24-hour oesophageal two-level pH monitoring in healthy children and adolescents

Serum interleukin--4 and tumor necrosis factor alpha concentrations in children with primary acid gastroesophageal reflux and acid gastroesophageal reflux secondary to cow's milk allergy

AIM

The possible role of serum interleukin 4 (IL-4) and tumor necrosis factor alpha (TNF- α) in pathogenesis of the reflux symptoms in children with primary acid gastroesophageal reflux (GER) and acid GER secondary to cow's milk allergy (CMA).

MATERIAL AND METHODS

Out of 264 children, 76 (28.8%) patients with primary GER and 62 (23.5%) patients with GER secondary to CMA (pH - monitoring) serum IL-4 and TNF- α concentrations were assessed before treatment, 1 and 2 years after the initiation of the periodically administered pharmacotherapy.

RESULTS

Children with primary GER had mean IL-4 concentrations 0.17 ± 0.06 pg/ml before treatment, 0.08 ± 0.07 pg/ ml after 1-year and 0.07 ± 0.06 pg/ml after 2-years of treatment. The mean IL-4 concentrations were 1.07 ± 0.24, 0.5 ± 0.22 and 0.44 ± 0.19 pg/ml respectively in children with GER secondary to CMA. The mean serum TNF- α concentrations was 3.62 ± 1.30 pg/ml before treatment , 2.16 ± 1,35 pg/ ml after 1 year and 1.65 ± 1.16 pg/ml after 2 years of treatment in children with primary GER. In group with GER secondary to CMA mean serum TNF- α concentrations were 4.95 ± 1.88, 2.53 ± 0.80 and 2.02 ± 0.78 pg/ml respectively. Statistical analysis of the concentration of both cytokines showed their differentiation between them and in the study groups.

CONCLUSIONS

The highest mean serum IL-4 and TNF-α concentrations were observed in children with GER secondary to CMA and in children in control group (with cow's milk allergy and/or other food allergy diagnosed - CMA/FA) before the treatment administration.

Serum gastrin concentrations in children with primary gastroesophageal reflux and gastroesophageal reflux secondary to cow's milk allergy

PURPOSE

The assessment of the serum gastrin concentrations and the role of enterohormone in children with primary acid gastroesophageal reflux (GER) and GER secondary to cow's milk allergy (CMA).

MATERIALS/METHODS

138 children were diagnosed with pathological acid GER on the basis of pH-metric examination. 76 (28.8%) patients had primary GER and 62 (23.5%) patients had GER secondary to CMA.Serum gastrin concentration (fasting and postprandial) was assessed before treatment and 1 and 2 years after initiation of the therapy.

RESULTS

The children with primary GER had the fasting gastrin concentration 69.46 ± 11.87 μU/ml before treatment, 77.86 ± 26.35 μU/ml after 1 year and 83.78 ± 25.21 μU/ml after 2 years of treatment. The children with GER secondary to CMA had gastrin concentrations 89.61 ± 26.75, 73.17 ± 19.49 and 73.90 ± 20.31 μU/ml respectively. The mean postprandial gastrin concentration after treatment was higher than before treatment in children with both primary and secondary GER. The primary GER group had postprandial gastrin concentration 96.07 ± 33.51 μU/ml before treatment and 116.06 ± 33.95 μU/ml and 118.48 ± 33.96 μU/ml after 1st and 2nd year of therapy respectively. The secondary GER group had postprandial gastrin concentration 85.33 ± 14.12 μU/ml before treatment and 106.55 ± 24.51 μU/ml and 110.36 ± 24.67 μU/ml after 1st and 2nd year of therapy respectively.

CONCLUSIONS

The mean fasting serum gastrin concentrations in patients with primary and secondary GER were similar and mean postprandial concentrations were higher than fasting concentrations in both study groups.

