Pharyngeal flow interval: a novel impedance-based parameter correlating with aspiration

BACKGROUND

The role of pharyngeal impedance recording for assessing pharyngeal function is yet to be established. The aim of this study was to evaluate impedance flow interval, a novel parameter, in relation to bolus residue and the occurrence of aspiration. The effect of catheter configuration was also assessed.

METHODS

We studied 12 children (1.8-13.5years) with cerebral palsy, who were all referred for a videofluoroscopy due to suspected aspiration risk. Pharyngeal impedance patterns during bolus swallowing were recorded simultaneously with fluoroscopy. Two different catheter configurations were used: Catheter 1, 1.9mm diameter with 1cm electrodes and Catheter 2, 3.2mm diameter with 2cm electrodes. The flow interval was based on the objective assessment of impedance drop and recovery across multiple impedance segments and was correlated with fluoroscopic evidence of postswallow bolus residue and deglutitive aspiration.

KEY RESULTS

One hundred and thirty two liquid swallows were evaluated. Patient swallows with aspiration compared to those without aspiration had a longer flow interval (Cath 1 P=0.005; Cath 2 P<0.001). Patient swallows with residue had a longer flow interval, however this was only significant for swallows recorded using Catheter 2 (P=0.004). Multiple logistic regressions showed that higher flow interval was a better marker of the presence of aspiration [odds ratio (OR) 13.4 (3.0, 59.2); P<0.001] than the presence of residue [OR 3.8 (1.4, 10.3); P=0.01].

CONCLUSIONS & INFERENCES

We present novel findings suggesting that impedance measurement can detect alterations in flow characteristics of pharyngeal swallow that have the potential to predict to deglutitive aspiration risk.

Characterization of intraluminal impedance patterns associated with gas reflux in healthy volunteers

Multichannel intraluminal impedance (MII) recording allows assessment of flow through the oesophagus and differentiation between liquid and gas contents. Existing MII criteria for recognition of gas gastro-oesophageal reflux (GOR) have not been validated during known gas GOR in humans.

AIMS

(i) Characterize MII patterns of known gas GOR and optimize criteria. (ii) Clarify interrelationships between magnitude of maximal impedance change, luminal diameter and electrode-mucosa contact. Ten healthy volunteers (six male, 21-37 years) were studied using an oesophageal MII-manometry catheter. After catheter placement, subjects were asked to drink 600 mL of carbonated soft drink. Recordings were made for 20 min and the protocol repeated. Reported belches confirmed manometrically (triggered by transient lower oesophageal sphincter relaxations) were included for analysis. Those episodes were compared against commonly used criteria. Another five subjects (three male, 26-52 years) underwent simultaneous MII and videofluoroscopy using the same protocol. Videofluoroscopic images were analyzed for luminal diameter and the presence of electrode-mucosa contact. All analyzed gas GOR episodes (n = 88) were associated with a pattern of impedance rise which was either retrograde (62.5%), synchronous (19.3%) or antegrade (18.2%). Depending on the exact criteria used, sensitivity ranged from 33% to 75%. A multivariate regression model including luminal diameter and the presence of electrode-mucosa contact as independent factors accounted for 53% of all variation in impedance changes. In conclusion, a significant number of gas GOR episodes does not meet criteria for their recognition. New criteria are proposed to include specific antegrade patterns of impedance rise. Luminal diameter and the extent of contact between the oesophageal mucosa and MII-electrodes influence the magnitude and patterning of impedance change.

Detection of treatable neonatal liver disease by expanded newborn screening

Two neonates were identified at age 48 h by expanded newborn screening, with abnormal methionine and tyrosine concentrations, which were confirmed on repeat samples. Evidence of previously unsuspected liver disease was found at recall, and there was radiological and biochemical evidence of severe liver disease with hepatic synthetic failure. After inborn errors of metabolism (IEMs) were excluded, both were considered to have neonatal haemochromatosis, on the basis of raised ferritin, iron saturation, and very high α-fetoprotein and confirmed by a mildly hyperferritinaemic sibling in the first case, and raised ferritin and iron saturation in the second. However, it was not feasible to obtain tissue confirmation as the requirement for early therapy precluded biopsy. The babies were treated with antioxidants and iron-chelating agents, and the coagulopathy and hypoalbuminaemia were corrected. Both made a complete recovery and remain well after follow-up. Newborn screening programmes could consider advising clinicians, when tyrosine and methionine values are elevated, that once IEMs are excluded liver disease from other causes must be sought. Neonatal haemochromatosis is an example of one such disease that is potentially treatable.

Yoghurts containing probiotics reduce disruption of the small intestinal barrier in methotrexate-treated rats

Small intestinal permeability was employed to assess the efficacy of commercially available yoghurts containing probiotics in a rat model of methotrexate (MTX)-induced mucositis. Male Sprague-Dawley rats were allocated to four groups (n = 8): MTX + water, MTX + cow's milk yoghurt (CY; fermented with Lactobacillus johnsonii), MTX + sheep's milk yoghurt (SY; containing Lactobacillus bulgaricus and Streptococcus thermophilus), and saline. Treatment gavage occurred twice daily for 7 days pre-MTX and 5 days post-MTX. Intestinal permeability was assessed on days -7, -1, 2, and 5 of the trial. Intestinal sections were collected at sacrifice for histological and biochemical analyses. Histology revealed that rats receiving CY and SY did not have a significantly damaged duodenum compared to controls. However, an improved small intestinal barrier function was evident, determined by a decreased lactulose/mannitol ratio. Probiotics containing SY and CY may be useful in preventing disruption to intestinal barrier function in MTX-induced mucositis.

Multipoint measurement of intragastric pH in healthy preterm infants

BACKGROUND

The diagnostic use of 24 hour oesophageal pH monitoring in infants is controversial because of the impact of feed buffering of gastric acidity.

