipients.

METHODS

We prospectively recruited 23 pediatric lung transplant recipients and 98 pediatric patients with respiratory symptoms undergoing combined endoscopy and bronchoscopy. Gastric, oropharyngeal, and bronchoalveolar lavage samples were collected for 16S sequencing. Gastric samples were also analyzed for bile composition using liquid chromatography.

RESULTS

Patients who underwent lung transplantation had significantly reduced alpha diversity in gastric and oropharyngeal sites compared with patients with respiratory symptoms. This reduction in alpha diversity was especially evident in gastric samples in patients with delayed gastric emptying defined as abnormal gastric emptying on nuclear scintigraphy or as an elevation in gastric bile concentration (p ≤ 0.05). Whereas monocolonies were seen in the lungs of patients who underwent transplantation, these were not the same microbes seen in the stomach; the microbial overlap between lung and gastric samples within patients was low, and data indicated high individual variation between lung transplant recipients. Other contributors to reduced alpha diversity included antibiotics in combination with proton pump inhibitors, especially in gastric and oropharyngeal samples.

CONCLUSIONS

Lung transplant recipients have reduced microbial diversity in gastric fluid (GF) and oropharynx compared with patients who did not undergo lung transplantation. The decreased alpha diversity in GF may be associated with dysmotility.

Gastric emptying of milk in infants and children up to 5 years of age: normative data and influencing factors

BACKGROUND

Gastric emptying scintigraphy is widely used in infants and children, but there is a lack of age-specific normative data.

OBJECTIVE

The objectives of this retrospective study were: 1) to establish a range of gastric emptying of milk or formula as a surrogate for normal gastric emptying in infants and young children ≤5 years of age, and 2) to investigate the effects of patient age, feeding volume, feeding route and gastroesophageal reflux on gastric emptying.

MATERIALS AND METHODS

The reports of 5,136 gastric emptying studies of children ≤5 years of age performed at Children's National Medical Center from January 1990 to August 2012 were reviewed. Demographic data, 1-h and 3-h gastric emptying values and gastroesophageal reflux status of all patients were stored in a database. Using stringent inclusion and exclusion criteria, the studies of patients as similar to healthy children as possible were selected for this study.

RESULTS

The study group included 2,273 children (57% male) ages 0-59 months (median: 4.6 months). The median 1-h gastric emptying was 43% (interquartile range [IQR] 34-54%). The median 3-h gastric emptying was 91% (IQR 79-98%). Sixty-one percent of patients with 1-h gastric emptying value of <50% had 3-h gastric emptying ≥80%. Gastric emptying was significantly faster in children ≤6 months as compared with all older age groups. In each age group, the median gastric emptying decreased with increasing feeding volume. Gastric emptying was significantly faster in patients fed via combined nasogastric tube and oral routes as compared with those fed exclusively orally. There was no significant difference in gastric emptying of children with and without gastroesophageal reflux.

CONCLUSION

Although there are statistically significant differences in gastric emptying based on age, volume and route of feeding, the data suggest that overall normal liquid gastric emptying in infants and children ≤5 years of age is ≥80% at 3 h. One-hour emptying measurements are not reliable for detecting delayed gastric emptying.

Risk assessment for extending the Biopharmaceutics Classification System-based biowaiver of immediate release dosage forms of fluconazole in adults to the paediatric population

OBJECTIVES

The paediatric population undergoes developmental changes in gastric pH, gastric emptying, intestinal transit time, membrane permeability, protein binding, body water, distribution and metabolism. It is widely recognised that changes in these parameters may result in an alteration of the plasma profile and thus in key bioequivalence parameters such as Cmax (maximum plasma concentration of drug) and area under the plasma concentration vs time profile curve. The aim of this work is to assess the risk of extending the biowaiver for immediate release dosage formulations of fluconazole from the adult to the paediatric population.

METHODS AND KEY FINDINGS

Fluconazole exhibits good solubility and very rapid dissolution characteristics in various pH media. The absorption of fluconazole in children is known to be complete (over 90%) and not impaired by elevated pH, which is prevalent during the early days of life. Dose numbers calculated using body surface area are less than 1. Therefore, the risk to drug absorption due to differences in gastric pH, gastric emptying, intestinal transit, membrane permeability and metabolising enzymes between adults and children is considered low.

