Incidence of gastroesophageal reflux in sleep, awake, fasted, and postcibal periods in asymptomatic and symptomatic infants

Gastroesophageal reflux disease in preterm infants: unmet needs

INTRODUCTION

Many preterm present somatic symptoms including aerodigestive and cardiorespiratory manifestations, in combination with irritability and/or distress, which are often attributed to gastroesophageal reflux (GER), albeit for unclear reasons.

AREAS COVERED

We searched in PubMed, Google Scholar, and MEDLINE for guidelines, reviews, and randomized controlled trials up to March 2024.

EXPERT OPINION

The diagnosis of GER-disease (GERD) in preterm is challenging because manifestations are atypical and diagnostic investigations difficult and not devoid of risk for adverse events. In case of vomiting or regurgitation, GER as a consequence of anatomical or metabolic conditions should be considered. Although many preterm infants are treated with proton pump inhibitors, this is seldom needed. Low-quality evidence for alginates is available, but needs further evaluation. There is a need for an effective and safe prokinetic favoring esophageal clearance, increasing lower esophageal sphincter pressure and stimulating gastric emptying. Non-drug treatment such as feeding adaptations (volume, duration, and composition) and positional changes are insufficiently applied. Thickened formula is not indicated in preterm babies. In case none of the above recommendations did result in sufficient improvement, and if documentation of acid GER is not possible, a 2-4 week trial of a proton pump inhibitor is acceptable.

Integrated multi-omics profiling of nonfunctioning pituitary adenomas

PURPOSE

Genetic and epigenetic alterations are involved in pituitary adenoma pathogenesis, however the molecular basis of proliferative nonfunctioning pituitary adenomas (NFPAs) remains unclear. Here, we analyzed integrated multi-omics profiling including copy number variation (CNV), DNA methylation and gene expression of 8 NFPAs.

METHODS

We collected 4 highly proliferative (hpNFPA, Ki-67 ≥ 3) and 4 lowly proliferative (Ki-67 ≤ 1) NFPAs, and comprehensively assessed CNV, DNA methylation, and gene expression by Illumina HumanMethylation450 BeadChip and Affymetrix GeneChip PrimeView Human Gene Expression Array. We performed Ingenuity Pathway Analysis (IPA) for differentially expressed genes to illustrate aberrant pathways and delineated protein-protein networks of selected key genes in dysregulated pathways.

RESULTS

Aberrant arm level CNV, dysregulated DNA methylation, and associated impacts on gene expressions were observed in 2 early occurring hpNFPAs. Chromosomal losses were associated with attenuated expression of DNA methyltransferases, further altering global methylation in these 2 samples. Correlation analysis between DNA methylation and gene expression in 8 NFPAs indicates methylation in promoter and gene body regions are both involved in gene regulation. IPA showed PPARα/RXRα, dopamine receptor signaling, cAMP-mediated signaling, and calcium signaling were all activated, while p38 MAPK and ERK5 signaling were inhibited in hpNFPAs. Moreover, selected key gene networks in hpNFPAs exhibited concurrent methylation status and expression levels of adenylate cyclase genes, G protein subunits, HLA genes, CXCL12, and CCL2.

CONCLUSION

This study presents comprehensive multi-omics views of CNV, DNA methylation, and gene expression in 8 NFPAs. Pathway analysis and network maps of key genes provide clues to elucidate the molecular basis of hpNFPA.

Primary mismatch repair deficient IDH-mutant astrocytoma (PMMRDIA) is a distinct type with a poor prognosis