GERD or not GERD: the fussy infant

A global evidence-based consensus has defined gastroesophageal reflux disease (GERD) as 'a condition, which develops when the reflux of stomach contents causes troublesome symptoms and/or complications.' The manifestations of GERD can be divided into esophageal and extraesophageal syndromes, and include vomiting, poor weight gain, dysphagia, abdominal or substernal/retrosternal pain, esophagitis and respiratory disorders. The extraesophageal syndromes have been divided into established and proposed associations: established would include cough, laryngitis, asthma and dental erosion ascribable to reflux, whereas proposed associations would include pharyngitis, sinusitis, idiopathic pulmonary fibrosis and recurrent otitis media. Uninvestigated patients with esophageal symptoms without evidence of esophageal injury would be considered to have asymptomatic esophageal syndromes, whereas those with demonstrable injury are considered to have esophageal syndromes with esophageal injury. Therefore, this allows symptoms to define the disease but permits further characterization if mucosal injury is found. Within the syndromes with associated injury are reflux esophagitis, stricture, Barrett's esophagitis and adenocarcinoma. This review will address definitions of GER and GERD-associated symptoms and treatment options.

Acid gastroesophageal reflux and intensity of symptoms in children with gastroesophageal reflux disease. Comparison of primary gastroesophageal reflux and gastroesophageal reflux secondary to food allergy

The ability to differentiate between primary and secondary causes of gastroesophageal reflux (GER) is extremely important during the diagnostic procedure. At the same time, the quality of symptoms and the intensity of the course of gastroesophageal reflux disease (GERD) should be estimated. Acid GER is assessed using 24-hour esophageal pH monitoring; the results of this diagnostic test should always be interpreted alongside the clinical picture.

PURPOSE

To establish the interdependence between the intensity of the clinical symptoms and the acid reflux index in children with primary GER and GER secondary to cow's milk protein allergy (CMA) and/or other food allergies (FA).

MATERIALS AND METHODS

A total of 138 children of various ages with symptoms of GERD were included in the study. The diagnostic procedure included 24-hour pH monitoring of the esophagus with a 2-channel probe (distal and proximal lead). For this purpose, ESPGAN diagnostic criteria were implemented. The type and intensity of typical manifestations of GERD were assessed with the help of our own scoring system. This diagnostic and therapeutic algorithm which includes an oral food challenge test, was applied to 138 children in order to differentiate primary GER from GER secondary to CMA/FA.

RESULTS

Primary GERD was diagnosed in 76 patients (55.1%) with a mean age: x=25.20 months+/-27.28 (group 1) and GERD secondary to CMA/FA was confirmed in 62 children (44.9%) with a mean age: x=21.53 months+/-17.79 (group 2). The most important pH-metric parameter analyzed in study groups 1 and 2 was the GER index: total and supine. An assessment of the intensity of symptoms and a comparative analysis of intensity was evaluated against the GER index: total and supine. Among study group 1, the following gradation of symptoms was found: in 31 children (40.8%)-degree 3, in 33 children (43.4%)-degree 4, and in 12 children (15.8%)-degree 5, whereas among the patients in group 2:25 (40.3%) were in degree 3, 27 (43.6%) were in degree 4, and 10 (16.1%) were in degree 5. It was estimated that the higher the GER result in both total and supine positions (for both leads), the higher the level of symptoms noted. This interdependence was demonstrated for both groups.

CONCLUSIONS

In seeking to determine any etiopathogenetic connection between primary GER or GER secondary to CMA/FA and their clinical consequences, 24-hour esophageal pH monitoring with a 2-channel probe is recommended, since it provides for better clinical control of GERD and its appropriate treatment.

Manometric study of lower esophageal sphincter in children with primary acid gastroesophageal reflux and acid gastroesophageal reflux secondary to food allergy

PURPOSE

The comparison of values of selected lower esophageal sphincter (LES) manometric parameters measured in children suspected of gastroesophageal reflux disease (GERD) (preliminary study) and in children with primary acid GER and acid GER secondary to cow's milk allergy and/or other food (CMA/FA) in relation to the duration of the disease (prospective study).

MATERIAL AND METHODS

A 24-hour esophageal pH monitoring was performed on 264 children of both sexes suspected of GERD (mean age x=20.78+/-17.23 months). Pathological acid gastroesophageal reflux (GER) was diagnosed and divided into primary and secondary reflux in 138 children (52.3%). 76 patients (28.8%) (x=25.2+/-27.28 months) with primary GER made up Group 1. Group 2 consisted of 62 patients (23.5%) (x=21.53+/-17.79 months) with GER secondary to CMA/FA. 32 patients (12.1%) (x=23.7+/-12.63 months) with CMA/FA symptoms made up Group 3 (reference group). Prospective assessment of LES manometric parameters, i.e. resting LES pressure and LES length, was performed on 138 children with GER. Manometric parameters, resting LES pressure and LES length, measured at the preliminary study (0) and control studies (after 1, 2 and 8 years), were prospectively assessed in 138 children. The assessment resulted from clinical observation and/or conservative treatment.