CONCLUSIONS

Thus, it can be safely concluded that fluconazole meets highly soluble and highly permeable criteria in the paediatric population and can be allocated to class 1 of the Biopharmaceutics Classification System (BCS) for this population as well as in adults. Additionally, fluconazole has an excellent safety profile in children, similar to that in adults. The BCS-based biowaiver claimed in adults can be safely extended to the paediatric population provided that the requirements in excipient selection and dissolution profile comparison using BCS-based dissolution conditions as stated in the biowaiver monograph for fluconazole immediate release dosage forms in adults are fulfilled.

Differential digestion of human milk proteins in a simulated stomach model

A key element in understanding how human milk proteins support the health and development of the neonate is to understand how individual proteins are affected during digestion. In the present study, a dynamic gastric model was used to simulate infant gastric digestion of human milk, and a subsequent proteomic approach was applied to study the behavior of individual proteins. A total of 413 human milk proteins were quantified in this study. This approach demonstrated a high degree of variability in the susceptibility of human milk proteins to gastric digestion. Specifically this study reports that lipoproteins are among the class of slowly digested proteins during gastric processes. The levels of integral lysozyme C and partial lactadherin in milk whey increase over digestion. Mucins, ribonuclease 4, and macrophage mannose receptor 1 are also resistant to gastric digestion. The retention or enhancement in whey protein abundance can be ascribed to the digestive release of milk-fat-globule-membrane or immune-cell enclosed proteins that are not initially accessible in milk. Immunoglobulins are more resistant to digestion compared to total milk proteins, and within the immunoglobulin class IgA and IgM are more resistant to digestion compared to IgG. The gastric digestion of milk proteins becomes more apparent from this study.

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.

Summary of the National Institute of Child Health and Human Development-best pharmaceuticals for Children Act Pediatric Formulation Initiatives Workshop-Pediatric Biopharmaceutics Classification System Working Group

BACKGROUND

The Biopharmaceutics Classification System (BCS) allows compounds to be classified based on their in vitro solubility and intestinal permeability. The BCS has found widespread use in the pharmaceutical community to be an enabling guide for the rational selection of compounds, formulation for clinical advancement, and generic biowaivers. The Pediatric Biopharmaceutics Classification System (PBCS) Working Group was convened to consider the possibility of developing an analogous pediatric-based classification system. Because there are distinct developmental differences that can alter intestinal contents, volumes, permeability, and potentially biorelevant solubilities at different ages, the PBCS Working Group focused on identifying age-specific issues that need to be considered in establishing a flexible, yet rigorous PBCS.

OBJECTIVE

We summarized the findings of the PBCS Working Group and provided insights into considerations required for the development of a PBCS.

METHODS

Through several meetings conducted both at The Eunice Kennedy Shriver National Institute of Child Health, Human Development-US Pediatric Formulation Initiative Workshop (November 2011) and via teleconferences, the PBCS Working Group considered several high-level questions that were raised to frame the classification system. In addition, the PBCS Working Group identified a number of knowledge gaps that need to be addressed to develop a rigorous PBCS.

RESULTS

It was determined that for a PBCS to be truly meaningful, it needs to be broken down into several different age groups that account for developmental changes in intestinal permeability, luminal contents, and gastrointestinal (GI) transit. Several critical knowledge gaps were identified, including (1) a lack of fully understanding the ontogeny of drug metabolizing enzymes and transporters along the GI tract, in the liver, and in the kidney; (2) an incomplete understanding of age-based changes in the GI, liver, and kidney physiology; (3) a clear need to better understand age-based intestinal permeability and fraction absorbed required to develop the PBCS; (4) a clear need for the development and organization of pediatric tissue biobanks to serve as a source for ontogenic research; and (5) a lack of literature published in age-based pediatric pharmacokinetics to build physiologically- and population-based pharmacokinetic (PBPK) databases.