Diffuse IDH-mutant astrocytoma mostly occurs in adults and carries a favorable prognosis compared to IDH-wildtype malignant gliomas. Acquired mismatch repair deficiency is known to occur in recurrent IDH-mutant gliomas as resistance mechanism towards alkylating chemotherapy. In this multi-institutional study, we report a novel epigenetic group of 32 IDH-mutant gliomas with proven or suspected hereditary mismatch repair deficiency. None of the tumors exhibited a combined 1p/19q deletion. These primary mismatch repair-deficient IDH-mutant astrocytomas (PMMRDIA) were histologically high-grade and were mainly found in children, adolescents and young adults (median age 14 years). Mismatch repair deficiency syndromes (Lynch or Constitutional Mismatch Repair Deficiency Syndrom (CMMRD)) were clinically diagnosed and/or germline mutations in DNA mismatch repair genes (MLH1, MSH6, MSH2) were found in all cases, except one case with a family and personal history of colon cancer and another case with MSH6-deficiency available only as recurrent tumor. Loss of at least one of the mismatch repair proteins was detected via immunohistochemistry in all, but one case analyzed. Tumors displayed a hypermutant genotype and microsatellite instability was present in more than half of the sequenced cases. Integrated somatic mutational and chromosomal copy number analyses showed frequent inactivation of TP53, RB1 and activation of RTK/PI3K/AKT pathways. In contrast to the majority of IDH-mutant gliomas, more than 60% of the samples in our cohort presented with an unmethylated MGMT promoter. While the rate of immuno-histochemical ATRX loss was reduced, variants of unknown significance were more frequently detected possibly indicating a higher frequency of ATRX inactivation by protein malfunction. Compared to reference cohorts of other IDH-mutant gliomas, primary mismatch repair-deficient IDH-mutant astrocytomas have by far the worst clinical outcome with a median survival of only 15 months irrespective of histological or molecular features. The findings reveal a so far unknown entity of IDH-mutant astrocytoma with high prognostic relevance. Diagnosis can be established by aligning with the characteristic DNA methylation profile, by DNA-sequencing-based proof of mismatch repair deficiency or immunohistochemically demonstrating loss-of-mismatch repair proteins.

Safety considerations when managing gastro-esophageal reflux disease in infants

Introduction: Gastro-esophageal reflux disease (GERD) in infants is worldwide diagnosed with increasing frequency, resulting in an increasing number of infants exposed to treatment. In this review, we focus on the safety of therapeutic options. Areas covered: English articles were searched from 1990 until May 2020 in PubMed and Google Scholar. Evidence suggests that non-pharmacological treatment is often effective and safe. Guidelines restrict pharmacological treatment to acid-suppressive medication, which is associated with adverse effects, often related to gastro-intestinal dysbiosis and consequences of the latter. Aluminum-free alginates have some efficacy and are not associated with relevant adverse effects. Especially in infants, GERD is often nonacid related. Prokinetics are not recommended because of lack of efficacy and numerous adverse effects. Expert opinion: Pediatric trials are underpowered regarding adverse effects. The number of infants exposed to anti-secretory agents is increasing worldwide, often without indication. Informing healthcare providers about adverse effects of acid-secretory medication may contribute to a more rational use. Acid inhibiting agents such as alginates are a drug class associated with limited efficacy and devoid of serious adverse effects. Regarding prokinetics, the risk of adverse effects outweighs the benefit. Reassurance of parents and nutritional management of GERD in infants is effective and safe.

The influence of Intrapulmonary percussive ventilation on gastroesophageal reflux in infants under the age of 1 year

BACKGROUND

Intrapulmonary percussive ventilation (IPV) is an airway clearance technique used at any age to facilitate the removal of secretions from the respiratory tract. The effect of IPV on gastroesophageal reflux(GER) is not well documented. This study aimed to determine the influence of IPV on GER in infants.

METHODS

During a 24-hour multichannel intraluminal impedance-pH monitoring (MII-pH), infants in the intervention group received a20 minutes session of IPV in upright position, 2 hours postprandial. The control group received no intervention and was placed in the same position for 20 minutes, 2 hours postprandial. The number of reflux episodes (REs) during IPV as compared to the number of REs in the control group during the 20 minutes period.

RESULTS

Fifty infants were included in each group;21 infants in the IPV group and 14 infants in the control group were diagnosed with abnormal MII-pH (P = .142). During IPV, the number of REs was significantly lower than in the control group (P < .001). Also in the subgroups with abnormal or normal MII-pH, a significantly lower number of REs during IPV was found (P = .011, P = .011 respectively).

CONCLUSION

IPV decreases the number of REs in infants independent of the results of MII-pH.

Influence of intrapulmonary percussive ventilation in upright position on gastro-oesophageal reflux in infants

OBJECTIVES

To determine the influence of physiotherapy using intrapulmonary percussive ventilation on gastro-oesophageal reflux (GOR) in infants <1 year.