AIM

To re-evaluate the effect of feeding on gastric pH and reflux using multipoint pH measurements.

SUBJECTS

Fifteen healthy premature infants fed every four hours.

METHODS

Oesophageal pH and intragastric pH at 3, 6, and 9 cm below the lower oesophageal sphincter were simultaneously measured using a four channel pH probe for four hours after bolus feeding. Parameters of pH were compared for the different levels within the stomach. During reflux episodes, the nadir pH was compared with intragastric pH at all levels.

RESULTS

The proximal stomach was more significantly buffered by feeding and slower to re-acidify postprandially than the mid and distal stomach (42.2% of the time at pH < 4 compared with 58.7% and 55.7% respectively). During 27 of 62 gastro-oesophageal reflux episodes, nadir oesophageal pH was lower than the pH of the proximal stomach but always equal to or higher than the pH of the distal stomach.

CONCLUSIONS

These data indicate that previous studies may have overestimated the effect of feeding on gastric acidity and reflux.

Pathophysiological mechanisms of gastroesophageal reflux disease in children

Gastroesophageal reflux (GER) is an extremely common pediatric problem, but only in the past few years have we developed a better understanding of its pathophysiology. This is related to the wider use of investigative tools such as flexible endoscopy, 24-hour pH monitoring, and more recently, micromanometric methods and noninvasive breath tests, which have been particularly useful in infants. This paper reviews our current understanding of the esophageal and gastric mechanisms contributing to the pathophysiology of GER. In this context, we also highlight areas where new therapeutic approaches may be beneficial.

The successful medical management of severe duodenal strictures secondary to eosinophilic gastroenteritis in an infant

Eosinophilic gastroenteritis is an uncommon condition of unknown etiology that has only been relatively recently reported. Its clinical manifestations range from a mild disease to more severe forms resembling Crohn's disease. Enteric strictures are a rare but recognized complication of this condition. We report a case of eosinophilic gastroenteritis in an infant presenting with severe duodenal strictures that was successfully managed with oral prednisolone. We believe that this is the first reported case of duodenal strictures secondary to eosinophilic gastroenteritis.

Mechanisms of gastro-oesophageal reflux in preterm and term infants with reflux disease

BACKGROUND

Transient lower oesophageal sphincter relaxation (TLOSR) is the predominant mechanism of gastro-oesophageal reflux (GOR) in healthy infants but the mechanisms of GOR in infants with GOR disease (GORD) are poorly understood.

AIMS

To measure the occurrence of TLOSR, GOR, and gastric emptying (GE) rate in preterm and term infants with GORD.

PATIENTS

Thirty six infants were studied and grouped as normals or GORD based on a routine clinical assessment and confirmation of an assessment of GORD by reflux symptom charts and oesophageal pH monitoring.

METHODS

A micromanometric assembly incorporating a micro pH electrode recorded oesophageal motility and pH. GE rate was determined using the (13)C-octanoic acid breath test.

RESULTS

TLOSR was the predominant mechanism of GOR, triggering 50-100% of GOR episodes (median 91.5%). Abdominothoracic straining significantly increased the occurrence of GOR in association with TLOSR. In infants with GORD, the number of TLOSRs overall was similar to normals but the proportion of TLOSRs accompanied by acid GOR was significantly higher than in normals (16.5% v 5.7%, respectively; p<0.001). Infants with GORD had a similar GE rate to normals.

CONCLUSIONS

In infant GORD, acid reflux associated TLOSRs are abnormally common and likely to be a major contributing factor to the pathophysiology of GORD. Infants with GORD do not have delayed GE.

Patterns of antropyloric motility in fed healthy preterm infants

BACKGROUND

Antropyloric motility is important for regulation of gastric emptying and has not been adequately characterised in premature infants.

AIM

To evaluate fed patterns of antropyloric motility in premature infants.

SUBJECTS

Forty three healthy premature infants, 30-38 weeks of postmenstrual age.

METHODS

Postprandial antropyloric motility was measured using a micromanometric feeding assembly (outer diameter 1.8 mm) incorporating a pyloric sleeve sensor. The occurrence of isolated pyloric pressure waves (IPPWs) and antral pressure wave sequences (PWSs) was characterised. Sequences were further classified as being antegrade, synchronous, antegrade-synchronous, and retrograde according to the direction of propagation.

RESULTS

A total of 7289 pressure wave events were recorded, 48% IPPWs and 52% PWSs (18% antegrade, 12% synchronous, 13% antegrade-synchronous, 2% retrograde, and 7% undefined). IPPWs predominated in the first postprandial hour, peaking at 30-60 minutes. PWSs predominated in the period after one hour postprandially. Mean (SEM) half gastric emptying time was 42 (4) minutes.

CONCLUSIONS

Monitoring of antropyloric motor patterns in healthy premature infants indicates that the neuroregulatory mechanisms responsible for the coordination of antropyloric motility and gastric emptying are well developed by 30 weeks of postmenstrual age.

Effect of cisapride on gastric emptying in premature infants with feed intolerance

OBJECTIVE

To assess the effect of cisapride on gastric emptying and gastro-oesophageal reflux (GOR) symptoms in preterm infants with feed intolerance.

METHODS

Sixteen preterm infants (gestational age 24-35 weeks) with feed intolerance were enrolled in the study. Infants were randomized to receive 7 days of cisapride 0.2 mg/kg four times a day, immediately followed by 7 days of placebo or vice versa. Gastric emptying was measured using the [13C]-octanoic acid breath test prior to study entry and repeated on day 5, 6 or 7 after randomization and 5, 6 or 7 days after crossover. The symptoms of GOR were monitored during the study period using a standardized reflux chart. Weight was recorded daily.

RESULTS

There was no change in gastric emptying in infants prescribed cisapride (gastric half-emptying time (t1/2) 31.9 +/- 4.7 vs 34.2 +/- 3.9 min for placebo vs cisapride, respectively; P = 0.65). Infants on cisapride had slower growth and there was no change in reflux symptoms.

