Pepsin, a marker of gastric contents, is increased in tracheal aspirates from preterm infants who develop bronchopulmonary dysplasia

Transpyloric feeding is associated with adverse in-hospital outcomes in infants with severe bronchopulmonary dysplasia

OBJECTIVE

To estimate the association of transpyloric feeding (TPF) with the composite outcome of tracheostomy or death for patients with severe bronchopulmonary dysplasia (sBPD).

STUDY DESIGN

Retrospective multi-center cohort study of preterm infants <32 weeks with sBPD receiving enteral feedings. We compared infants who received TPF at 36, 44, or 50 weeks post-menstrual age to those who did not receive TPF at any of those timepoints. Odds ratios were adjusted for gestational age, small for gestational age, male sex, and invasive ventilation and FiO2 at 36 weeks.

RESULTS

Among 1039 patients, 129 (12%) received TPF. TPF was associated with an increased odds of tracheostomy or death (aOR 3.5, 95% CI 2.0-6.1) and prolonged length of stay or death (aOR 3.1, 95% CI 1.9-5.2).

CONCLUSIONS

Use of TPF in sBPD after 36 weeks was infrequent and associated with worse in-hospital outcomes, even after adjusting for respiratory severity at 36 weeks.

Pediatric Laryngopharyngeal Reflux in the Last Decade: What Is New and Where to Next?

BACKGROUND

Laryngopharyngeal reflux may affect people of any age; still, most of the accumulated knowledge concerns adults, and evidence regarding pediatric populations remains relatively restricted. This study aims to review the most recent and emerging aspects of pediatric laryngopharyngeal reflux from the last ten years. It also attempts to identify gaps in knowledge and highlight discrepancies that future research should urgently address.

METHODS

An electronic search of the MEDLINE database was conducted, limited to January 2012 through December 2021. Non-English language articles, case reports, and studies that concerned a purely or predominantly adult population were excluded. The information from the articles with the most relevant contribution was initially categorized by theme and subsequently synthesized into a narrative form.

RESULTS

86 articles were included, of which 27 were review articles, eight were surveys, and 51 were original articles. Our review systematically maps the research done in the last decade and provides an updated overview and the current state-of-the-art in this subject.

CONCLUSIONS

Despite discrepancies and heterogeneity in accumulating research, evidence gathered so far endorses a need for refining an escalating multiparameter diagnostic approach. A step-wise therapeutic plan appears to be the most reasonable management approach, starting with behavioral changes for mild to moderate, uncomplicated cases and escalating to personalized pharmacotherapy options for severe or nonresponsive cases. Surgical options could be considered in the most severe cases when potentially life-threatening symptoms persist despite maximal medical therapy. Over the past decade, the amount of available evidence has been gradually increasing; however, its strength remains low. Several aspects remain markedly under-addressed, and further adequately powered, multicenter, controlled studies with uniformity in diagnostic procedures and criteria are urgently needed.

Oral Care Associated With Less Microaspiration in Ventilated Cardiac Patients

Aspiration is common in mechanically ventilated patients and may predispose patients to aspiration pneumonia, chemical pneumonitis, and chronic lung damage. Pepsin A is a specific marker of gastric fluid aspiration and is often detected in ventilated pediatric patients. We investigated the effect of oral care and throat suctioning in the detection of pepsin A in tracheal aspirates (TAs) up to 4 hours after these procedures.

Methods

Twelve pediatric patients between age 2 weeks to 14 years who underwent intubation for cardiac surgery were enrolled in this study. Six of the 12 patients were consented before their surgery with initial specimen collected at the time of intubation and last one shortly before extubation (intubation duration < 24 hours). The remaining 6 patients were consented after cardiac surgery. All specimens were collected per routine care per respiratory therapy protocol and shortly before extubation (intubation duration > 24 hours). Tracheal fluid aspirates were collected every 4 to 12 hours in the ventilated patients. Enzymatic assay for gastric pepsin A and protein determination were performed. The time of oral care and throat suctioning within 4 hours prior was recorded prospectively.

Results

A total of 342 TA specimens were obtained from the 12 intubated pediatric patients during their course of hospitalization; 287 (83.9%) showed detectable total pepsin (pepsin A and C) enzyme activity (> 6 ng/mL) and 176 (51.5%) samples had detectable pepsin A enzyme levels (>6 ng/mL of pepsin A). Only 29 samples of 76 samples (38.2%) had evidence of microaspiration after receiving oral care, while 147 of 266 (55.3%) samples were pepsin A positive when no oral care was provided. Odds ratio is 0.50 (Cl 0.30-0.84), and the number needed to treat is 5.8 (Confidence interval 3.4-22.3). Testing air filters for pepsin was not beneficial.