METHODS

In this controlled trial with intra-subject design, children were studied using multichannel intraluminal impedance pH (pH-MII) monitoring over 24 hr, during which they received one 20-min session of intrapulmonary percussive ventilation in upright position (IPV_R ), 2 hr after their latest feeding. Two hours after each feeding, the number of reflux episodes (RE) over a 20-min period was registered for each infant and a mean per 20 min was calculated in order to obtain a baseline value. The number of RE during IPV_R intervention was compared to baseline.

RESULTS

Fifty infants with a median age of 133 days were recruited of whom 21 were diagnosed with pathological GOR. During IPV_R , the incidence of RE in the entire group was significantly lower compared to baseline; median (inter-quartile range [IQR]) 0 (0-1) versus 0.71 (0-1.33) RE, respectively, P = 0.003. The subgroup with abnormal GOR showed also a significant decrease of RE during IPV_R ; median (IQR) 0 (0-1) versus 1.17 (0.55-2.16) RE, respectively, P = 0.03. No difference was detected in the group with normal reflux; median (IQR) 0.6 (0-1) compared to 0 (0-1) RE, respectively, P = 0.34.

CONCLUSION

IPV_R does not induce, nor aggravate GOR in infants without and with pathological GOR, respectively, but on the contrary decreases the number of RE in patients with pathological reflux. Pediatr Pulmonol. 2016;51:1065-1071. © 2016 Wiley Periodicals, Inc.

The Role of Sleep in the Modulation of Gastroesophageal Reflux and Symptoms in NICU Neonates

BACKGROUND

Newborns sleep about 80% of the time. Gastroesophageal reflux disease is prevalent in about 10% of neonatal intensive care unit infants. Concurrent polysomnography and pH-impedance studies clarify the relationship of gastroesophageal reflux with sleep.

AIMS

To characterize spatiotemporal and chemical characteristics of impedance-positive gastroesophageal reflux and define symptom associations in sleep and wake states in symptomatic neonates. We hypothesized that frequency of impedance-positive gastroesophageal reflux events and their association with cardiorespiratory symptoms is greater during sleep.

METHODS

Eighteen neonates underwent concurrent polysomnography with a pH-impedance study. Impedance-positive gastroesophageal reflux events (weakly acidic or acidic) were categorized between sleep versus wake states: Symptom Index = number of symptoms with gastroesophageal reflux/total symptoms*100; Symptom Sensitivity Index = number of gastroesophageal reflux with symptoms/total gastroesophageal reflux*100; Symptom Association Probability = [(1 - probability of observed association between reflux and symptoms)*100]).

RESULTS

We analyzed 317 gastroesophageal reflux events during 116 hours of polysomnography. During wake versus sleep, respectively, the median (interquartile range) frequency of impedance-positive gastroesophageal reflux was 4.9 (3.1-5.8) versus 1.4 (0.7-1.7) events/hour (P < 0.001) and the proximal migration was 2.6 (0.8-3.3) versus 0.2 (0.0-0.9) events/hour (P < 0.001). The Symptom Index for cardiorespiratory symptoms for impedance-positive events was 22.5 (0-55.3) versus 6.1 (0-13), P = 0.04, whereas the Symptom Sensitivity Index was 9.1 (0-23.1) versus 18.4 (0-50), P = 0.04, although Symptom Association Probability was similar (P = 0.68).

CONCLUSIONS

Contrary to our hypothesis, frequency of gastroesophageal reflux in sleep is lower; however, spatiotemporal and chemical characteristics of gastroesophageal reflux and symptom-generation mechanisms are distinct. For cardiorespiratory symptoms during sleep, a lower Symptom Index entails evaluation for etiologies other than gastroesophageal reflux disease, a higher Symptom Sensitivity Index implies heightened esophageal sensitivity, and similar Symptom Association Probability indicates other mechanistic possibilities.

Diagnosis of gastroesophageal reflux disease in infants

Gastroesophageal reflux is commonly encountered in the infant population. Most children will outgrow their reflux but some develop pervasive disease and require medical or surgical treatment. Many tools exist for use in the workup of pediatric gastroesophageal reflux disease; however, the most effective method of diagnosis is not clear. Delineating which patients will benefit from more definitive therapy is a remarkable challenge in this group, often borrowing tools and principles from the adult patient population. Therefore, we reviewed the available literature to critically evaluate the merits and limitations of the current diagnostic modalities available for the evaluation of infantile gastroesophageal reflux.