CONCLUSIONS

To begin the process of establishing a PBPK model, 10 pediatric therapeutic agents were selected (based on their adult BCS classifications). These agents should be targeted for additional research in the future. The PBCS Working Group also identified several areas where greater emphasis on research was needed to enable the development of a PBCS.

Clinical presentation, response to therapy, and outcome of gastroparesis in children

OBJECTIVES

The aims of the present study was to define the clinical features, response to therapy, and outcome of pediatric gastroparesis.

METHODS

Retrospective review of 230 children with gastroparesis. Demographics, gastric emptying times, symptoms, response to medications, and outcome were determined for each of 3 groups (infants, children, and adolescents).

RESULTS

Mean age was 9 years, with boys predominating among infants and girls among adolescents. Postviral gastroparesis occurred in 18% and mitochondrial dysfunction (MD) in 8%. Symptoms varied with age, with children experiencing more vomiting and adolescents reporting more nausea and abdominal pain. The addition of promotility drugs was an effective therapy. Overall rates of symptom resolution were 22% at 6 months, 53% at 18 months, and 61% at 36 months, with median time to resolution of 14 months. Factors associated with symptom resolution included younger age, male sex, postviral gastroparesis, shorter duration of symptoms, response to addition of promotility therapy, and absence of MD. In multivariate analysis, longer duration of symptoms and MD both predicted lower rates of resolution, whereas younger age and response to addition of promotility therapy predicted a higher rate.

CONCLUSIONS

Pediatric gastroparesis is a complex condition with variable symptomatology and outcome depending on multiple parameters. Understanding the clinical features and response to therapy will improve our diagnosis and treatment of this disorder.

Role of laryngoscopy in children with respiratory complaints and suspected reflux

BACKGROUND

In recent years, laryngopharyngeal reflux (LPR) in children has been taken into consideration.

OBJECTIVE

The aim of this study was to assess the laryngoscopic findings in children diagnosed LPR and/or gastro-oesophageal reflux (GERD).

METHODS

The findings of 49 patients with at least one or more respiratory complaint such as chronic cough, wheezing, hoarseness, recurrent laryngitis, and throat clearing/postnasal discharge suggesting LPR were evaluated retrospectively. The diagnosis of LPR+GERD or GERD was done by the clinical history and 24 h double-probe pH monitoring and/or scintigraphy.

RESULTS

Thirty eight out of 49 patients examined by laryngoscopy underwent 24 h double-probe pH monitoring and/or scintigraphy. Thirty of them were diagnosed as LPR+GERD or GERD by any test positivity. Twelve of 30 patients diagnosed with LPR+GERD or GERD had a positive laryngeal finding on the examination of fibre optic laryngoscopy. The most common finding with eight cases was arytenoid erythema A sensitivity of 40% and specificity of 50% for the laryngoscopy in the diagnosis of LPR/GERD were found.

CONCLUSION

In children with unexplained respiratory symptoms, laryngopharyngeal reflux should be suspected. Therefore, until enough data on this issue in the literature accumulates, the history and the laboratory findings of the patients obtained from various techniques to document paediatric LPR should be evaluated together.

Ontogeny of oral drug absorption processes in children

INTRODUCTION

A large proportion of prescribed drugs to children are administered orally. Age-related change in factors affecting oral absorption can have consequences for drug dosing.

AREAS COVERED

For each process affecting oral drug absorption, a systematic search has been performed using Medline to identify relevant articles (from inception till February 2012) in humans. This review presents the findings on age-related changes of the following processes affecting oral drug absorption: gastric pH, gastrointestinal motility, bile salts, pancreatic function, intestinal pH, intestinal drug-metabolizing enzymes and transporter proteins.

EXPERT OPINION

Clinicians should bear in mind the ontogeny of oral drug absorption processes when prescribing oral drugs to children. The authors' review shows large information gaps on almost all drug absorption processes. It is important that more knowledge is acquired on intestinal transit time, intestinal pH and the ontogeny of intestinal drug-metabolizing enzymes and drug transporter proteins. Furthermore, the ultimate goal in this field should be to predict more precisely the oral disposition of drugs in children across the entire pediatric age range.