CONCLUSIONS

The use of cisapride in preterm infants with feed intolerance cannot be recommended.

Characterization of anorectal pressure and the anorectal inhibitory reflex in healthy preterm and term infants

OBJECTIVES

To evaluate anorectal motor function in healthy premature and term infants with the use of micromanometric techniques.

STUDY DESIGN

Anorectal manometry was performed in 22 healthy neonates (9 female) with a mean postmenstrual age of 32 weeks (range, 30 to 38 weeks) with a micromanometric anorectal assembly (od 2.0 mm). The assembly incorporated a 2-cm-long sleeve sensor for measurement of resting anal sphincter pressures and relaxation, and 4 sideholes recorded anal and rectal pressures. Rectal distension was performed with a latex balloon or direct air insufflation to elicit the anorectal inhibitory reflex (AR).

RESULTS

The mean anal sphincter pressure, rectal pressure, and rhythmic wave frequency were 40 mm Hg (range, 7 to 65 mm Hg), 11 mm Hg (range, 1 to 27 mm Hg), and 10/min (range, 8 to 14/min), respectively. A normal AR could be elicited in 21 of the 22 infants studied.

CONCLUSION

An anorectal micromanometric sleeve catheter is suitable for use in evaluating anorectal pressures in preterm and term neonates. Insufflation of air without the use of a balloon to elicit the AR is reliable and suitable for use in infants <34 weeks. Premature infants older than 30 weeks' postmenstrual age have normal anorectal pressures and a normal AR.

Survival of rotavirus antibody activity derived from bovine colostrum after passage through the human gastrointestinal tract

BACKGROUND

Rotavirus is a major cause of infectious diarrhea in infants and young children. Several studies have shown that hyperimmune bovine colostrum, derived from cows immunized with rotavirus, can prevent rotavirus diarrhea when given passively. The objective of this study was to determine whether colostral antibody activity survived transit through the gut by measuring the level of rotavirus antibody activity in the feces.

METHODS

Hyperimmune colostrum containing different levels of rotavirus antibody was administered to 105 children attending nine Adelaide childcare centres. Subjects were asked to drink 100 ml of whole milk supplemented with colostrum 3 times a day, for a period of 6 days. Stool samples were collected from the subjects before, during, and after consumption of the study product. Rotavirus activity was determined using a novel virus reduction enzyme-linked immunosorbent assay (ELISA) and a virus neutralization assay.

RESULTS

Rotavirus antibody activity was detected in 521 (86%) of 602 fecal specimens obtained during the study using the virus reduction ELISA. The antibody activity was detected as early as 8 hours after ingestion of hyperimmune colostrum and up to 72 hours after consumption had ceased. There was a strong relation (r = 0.81) between the titer of rotavirus antibody administered to subjects and the level of antibody activity detected in the feces.

CONCLUSIONS

The results show that antirotavirus activity survived passage through the gut. Therefore, passive immunotherapy may be used to prevent or treat infectious diseases that affect the entire length of the gastrointestinal tract.

Non-alcoholic steatohepatitis in children and adolescents

We describe 17 children with non-alcoholic steatohepatitis. All had elevated levels of serum liver enzymes and 16 were morbidly obese. Liver biopsy showed variable steatosis and fibrosis in nine patients. At follow-up, 12 of 14 patients had persistent morbid obesity and 11 had elevated liver enzyme levels.

Probiotics in pediatric gastrointestinal disorders

Probiotics have been defined most recently as living microorganisms which, upon ingestion in certain numbers, exact health benefits beyond inherent general nutrition. They have been a part of human nutrition for centuries, but in recent years they have been more closely studied for their potential to improve health and treat disease. This review of probiotics is not extensive, highlighting the most recent reviews and well controlled clinical studies in both animals and humans. The safety issues are also discussed as well as potential mechanisms of action. The importance of studying each probiotic bacterium individually in each condition where a health benefit is claimed is highlighted by Lactobacillus GG, the most widely studied probiotic which has proven benefit in reducing the severity and duration of viral diarrhea but no benefit against bacterial diarrhea.

Reflux in children

Gastro-oesophageal reflux (GOR) is an extremely common paediatric problem that often runs a harmless and self-limited course. Physiological GOR however can lead to marked parental anxiety, many unnecessary investigations and often unwarranted and potentially harmful therapeutic interventions. Our ability to better define GOR and gastro-oesophageal reflux disease (GORD) has improved in the past 15 years with a better understanding of the pathophysiology in infants and children due to the development and wider use of flexible endoscopy, 24-hour oesophageal pH monitoring and, more recently, the use of micromanometric methods for studying oesophageal motility. This will be further enhanced in the future with the development of non-invasive breath testing to study gastrointestinal motility and the use of electrical impedance to study fluid movement. Our therapeutic interventions have also improved particularly in the areas of acid suppression, improved surgical techniques and most recently laparoscopic fundoplication. This chapter reviews these advances in the paediatric area especially with regard to pathophysiology, diagnostic testing and therapeutic intervention.

Analysis of the breath hydrogen test for carbohydrate malabsorption: validation of a pocket-sized breath test analyser

OBJECTIVE

To assess the validity and clinical application of a hand-held breath hydrogen (H2) analyzer (BreatH2, Europa Scientific, Crewe, UK).

METHODOLOGY

Breath samples of patients referred to the Gastroenterology Unit, Women's and Children's Hospital, North Adelaide, South Australia, for confirmation of the diagnosis of carbohydrate malabsorption were analysed with the Quintron microlyzer (Quintron Instrument Co., Milwaukee, USA) and the BreatH2 analyser, using the Quintron microlyzer as the gold standard.