Excessive crying and gastro-oesophageal reflux disease in infants: misalignment of biology and culture

Excessive crying is the most common problem presenting to the doctor in the first months of life in western industrialised societies, affecting up to 30% of infants. There has been an exponential increase in the diagnosis of gastro-oesophageal reflux disease (GORD) in babies who cry excessively over the past few decades, and many parents believe their crying infant "has reflux". This paper proposes that culturocentric assumptions have confused interpretation of research into GORD, and re-examines the findings of GORD research from the perspective of evolutionary biology. Evolutionary biologists argue that the human infant is an exterogestate foetus for at least the first six months of life, dependent on maternal co-regulation for optimal physiological function. However, infant-care practices in western industrialised societies shifted towards an emphasis on infant autonomy at the time of the Industrial Revolution. From the perspective of evolutionary biology, a misalignment between western culture and the biological expectations of the infant developed over two million years of evolution may result in excessive crying in less adapted babies. The key biocultural factors that impact on infant distress are feeding management, parental responsiveness, sensory nourishment and sleep management. When the concept of the human infant as an exterogestate foetus is integrated with the findings of GORD research, a hypothesis and its corollary emerge. This hypothesis proposes that infant GORD is a physiological manifestation of misalignment between biology and culture, and proposes, as a corollary, that if the impact of biocultural factors upon the physiology of otherwise well crying babies is not addressed in the first months of life, populations of infants who cry excessively may be predisposed to GORD after three to four months of age. If this hypothesis is correct, an integrated clinical approach to crying babies less than three to four months of age that considers feeding management (e.g., frequent feeds, breast- or bottle-feeding technique, referral to a lactation consultant, cow's milk allergy), parental responsiveness (e.g., prompt response to infant cues), sensory nourishment (e.g., sling or backpack, walks, massage) and sleep management (e.g., nocturnal co-sleeping) should, firstly, decrease crying when applied to infants less than three to four months of age, and secondly, decrease the incidence of GORD in these infants once they are older than three to four months of age. Thirdly, if this hypothesis is correct, combining the integrated approach with pharmaceutical intervention should improve outcomes in infants diagnosed with GORD.

Chest physiotherapy, gastro-oesophageal reflux, and arousal in infants with cystic fibrosis

BACKGROUND

Postural drainage chest physiotherapy in infants with cystic fibrosis (CF) exacerbates gastro-oesophageal reflux (GOR) and may contribute to a more rapid deterioration in lung function.

AIMS

To compare standard postural drainage chest physiotherapy (SPT) and a modified physiotherapy regimen (MPT) without head-down tilt, with regard to GOR, arousal state, and cardiorespiratory function.

METHODS

Twenty infants with CF underwent 30 hour oesophageal pH monitoring, during which four chest physiotherapy sessions were administered (day 1: MPT-SPT; day 2: SPT-MPT). Arousal state, heart rate, and oxygen saturation were documented for each of the physiotherapy positions (supine, prone, right lateral, and left lateral with (SPT) or without (MPT) 30 degrees head-down tilt).

RESULTS

Significantly more reflux episodes occurred during SPT than during MPT, but there were no significant differences in median episode duration or fractional reflux time. During SPT, left lateral positioning was associated with fewer reflux episodes compared to other positions. During supine and prone positioning, more reflux episodes occurred during SPT than during MPT. Infants were significantly more likely to be awake or cry during SPT. There was a significant association between crying and reflux episodes for SPT. Non-nutritive sucking was associated with a significant reduction in reflux episodes during SPT. Oxygen saturation during SPT was significantly lower during crying and other waking, and non-nutritive sucking during SPT was associated with a significant increase in oxygen saturation.

CONCLUSIONS

SPT is associated with GOR, distressed behaviour, and lower oxygen saturation.