Diagnostic modalities for gastro-esophageal reflux in infantile wheezers

OBJECTIVE

To compare the diagnostic value of Gastro-intestinal (GI) scintiscan with 24-h pH study in detecting gastro-esophageal reflux (GER) among infantile wheezers.

SUBJECTS

Fifty-two children < 2 years of age.

METHODS

All patients, irrespective of symptom underwent study to evaluate for GER.

RESULTS

GER studies were positive in almost 45% of cases. The agreement between positivity of these two tests is best among children between 7 and 12 months of age (κ = 0.591, p = 0.002). Overall GI scintiscan was a better test with higher sensitivity and specificity as compared to 24-h pH study when compared with the history suggestive of reflux and clinical response with anti-reflux treatment as standard (p ≤ .001).

CONCLUSION

Both GER scan and 24-h pH study are complimentary to each other, however, if both the tests are available then GI scintiscan is better as a single test for GER in these early wheezers.

Temporal relationship between gastroesophageal reflux and rate of gastric emptying in children

OBJECTIVES

There are conflicting reports for the relationship of reflux and the gastric emptying rate. In addition, the acquisition period is not well defined for the gastroesophageal reflux studies. The aim of our study was to evaluate the temporal distribution of the reflux episodes and to evaluate whether the gastric emptying rate changed with the gastroesophageal reflux time or amount.

METHODS

We used radionuclide scintigraphy to evaluate 211 pediatric patients (0-10 years of age). Scintigraphic studies were performed by acquiring 15 s images for 1 h in a supine position after ingesting milk containing 0.5 mCi (18.5 MBq) Tc-99m colloid. Reflux episodes were calculated every 10 min for each patient who had reflux. The gastric emptying rate was measured by drawing an region of interest over the gastric activity.

RESULTS

Gastric reflux was observed in 104 patients (49.28%). The number of reflux episodes was higher in the first and second 10 min (33.7 and 29.1% respectively). The lowest reflux episode was observed in the last 10 min (between 50 and 60 min) (2.6%) suggesting that the reflux episode was decreasing by the gastric emptying. Within the first 30 min, reflux was observed in 98 of 104 patients (94.23%). The gastric emptying rate was calculated to be 73 min in patients with a higher incidence of reflux and 62 min in patients who had delayed and lower incidence of reflux episodes. In 104 patients, the average gastric emptying rate was 71.60 min. There were no significant differences in the gastric emptying rates between patients who had reflux episodes beginning in the first 30 min of the study and those who had reflux episodes in the last 30 min of the study (P>0.05).

CONCLUSION

This study has suggested that the number of reflux episodes were not related with the gastric emptying rate. However, reflux could be observed in a higher frequency before gastric emptying, which also suggested that a 30-min period may be sufficient when reflux is shown early. In negative cases, a 60-min acquisition time is recommended for the diagnosis of gastroesophageal reflux.

Pediatric Gastrointestinal Nuclear Medicine

General localization of gastrointestinal bleeding through the use of labeled red blood cells may be performed in children, or (99m)Tc-pertechnetate may be used if a Meckel's diverticulum is suspected. As in adults, cholecystitis and biliary leak may be assessed in children via (99m)Tc-IDA derivatives. Gastroesophageal reflux can be evaluated by oral consumption of the child's usual diet labeled with (99m)Tc sulfur colloid. For the scintigraphic determination of pulmonary aspiration, a relatively high concentration of tracer within a drop of liquid is placed beneath the child's tongue followed by dynamic imaging of the respiratory tract. Colonic transit scintigraphy can aid in the identification and therapeutic decision-making in patients with functional fecal retention, the most common cause of chronic constipation in children. (18)F-DOPA positron emission tomography is useful for classifying pancreatic involvement in infantile hyperinsulinism as focal or diffuse, thereby differentiating between patients who should receive curative focal pancreatic resection versus those who should receive medical management. Assessment of protein-losing enteropathy can be conducted scintigraphically and, compared with fecal alpha-1 antitrypsin collection, the scintigraphic method can detect esophageal and gastric protein loss. Also, scintigraphic quantification of protein loss can be performed without the requirement for fecal collection. Intestinal inflammation in children with inflammatory bowel disease can be evaluated using (99m)Tc white blood cells. The scintigraphic method is safe, accurate, well-tolerated by children and complementary to endoscopy in most patients.