RESULTS

The mean value of resting LES pressure (mm Hg) before treatment was x=11.75+/-3.98 in Group 1, x=11.05+/-3.31 in Group 2, and x=14.17+/-3.86 in Group 3 (reference group). After 2 years of clinical observation, the mean value of resting LES pressure accounted for x=13.71+/-3.88 in Group 1, x=13.01+/-2.94 in Group 2, and x=17.92+/-3.36 in Group 3. The mean LES length (cm) before treatment accounted for x=1.68+/-0.72 in Group 1, x=1.78+/-0.70 in Group 2, and x=2.0+/-0.86 in Group 3. After 2 years of clinical observation, the mean LES length was x=2.80+/-0.40 in Group 1, x=2.76+/-0.40 in Group 2, and x=2.97+/-0.48 in Group 3. 12 children with persistent GERD (Group 1) and 8 children with persistent GERD and food allergy (Group 2) underwent manometric evaluation of LES after 8 years. No statistical differentiation of the mean values of resting LES pressure and LES length were shown in examined children of Groups 1 and 2 during prospective studies.

CONCLUSIONS

Manometric studies of LES assessing only resting LES pressure and its length in the examined children with acid GER do not clearly differentiate GER into primary and secondary refluxes to food allergy.

24-hour esophageal pH-monitoring in children suspected of gastroesophageal reflux disease: Analysis of intraesophageal pH monitoring values recorded in distal and proximal channel at diagnosis

AIM: To assess values of 24-h esophageal pH-monitoring parameters with dual-channel probe (distal and proximal channel) in children suspected of gastroesophageal reflux disease (GERD).

METHODS: 264 children suspected of gastroesophageal reflux (GER) were enrolled in a study (mean age χ = 20.78 ± 17.23 mo). The outcomes of this study, immunoallerrgological tests and positive result of oral food challenge test with a potentially noxious nutrient, enabled to qualify children into particular study groups.

RESULTS: 32 (12.1%) infants (group 1) had physiological GER diagnosed. Pathological acid GER was confirmed in 138 (52.3%) children. Primary GER was diagnosed in 76 (28.8%) children (group 2) and GER secondary to allergy to cow milk protein and/or other food (CMA/FA) in 62 (23.5%) children (group 3). 32 (12.1%) of them had CMA/FA (group 4-reference group), and in remaining 62 (23.5%) children neither GER nor CMA/FA was confirmed (group 5). Mean values of pH monitoring parameters measured in distal and proximal channel were analyzed in individual groups. This analysis showed statistically significant differentiation of mean values in the case of: number of episodes of acid GER, episodes of acid GER lasting > 5 min, duration of the longest episode of acid GER in both channels, acid GER index total and supine in proximal channel. Statistically significant differences of mean values among examined groups, especially between group 2 and 3 in the case of total acid GER index (only distal channel) were confirmed.

CONCLUSION: 24-h esophageal pH monitoring confirmed pathological acid GER in 52.3% of children with typical and atypical symptoms of GERD. The similar pH-monitoring values obtained in group 2 and 3 confirm the necessity of implementation of differential diagnosis for primary vs secondary cause of GER.

Twenty-four-hour esophageal pH monitoring in children and adolescents with chronic and/or recurrent rhinosinusitis

Gastroesophageal reflux (GER) disorder was studied in children and adolescents with chronic and/or recurrent rhinosinusitis not associated with bronchial asthma. Ten children with a clinical and radiological diagnosis of chronic and/or recurrent rhinosinusitis, consecutively attended at the Pediatric Otolaryngology Outpatient Clinic, Federal University of São Paulo, were evaluated. Prolonged esophageal pH monitoring was used to investigate GER disorder. The mean age of the ten patients evaluated (eight males) was 7.4 +/- 2.4 years. Two patients presented vomiting as a clinical manifestation and one patient presented retrosternal pain with a burning sensation. Twenty-four-hour esophageal pH monitoring was performed using the Sandhill apparatus. An antimony probe electrode was placed in the lower third of the esophagus, confirmed by fluoroscopy and later by a chest X-ray. The parameters analyzed by esophageal pH monitoring included: total percent time of the presence of acid esophageal pH, i.e., pH below 4 (<4.2%); total number of acid episodes (<50 episodes); number of reflux episodes longer than 5 min (3 or less), and duration of the longest reflux episode (<9.2 min). One patient (1/10, 10%) presented a 24-h esophageal pH profile compatible with GER disorder. This data suggest that an association between chronic rhinosinusitis not associated with bronchial asthma and GER disorder may exist in children and adolescents, especially in those with compatible GER disorder symptoms. In these cases, 24-h esophageal pH monitoring should be performed before indicating surgery, since the present data suggest that 10% of chronic rhinosinusitis surgeries can be eliminated.

