Cyclic vomiting syndrome in adults.

Cyclic vomiting syndrome (CVS) was initially described in children but can occur in all age groups. Cyclic vomiting syndrome is increasingly recognized in adults. However, the lack of awareness of CVS in adults has led to small numbers of diagnosed patients and a paucity of published data on the causes, diagnosis and management of CVS in adults. This article is a state-of-knowledge overview on CVS in adults and is intended to provide a framework for management and further investigations into CVS in adults.

Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society for Pediatric Gastroenterology and Nutrition.

Gastroesophageal reflux (GER), defined as passage of gastric contents into the esophagus, and GER disease (GERD), defined as symptoms or complications of GER, are common pediatric problems encountered by both primary and specialty medical providers. Clinical manifestations of GERD in children include vomiting, poor weight gain, dysphagia, abdominal or substernal pain, esophagitis and respiratory disorders. The GER Guideline Committee of the North American Society for Pediatric Gastroenterology and Nutrition has formulated a clinical practice guideline for the management of pediatric GER. The GER Guideline Committee, consisting of a primary care pediatrician, two clinical epidemiologists (who also practice primary care pediatrics) and five pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests and treatment modalities commonly used for the management of GERD, and how those interventions can be applied to clinical situations in the infant and older child. The guideline provides recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management and indications for consultation by a specialist. The guideline also provides recommendations for management by the pediatric gastroenterologist. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology and Nutrition on the evaluation and treatment of gastroesophageal reflux in infants and children. The American Academy of Pediatrics has also endorsed these recommendations. The recommendations are summarized in a synopsis within the article. This review and recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the management of all patients with this problem.

Pediatric laryngopharyngeal sensory testing during flexible endoscopic evaluation of swallowing: feasible and correlative.

Laryngopharyngeal sensory testing can predict aspiration risk in adult patients. Its feasibility and potential role in the evaluation of pediatric swallowing is undetermined. The goals of this study were to determine the feasibility of performing laryngopharyngeal sensory testing in awake pediatric patients and to assess whether the sensory testing results correlated with aspiration during a feeding assessment or correlated with a history of pneumonia. Fiberoptic endoscopic evaluation of swallowing with sensory testing was performed in 100 pediatric patients who were evaluated for feeding and swallowing disorders. The swallowing function parameters evaluated were pooled secretions, laryngeal penetration, and aspiration. The laryngopharyngeal sensory tests were performed by delivering a pressure-controlled and duration-controlled air pulse to the aryepiglottic fold through a flexible laryngoscope to induce the laryngeal adductor response (LAR). The air pulse stimulus ranged in intensity from 3 to 10 mm Hg. The patients tested ranged from 1 month to 24 years of age, with a median age of 2.7 years. Sensory testing was completed in 92% of patients. Patients who had an LAR at less than 4 mm Hg rarely if ever had episodes of laryngeal penetration or aspiration. Those with an LAR at 4 to 10 mm Hg had variable amounts of aspiration and laryngeal penetration. The LAR could not be elicited at the maximum level of intensity (10 mm Hg) in 22 patients, who demonstrated severe laryngeal penetration and/or aspiration. Elevated laryngopharyngeal sensory thresholds correlated positively with previous clinical diagnoses of recurrent pneumonia, neurologic disorders, and gastroesophageal reflux, and correlated positively with findings of pooled secretions, laryngeal penetration, and aspiration. Laryngopharyngeal sensory testing in children is feasible and correlative.

Gastrointestinal manometry studies in children.

Children with gastrointestinal motility disorders present with diverse symptoms, and obtaining a detailed history is often impossible. As in adults, evaluation of a suspected motility disorder begins with exclusion of mechanical obstruction or primary inflammatory disorders. Subsequently, coordination of peristaltic function is evaluated in those segments of the gastrointestinal tract that are suspected to be abnormal based on the clinical history. Evaluation of gastrointestinal motility in children is particularly challenging because of frequent lack of patient cooperation and difficulties in adapting the equipment to patient size. This review discusses the indications and approach to the evaluation of motility of each region of the gastrointestinal tract in infants and children.

Effect of increased intra-abdominal pressure on hepatic extraction and clearance of fentanyl in neonatal lambs.

Fentanyl, an opioid metabolized by hepatic mixed function oxidases, is commonly administered as the primary anesthetic for neonates undergoing surgery. Pharmacokinetic studies have suggested that abdominal surgery in neonates decreases fentanyl clearance, contending that this results from increases in intra-abdominal pressure (IAP) decreasing hepatic blood flow. To examine the effects of IAP on hepatic blood flow and fentanyl clearance, we infused fentanyl to eight neonatal lambs, measured regional blood flows by using the radionuclide-labeled microsphere technique and determined hepatic fentanyl extraction and clearance and hepatic oxygen extraction and consumption at three levels of IAP: 0, 12 and 18 mm Hg. Increased IAP did not affect portal or hepatic blood flow or ductus venosus shunt. Fentanyl extraction was 16.5 +/- 3.0% (mean +/- S.E.) at 0 mm Hg of IAP. Increased IAP decreased hepatic extraction of fentanyl, thereby decreasing fentanyl clearance. Increased IAP did not affect hepatic oxygen extraction or consumption. In two additional animals in which serial measurements of hepatic blood flow were obtained, increased IAP (15 mm Hg) transiently decreased hepatic blood flow with recovery to control values at 2 hr. The authors conclude that fentanyl is poorly extracted by neonatal livers, in contrast to its large extraction ratio in adults. The decrease in fentanyl clearance with increased IAP is consistent with pharmacokinetic studies demonstrating decreased clearance in neonates undergoing abdominal surgery. However, the present study suggests that the mechanism of decreased clearance is decreased hepatic function (decreased fentanyl extraction) rather than decreased hepatic blood flow.