Comparison of the effect of a cornstarch thickened formula and strengthened regular formula on regurgitation, gastric emptying and weight gain in infantile regurgitation

The purpose of this study was to evaluate the efficacy of a specially selected cornstarch-supplemented formula on clinical symptoms, gastric emptying and weight gain in infants with regurgitation. We performed a prospective randomised trial evaluating the therapeutic efficacy of two different formula feedings (cornstarch-thickened formula, group A; 25% strengthened formula, group B) in 81 young infants with regurgitation/vomiting > or = 3 times/day. A Tc-99 m milk scintigraphy was performed at inclusion and after 2 months to quantify gastric emptying time; all studied infants underwent a 2-month period of clinical follow-up evaluating regurgitation and body weight gain. At inclusion, group A and B had a similar age and weight. After the 2-month period of intervention, regurgitation and vomiting had both greater decrease (both P < 0.001 at 1 and 2 months) in group A (from a score of 4.19 +/- 1.71 to 0.93 +/- 0.42) than in group B (from a score of 4.15 +/- 1.68 to 2.89 +/- 1.16). Non-regurgitation symptoms (irritability, cough, choking, night-waking) decreased (P = 0.045 at 1 month and 0.017 at 2 months) in group A (from a score of 18 at baseline to 3 after 8 weeks) as compared to group B (from a score of 18 at baseline to 11 after 8 weeks). Weight increased more in group A (29.1 +/- 3.9 g/day over 8 weeks) versus group B (23.6 +/- 3.5 g/day over 8 weeks) (P < 0.01 at 1 and 2 months) Gastric emptying improved significantly in group A as compared with group B (all P < 0.001 for T1/2, and residual volume at 60 and 90 min). Ingested feeding volume was significantly larger in the group receiving cornstarch-thickened formula, both at 4 weeks (109.4 +/- 24.5 vs. 98.5 +/- 23.6 mL/meal) (P: 0.042) and at 8 weeks (137.6 +/- 27.9 vs. 115.7 +/- 26.5 mL/meal) (P < 0.001). Cornstarch-thickened formula feeding decreases the frequency of regurgitation/vomiting, provides better body weight gain and has an accelerated gastric emptying in comparison to a 25% strengthened regular formula in infants with regurgitation.

Gastric emptying and small intestinal transit time in preterm infants: a scintigraphic method

OBJECTIVES

Practical methods to determine gastric emptying (GE) and small intestinal transit time in preterm infants are required. The aim of this study was to develop a scintigraphic method to determine GE and small intestinal transit time in preterm infants which produce minimal radiation exposure and physical disturbance in these infants.

METHODS

Ten premature infants were studied. Median (and range) for gestational age was 28.9 (26-33) weeks, postnatal age was 19 (6-37) days, birth weight was 1194 (687-2300) grams and feeding volume was 173 (6-205) mL/kg/day. Nine of the patients were on nasal continuous positive airway pressure; one patient was on mechanical ventilation. A dose (0.2-0.4 MBq) of 99mTc-DTPA (0.5 mL) was given at the end of a meal administered by naso-gastric tube. Static images were obtained with a mobile gamma camera during the next 9 to 12 hours. The radiation dose was at most 0.30 mSv. Regions of interest (ROIs) were drawn around the stomach and the cecum. Time-activity curves were generated. Gastric emptying half-time (T(1/2)GE) was calculated. Residual gastric activity after 1 hour (R(1h)) and after 2 hours (R(2h)) was determined. Orocecal transit time was defined as the time until significant increase in activity was detected in the cecal ROI.

RESULTS

Images showed gastric emptying in all cases. Median (range) half time was 1.0 (0.5-3.0) h. R(1h) was 37.5% (19% to 100%), R(2h) was 23% (6% to 61%). In one patient the tracer did not reach the cecum within 12 hours. In the remaining nine patients orocecal transit time was 3.1 (1.3-6.1) h.

CONCLUSIONS

We present a new scintigraphic method to determine GE and orocecal transit time. It appears safe and practicable as a research tool in preterm infants.

