Pathophysiology of aerodigestive pulmonary disorders in the neonate

Near-Fatal Aspiration in a Child With Pierre Robin Sequence and Aero-Digestive Disorder: A Case Report

Pierre Robin sequence (PRS) presents significant challenges in airway management and postoperative care, especially in infants undergoing cleft palate repair. The most critical task for paediatric anaesthetists is securing the airway. The presence of aero-digestive disorders makes postoperative care equally challenging, which is often underemphasised. This report describes the management of a 17-month-old male child with PRS and a partial cleft palate who aspirated postoperatively following palatoplasty. Prompt intervention with nebulised bronchodilators, oxygen therapy, and intravenous antibiotics led to significant clinical improvement. The case underscores the necessity of developing standardised guidelines for managing children post-surgery.

The follow up of complex infants in an aerodigestive clinic

The current available literature evaluating pediatric multidisciplinary aerodigestive programs for the management of aerodigestive disorders in infants was reviewed. Multidisciplinary aerodigestive programs have emerged to provide coordinated and comprehensive care for the growing population of children with aerodigestive conditions, including complex airway, pulmonary, gastrointestinal, and feeding disorders, which are prevalent among infants discharged from the neonatal intensive care unit (NICU). The team approach central to aerodigestive clinics offers a comprehensive diagnostic workup and unified management plan through consolidated interdisciplinary clinics, combined endoscopic procedures, and regular team discussions, leading to improved resource utilization and health care outcomes. We review common conditions presenting in the NICU that benefit from the aerodigestive model of care, including esophageal atresia, prematurity, bronchopulmonary dysplasia with or without tracheostomy or ventilator dependence, and dysphagia.

Impact of esophageal mucosal permeability markers on provocation-induced esophageal reflexes in high-risk infants

Esophageal distal baseline impedance (DBI) is an indicator of mucosal integrity; lower values suggest increased permeability. Aims were to characterize the (1) effect of DBI category (<900 Ω, 900-2000 Ω, and >2000 Ω) on sensory-motor characteristics of mid-esophageal provocation-induced motility reflexes, and (2) clinical outcomes among high-risk human infants evaluated for gastroesophageal reflux disease. Symptomatic infants (N = 49, 41 ± 3 weeks postmenstrual age) underwent pH-impedance testing to characterize acid reflux index (ARI) and DBI, and pharyngo-esophageal manometry to examine upper esophageal sphincter (UES), peristaltic, and lower esophageal sphincter (LES) functions. Sensory-motor response characteristics included response threshold (ml), occurrence (%), latency (s), duration (s), and magnitude (mmHg) upon mid-esophageal stimulations (0.1-2.0 ml of air, water, and apple juice). Motility and clinical outcomes were compared among DBI groups. In infants with DBI <900 Ω and 900-2000 Ω (vs. >2000 Ω): (a) Long-term feeding milestones did not differ (p > 0.05); (b) complete peristaltic propagation decreased in 900-2000 Ω (p < 0.05), polymorphic waveforms increased in <900 Ω and 900-2000 Ω (p < 0.05); (c) media effects were noted with liquids (vs. air) wherein UES and esophageal contractility were prolonged in <900 Ω and 900-2000 Ω (p < 0.05), and esophageal sensitivity heightened for <900 Ω with water and for 900-2000 Ω with air (both p < 0.05). ARI was not correlated with DBI in infants with chronic lung disease (r = 0.05, p = 0.82). We conclude that pharyngo-esophageal motility sensory-motor characteristics in infants are modified by DBI category. These preliminary findings pave-the-way for further physiological testing in convalescing high-risk infants to ascertain potential mechanisms of airway-digestive reflex interactions and symptom generation, which may lead to targeted therapies.