RESULTS

Twenty-nine breath H2 tests (BHT) were performed in 29 patients aged 2 months to 61 years. The sensitivity and specificity of the BreatH2 analyser in detecting a positive BHT using the Quintron microlyser as the gold standard were 0.90 and 0.95 with positive and negative predictive values of 0.90 and 0.95, respectively. There was one false positive and one false negative reading. Bland-Altman plots showed a high degree of agreement between the values obtained with two different methods.

CONCLUSIONS

The diagnosis of carbohydrate malabsorption, using a portable breath H2 analyser (BreatH2), achieved an acceptable degree of sensitivity and specificity, enabling it to be used where no alternative is available.

Malrotation with recurrent volvulus presenting with cholestasis, pruritus, and pancreatitis

A patient aged 16 years was referred following numerous episodes of intense pruritus associated with persistently altered liver function tests. Ultrasound (US) demonstrated the superior mesenteric vein positioned more to the left than usual and abnormal orientation of the duodenum, consistent with a midgut malrotation. Endoscopic retrograde cholangiopancreatography the common bile duct, suggesting a malrotation with chronic or recurrent volvulus. A classic malrotation with 180 degrees volvulus was noted at operation. A second child previously thought to have recurrent idiopathic pancreatitis was noted to have ampullary distortion secondary to malrotation following presentation with an intestinal obstruction. Pruritus and pancreatitis have not been previously reported with malrotation, although cholestatic jaundice has been described. The diffculties in diagnosis and the role of US are discussed. Ladd's procedure is the appropriate treatment for this condition.

Behavior and gastroesophageal reflux in the premature neonate

BACKGROUND

The belief that behavioral observations assist in the clinical diagnosis of gastroesophageal reflux (GER) disease in premature neonates has not been formally tested. The purpose of this study was to determine whether esophageal acidification was associated with a recognizable pattern of behavioral changes in these infants.

METHODS

The behavior of 14 healthy premature infants was recorded by a video camera while esophageal pH was simultaneously monitored. For each of 20 acid GER episodes recorded, a 10-minute video epoch, encompassing the onset of acid GER and lasting at least 4 minutes after the onset of GER, was examined. Two independent observers each scored reflux-associated epochs of "general" infant behavior and behavior previously shown to be indicative of reflux in normal term infants.

RESULTS

The occurrence of esophageal acidification due to reflux did not significantly alter scores for general behavior. Infants frequently demonstrated reflux-specific behavior, including discomfort, head retraction, and mouthing; however, none of these behavioral patterns was temporally associated with the occurrence of acid GER.

CONCLUSIONS

These data indicate that reflux-specific behavioral criteria, established in older term infants, may be inappropriate as diagnostic criteria for GER in premature neonates and may lead to the unnecessary use of antireflux therapy.

Factors affecting the validity of the 13C-urea breath test for in vivo determination of Helicobacter pylori infection status in a mouse model

BACKGROUND

The mouse model using a human isolate of Helicobacter pylori is being widely accepted as an economical means of studying gastric infection. A noninvasive monitoring method would be useful for repeated testing to establish the time course of infection and the efficacy of treatments. In this study, we describe factors that affected interpretation of 13C urea breath test results for the assessment of H. pylori infection status in this model.

MATERIALS AND METHODS

Female C57B1/6 mice that underwent gavage with H. pylori or saline were breath-tested using 50 micrograms of 13C urea at intervals up to 2 months after inoculation. The generation of 13CO2 (excess delta 13CO2) by infected mice was compared to that of uninfected controls. The effects of diet, fasting, and coprophagy on the reliability of the 13C urea breath test were quantitated.

RESULTS

Both commercial and synthetic mouse diets exhibited marked in vitro urease activity. A minimum fasting time of 13 hours prior to breath testing significantly reduced this dietary contribution to excess delta 13CO2 values. The coprophagic tendency of the mice caused spuriously high excess delta 13CO2 counts in the breath of both control and H. pylori-infected mice.

CONCLUSIONS

Although the dietary contribution to spuriously high values of excess delta 13CO2 in mice breath-tested for H. pylori infection was reduced by fasting, the high nonspecific urease activity generated by coprophagy severely limited the reliability of the urea breath test in the assessment of H. pylori infection status.

Lower esophageal sphincter position in premature infants cannot be correctly estimated with current formulas

OBJECTIVES

Strobel's formula (Esophageal length = 5 + 0.252 x Height) is frequently used as a guide for determining the distance from the nares to the lower esophageal sphincter (LES) in term infants. The aim of this study was to examine this relationship in premature infants.

STUDY DESIGN

The distance from nares to LES was manometrically determined in 156 premature infants (26-40 weeks' postmenstrual age; body weights of 610-3050 g). The ability of body weight, height (body length), head circumference, and postmenstrual age to predict the manometrically determined LES position was evaluated with linear and non-linear regression analyses.

RESULTS

Body weight and body length were the most predictive of distance from nares to LES (r(2) = 0.848 and 0.802, respectively). These relationships were non-linear and, in the case of body length, deviated substantially from Strobel's model.

CONCLUSIONS

In premature neonates, a different formula is needed for prediction of the distance between nares and LES than that applied to term infants and children.

Characterization of esophageal body and lower esophageal sphincter motor function in the very premature neonate

OBJECTIVES

To characterize esophageal body and lower esophageal sphincter (LES) motor function in very premature infants.

STUDY DESIGN

Esophageal manometry was performed in 12 very premature infants of 26 to 33 weeks' postmenstrual age (PMA) (body weights of 610-1360 g). Esophageal motor patterns were recorded for 30 minutes with a perfused micromanometric sleeve assembly (outer diameter, 2.0 mm).