Gastric electric activity assessed by electrogastrography and gastric emptying scintigraphy in adolescents with eating disorders

BACKGROUND

Patients with eating disorders can refer to a variety of gastrointestinal symptoms, sometimes to justify reduced food intake and vomiting. The authors investigated whether adolescent patients with eating disorders and dyspeptic symptoms have altered gastric electric activity and abnormal gastric emptying as assessed respectively by electrogastrography and scintigraphy.

METHODS

Twenty-eight patients (18 with anorexia and 10 with bulimia) and 16 healthy volunteers underwent electrogastrography; 20 of the 28 patients (14 with anorexia and 6 with bulimia) underwent gastric emptying scintigraphy. Electrogastrography with bipolar recording lasted 1 hour, 30 minutes before and after a standard meal. Before gastric emptying scintigraphy, patients fasted overnight; during testing, they ingested a solid meal labeled with technetium-99m sulfur colloid. The ratio of fasting to postprandial electrogastrographic variables was evaluated using the Wilcoxon matched-pair test. The Mann- Whitney test was used to compare absolute values for electrogastrographic data in each group. The Student paired t test was used to compare scintigraphic results expressed as percentage of gastric emptying at 60 minutes and as the gastric emptying time (T(1/2)).

RESULTS

Patients with bulimia significantly differed from those with anorexia and control subjects regarding the amount of normal gastric electric activity and bradygastria, and from patients with anorexia only regarding tachygastria. These electrogastrographic variables did not differ significantly between patients with anorexia and control subjects. Gastric emptying time (T(1/2)) was significantly longer in patients with bulimia than in those with anorexia.

CONCLUSIONS

Adolescent patients with bulimia who complain of dyspeptic symptoms have documentable abnormalities of gastric electric activity and emptying, whereas their counterparts with anorexia, probably owing to their shorter disease duration, do not.

Clinical presentation as a guide to the identification of GERD in children

OBJECTIVE

to determine if there is a correlation between common otolaryngologic symptoms and presence of gastroesophageal reflux disease (GERD) in children.

METHODS

charts of 295 children presenting with suspicion of GERD were reviewed for presenting symptoms including: (1) airway symptoms: stertor, stridor, frequent cough, recurrent croup, wheezing, nasal congestion, obstructive apnea, blue spells, hoarseness, throat clearing; (2) feeding symptoms: wet burps, globus sensation, frequent emesis, dysphagia, choking/gagging, sore throat, halitosis, food refusal, stomach aches, arching, drooling, chest pain, irritability, and failure to thrive. At least one positive test of barium esophagram, gastric scintiscan, pH probe or esophageal biopsy resulted in inclusion in the GERD positive group.

RESULTS

214 children had GERD diagnosed while 81 had no positive tests for GERD. Between the GERD positive and GERD negative groups, the significantly different symptoms were stertor (P=0.040), cyanotic spells (P=0.043), frequent emesis (P=0.007), failure to thrive (P=0.006), and choking/gagging (P=0.044). Three pooled variables were created: airway flow (stertor, stridor, cyanotic spells), airway irritation (frequent cough, recurrent croup, throat clearing), and feeding (dysphagia, failure to thrive, frequent emesis). GERD patients who were 2 years or less were compared to those older than 2 years and all three of these pooled variables were significantly different between these groups (P<0. 001).

CONCLUSION

children who present with a certain constellation of airway or feeding symptoms are more likely to have a positive GERD test. Children 2 years old or less are more likely to present with airway symptoms or feeding difficulties while children older than 2 years are more likely to present with airway irritation.

Delayed gastric emptying affects outcome of Nissen fundoplication in neurologically impaired children

BACKGROUND

Nissen fundoplication (NF) has a relatively high failure rate in neurologically impaired children with gastroesophageal reflux (GER). In 1990 we began to use routine technetium 99m sulfur colloid emptying scans and pyloroplasty with NF for delayed gastric emptying (DGE) in our neurologically impaired patients. The aim of this study was to determine the influence of DGE and pyloroplasty on the outcome of NF in neurologically impaired children.