GASTROESOPHAGEAL REFLUX DISEASE IN INFANTS WHO PRESENTED BRIEF RESOLVED UNEXPLAINED EVENT (BRUE)

BACKGROUND

The term brief resolved unexplained events (BRUE) is a description of the acute event occurring in infants less than 1-year-old that includes at least one of the following characteristics: cyanosis or pallor; absent, decreased, or irregular breathing; marked change in tone or altered level of responsiveness. An investigative proceeding is required to identify the triggering phenomenon in those who are at high risk of complications. Prolonged esophageal pHmetry has been used as a tool in searching for gastroesophageal reflux disease (GERD) as one of the underlying etiologies.

OBJECTIVE

The study aims to verify the frequency of GERD in infants up to 1-year-old, when pHmetry has been performed for investigating high-risk BRUE (HR-BRUE) and to analyze if clinical characteristics or any particular symptom related by caregivers during BRUE could be correlated to GERD.

METHODS

It was performed a cross-sectional study. The data was collected retrospectively of patients less than 1-year-old, who had performed pHmetry in a tertiary hospital for investigating HR-BRUE between October 2008 and January 2018. For the analysis of medical records, a data collection protocol included: gender, age at the first HR-BRUE episode, age at the time of the pHmetry, gestational age, type of delivery (normal or caesarean) and birth weight and symptoms associated to HR-BRUE related by caregivers. Relation between variables were assessed using Fisher's exact test and Mann-Whitney test. The significance level was set at 0.05.

RESULTS

A total of 54 infants were included (preterm 25, term 29), 62.9% males, median age at the HR-BRUE was 36 days, 53.7% HR-BRUE episodes had occurred during or right after feeding. According to pHmetry results: nine pHmetry results were considered inconclusive, physiological reflux (n=30) and GERD (n=15). The frequency of GERD diagnosed by pHmetry was 33%. GERD was not statistically related to gender (P-value=0.757), age at first HR-BRUE episode (P-value=0.960), age at the time of the pHmetry (P-value=0.720), prematurity (P-value=0.120) or type of delivery (P-value=0.738). GERD was statistically related to low birth weight (P-value=0.023). There was no association between symptoms reported by caregivers during HR-BRUE and GERD.

CONCLUSION

GERD diagnosed by the pHmetry was found in one third of infants that experiencing a HR-BRUE, showing the importance of properly investigation. In half of infants BRUE occurred during or right after feeding. Besides low birth weight, it was not possible to select other data from the clinical history that suggest that these patients would be more likely to have GERD.

Instrumental Swallowing Assessments in the Neonatal and Pediatric Populations: A Systematic Review

The scientific scope of swallowing disorders in the neonatal and pediatric populations is growing exponentially; however, the preponderance of evidence for evaluation protocols has been concentrated in non-instrumental evaluations creating a lack of research about protocols for instrumental swallowing assessment. Thus, the purpose of this study was to systematically review the literature to identify and to report protocols used in instrumental assessments through videofluoroscopic swallow study (VFSS) and fiberoptic endoscopic evaluation of swallowing (FEES) in the neonatal and pediatric populations to support clinical decision making. The search strategy was applied in five online databases, no filters were applied to restrict languages or publication dates and the gray literature was reviewed. PRISMA statement was used to guide the construction of this review. The studies included validated and unvalidated protocols, the validated protocols had their risk of bias estimated using the QUADAS-2. In total, 13 studies were included in the final review, of these eleven assessed through QUADAS-2, and two classified with low risk of bias. One study is in the process of standardization and validation of an instrumental assessment protocol for swallowing in bottle-fed infants through VFSS. Information about validity and reliability of published protocols for instrumental evaluation in the neonatal and pediatric populations is limited. Therefore, further research is needs to development studies aiming to standardize and validate protocols for instrumental assessments in these populations.

Continuous versus bolus intermittent intragastric tube feeding for preterm and low birth weight infants with gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease is a particularly common condition among preterm and low birth weight infants. These infants are more likely to have excessive regurgitation, as they do not have a fully developed antireflux mechanism. Preterm and low birth weight infants who are unable to suck oral feeds are required to be fed via an intragastric tube for varying lengths of time. Intragastric tube feeding can be delivered by the intermittent bolus method or by the continuous feeding method. Use of continuous or intermittent bolus intragastric feeding may have a positive or negative effect on the incidence or severity of gastro-oesophageal reflux disease.