RESULTS

Esophageal pressure waves triggered by dry swallows were predominantly (84%) peristaltic in propagation sequence. All infants showed tonic LES contraction; the mean resting LES pressure (LESP) for individual infants ranged from 5.0 +/- 4.1 mm Hg to 20.0 +/- 4.8 mm Hg. In all infants the LES relaxed (duration, 5.8 +/- 3.0 seconds; nadir pressure, 1.8 +/- 2.6 mm Hg) in response to pharyngeal swallows. Transient LES relaxations (TLESRs) (duration, 21.7 +/- 8.7 seconds; nadir pressure, 0.1 +/- 1.8 mm Hg) occurred on average 2.6 +/- 1.6 times per study; 86% of these relaxations triggered esophageal body common cavity events known to be associated with gastroesophageal reflux.

CONCLUSIONS

Esophageal motor function is well developed in very premature infants. Our data also suggest that TLESR is the predominant mechanism of reflux in these babies.

Cisapride in the control of symptoms in infants with gastroesophageal reflux: A randomized, double-blind, placebo-controlled trial

OBJECTIVE

To evaluate the efficacy of cisapride in the treatment of uncomplicated gastroesophageal reflux in children younger than 36 months of age.

STUDY DESIGN

A total of 95 patients satisfied the entry criteria and were randomly assigned to double-blind treatment with either cisapride (n = 50), 0.2 mg/kg 4 times daily, or placebo (n = 45) for 2 weeks. At the end of the 2-week treatment period, symptom diary and parental evaluation with repeat 24-hour pH study were performed.

RESULTS

Sixty-eight patients completed the trial (38 in the cisapride group and 30 in the placebo group). There were no significant differences in the symptoms of crying, vomiting, or gagging; the overall symptom intensity score; or parental global evaluations. There was a significant difference (P <.03) in the percent time pH <4, the number of reflux episodes lasting more than 5 minutes, and the duration of the longest episode. No significant difference was demonstrated for the number of episodes with pH <4 or the reflux score.

CONCLUSIONS

Cisapride was no better than placebo for relief of symptoms in children with uncomplicated gastroesophageal reflux. A beneficial effect was demonstrated in the cisapride group in relation to the measured parameters for esophageal acid exposure time.

The sugar permeability test reflects disease activity in children and adolescents with inflammatory bowel disease

OBJECTIVES

To investigate the relationship of intestinal permeability in children and adolescents with inflammatory bowel disease (IBD) to disease activity, disease extent, and response to therapy.

STUDY DESIGN

Patients with new and established diagnoses of IBD (12 Crohn's disease [CD] and 18 ulcerative colitis [UC]) were studied. Intestinal permeability was evaluated by measuring with high-performance liquid chromatography 5-hour urinary excretion ratio of lactulose/L-rhamnose (L/Rh).

RESULTS

In 8 of 9 patients with active CD, the L/Rh ratio was higher than the reference range (0.006 to 0.074, n = 36). In inactive CD (n = 3) the L/Rh ratio was within the reference range. In 6 of 7 patients with active extensive UC, the L/Rh ratio was elevated. In inactive extensive UC (n = 6) the normal permeability ratio was shown. In both active CD and active extensive UC, the frequency of elevated intestinal permeability was significantly greater than values in both inactive forms. The permeability ratio was normal in 4 of 5 patients with active left-sided colitis. In 5 of 7 patients (3 CD, 4 UC), repeat permeability values entered the reference range after acute phase therapy. Two patients with persistently elevated intestinal permeability (1 CD, 1 UC) had a disease flare-up within 6 months.

CONCLUSIONS

Intestinal permeability is a marker of disease activity in CD and extensive UC. Serial permeability test may be useful in monitoring disease activity.

Bowel dysfunction in cystic fibrosis: importance of breath testing

OBJECTIVE

To investigate the prevalence of carbohydrate malabsorption and bacterial overgrowth in children with cystic fibrosis (CF) and abnormal stool pattern referred for breath hydrogen testing.

METHODS

Results from 89 tests using lactose, sucrose and lactulose in 54 children with CF were compared with 5430 tests on children with non-CF-related stool abnormalities.

RESULTS

Children with CF were more frequently unable to ferment lactulose to hydrogen (39% vs. 20%, P<0.03); they had significantly longer oro-caecal transit times (mean 99 vs. 68 min, P<0.0003); they had a higher incidence of bacterial overgrowth (32% vs. 7%, P<0.003) and sucrose malabsorption (47% vs. 14.5%, P<0.004); but they had no increase in lactose malabsorption (40% vs. 31%). Children with bacterial overgrowth in both groups had longer transit times (CF 123 min, non-CF 108 min) compared to the non-CF children without overgrowth (68 min) and reference normal children (69 min).

CONCLUSIONS

Bacterial overgrowth and carbohydrate malabsorption, particularly of sucrose, should be considered when assessing children with CF and abnormal stool patterns.

Tandem balloon dilatation for childhood achalasia

BACKGROUND

There are no previous reports of tandem balloon dilatation in childhood achalasia.

OBJECTIVE

To report the treatment of four cases of paediatric achalasia using tandem balloon dilatation of the lower oesophageal sphincter. A review of the literature since 1986 was undertaken to compare outcomes of balloon dilatation and surgery.

MATERIALS AND METHODS

A retrospective review of the patients diagnosed with this condition and treated at our institution over the past 6 years: all four patients were treated by balloon dilatation of the lower oesophageal sphincter using two or three balloons in tandem. The definition of technical success was demonstration of a waist at 1-1.5 atmospheres of inflation pressure followed by abolition of the waist at higher pressures. Where this was unable to be achieved using a single balloon, two or three balloons in tandem were used.

RESULTS

No patient required oesophagomyotomy, and symptomatic control has been good to excellent in three of four patients. No significant side effects were encountered.

CONCLUSIONS

Balloon dilatation and surgery have similar success rates in paediatric achalasia. Because of the low morbidity associated with balloon dilatation, the procedure should be considered as first line treatment of this condition. If the lower oesophageal sphincter is stretched insufficiently using a single balloon, tandem balloon dilatation should be utilised.