Conclusion

Oral care is a highly effective measure to prevent microaspiration of gastric fluid in ventilated pediatric patients. The number needed to treat (5.8) suggests this is a very effective prevention strategy. Our study suggests that pepsin A is a useful and sensitive biomarker that allows identification of gastric aspiration.

Transpyloric Feeding is Associated With Improved Oxygenation Compared With Gastric Feeding Among Nonintubated Extremely Low Birth Weight Infants

OBJECTIVE

To study the impact of transpyloric (TP) feed initiation on short-term oxygenation and manual oxygen blender titration among extremely low birth weight infants.

STUDY DESIGN

This retrospective study evaluated several measures of oxygenation among extremely low birth weight infants receiving positive pressure respiratory support for 96 hours before and after TP tube placement in a single neonatal intensive care unit during the years 2017- 2020. The measures included the achieved oxygen saturation (SpO₂), the baseline fraction of inspired oxygen (FiO₂), the SpO₂/FiO₂ ratio, the number and severity of hypoxemic episodes and the frequency of manual oxygen titrations (titration index) and were analyzed using an interrupted time series regression approach.

RESULTS

A total of 56 infants were evaluated. No significant differences were observed in any oxygenation measures during TP vs gastric feeding among 14 intubated infants. However, among 42 nonintubated patients, significant improvements were observed in the median SpO₂/FiO₂ ratios (P = .001), median titration index (P = .05), median number of hypoxemic episodes (P = .02), and median severity of hypoxemic episodes (P = .008) after TP tube placement.

CONCLUSIONS

The transition from gastric to TP tube feeding was temporally associated with acute improvement in oxygenation for nonintubated infants, but not for intubated infants.

Respiratory and Gastrointestinal Management of an Infant with a Birth Weight of 258 Grams

Today, more infants weighing less than or equal to 300 g are born, and they survive because of the improvements in neonatal care and treatment. However, their detailed clinical course and neonatal intensive care unit management remain unknown due to their low survival rate and dearth of reports. A male infant was born at 24 weeks and 5 days of gestation and weighed 258 g. The infant received 72 days of invasive and 92 days of noninvasive respiratory support, including high-frequency oscillatory ventilation with volume guarantee and noninvasive neurally adjusted ventilatory assist. Meconium-related ileus was safely treated using diatrizoate. Although the infant was diagnosed with severe bronchopulmonary dysplasia and retinopathy of prematurity requiring laser photocoagulation, he had no other severe complications. He was discharged 201 days postdelivery (3 months of corrected age) with a weight of 3.396 kg. Although managing infants weighing less than or equal to 300 g is difficult, our experience shows that it is possible by combining traditional and modern management methods. The management of such infants requires an understanding of the expected difficulties and adaptation of existing methods to their management. The management techniques described here should help improve their survival and long-term prognosis.

Association of Pepsin With Inflammatory Signaling and Effusion Viscosity in Pediatric Otitis Media

OBJECTIVE

Otitis media (OM) is a common inflammatory disease spectrum. Cytokine signaling, neutrophil activity, and mucin hypersecretion during recurrent and chronic OM contribute to persistent, viscous middle ear (ME) effusions, hearing loss, and potential for developmental delay. Extraesophageal reflux (EER), specifically pepsin, triggers inflammatory signaling in respiratory mucosa and is associated with OM. The objective of this study was to investigate the association of pepsin with ME inflammatory signaling and the outcomes and examine causality in vitro.

STUDY DESIGN

Cross-sectional study.

METHODS

ME fluid (MEF) and preoperative audiometric data were collected from 30 pediatric subjects undergoing tympanostomy tube placement for recurrent OM or OM with effusion. MEF viscosity was characterized by the surgeon. Pepsin, inflammatory molecules, and mucin were assayed by enzyme-linked immunosorbent assay (ELISA). ME epithelial primary culture was exposed to 0.1 to 1 mg/ml pepsin at pH 5, 6, and 7 for 30 minutes, and cytokine expression was assayed via qPCR.