OBJECTIVES

• To determine whether continuous or intermittent bolus intragastric tube feeding reduces the number of episodes and the duration of gastro-oesophageal reflux disease (GORD) in preterm and low birth weight infants • To perform subgroup analyses for gestational age; birth weight; age in days from birth at full enteral feeding via intragastric tube (breast versus bottle); frequency of intermittent bolus feed; and type of medication for treatment of GORD (only if medication was prescribed and was given similarly to both intervention groups) SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 7), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 8 July 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

Published and unpublished RCTs and quasi-RCTs were eligible for inclusion in this review, as were cluster-randomised and cross-over randomised trials that compared the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and quality. We planned to use the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We did not identify any randomised trials that evaluated the effects of continuous versus intermittent bolus intragastric tube feeding on gastro-oesophageal reflux disease in preterm and low birth weight infants. Well-designed and adequately powered trials are needed.

NICU infants who require a feeding gastrostomy for discharge

OBJECTIVE

To determine population data for infants receiving a gastrostomy tube (GT) in our Neonatal Intensive Care Unit (NICU) to better understand the premature infant population at risk for GT prior to discharge.

STUDY DESIGN

We identified all NICU infants born 2015-2016 who received a GT and determined the birth gestational age below which GTs were placed due to oral feeding failure secondary to prematurity-related comorbidities, rather than anomalies or other reasons. Aggregate data were used to compare infants born <30 weeks (w) gestation who received a GT with those who did not.

RESULTS

GTs were placed in 117 infants. More than half of the NICU patients who receive GTs were actually >32 weeks gestation; a cut-off of <30w was a good identifier for those who failed achieving full oral feeds due to prematurity-related problems. Infants born <30w (n = 282) not receiving GTs were discharged at a significantly lower postmenstrual age (36w) and lower weight (2.3 kg) compared with infants who received a GT (49w, 5 kg).

CONCLUSIONS

The population of premature infants born <30w gestation constitute the population of infants at risk for a GT based solely on prematurity.

LEVELS OF EVIDENCE

III.

Multidisciplinary approach to paediatric aerodigestive disorders: A single-centre longitudinal observational study

AIM

Aerodigestive clinics (ADCs) are multidisciplinary programmes for the care of children with complex congenital or acquired conditions affecting breathing, swallowing and growth. Our objective was to describe the demographic, clinical, etiological and investigational profile of children attending the inaugural ADC at a tertiary paediatric centre in Queensland.

METHODS

Children referred to the ADC at Queensland Children's Hospital from August 2018 to December 2019 were included. Data on clinical, growth and lung function parameters, bronchoscopy and upper gastrointestinal endoscopy findings, thoracic imaging and comorbidities were retrospectively analysed.

RESULTS

Fifty-six children (median (range) age 4 years (3 months-15 years); 18 female) attended the ADC during this 17-month period. Forty-six (82%) children had previous oesophageal atresia with tracheo-oesophageal fistula; 43 of these were type C. Previous isolated oesophageal atresia, congenital diaphragmatic hernia and congenital pulmonary malformation were the underlying disorder in three (5%) children each, with one child having a repaired laryngeal cleft. Vertebral Anal Tracheo Esophageal Renal Limb anomalies (VACTERL)/Vertebral Anal Tracheo Esophageal renal anomalies (VATER) association was seen in 21 (38%) children. Growth was adequate (median weight and body mass index z-score -0.63 and -0.48, respectively). Thirty-four (61%) children reported ongoing wet cough, with 12 (21%) requiring previous hospital admission for lower respiratory tract infection. Fourteen (25%) had bronchiectasis on computed tomography chest and 33 (59%) had clinical tracheomalacia, apparent on bronchoscopic examination in 21 patients. Dysphagia was reported in 15 (27%) children, 11 (20%) were gastrostomy feed-dependent and 5 (9%) had biopsy-proven eosinophilic oesophagitis.