Development of gastrointestinal motility in the infant and child.

The neuromuscular apparatus of the gastrointestinal tract develops early in gestation, but normal patterns of innervation and contractile activity are not achieved until near birth. This article reviews the ontogeny of gastrointestinal neuromuscular anatomy and the development of coordinated peristaltic function in the different regions of the gastrointestinal tract. This information provides a basis for understanding the difficulties encountered in successfully providing enteral feeding to the preterm infant.

Introduction to pediatric esophagogastroduodenoscopy and enteroscopy.

Pediatric esophagogastroduodenoscopy is now an integral part of the practice of pediatric gastroenterology. Children are not just small adults. The differing clinical indications, approaches to patient preparation, sedation, and complications are discussed in this article.

Chronic recurrent esophageal strictures treated with balloon dilation in children with autosomal recessive epidermolysis bullosa dystrophica.

Two children (8- and 17-yr old) with autosomal recessive epidermolysis bullosa dystrophica and chronic esophageal strictures were treated with repeated balloon dilations. General anesthesia was by face mask adapted specifically for this procedure, with careful attention to avoid skin and mucus membrane damage. A balloon dilator positioned fluoroscopically over an angiographic guidewire was gently inflated until narrowings resolved. Dilations have been performed every 1-11 [4.3 +/- 3.2 (mean +/- SD)] months in the younger patient over the last 4.3 yr, and every 8-20 (14.5 +/- 5.9) months in the older patient over the last 4.8 yr, without serious complications. Both patients were able to swallow normal foods following dilations. Repeated balloon dilations of esophageal strictures in patients with epidermolysis bullosa dystrophica can be done safely. Further studies are indicated to determine its effectiveness and appropriateness as an alternative to colonic interposition.

Amino acid gradients across the intestinal circulation in fetal lambs.

Amino acids, including glutamine, glutamate and asparagine are major metabolic substrates for the adult enterocyte of several species. To determine whether circulating amino acids are utilized by the fetal intestine, we studied nine fetal sheep (mean gestational age 128 +/- 5 days; term: 147 days). Catheters were inserted into the descending aorta (DA) and the mesenteric vein (MV) to allow for simultaneous blood sampling across the intestine. Fetal blood gas, haemoglobin; O2 saturation and O2 tension were measured. Ammonia was determined by an enzymatic method and HPLC analysis was used to measure the content of all amino acids in DA (descending aorta) and MV (mesenteric vein). Intestinal blood flow measurements were obtained using the radionuclide microsphere method. Intestinal blood flow (81 +/- 28 ml/min/100g) and arterial pH (7.37 +/- 0.04) were within normal range for unstressed fetal lambs. Glutamine and glutamate were the only amino acids that were significantly taken up across the fetal intestinal circulation. The fetal intestine extracted approximately 21% of the delivered glutamine (6.8 +/- 4.5 mumol/min/100g), 7% of the delivered glutamate (1.3 +/- 1.1 mumol/min/100g) and 2.7% of the delivered oxygen (43.0 +/- 19.1 mumol/min/100g). These data suggest that glutamine and glutamate are major substrates for the intestine in unstressed fetal lambs.

No-enema therapy for idiopathic constipation and encopresis.

Idiopathic constipation and encopresis of childhood are thought to occur when children volitionally withhold stool. Withholding may be prompted by social pressures or by episodes of painful defecation. Repetitive withholding may result in colonic dilatation and colorectal dysfunction. Therapy involves removal of impacted stool, stool softening, and behavioral therapy. The use of enemas in this therapy is widespread but may be counterproductive. A retrospective review of patients treated without enemas revealed 45 patients whose course could be followed for six months. Ninety-eight percent of these had successful initial cleanouts without enemas; 94% had continued success at six months. These results, comparable with other treatment programs, demonstrate that therapy without enemas is a reasonable alternative in the treatment of childhood constipation and encopresis.

Effects of maternal fasting on hepatic gluconeogenesis and glucose metabolism in fetal lambs.

In unstressed, normoglycaemic fetal lambs, the liver produces little glucose, and gluconeogenesis is insignificant. Indirect measurements have suggested that the fetus may produce glucose endogenously during hypoglycaemia induced by prolonged maternal starvation. In eight fetal lambs we directly measured total and radiolabelled substrate concentration differences across the liver to determine whether the fetal liver produces glucose after four days of fasting-induced hypoglycaemia. Simultaneously we measured umbilical glucose uptake and fetal glucose utilization. Glucose concentrations in ewes (1.78 +/- 0.44 mmol.-1) and fetuses (0.61 +/- 0.17 mmol.l-1) were decreased. Fetal glucose utilization rate (21.7 +/- 8.9 mumol.min-1.kg-1) was not significantly different from umbilical glucose uptake (17.2 +/- 8.9 mumol.min-1.kg-1). Hepatic glucose production (8.9 +/- 17.2 mumol.min-1.100 g-1) and gluconeogenesis (6.1 +/- 4.4 mumol.min-1.100 g-1) were present, but could account for only 13% and 8% of fetal glucose requirements, respectively. To determine whether glucose output by the fetal liver was limited by substrate availability, we infused lactate, acetate, and acetone into the umbilical veins of four fasted animals, increasing hepatic substrate delivery. Hepatic glucose output did not increase during infusion of gluconeogenic substrates, indicating that substrate availability did not limit gluconeogenesis. We conclude that the gluconeogenic pathway is intact in late-gestation fetal lambs and that the fetal liver is capable of gluconeogenesis. However, the primary change in fetal metabolism during maternal starvation is the reduction in fetal glucose utilization, obviating the need for substantial hepatic glucose production. The factors stimulating this modest increase in fetal hepatic glucose production remain to be elucidated.