Pediatric otolaryngologic manifestations of gastroesophageal reflux disease

In adults, an estimated 4% to 10% of chronic, nonspecific laryngeal disease seen in otolaryngologic clinics is associated with gastroesophageal reflux disease (GERD). Although no such estimates exist in children, many investigators have reported extraesophageal manifestations of GERD, of which the most common is the association of GERD with asthma and chronic cough. A variety of signs and symptoms of otolaryngologic disease also have been attributed to GERD, including hoarseness, laryngitis, chronic rhinitis, sinusitis, globus pharyngeus, recurrent croup, laryngomalacia, stridor, subglottic stenosis, otalgia, vocal cord granulomas, and oropharyngeal dysphagia. However, proof of the association between these manifestations of otolaryngologic disease and GERD is sparse. Furthermore, the manifestations of otolaryngologic disease often occur in the absence of such classic systems of GERD as heartburn or chest pain. This review explores the role of GERD in otolaryngologic disease in children.

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.

Role of laryngoscopy, dual pH probe monitoring, and laryngeal mucosal biopsy in the diagnosis of pharyngoesophageal reflux

There is no standard for determining significant pharyngoesophageal reflux. This prospective blind comparison study compared dual pH probe studies, direct laryngoscopy, and mucosal biopsy in children without symptoms of gastroesophageal reflux who underwent airway evaluation. Significant reflux to the lower esophageal probe did not correlate with statistical significance with reflux to the upper probe. In this group of asymptomatic patients, a positive lower pH probe finding did not correlate with upper or lower esophageal mucosal inflammation. Eosinophilia in the esophageal mucosa is diagnostic of gastroesophageal reflux disease, and was seen in 5 of the laryngeal biopsies. A weak correlation was seen between positive findings at laryngoscopy and positive posterior cricoid biopsy in this group. There may be no consistent way to predict significant pharyngoesophageal reflux in asymptomatic patients. Single-probe pH testing will not predict significant pharyngoesophageal reflux with mucosal changes. Laryngoscopy and upper pH probe findings only weakly correlate with significant histologic findings. Laryngeal and posterior cricoid biopsy may be the only sensitive test for mucosal injury. Clinical trials of empiric antireflux therapy should be used to determine whether the laryngeal changes seen in these patients are reversible.

PH monitoring in the distal and proximal esophagus in symptomatic infants

BACKGROUND

Standard distal esophageal pH monitoring data are sometimes within normal ranges in children with clinically suspected gastroesophageal reflux disease. Therefore, the authors hypothesized that the amount of acid reflux reaching the proximal esophagus may be greater in some subgroups of patients than in healthy controls or in other subgroups of patients.

METHODS

The parameters of 24-hour pH monitoring in the proximal part of the esophagus were analyzed in 120 symptomatic infants in who the reflux parameters in the lower esophagus were clearly within normal ranges (reflux index < 5.0%). The infants were classified into four patient groups: excessive regurgitation (n = 41): inconsolable crying (n = 31), apparent life-threatening event (ALTE) (n = 18), and chronic respiratory disorders (n = 30). The control group consisted also of 120 infants. The following parameters were calculated: reflux index, the number of reflux episodes, the number of reflux episodes lasting longer than 5 minutes, the duration of the longest reflux episode, and the acid clearance time (ACT, duration of reflux episodes divided by number of reflux episodes).