CONCLUSION

High proportion of children attending the ADC have ongoing respiratory symptoms resulting in chronic pulmonary suppuration and bronchiectasis. Potential benefits of this model of care need to be studied prospectively to better understand the outcomes.

Individualising care in severe bronchopulmonary dysplasia: a series of N-of-1 trials comparing transpyloric and gastric feeding

OBJECTIVE

Compare rates of hypoxaemia during transpyloric and gastric feedings in very preterm infants with severe bronchopulmonary dysplasia.

DESIGN

N-of-1 multiple crossover trials with individual patient and pooled data analyses.

SETTING

Level IV intensive care nursery.

PATIENTS

Infants receiving positive airway pressure between 36 and 55 weeks postmenstrual age were enrolled between December 2014-July 2016.

INTERVENTION

N-of-1 trial consisting of two blocks, each with a 4-day gastric and 4-day transpyloric feeding period assigned in random order.

MAIN OUTCOME MEASURES

The primary outcome was the frequency of daily intermittent hypoxaemic events (SpO₂ ≤80% lasting 10-180 s). Secondary outcomes included the daily proportion of time with an SpO₂ ≤80% and mean daily fraction of inspired oxygen.

RESULTS

Of 15 infants, 13 completed the trial and 2 stopped early for transient worsening in respiratory status during gastric feedings. In the intention-to-treat analyses, transpyloric feedings resulted in increased rates of intermittent hypoxaemia in five infants, greater time per day in hypoxaemia in three infants and more supplemental oxygen use in three infants. One infant received more supplemental oxygen during gastric feedings. The remaining study outcomes were similar between the feeding routes in all other infants. Pooling all data, transpyloric feedings resulted in a higher frequency of intermittent hypoxaemic events (median 7.5/day (IQR 1-23.5) vs 3/day (1-11); adjusted incidence rate ratio 1.8, 95% CI 1.3 to 2.5) and a greater proportion of daily hypoxaemia time (median 0.8% (IQR 0.1-2.3) vs 0.4% (0.07-1.8); adjusted mean difference 1.6, 95% CI 1.1 to 2.5).

CONCLUSIONS

Transpyloric compared with gastric feedings modestly increased rates of hypoxaemia among study participants.

TRIAL REGISTRATION NUMBER

NCT02142621.

Physiological Basis of Neonatal Aerodigestive Difficulties in Chronic Lung Disease

In the United States, preterm birth rates have steadily increased since 2014. Despite the recent advances in neonatal-perinatal care, more than 40% of very low-birth-weight infants develop chronic lung disease (CLD) and almost 25% have feeding difficulties resulting in delayed achievement of full oral feeds and longer hospital stay. Establishment of full oral feeds, a major challenge for preterm infants, becomes magnified among those on respiratory support and/or with CLD. The strategies to minimize aerodigestive disorders include supporting nonnutritive sucking, developing infant-directed feeding protocols, sensory oromotor stimulation, and early introduction of oral feeds.

The enigma of gastroesophageal reflux disease among convalescing infants in the NICU: It is time to rethink

Gastroesophageal reflux (GER) can be a normal physiological process, or can be bothersome, when aerodigestive consequences are associated; the latter is often interpreted as GER disease (GERD). However, the distinction between these two entities remains an enigma among infants surviving after neonatal intensive care (NICU) care. Symptoms related to GERD are heterogeneous, and are often managed with changes in diet, feeding methods, and acid suppressive therapy. However, none of these approaches have been well-tested in neonates; hence practice variation is very high world-wide. In this paper, we explain the variation in diagnosis, pathophysiology of the clinical presentation, and highlight approaches to diagnosis and management.

Gastroesophageal Reflux Disease in the Neonatal Intensive Care Unit Infant: Who Needs to Be Treated and What Approach Is Beneficial?

Gastroesophageal reflux (GER) and GER disease (GERD) pertaining to infants in the neonatal intensive care unit (NICU) are reviewed, based on research in this specific population. The developmental biology of the gastroesophageal junction, physiology of GER, and pathophysiology of GERD in this setting are summarized, and risk factors for GER and GERD identified. The epidemiology, economic burden, and controversies surrounding GERD in NICU infants are addressed, and an approach to GER and GERD in these patients formulated. Recent advancements in individual assessment of GER and GERD in the NICU infant are examined, and evidence-based guidelines for their adoption provided.