METHODS

One hundred neurologically impaired children underwent NF by a single surgeon between August 1986 and July 1995. Beginning in January 1990 emptying scans were routinely obtained, and patients with DGE underwent pyloroplasty with NF. Outcome analysis was performed for recurrence/wrap failure and other parameters. Mean follow-up was 5.8 years, with a minimum of 18 months.

RESULTS

DGE was found in 35 (65%) of the 54 children who had emptying scans. All 11 children with normal scans had successful NF without recurrent reflux (100%). Forty (93%) of 43 children who underwent pyloroplasty and NF had successful outcomes. Thirty-eight children underwent NF without evaluation of gastric emptying with success in 30 of them (78.9%). Overall success improved from 34 (83%) of 41 in the first half of the study, when 3 (7%) of 41 children underwent emptying scans, to 55 (93%) of 59 in the second half, when 51 (86%) of 59 of the children underwent emptying scans.

CONCLUSIONS

DGE is common in neurologically impaired children with GER. NF in children with normal gastric emptying has a high probability of success. Pyloroplasty improves the outcome of NF in children with DGE. Neurologically impaired children should be evaluated for DGE before operation for GER.

The 13C-octanoic acid breath test: a noninvasive technique to assess gastric emptying in preterm infants

Gastric emptying (GE) is difficult to evaluate properly in preterm infants because of the lack of safe and reliable noninvasive methods. The 13C-octanoic acid breath test, a noninvasive method to assess GE, was validated in adults. The aim of this study was to adapt the methodology of the 13C-octanoic acid breath test regarding test meal and sampling methods and to define normal values for healthy preterm infants. We tested 11 clinically stable preterm infants who demonstrated normal fetal growth. The infants mean gestational age at birth was 33 weeks, mean birth weight was 1754 g, mean postnatal age at the day of study was 26 days, and mean weight was 2296 g. After a fasting period of 3 h, the subject was fed a test meal with low and stable 13C background activity mixed with 50 microliters of 13C-labeled octanoic acid and 1 g polyethylene glycol 3350. Breath samples were collected using a nasal prong in basal conditions and after the test meal. CO2 production according to weight and age was used in the calculations for 13CO2 enrichment of exhaled air. Results were expressed as percentage of 13C dose excretion per hour and percentage of cumulative 13C after 4h. gastric emptying coefficient (GEC), and gastric half-emptying time (t1/2b). The values for percent of cumulative 13C after 4 h ranged from 30.7 to 52.6% (mean, 40.2%), GEC ranged from 2.7 to 3.4 (mean, 3.0), and the values for t1/2b ranged from 17 to 100 min (mean, 57 min). We conclude that the 13C-octanoic acid breath test can be adapted to preterm infants to allow the study of GE in various conditions.

Malrotation discovered during routine radionuclide gastric emptying study

In infants with recurrent vomiting, and especially bilious vomiting, the algorithmic approach is to perform conventional barium upper gastrointestinal radiography to rule out malrotation and midgut volvulus, which are surgical emergencies. However, children with protracted vomiting and failure to thrive are candidates for medical treatment. These children are often evaluated by radionuclide gastric emptying studies to assess gastric emptying. Three patients are presented in whom the radionuclide gastric emptying study revealed the presence of a malrotation anomaly which had been undetected by antecedent barium gastrointestinal radiographic studies.

Pediatric gastrointestinal motility studies

Radionuclide studies for evaluating gastrointestinal transit in adults have been adapted for use in infants and children for assessing esophageal transit, gastroesophageal reflux, and gastric emptying. However, the measurement of small- and large-bowel transit times in these patients has been limited.