RESULTS

The patients with chronic respiratory disorders were significantly older than the patients in the other groups and the controls. In the distal esophagus, there was no statistically significant difference between the reflux parameters. As could be expected, every parameter was statistically (paired t test, Wilcoxon signed-rank test) significantly smaller in the proximal than in the distal esophagus, except for the ACT in infants who presented with inconsolable crying. In the proximal esophagus, there was no statistically significant difference between the different patient subgroups or controls, except for the number of reflux episodes in the group with chronic respiratory disorders and the group with inconsolable crying, applying one-way analysis of variance. As determined by applying the Mann-Whitney test, the number of reflux episodes in the upper esophagus was significantly higher in the group with chronic respiratory disorders than in the other patient groups and controls. Therefore, the authors' data do not support the hypothesis that reflux reaching the proximal esophagus is a frequent cause of ALTE. However, the data may suggest that the number of reflux episodes reaching the proximal esophagus in children with chronic respiratory disorders and with distal pH monitoring data within normal ranges may be increased. Whether this finding reflects reality or a statistical coincidence, or is influenced by the older age of this patient group, needs further evaluation.

CONCLUSIONS

In theory, dual simultaneous esophageal pH monitoring in the distal and proximal esophagus may increase the diagnostic accuracy of pH monitoring in infants. Our results do not support a substantial advantage of a systematic application of this new technique, especially not in infants presenting with ALTE, excessive regurgitation, or inconsolable crying. In the subgroup of patients with chronic respiratory disorders, more data are needed before conclusions can be determined and recommendations can be made.

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.

Gastroesophageal reflux in preterm infants: norms for extended distal esophageal pH monitoring

BACKGROUND

Preterm infants are predisposed to gastroesophageal reflux, which may manifest itself in many ways ranging from failure to thrive to vomiting. Extended distal esophageal pH monitoring is the gold standard for diagnosing reflux in the preterm infants and it is our objective to establish extended distal esophageal pH norms (reference values) for well, asymptomatic preterm infants and to compare with norms already established for term infants, children, adolescents, and adults.

METHODS

Twenty-one well, asymptomatic preterm infants consuming at least 70% of required maintenance oral feedings were recruited. The mean +/- standard deviation birth weight was 1549 +/- 439 g (range, 670-2470 g); the mean postconceptional age was 30.7 +/- 2.6 weeks (range, 25-35 weeks) and the mean postnatal age was 14 +/- 9 days (range, 2-40 days). Extended distal esophageal pH monitoring was performed on each of the infants, and the following parameters were calculated: reflux index, number of reflux episodes per day, number of reflux episodes lasting more than 5 minutes per day, and the longest recorded reflux episode.

RESULTS

The mean reflux index was 0.7 +/- 1.1%, the mean number of reflux episodes per day was 7.6 +/- 11.2, the mean number of reflux episodes lasting more than 5 minutes per day was 0.5 +/- 1.1 and the mean longest recorded reflux episode was 4.2 +/- 6.1 minutes. These results were comparable to those seen in term infants, children, adolescents, and adults. The trends for pH norms according to postconceptional age and postnatal age seemed to suggest that lower esophageal sphincter maturation might be related to postconceptional age, but the differences observed were not statistically significant (p > 0.05).

CONCLUSION

The norms (reference values) for well, asymptomatic preterm infants were comparable to those seen in term infants, children, adolescents, and adults. With the establishment of these norms, the search for a causal link between many of the respiratory problems encountered in prematurity and gastroesophageal reflux may be aided and the complications associated with gastroesophageal reflux may consequently be reduced.

Gastro-oesophageal reflux and oesophageal dysfunction in children and adolescents with brain damage

The prevalence of pathological gastro-oesophageal reflux (GOR) and oesophageal dysfunction (OD) was investigated in 32 children, 0.7-19 years of age (mean 11.2 years), with brain damage, mainly severe cerebral palsy and tetraplegia. They underwent 24-h pH monitoring in the distal oesophagus and oesophageal manometry. In addition, radiological examination of the oesophagus, chest radiography, blood counts and blood tests for iron deficiency were carried out. Fifteen (47%) patients had mild pathological acid reflux, 5 (16%) had moderately severe and 5 (16%) severe acid GOR. Seven of 32 (22%) patients had no pathological GOR. Ten patients had abnormal manometry findings and 9 had a pathological radiological oesophagus examination. Three patients had radiographic lung consolidations. Thirteen patients had iron deficiency and 5 were anaemic. Two patients with severe acid reflux have died, presumably from aspiration-induced pneumonia. Findings of OD and GOR are frequent in children with brain damage and are related to significant complications, including fatal course.

pH monitoring: the gold standard in detection of gastrointestinal reflux disease?