Reflex cardiorespiratory events from esophageal origin are heightened by preterm birth

The involvement of gastroesophageal refluxes in cardiorespiratory events of preterm infants remains controversial. While a few studies in full-term newborn animals have shown that stimulation of esophageal receptors leads to cardiorespiratory reflexes, the latter remain largely unknown, especially after premature birth. The present study aimed to 1) characterize the cardiorespiratory reflexes originating from esophageal receptors in newborn lambs and 2) test the hypotheses that preterm birth enhances reflex cardiorespiratory inhibition and that C-fibers are involved in these reflexes. Eight full-term lambs and 10 lambs born 14 days prematurely were studied. Following surgical instrumentation, a 6-h polysomnography was performed without sedation to record electrocardiogram, respiratory movements, arterial pressure, laryngeal constrictor muscle activity, state of alertness, and hemoglobin oxygen saturation. Five esophageal stimulations of the upper and/or lower esophagus, including rapid balloon inflation and/or HCl injection, were performed in random order. A second recording was performed in full-term lambs 24 h later, after C-fiber blockade by capsaicin. Results confirmed that esophageal stimulations induced inhibitory cardiorespiratory reflexes combined with protective mechanisms, including laryngeal closure, swallowing, coughing, increased arterial pressure, and arousal. Preterm birth heightened cardiorespiratory inhibition. The strongest cardiorespiratory inhibition was observed following simultaneous stimulation of the lower and upper esophagus. Finally, cardiorespiratory inhibition was decreased after C-fiber blockade. In conclusion, esophageal stimulation induces inhibitory cardiorespiratory reflexes, which are partly mediated by C-fibers and more pronounced in preterm lambs. Clinical relevance of these findings requires further studies, especially in conditions associated with increased cardiorespiratory events, e.g., neonatal infection.NEW & NOTEWORTHY Preterm birth heightens the cardiorespiratory events triggered by esophageal stimulation. The most extensive cardiorespiratory events are induced by simultaneous stimulation of the proximal and distal esophagus.

Feeding Methods at Discharge Predict Long-Term Feeding and Neurodevelopmental Outcomes in Preterm Infants Referred for Gastrostomy Evaluation

OBJECTIVE

To test the hypothesis that oral feeding at first neonatal intensive care unit discharge is associated with less neurodevelopmental impairment and better feeding milestones compared with discharge with a gastrostomy tube (G-tube).

STUDY DESIGN

We studied outcomes for a retrospective cohort of 194 neonates <37 weeks' gestation referred for evaluation and management of feeding difficulties between July 2006 and July 2012. Discharge milestones, length of hospitalization, and Bayley Scales of Infant Development-Third Edition scores at 18-24 months were examined. χ², Mann-Whitney U, or t tests and multivariable logistic regression models were used.

RESULTS

A total of 60% (n = 117) of infants were discharged on oral feedings; of these, 96% remained oral-fed at 1 year. The remaining 40% (n = 77) were discharged on G-tube feedings; of these, 31 (40%) remained G-tube dependent, 17 (22%) became oral-fed, and 29 (38%) were on oral and G-tube feedings at 1 year. Infants discharged on a G-tube had lower cognitive (P <.01), communication (P = .03), and motor (P <.01) composite scores. The presence of a G-tube, younger gestation, bronchopulmonary dysplasia, or intraventricular hemorrhage was associated significantly with neurodevelopmental delay.

CONCLUSIONS

For infants referred for feeding concerns, G-tube evaluations, and feeding management, the majority did not require a G-tube. Full oral feeding at first neonatal intensive care unit discharge was associated with superior feeding milestones and less long-term neurodevelopmental impairment, relative to full or partial G-tube feeding. Evaluation and feeding management before and after G-tube placement may improve long-term feeding and neurodevelopmental outcomes.