Bowel habits of healthy Australian children aged 0-2 years

OBJECTIVE

To define the bowel habits of healthy Australian children aged up to 2 years.

METHODOLOGY

One hundred and forty children were recruited in six age categories with a minimum of 20 children per category. Data on bowel habit was recorded by parents daily for 1 week.

RESULTS

Stool frequency decreased with age. Ninety-five per cent of infants 0-14 days passed more than two stools per day compared with 21% at age 13-24 months. Breastfed infants passed more frequent and looser stools than children fed infant formula and solids and also showed a wider variation in frequency.

CONCLUSIONS

Mean stool frequency decreased with age as did the variation. This is a combined effect of age and feed type. These data can be used as a guide to the bowel habit of healthy Australian children.

The nutritional management of acute diarrhea in young infants: effect of carbohydrate ingested

To compare the efficacy of a low-lactose hydrolyzed milk formula, a lactose-free corn syrup-based milk formula, and a standard lactose-containing formula during refeeding after rehydration in infants with gastroenteritis, 135 patients older than 2 years were studied by randomized trial. Clearly demonstrated disadvantages in terms of early weight loss and longer duration of diarrhea were observed with the lactose-based formula compared with early weight gains on both the low-lactose formulae, and thus the lactose-containing formula was discontinued after 91 patients. The early weight loss with the lactose-containing formula was statistically significantly related to the degree of relative (rehydrated) underweight. The two low-lactose formulae were further compared in the remaining 44 patients. Early weight gain (48 h) was significantly greater with the lactose-hydrolyzed formula compared with the corn syrup-based formula, but no statistically significant differences were observed in duration of diarrhea, energy intake, treatment failures, or late weight gain. We conclude that the routine use of a low-lactose formula during refeeding after rehydration in infants with gastroenteritis may have some advantages in underweight infants and toddlers in whom it is important to prevent further weight loss.

Strain induced augmentation of upper oesophageal sphincter pressure in children

The hypothesis that troublesome oesophagopharyngeal reflux arises from defective upper oesophageal sphincter response to straining has been evaluated in 53 children aged two to 81 months (median 13) referred with symptoms thought to be related to gastro-oesophageal reflux. Spontaneously occurring pharyngeal, upper oesophageal sphincter, oesophageal body, and gastric pressures were analysed after feeding. Inspiratory strain was the most common spontaneously occurring strain (172 episodes), defined as an oesophageal body inspiratory negative pressure dip at least twice the size of the normal inspiratory wave. Overall, during inspiratory strain, upper oesophageal sphincter pressure was significantly higher than before straining (p < 0.01) (5 v 27 mm Hg, p < 0.01). Sustained strains defined as increases in gastric and oesophageal body pressure for two to 20 seconds were also common (149 episodes) and when compared with just before straining, also augmented upper oesophageal sphincter pressure (60 v 39 mm Hg, p < 0.01). The vigour of straining, estimated as increase of gastric pressure, correlated significantly with the degree of augmentation of upper oesophageal sphincter pressure (p < 0.05). Children with and without evidence of troublesome oesophagopharyngeal reflux showed no difference in upper oesophageal sphincter response patterns to straining. Failure of augmentation of upper oesophageal sphincter tone in the face of strain induced increases of oesophageal body pressure is probably a secondary factor in the production of oesophagopharyngeal reflux in children.

Effect of gastro-oesophageal reflux on upper oesophageal sphincter motility in children

Motor events of the upper oesophageal sphincter associated with gastro-oesophageal reflux were evaluated in 53 symptomatic children (median age 13 months) who were studied recumbent and unsedated. Children were divided into four groups according to symptoms, and then into two groups according to the presence or absence of neurological deficit. No grouping had basal upper oesophageal sphincter pressure that differed significantly from any other. Oesophageal distention due to gastro-oesophageal reflux, which was recognisable as oesophageal common cavity episodes, was associated with augmentation of mean basal upper oesophageal sphincter pressure from 36.5 (SD 18) mm Hg to 48.5 (18) mm Hg (p < 0.0001), irrespective of whether gastro-oesophageal reflux caused oesophageal acidification. Abrupt relaxations of the upper oesophageal sphincter independent of swallowing and lasting up to three seconds occurred during 54% of common cavity episodes. Forty nine per cent of these relaxations occurred within four seconds after the onset of distention. The oesophageal distention caused by gastro-oesophageal reflux is a potent stimulus of transient upper oesophageal sphincter relaxations in children. These relaxations are a more likely explanation for oesophagopharyngeal reflux than defective basal upper oesophageal sphincter tone.

Epidermolysis bullosa and severe ulcerative colitis in an infant

An infant with epidermolysis bullosa simplex had diarrhea at 3 weeks of age; severe ulcerative colitis was subsequently diagnosed. Epidermolysis bullosa simplex has not been associated with gastrointestinal disease except for buccal ulceration.

Monitoring of upper oesophageal sphincter pressure in children

In children technical limitations of upper oesophageal sphincter manometry have restricted investigation to the pull through technique under sedation. In this study we have used an adapted sleeve manometric technique for upper oesophageal sphincter monitoring in unsedated children and determined the influence of the state of arousal on upper oesophageal sphincter pressure. Twenty six children aged 3 to 42 months (median 17.5 months), who were referred for evaluation of oesophageal motor function, were studied with dual sleeve manometric assemblies which monitored upper and lower oesophageal sphincter pressures simultaneously. Pharyngeal, oesophageal body, and gastric pressures were also monitored with seven perfused side holes. Recordings were made for four hours after a meal and were technically successful in 24 children. The child's state of arousal was scored every 12th minute as follows: (A) resting, eyes closed, (B) resting, eyes open, (C) moving but comfortable, (D) restless and uncomfortable, (E) crying. In 67% of the 12 minute samples the children showed good adaptation to the procedure (arousal states A to C). There was a highly significant difference in upper oesophageal sphincter pressure between each of the arousal states (p less than 0.0001), being lowest in category A at (mean (SD) 18.1 (10.3) mmHg and highest in category D 55.7 (13.2) mm Hg. Abrupt changes in the state of arousal were associated with equally abrupt changes in upper oesophageal sphincter pressure. The state of arousal of unsedated children has an important influence on upper oesophageal sphincter pressure. It is essential that this factor is controlled for in any studies of upper oesophageal sphincter tone in children. The sleeve technique is capable of monitoring upper oesophageal sphincter motility for prolonged periods in unsedated children.