Gastroesophageal reflux disease (GERD) is one of the most frequent benign diseases of the gastrointestinal tract and in some cases the diagnosis may be very difficult. There are many diagnostic procedures but none of them could prove or definitely exclude the disease. The 24-h pH-monitoring is the "gold standard" for detection of gastroesophageal reflux and in many patients the reflux correlates with the GERD. The evaluation of a diagnostic method has to be done in a similar manner to the evaluation of therapeutic study (phase 1 to phase 4). For the definition of the "gold standard" for detection of a special diagnosis (e.g., the gastresophageal reflux disease), the results of phase 3 studies for different methods had to be compared. The method with the best values for sensitivity and specificity is yet to be discovered. Until now, pH monitoring has been the gold standard for the diagnosis of GERD. However, there are many problems connected with using this method in clinical practice.

Alkaline oesophageal reflux--an artefact due to oxygen corrosion of antimony pH electrodes

Antimony electrodes are widely used for gastro-oesophageal pH monitoring. They are also sensitive to oxygen, however, especially at low PO2 levels, which are known to shift recorded values in the alkaline direction. This study, which compares antimony and glass electrodes for oesophageal pH monitoring in six adults, shows that values recorded by antimony electrodes are 2.1 +/- 0.8 pH units (mean +/- SD) higher than by glass electrodes (p < 0.001; n = 7642). A further 52 patients with suspected gastro-oesophageal reflux were investigated by 24-h pH monitoring by means of antimony electrodes. In these patients the oesophageal pH was higher than 8.0 for 7% of the time (range, 0-60%). The alkaline periods recorded with antimony electrodes were all protracted in time, smoothly increasing from a neutral pH, and did not correspond to a sudden increase in pH, which would be expected if alkaline reflux had occurred. It is concluded that high pH values obtained by antimony electrodes are due to the oxygen sensitivity of the electrodes. The diagnosis of alkaline reflux seems to be valid only when pH monitoring is performed with glass electrodes or when values obtained with antimony electrodes are adjusted for the influence of the oxygen tension in the oesophagus.

Gastro-oesophageal reflux and severity of pulmonary disease in cystic fibrosis

The correlation between oesophageal dysfunction (OD), pathologic gastro-oesophageal reflux (GOR), and severity of pulmonary disease was studied in 12 patients with cystic fibrosis (CF). They were interviewed about symptoms of OD and underwent 24-h pH recording in the oesophagus, oesophageal manometry combined with reflux provocation tests, the acid perfusion test, the acid clearance test, lung function tests, and scoring of the chest radiograph. Six of the 12 patients reported symptoms of OD. Abnormal GOR, as shown by 24-h pH monitoring of the oesophagus, was found in eight of them. Altogether 9 of the 12 participants had at least one pathologic oesophagus test result. Results of radiologic examinations of the oesophagus, performed in six patients, were pathologic. The four patients with the best chest radiograph scores and the best lung function had significantly less signs and symptoms of OD and GOR than the other eight patients. We conclude that OD, GOR, and pulmonary disease covariate in CF.

Bronchial asthma and acid reflux into the distal and proximal oesophagus

The prevalence of pathological gastro-oesophageal reflux in children and adolescents with asthma was studied by 24 hour two level oesophageal pH monitoring in 42 subjects aged 9-20 years with moderate or severe bronchial asthma. The importance of oesophagobronchial nerve reflexes and of aspiration of gastric acid as triggers in asthma was assessed by studying whether episodes of reflux into the distal and into the proximal oesophagus were followed by asthma attacks. Twenty-one subjects (50%) had a pathological total reflux time in the distal oesophagus and six (16%) in the proximal oesophagus. Nine patients had pathological gastro-oesophageal reflux into the distal oesophagus together with symptoms of asthma during the day on which the recording took place. In three of them the episodes of asthma symptoms were significantly correlated with preceding episodes of reflux into the distal oesophagus, and in one subject to reflux into the proximal oesophagus. We conclude that pathological gastro-oesophageal reflux is common in children and adolescents with asthma, but it seems to provoke symptoms of asthma in only a few. Symptoms of asthma were more often elicited by exposure of the distal oesophagus to gastric acid, possibly by a vagal reflex, than by aspiration of gastric juice.