Correlation of gastric emptying at one and two hours following formula feeding

The acquisition of gastric emptying (GE) data by scintigraphy has become an important component of the evaluation of the pediatric patient for gastroesophageal reflux (GER). Delay of GE can contribute to ongoing gastric distension and hence increase propensity to reflux. Generally, only 1 h GE is determined during scintigraphy. Infants with GER have variable patterns of symptoms: some have spitting, vomiting, choking, and/or apparent life-threatening events in the immediate post-prandial period only, whereas in others symptoms persist until the time of next feeding. It is not clear whether differential rates of GE contribute towards such disparity of symptoms. We performed this prospective study to determine the correlation between GE at 1 h or 2 h, respectively, and for 2 h following a feeding in 27 infants under one year of age, who were referred for evaluation of GER. Continuous scintigraphy was performed for 2 h following a formula feeding. Gastric emptying at 1 h was calculated as percent of original dose emptied by 60 min; GE at 2 h was calculated as percent of isotope remaining in the stomach at 60 min which was emptied by 120 min. The median GE between 0 to 60 min was 36% (95% CI 26.0-42.0) and median GE of the residual formula between 60 to 120 min was 45% (95% CI 34.3-51.3). The correlation coefficient of GE, at 1 h with total GE over 2 h was 0.75 and of GE during the 2nd h with total GE over 2 h was 0.76. We conclude that routine determination of GE for 2 h continuously does not appear to offer clinically significant additional information.

Developmental characteristics of the kitten antrum

The changes in dietary constituents during growth and development from predominantly liquid to mixed solid liquid meals places an increasing burden on the antrum, which is required to triturate solids. The authors hypothesize that concomitant with these changing dietary constituents different pathways are used to mediate contraction in response to acetylcholine. Smooth muscle cells were isolated by collagenase digestion from the fundus and circular muscle layer of the antrum in the adult cat and 1-week-old kitten. The unstimulated cells from the fundus and antrum were larger in the adult than in the kitten. In normal physiological salt solution, all cells contracted in a similar dose dependent manner in response to acetylcholine in both age groups. Fundic muscle cell contraction in response to acetylcholine was unchanged in calcium-free physiological salt solution or in the presence of the calcium channel blocker, methoxyverapamil. In the adult, antral cells contracted 50% less in the absence of extracellular calcium. In the kitten, antral cells did not contract under the same conditions. After permeabilization with saponin, fundic muscle cells from the adult and kitten contracted fully in response to 1,4,5-inositol trisphosphate, whereas contraction of adult antral cells was reduced by 50% and contraction of kitten antral cells was completely blocked. These data suggest that isolated muscle cells from the fundus of both the adult cat and newborn kitten use intracellular calcium stores to contract in response to acetylcholine and 1,4,5-inositol triphosphate. In adult antral cells, acetylcholine-induced contraction requires both influx of extracellular calcium and release of intracellular calcium. In kitten antral cells, intracellular calcium stores are not used or available to mediate contraction in response to acetylcholine.

Gastroesophageal reflux: update on pathogenesis and diagnosis

The study of GER has been hindered by the lack of a good animal model and by the presence of some reflux in all normal individuals. By the painstaking process of studying normal infants, children, and adults, it is becoming evident that abnormalities of acid clearance, especially in the recumbent position (or during sleep), may be critical to an understanding of this disorder. As more is learned about the conditions surrounding "normal" reflux, it will be possible to refine the techniques of diagnosis and thereby identify the abnormal with more security.

Thickening of infant feedings for therapy of gastroesophageal reflux

To assess the effect of thickening of feedings on gastroesophageal reflux and gastric emptying, 20 infants were examined with technetium scintigraphy and detailed behavioral observation after each of a pair of feedings, one with radiolabeled infant formula alone and the other with radiolabeled formula thickened with dry rice cereal. The thickened and unthickened meals were followed by similar amounts of scintigraphically demonstrated gastroesophageal reflux. However, the number of episodes of emesis (1.2 +/- 0.7 vs 3.9 +/- 0.9 per 90 minutes postprandial), the percent of gastric emptying at 30 minutes (17.8% +/- 2.7% vs 22.4% +/- 2.4%), the time spent crying (11.7 +/- 3.1 minutes vs 17.6 +/- 3.8 minutes per 90 minutes), and the total time spent awake (45.2 +/- 5.9 minutes vs 53.1 +/- 4.9 minutes per 90 minutes) were significantly less after the thickened feedings. Because thickening of infant feedings increases the caloric density, decreases emesis, decreases crying time, and increases sleep time in the postprandial period, it is likely to be beneficial in the treatment of infants with gastroesophageal reflux associated with failure to thrive.