The role of gastro-oesophageal reflux in the aetiology of SIDS

Gastro-oesophageal reflux (GOR) has been identified as a possible cause of SIDS. Several features of GOR unique to infants presenting with apparent life-threatening events (ALTEs) have led to its 'pathogenic' definition. One is that the life-threatening apnoea itself is initiated by GOR, another is that the ALTE relates to prolonged reflux during sleep, in a vulnerable sleep-state, and finally that the ALTE relates to excessive quantities of GOR. The presumption of GOR 'pathology' as a cause of SIDS however, is questionable in these susceptible infants for three reasons: firstly, GOR is physiological and occurs in most infants; secondly, there is no general consensus on what constitutes normal physiological reflux, and thirdly, variation in the recording technique and methods of data analysis and interpretation may account for the differences between study groups. It seems likely therefore if GOR is implicated in SIDS, additional factors are involved. Under certain circumstances, physiological GOR may trigger life-threatening apnoea in apparently healthy infants, that leads to SIDS. One mechanism that could explain such a death is reflex apnoea by stimulation of laryngeal chemoreceptors (LCR) during sleep. The conditions under which this could be fatal are the occurrence of gastric contents refluxed to the level of the pharynx during sleep, in the young infant who has depressed swallowing and arousal. That is, the occurrence of GOR to the level of the pharynx during sleep, an infrequent event that is usually innocuous, could be converted to a fatal event if swallowing is impaired and arousal depressed, by a variety of mediating factors such as prone sleeping, prematurity, sedatives, seizures or upper respiratory tract infections. The identification of LCR responses, particularly in prone sleeping and premature infants provide further evidence that this mechanism may be implicated in the aetiology of SIDS in apparently healthy infants.

Enteral feeding in the preterm infant

In planning enteral feeding in the preterm infant, decisions need to be made regarding the feeding schedule, choice of milk, and the route of administration. Feeds should be commenced within a week after birth beginning with subnutritional quantities. Preterm human milk from the infant's own mother is the milk of choice. When full enteral feeding is established, supplementation with human milk fortifier is recommended. Donor human milk and preterm formula are alternatives. Early establishment of enteral nutrition and maintenance of optimal nutrition during infancy are important as dietary manipulations in preterm infants have potential long-term influences on their health, growth and neurodevelopment.

Gastroesophageal reflux and respiratory phenomena in infants: status of the intraluminal impedance technique

BACKGROUND

The coincidence of recurrent respiratory symptoms and gastroesophageal reflux (GER) is a well-known phenomenon in infants. Twenty-four-hour pH metry is the presumed gold standard of diagnostic tools for this symptom complex, but with this method, only acid (pH <4) and alkaline (pH >7) GER can be detected. Gastroesophageal reflux with an esophageal pH in the physiological range (pH 5-6.8) may represent many cases of clinically relevant GER unrecognized by pH metry. In this study the intraluminal multiple electrical impedance (IMP) procedure for complete registration of GER was compared with pH metry for its diagnostic value in the presence of respiratory symptoms.

METHODS

Twenty-two infants with recurrent regurgitation or pulmonary problems were investigated simultaneously with IMP, pH metry, and polygraphy during two feeding periods. Heart rate, oxygen saturation, sleep states, and oronasal flow were recorded, among other parameters.

RESULTS

Three hundred sixty-four occurrences of GER were detected by IMP; only 11.4% had a pH less than 4 and were therefore recognized by pH metry. Three hundred twelve (84.8%) occurrences were associated with breathing abnormalities, and 11.9% of these were detected by pH metry. Nineteen instances were accompanied by a decrease of oxygen saturation of more than 10% of the initial value. Only three (15.8%) of these had a pH less than 4. The remaining 16 reflux episodes were recognized by IMP only. After software-aided preselection, 165 instances of apnea were visually validated, 49 of which were accompanied by GER. Thirty-eight (77.6%) of these were exclusively recorded by IMP.

CONCLUSIONS

The use of pH metry alone cannot detect most GER incidents accompanied by respiratory symptoms and therefore does not appear to be suitable for this approach. The pH-independent IMP technique promises to be a reliable tool for presumably GER-associated respiratory symptoms.

Gastro-oesophageal reflux in infancy

Gastro-oesophageal reflux (GOR) is a common phenomenon in infants, which may occur with or without accompanying symptoms. Although most infants presenting with regurgitation have a normal physical examination, it is now recognized that infants may also present with a wide variety of symptoms. Oesophagitis is associated with increased oesophageal acid exposure. The determination of cause and effect is difficult, as there are many aspects of reflux disease where cause and effect relationships are cyclic. Reflux disease is present when there is an imbalance between a number of factors that can contribute to a decrease, as well as an increase, of GOR. Oesophageal pH monitoring with a semi-disposable monocrysant antimony pH catheter with three sensors is very good at documenting oesophageal acidification and gastric buffering and, therefore, quantifies acid reflux frequency and duration. However, the interpretation of the data is complex as they are influenced by numerous factors, such as position, activity (sleep, crying), feeding (frequency and composition) or medication. The duration of buffering of gastric acidity during pH monitoring might, in the future, appear to be a relevant factor in the interpretation of oesophageal pH data.