Neonatal Histamine-2 Receptor Antagonist and Proton Pump Inhibitor Treatment at United States Children's Hospitals

OBJECTIVE

To determine treatment frequency and duration of histamine-2 receptor antagonist (H2RA)/proton pump inhibitor (PPI) use among infants hospitalized within US children's hospital neonatal intensive care units and evaluate diagnoses/demographic factors associated with use.

STUDY DESIGN

We retrospectively analyzed a cohort of neonatal intensive care unit infants admitted to 43 US children's hospitals within the Pediatric Health Information System database between January 2006 and March 2013 to determine H2RA/PPI treatment frequency, timing/duration of treatment, factors associated with use, percent of infants remaining on treatment at discharge, and interhospital prescribing variation. We used a modified Poisson regression to calculate the adjusted probability of infants ever receiving H2RAs/PPIs in relation to diagnosis, gestation, and sex.

RESULTS

Of the 122 002 infants evaluated, 23.8% (n = 28 989) ever received an H2RA or PPI; 19.0% received H2RAs (n = 23 187), and 10.5% (n = 12 823) received PPIs. Extremely preterm infants and term infants were the most likely to receive H2RA and PPI treatment. Infants with gastroesophageal reflux disease (relative risk [RR] = 3.13) and congenital heart disease (RR = 2.41) had the highest H2RA/PPI treatment probabilities followed by those with an ear, nose, and throat diagnosis (RR = 2.34; P < .05). The majority of treated infants remained treated at discharge.

CONCLUSIONS

Despite limited evidence and increasing safety concerns, H2RAs/PPIs are frequently prescribed to extremely preterm neonates and those with congenital anomalies and continued through discharge. Our findings support the need for innovative studies to examine the comparative effectiveness and safety of H2RA/PPIs vs no treatment in these high-risk neonatal populations.

Effect of nasal noninvasive respiratory support methods on pharyngeal provocation-induced aerodigestive reflexes in infants

The pharynx is a locus of provocation among infants with aerodigestive morbidities manifesting as dysphagia, life-threatening events, aspiration-pneumonia, atelectasis, and reflux, and such infants often receive nasal respiratory support. We determined the impact of different oxygen delivery methods on pharyngeal stimulation-induced aerodigestive reflexes [room air (RA), nasal cannula (NC), and nasal continuous positive airway pressure (nCPAP)] while hypothesizing that the sensory motor characteristics of putative reflexes are distinct. Thirty eight infants (28.0 ± 0.7 wk gestation) underwent pharyngoesophageal manometry and respiratory inductance plethysmography to determine the effects of graded pharyngeal stimuli (n = 271) on upper and lower esophageal sphincters (UES, LES), swallowing, and deglutition-apnea. Comparisons were made between NC (n = 19), nCPAP (n = 9), and RA (n = 10) groups. Importantly, NC or nCPAP (vs. RA) had: 1) delayed feeding milestones (P < 0.05), 2) increased pharyngeal waveform recruitment and duration, greater UES nadir pressure, decreased esophageal contraction duration, decreased distal esophageal contraction amplitude, and decreased completely propagated esophageal peristalsis (all P < 0.05), and 3) similarly developed UES contractile and LES relaxation reflexes (P > 0.05). We conclude that aerodigestive reflexes were similarly developed in infants using noninvasive respiratory support with adequate upper and lower aerodigestive protection. Increased concern for GERD is unfounded in this population. These infants may benefit from targeted oromotor feeding therapies and safe pharyngeal bolus transit to accelerate feeding milestones.

Mechanisms of cough provocation and cough resolution in neonates with bronchopulmonary dysplasia

BACKGROUND

Cough and deglutition are protective mechanisms that defend against aspiration. We identified mechanisms associated with cough provocation as well as those associated with cough resolution in infants with bronchopulmonary dysplasia (BPD).

METHODS

Manometry signatures of cough were recognized in 16 premature infants with BPD undergoing concurrent esophageal manometry, respiratory inductance plethysmography, and nasal air flow measurements. Pretussive and post-tussive pharyngo-esophageal motility changes were analyzed. Mechanisms associated with cough and mechanisms that restored respiratory and esophageal normalcy were analyzed.