Recovery of the small intestine in coeliac disease on a gluten-free diet: changes in intestinal permeability, small bowel morphology and T-cell activity

Intestinal permeability was assessed before and 1, 2, 4, 8 and 12 weeks after commencing a gluten-free diet (GFD) in eight coeliac subjects. Intestinal morphology was quantified in six coeliac subjects on a normal diet, six coeliac subjects on a GFD, and 21 normal subjects. T-cell activity was measured in the eight coeliac subjects by soluble interleukin-2 receptor (sIL-2R) concentration (normal less than 477 U/mL). Intestinal permeability was increased 10-fold with a geometric mean value of 0.72 on a normal diet, and decreased to 0.17 at 4 weeks (P = 0.04), to 0.07 at 8 weeks (P = 0.010), and to 0.20 at 12 weeks (P = 0.015) of a GFD. Two of the eight subjects showed a poor response to gluten withdrawal. Quantitative intestinal morphology showed no significant improvement after 3 to 6 months of a GFD. Mean +/- s.d. sIL-2R concentrations in the eight subjects were increased 5-fold higher than control values at 1400 +/- 530 U/mL on a normal diet and decreased to 750 +/- 200 U/mL after 12 weeks of a GFD (P = 0.004). We conclude that intestinal permeability improves rapidly in the majority of coeliac subjects after commencing a GFD, although some abnormal permeability and increased T-cell activity persists. This may be due to varying degrees of gluten ingestion resulting in continued immune activation.

Sensitivity enhancement of optical immunosensors by the use of a surface plasmon resonance fluoroimmunoassay

Optical immunosensors employing evanescent wave techniques have the potential to address the requirements of the 'alternative site' market; however, this potential has yet to be realised. The development of 'direct' sensors, such as those using surface plasmon resonance (SPR), has been hampered by problems of non-specific binding and poor sensitivity to small molecules. 'Indirect' sensors (for example, those employing a fluorescently labelled reagent) overcome many of the problems of direct sensors but require more sophisticated instrumentation because of the low light levels detected. In an attempt to combine the best features of the two techniques, an indirect SPR fluoroimmunoassay (SPRF) technique has been investigated. The surface field intensity enhancement produced by SPR is used to boost the emission from a fluorescently labelled immunoassay complex at a metal surface. The potential of the method is demonstrated by assaying for human Chorionic Gonadotrophin (hCG) in serum. Enhanced sensitivity over conventional total internal reflection fluorescence (TIRF) and SPR techniques was achieved.

An assay for human chorionic gonadotrophin using the capillary fill immunosensor

Recently there has been much research effort directed towards the development of immunosensors. Optical technologies are currently proving very attractive for the construction of such sensors. The fluorescence capillary fill device (FCFD) has been designed to fulfil these needs. The development of an assay for human chorionic gonadotrophin (hCG) in the FCFD for a variety of body fluids (whole blood, serum, urine and saliva) demonstrates the versatility and assay performance of the device.

Polymeric IgA antibody to gliadin in the serum of patients with coeliac disease

Secretory component (SC) binding assays which detect polymeric IgA (pIgA) in serum were used to measure serum antigliadin pIgA and total pIgA in patients with coeliac disease. Total IgA antigliadin antibody in serum and intestinal fluid was measured by enzyme linked immunosorbent assay (ELISA). The relationship of pIgA antibody to dietary gluten and the antigliadin IgA antibody in intestinal fluid was examined. Twenty-nine serum samples were assayed, twelve from patients ingesting gluten and seventeen from patients who had excluded gluten from their diet for 6 months. Eight of these were paired samples from 4 adults on and off gluten. In addition, paired samples of both intestinal fluid and serum were obtained from 7 children on and off gluten. Polymeric IgA antibody to gliadin was detected in 11 of 12 subjects on gluten but in only 3 of 17 who had excluded gluten. Three of the four adults from whom paired serum samples were obtained had pIgA antigliadin, but only while on gluten. Three of the seven children in whom intestinal and serum antibody were assayed had pIgA to gliadin, which could not be detected after exclusion of gluten, although their intestinal antibody level remained elevated. There was no change in total pIgA levels with diet although the levels were higher than those seen in normal subjects. We conclude that pIgA antibody to gliadin is frequently found in the serum of coeliac patients ingesting gluten. It disappears with gluten elimination at a time when the IgA antigliadin antibody in intestinal fluid has not altered.

Anal size in children: the influence of age, constipation, rectal examination and defaecation

With the increase in the number of reported cases of child abuse it is important that medical practitioners should know the normal values for the size of the anus. Children aged 3 months to 15 years, attending a paediatric gastroenterology clinic for a routine examination, had a photographic record made of the anus 30 seconds after exposure of the anus as part of a standardised examination protocol. Anorectal disease, including Crohn's disease was present in eight children. Analysis of the 54 children without anorectal disease indicated that the anteroposterior diameter of the anus was less than 10.0 mm and the transverse diameter was less than or equal to 2.0 mm. Age, sex of the child, digital rectal examination, time since last defaecation and the capacity and contents of the rectum were unrelated to the size of the anus. In view of the difficulties which arise in suspected child abuse, medical practitioners should gain experience of the normal appearance and size of the anus. This can best be validated within a medicolegal framework if some form of standardised examination protocol is used. The key element of such an examination is not the position in which the child is examined but the time taken to observe the anus, to allow any dynamic changes to occur. An inspection time of 30 seconds in a cooperating conscious child is recommended.