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.

Posture and gastro-oesophageal reflux: a case for left lateral positioning

AIM

Prone posture is often recommended for symptomatic gastroesophageal reflux in young infants, but prone positioning has been associated with sudden infant death. The aim of this study was thus to establish the optimal alternative posture for reducing reflux.

METHODS

24 infants (< 5 months) with symptomatic gastro-oesophageal reflux were studied prospectively with 48 h pH monitoring. They were randomly assigned to one of the 24 permutations of the four positions (supine, prone, right, left). During the first 24 hours the infant was held horizontally, and then the permutation was repeated at 30 degrees head elevation, giving a total of eight study segments for each infant. Data were edited to remove all time when the infants were not in the prescribed positions. Results were evaluated using analysis of covariance.

RESULTS

Gastro-oesophageal reflux expressed as reflux index (mean % (SEM)) was significantly less in the prone and left lateral positions (6.72 (1.06) and 7.69 (1.03) respectively) than in the supine and right lateral positions (15.33 (2.33) and 12.02 (1.38); p < 0.001). Head elevation did not affect any variables significantly.

CONCLUSIONS

Head elevation may not always be of clinical value. The left lateral position is a suitable alternative to prone for the postural management of infants with symptomatic gastro-oesophageal reflux.

Gastroesophageal reflux in childhood

Gastroesophageal reflux (GER) is one of the most frequent symptomatic clinical disorders affecting the gastrointestinal tract of infants and children. During the past 2 decades, GER has been recognized more frequently because of an increased awareness of the condition and also because of the more sophisticated diagnostic techniques that have been developed for both identifying and quantifying the disorder. Gastroesophageal fundoplication is currently one of the three most common major operations performed on infants and children by pediatric surgeons in the United States. Normal gastroesophageal function is a complex mechanism that depends on effective esophageal motility, timely relaxation and contractility of the lower esophageal sphincter, the mean intraluminal pressure in the stomach, the effectiveness of contractility in emptying of the stomach, and the ease of gastric outflow. More than one of these factors are often abnormal in the same child with symptomatic GER. In addition, in patients with GER disease, and particularly in those patients with neurologic disorders, there appears to be a high prevalence of autonomic neuropathy in which esophagogastric transit and gastric emptying are frequently delayed, producing a somewhat complex foregut motility disorder. GER has a different course and prognosis depending on the age of onset. The incompetent lower esophageal sphincter mechanism present in most newborn infants combined with the increased intraabdominal pressure from crying or straining commonly becomes much less frequent as a cause of vomiting after the age of 4 months. Chalasia and rumination of infancy are self-limited and should be carefully separated from symptomatic GER, which requires treatment. The most frequent complications of recurrent GER in childhood are failure to thrive as a result of caloric deprivation and recurrent bronchitis or pneumonia caused by repeated pulmonary aspiration of gastric fluid. Children with GER disease commonly have more refluxing episodes when in the supine position, particularly during sleep. The reflux of acid into the mid or upper esophagus may stimulate vagal reflexes and produce reflex laryngospasm, bronchospasm, or both, which may accentuate the symptoms of asthma. Reflux may also be a cause of obstructive apnea in infants and possibly a cause of recurrent stridor, acute hypoxia, and even the sudden infant death syndrome. Premature infants with respiratory distress syndrome have a high incidence of GER. Esophagitis and severe dental carries are common manifestations of GER in childhood. Barrett's columnar mucosal changes in the lower esophagus are not infrequent in adolescent children with chronic GER, particularly when Heliobacter pylori is present in the gastric mucosa. Associated disorders include esophageal dysmotility, which has been recognized in approximately one third of children with severe GER. Symptomatic GER is estimated to occur in 30% to 80% of infants who have undergone repair of esophageal atresia malformations. Neurologically impaired children are at high risk for having symptomatic GER, particularly if nasogastric or gastrostomy feedings are necessary. Delayed gastric emptying (DGE) has been documented with increasing frequency in infants and children who have symptoms of GER, particularly those with neurologic disorders. DGE may also be a cause of gas bloat, gagging, and breakdown or slippage of a well-constructed gastroesophageal fundoplication. The most helpful test for diagnosing and quantifying GER in childhood is the 24-hour esophageal pH monitoring study. Miniaturized probes that are small enough to use easily in the newborn infant are available. This study is 100% accurate in diagnosing reflux when the esophageal pH is less than 4.0 for more than 5% of the total monitored time.