RESULTS

We analyzed 312 cough events during 88 cough clusters; 97% were associated with recognizable manometric patterns. Initial mechanisms related with coughing included nonpropagating swallow (59%), upper esophageal sphincter (UES) reflex contraction (18%), and lower esophageal sphincter (LES) relaxation (14%). UES and LES dysfunction was present in 69% of nonpropagating swallow-associated cough clusters. Mechanisms restoring post-tussive normalcy included primary peristalsis (84%), secondary peristalsis (8%), and none recognized (8%). UES contraction reflex was associated with cough clusters more frequently in infants on nasal continuous positive airway pressure (NCPAP) (OR = 9.13, 95% CI = 1.88-44.24).

CONCLUSION

Cough clusters in infants with BPD had identifiable etiologies associated with esophageal events; common initial mechanisms were of upper aerodigestive origin, while common clearing mechanisms were peristaltic reflexes.

Upper gastrointestinal motility: prenatal development and problems in infancy

Deglutition, or swallowing, refers to the process of propulsion of a food bolus from the mouth into the stomach and involves the highly coordinated interplay of swallowing and breathing. At 34 weeks gestational age most neonates are capable of successful oral feeding if born at this time; however, the maturation of respiration is still in progress at this stage. Infants can experience congenital and developmental pharyngeal and/or gastrointestinal motility disorders, which might manifest clinically as gastro-oesophageal reflux (GER) symptoms, feeding difficulties and/or refusal, choking episodes and airway changes secondary to micro or overt aspiration. These problems might lead to impaired nutritional intake and failure to thrive. These gastrointestinal motility disorders are mostly classified according to the phase of swallowing in which they occur, that is, the oral preparatory, oral, pharyngeal and oesophageal phases. GER is a common phenomenon in infancy and is referred to as GERD when it causes troublesome complications. GER is predominantly caused by transient relaxation of the lower oesophageal sphincter. In oesophageal atresia, oesophageal motility disorders develop in almost all patients after surgery; however, a congenital origin of disordered motility has also been proposed. This Review highlights the prenatal development of upper gastrointestinal motility and describes the most common motility disorders that occur in early infancy.

Respiratory events in infants presenting with apparent life threatening events: is there an explanation from esophageal motility?

OBJECTIVE

To test the hypothesis that proximal aerodigestive clearance mechanisms mediated by pharyngoesophageal motility during spontaneous respiratory events (SREs) are distinct in infants with apparent life threatening events (ALTEs).

STUDY DESIGN

Twenty infants (10 with proven ALTE, 10 healthy controls) had pharyngoesophageal manometry to investigate motility changes concurrent with respiratory events detected by respiratory inductance plethysmography and nasal thermistor methods. We measured changes in resting upper esophageal and lower esophageal sphincter pressures, esophageal peristalsis characteristics, and gastroesophageal reflux. Statistical analysis included mixed models; data presented as mean±SD, median (range), or percentage.

RESULTS

Infants with ALTE (vs controls) had: (1) delays in restoring aerodigestive normalcy as indicated by more frequent (P=.03) and prolonged SREs (P<.01); (2) a lower magnitude of protective upper esophageal sphincter contractile reflexes (P=.01); (3) swallowing as the most frequent esophageal event associated with SREs (84%), with primary peristalsis as the most prominent aerodigestive clearance mechanism (64% vs 38%, P<.01); (4) a higher proportion of failed esophageal propagation (10% vs 0%, P=.02); and (5) more frequent mixed apneic mechanisms (P<.01) and more gasping breaths (P=.04).

CONCLUSIONS

In infants with ALTE, prolonged SREs are associated with ineffective esophageal motility characterized by frequent primary peristalsis and significant propagation failure, thus suggestive of dysfunctional regulation of swallow-respiratory junction interactions. Hence, treatment should not target gastroesophageal reflux, but rather the proximal aerodigestive tract.