Passive immunisation of children with bovine colostrum containing antibodies to human rotavirus

The efficacy of a 10-day course of bovine colostrum with high antibody titre against the four known human rotavirus serotypes in protecting children against rotavirus infection was examined in patients admitted to hospital. Children aged 3 to 15 months were blocked in pairs according to ward accommodation (ie, isolation or open area). Each block contained 1 treated and 1 control child. The allocation to treatment or control (an artificial infant formula) was randomised. 9 of 65 control children but none of 55 treated children acquired rotavirus infection during the treatment period (p less than 0.001). The importance of protecting against rotavirus infection was highlighted by the fact that parents of symptomatic rotavirus-positive children sought medical attention seven times more often than did parents of symptomatic rotavirus-negative children (p less than 0.05).

Current issues in the nutritional management of children with cystic fibrosis

Recent evidence suggests that malnutrition has a negative impact on pulmonary function in children with cystic fibrosis. In the past, dietary management has aimed at high energy low fat intake, but this has recently been shown to fall far short of the 120-150% of the recommended daily allowance for energy cystic fibrosis patients require. This paper outlines the current principles of nutritional management for children with cystic fibrosis. These include a high energy, high fat containing diet (within limits of individual tolerance); high carbohydrate intake; high salt intake; replacement of fat-soluble vitamins; appropriate use of pancreatic enzyme preparations; and supplemental feeding when indicated. It is vital that a nutrition education programme be established for each child and his or her family so that the emphasis shifts from treatment of malnutrition to prevention. The long-term aim must be to promote an independent, healthy lifestyle which incorporates good nutrition and other healthy pursuits such as exercise.

Passive immunisation of children with bovine colostrum containing antibodies to human rotavirus

The efficacy of a 10-day course of bovine colostrum with high antibody titre against the four known human rotavirus serotypes in protecting children against rotavirus infection was examined in patients admitted to hospital. Children aged 3 to 15 months were blocked in pairs according to ward accommodation (ie, isolation or open area). Each block contained 1 treated and 1 control child. The allocation to treatment or control (an artificial infant formula) was randomised. 9 of 65 control children but none of 55 treated children acquired rotavirus infection during the treatment period (p less than 0.001). The importance of protecting against rotavirus infection was highlighted by the fact that parents of symptomatic rotavirus-positive children sought medical attention seven times more often than did parents of symptomatic rotavirus-negative children (p less than 0.05).

Prospective study of nosocomial rotavirus infection in a paediatric hospital

Hospital-acquired enteric infections, particularly those due to rotavirus, were investigated by studying 220 patients under 3 years of age who were admitted without gastroenteritis to two paediatric general medical wards during a 10 month period. Faecal specimens were collected within 48 h of admission and then daily until the patients were discharged. Samples were also collected after discharge if patients developed enteric symptoms within 2 days of discharge. Fourteen per cent (31 of 220) of patients acquired rotavirus infections while in hospital, 23% (seven of 30) excreted rotavirus only after discharge; 29% of patients infected with rotavirus were asymptomatic (nine of 31). Acquisition of rotavirus infection was most prevalent during the months May-August, with a prevalence of 34% (12 of 35) in May. Hospitalization was prolonged in those patients who acquired rotavirus (11.1 days compared with 8.0 days, P less than 0.05). This study highlights the importance of rotavirus as a cause of hospital cross-infection, particularly in the very young patient, and emphasizes the need for further assessment of factors involved in its acquisition. In order to determine correctly the incidence of hospital-acquired illness, it is essential to follow patients after discharge from hospital. This study reinforces the importance of developing preventive measures in order to reduce the frequency of this illness.

Supplemental nasogastric feeding in cystic fibrosis patients during treatment for acute exacerbation of chest disease

The use of overnight, nasogastric, nutritional supplementation during hospitalization of children with cystic fibrosis (CF) receiving antibiotic therapy for acute exacerbations of respiratory disease was evaluated in 11 children (mean age = 7.75 years). Supplementary feeding significantly increased inpatient energy intake from 116 +/- 30% to 165 +/- 30% (P less than 0.001) of recommended dietary allowance with minimal effect on oral intake. It also resulted in significantly improved weight gains but neither increased energy intakes nor weights were sustained at short-term (mean = 5.7 weeks) or long-term (mean = 21.6 weeks) follow-up. The notion that short bursts of nasogastric feeding for inpatients with CF improve growth status is not supported. However, the study did show that treatment of chest infections alone does not positively affect spontaneous oral energy intake.

Development of hydrogen excretion between feeds in breast and artificially fed full-term normal neonates

The breath hydrogen test for carbohydrate malabsorption has been proved to be sensitive, specific and noninvasive. This study was performed to determine its applicability in the newborn period. Postprandial hydrogen excretion in the first 5 days of life was measured in 105 full-term normal newborns, who were either artificially or breast fed. Samples of expired air were collected via a nasopharyngeal catheter at 30 min intervals between feeds. Some babies showed no hydrogen production after 5 days, while others produced high (200 parts/10(6] levels. The incidence of hydrogen production increased postnatally--more than 80% of babies produced hydrogen by 5 days of age. None of the babies was unwell or developed frequent or loose stools suggestive of clinical carbohydrate malabsorption. It is therefore postulated that these high hydrogen levels reflect biochemical evidence of clinically insignificant carbohydrate malabsorption in this age group. This study shows clearly that an interfeed interval of 4 h in these babies is insufficient to cause breath hydrogen levels to fall in a predictable way. The ethical and practical difficulties in fasting these infants for longer periods suggest that conventional carbohydrate challenges with breath hydrogen estimations will be difficult in the neonate.