Color doppler in the diagnosis of the gastroesophageal reflux in children: comparison with pH measurements and B-mode ultrasound

Eighty-four high risk children were examined for suspected gastroesophageal reflux comparing 24-h esophageal pH measurements with ultrasound (US) scans with and without the use of color Doppler (CD). In 83.3 % of the patients there was unequivocal agreement (reflux or no reflux) among all three techniques; 60.7 % of the children showed reflux by pH-metry as compared to 51.2 % by B-mode US and 59.5 % by CD US. In 87 % of patients there was agreement between pH-metry and B-mode US as compared to 94 % between pH-metry and CD US. The sensitivity of reflux detection increased from 84.4 % to 98 % when CD was added to B-mode US. This improvement was thought to be due to the higher sensitivity of CD for rapid and small quantities of reflux. The small number of discrepancies between pH-metry and CD US is probably due to the inability of the former to detect neutral reflux of contents or short duration (< 30 s), while CD US may miss some cases of acid reflux due to the short time of the examination (10 min). The addition of CD increases the sensitivity of US for detecting reflux. This rapid, easy and reliable method can be used to screen high risk populations when reflux is thought to be the cause of respiratory symptoms.

Respiratory manifestations of gastroesophageal reflux disease in pediatric patients

Respiratory manifestations of gastroesophageal reflux disease (GERD) are being recognized with increasing frequency. We present the evaluation and management of four infants and children with unusual respiratory symptoms attributed to GERD. The advantages and disadvantages of diagnostic studies of GERD are discussed, and an evaluation and treatment protocol is presented. Treatment must be tailored to the nature and severity of the patient's presenting symptoms and includes conservative, pharmacologic, and/or surgical management.

Gastroesophageal reflux and ENT disorders in childhood

Among controversies in pediatric otorhinolaryngology, the role of gastroesophageal reflux (GER) in inflammatory disorders of the upper airway remains of major concern. A laryngeal involvement by GER was demonstrated in adults and a correlation with GER has been found in pediatric populations with recurrent croup. However, although considered statistically significant, these results concern a few patients only and are inconclusive for a causal relationship. In addition, pH monitoring, often considered as the gold standard for the diagnosis of GER disease, has failed in giving normal values in ENT disorders. Eventually, upper pharyngeal and nasal involvements by GER and GER-related otitis media or otalgia have been suggested by some authors. In the 6th International Congress on Pediatric Otolaryngology, the Symposium on GER was designed to help physicians in improving their knowledge of the data from the literature and their understanding of the involved mechanisms. Bearing in mind the potential severity of GER disease, the audience also heard and debated the most up-to-date methods of assessing GER and treating it in patients with possibly related otorhinolaryngological symptoms. Here is the summary of this symposium.

Developmental maturation of gastro-oesophageal reflux in preterm infants

The frequency and duration of gastro-oesophageal reflux were examined in 40 preterm infants and compared with a previously published healthy cohort of 74 term infants. Selection required that the infants were born between 24 and 32 weeks' gestation, had a normal head ultrasound and were studied at term post-menstrual age. Multi-channel pen recordings of sleep state, movement, breathing and acid reflux were made. In term and preterm infants the frequency and duration of reflux were greatest in active sleep, rare in quiet sleep and significantly less in preterm than term infants in wakefulness and active sleep (p < 0.05). The fewer and shorter episodes in preterm infants could not be explained by sleep state movement, gestational or postnatal age, days intubated, days on oxygen or the lowest pH of reflux episodes.

Abbreviated oesophageal pH monitoring in infants

The results of 24 h oesophageal pH monitoring, performed in 129 infants aged 6-10 weeks, were compared to those in the same patients after shorter periods (3, 6, 9 and 12 h). In the investigated population there was no significant difference between the reflux index (percentage of time with a pH < 4.0) after 12 or 24 h. Moreover, the correlation coefficient between the reflux index after 12 and 24 h was excellent (r 0.95). However, the intra-individual difference in reflux index after 12 and 24 h was 5% in 19% of the infants, and even exceeded 10% in more than 5% of the infants, making the interpretation of the results unreliable. Even in this particular population of infants in whom a 24-h period could be divided into almost identical periods (including a feeding and a sleeping period), 24-h registrations provided the most reliable results. However, if for some reason the investigation had to be interrupted after a minimum of 12 h, the risk for erroneous interpretation of the data appeared to be acceptable. The results of this study must not be extrapolated to older children.

The role of sonography in the evaluation of gastro-oesophageal reflux--correlation to pH-metry

Sonography was compared to pH-metry and/or oesophagomanometry to evaluate the accuracy of sonography in the early diagnosis of gastro-oesophageal reflux. Thirty children with a mean age of 72 days (21-252 days) were studied. The results showed that specificity of sonographic diagnosis was 87.5% and sensitivity was 100% (with P less than 0.001). Sonography also proved helpful in providing both functional and morphological data in addition to pH-metric results. This study therefore suggests that sonography is useful as the first approach in the diagnosis of vomiting babies as it is non-invasive and provides sufficient diagnostic accuracy.

Lack of temporal relation between acid reflux in the proximal oesophagus and cardiorespiratory events in sleeping infants

We studied sleeping infants in order to investigate whether a temporal relation exists between acid reflux extending to the proximal portion of the oesophagus and cardiorespiratory events. One hundred infants with occasional regurgitations were studied: 50 infants admitted after an apparently life-threatening event (ALTE) that occurred during sleep and that remained unexplained despite medical investigation, and 50 asymptomatic infants (non-ALTE). The infants had a median age of 8 weeks (range 4-26 weeks); 54 were boys. In each child a pH probe was placed in the proximal portion of the thoracic oesophagus, under radiological control. Polygraphic monitoring of state of alertness, cardiorespiratory activity, and proximal oesophageal pH changes was conducted continuously during 1 night. The data were analysed blind. In 80 infants a total of 186 decreases in oesophageal pH below 4 units were seen; 37% occurred during wakefulness, and 40% during rapid eye movement (REM) sleep. A total of 7029 central and 61 obstructive apnoeas were monitored, mainly during REM sleep. Within 5 min before, and 5 min after the drops in pH, there was no difference in the number, or the duration of bradycardia, central, mixed, or obstructive apnoea. The infants with an ALTE could not be differentiated from the non-ALTE infants for any of the variables studied. It is concluded that spontaneous acid refluxes extending to the proximal portion of the oesophagus during sleep are usually not temporally related with the development of apnoeas or bradycardias.

The interpretation of oesophageal pH monitoring data

Continuous monitoring of oesophageal pH is regarded as the gold standard for all reflux investigations. However, since gastro-oesophageal reflux is considered a normal phenomenon which occurs to a certain extent in each individual, the distinction between "normal" and "abnormal" is not always obvious and is not possible to achieve with a single test. Moreover, data depend on technical hardware such as recording devices and electrodes together with such patient characteristics as age, position, activity, and medication. Although much literature on pH monitoring has appeared recently, many investigations have failed to take into account the basic principles that are of major importance for any biomedical test such as reproducibility, sample reliability, and indications. There is a need to standardize the technique in order to compare studies performed in different centres, provided the technique is reproducible.

Reproducibility of continuous 24 hour oesophageal pH monitoring in infants and children

The reproducibility of 24 hour oesophageal pH monitoring was studied in 30 infants and children including the proportions of the investigation time with a pH less than 4 (reflux index), the number of episodes with a pH less than 4 or lasting longer than five minutes, and the duration of the longest episodes with a pH less than 4. Twenty four hour pH monitoring was performed using identical equipment on two consecutive days under similar conditions. Pearson correlation coefficients range from 0.88 to 0.98. The results obtained on two consecutive days were similar. The reflux index and the number of reflux episodes greater than five minutes were the most reproducible parameters. Despite the many patient related factors influencing pH data, the reproducibility of 24 hour pH monitoring data are satisfactory for routine clinical application.