RESULTS

Pepsin was observed in the MEF of 77% of patients (range 71-2,734 ng/ml). Pepsin correlated with effusion viscosity, interleukins -6 and -8, neutrophil elastase, and mucin 5B (P < .05). Pepsin-negative MEF was more frequently absent of interleukin 8 or mucin 5B (P < .05). Weak acid was generally insufficient to elicit cytokine expression in ME cells in vitro, however, pepsin induced IL6, IL8, and TNF at pH 7 (P < .05) and weak acid (pH 6) facilitated a response at lower pepsin concentration.

CONCLUSIONS

Pepsin may contribute to inflammatory signaling, persistent viscous effusion, and poorer OM outcomes.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Acute respiratory effect of transpyloric feeding for respiratory exacerbation in preterm infants

OBJECTIVES

Gastroesophageal reflux may exacerbate chronic lung disease in preterm infants. We evaluated the short-term effects of transpyloric feeding on respiratory status in preterm infants during mechanical ventilation.

METHODS

We retrospectively collected data from the hospital information management system. To evaluate the effect of transpyloric feeding on oxygenation, we compared changes in SpO2/FiO2 ratios before and after commencing transpyloric feeding by a piecewise linear regression model.

RESULTS

We examined 33 infants (median gestational age, 25.4 weeks; median birth weight, 656 g) who underwent transpyloric feeding. All tubes were placed at the bedside without fluoroscopy. No cases of unsuccessful placement, gastroduodenal perforation, or tracheal misinsertion occurred. Transpyloric feeding began at a median age of 18 (interquartile range, 15-23) days. Mean SpO2/FiO2 (±SD) ratios were 391 (±49), 371 (±51), 365 (±56), and 366 (±53) 72-96 h before, 0-24 h before, 48-72 h after, and 96-120 h after starting transpyloric feeding, respectively. The rate of change per hour of SpO2/FiO2 ratios increased 48-120 h after compared with 0-96 h before transpyloric feeding (0.03 [95% confidence interval, -0.10 to 0.17] vs. -0.29 [-0.47 to -0.12]) (p=0.007). No apparent changes occurred in the mean airway pressure, amplitude pressure, or pCO2.

CONCLUSIONS

Transpyloric feeding during mechanical ventilation can prevent the deterioration of oxygenation without major complications at the stage of respiratory exacerbation in preterm infants.

[Reflux Symptoms - No Difference in Severity and Intensity in Patients with and without Functional Verified Gastroesophageal Reflux Disease]

BACKGROUND

Patients with gastroesophageal reflux disease (GERD) often suffer greatly from their symptoms. The aim of this study was to determine if there is a difference in quality of life and gastrointestinal symptom complexes between patients with purely functional complaints and patients with objective GERD.

MATERIAL AND METHODS

We included all patients with typical reflux symptoms, who had a GERD examination in 2017 at our department. All patients underwent high resolution manometry, 24-h-pH-metry impedance measurement and gastroscopy. Quality of life was assessed using the Gastrointestinal Quality of Life Index (GIQLI) and gastrointestinal symptoms were rated by a symptom checklist (SCL), assessing the severity and intensity of 14 different symptoms. Based on the results of the 24-h-pH-metry impedance measurement, patients were divided into 2 groups: patients with functional reflux symptoms and patients with true GERD. These two groups were compared.

RESULTS

Complete data were available in 162 patients, of whom 86 (52.2%) were objectively suffering from reflux (DeMeester score mean: 37.85; SD ± 29.11) and 76 (46.1%) had a normal DeMeester score (Mean: 7.01; SD ± 4.09). No significant difference in quality of life was found between the two groups (mean GIQLI of GERD patients: 94.81, SD ± 22.40, and mean GIQLI of patients with functional reflux symptoms: 95.26, SD ± 20.33, p = 0.988). Furthermore, no significant difference could be found in the evaluated symptoms (mean general SCL score of GERD patients: 46.97; SD ± 29.23; patients with functional reflux symptoms: 48.03; SD ± 29.17, p = 0.827).

CONCLUSION

Patients with functional complaints suffer just as much from their symptoms as patients with objectively diagnosed GERD. Differentiation between gastroesophageal reflux disease and functional reflux symptoms is only possible by means of functional diagnostic testing.

Pulmonary Manifestations of Gastrointestinal, Pancreatic, and Liver Diseases in Children

Pulmonary manifestations of gastrointestinal (GI) diseases are often subtle, and underlying disease may precede overt symptoms. A high index of suspicion and a low threshold for consultation with a pediatric pulmonologist is warranted in common GI conditions. This article outlines the pulmonary manifestations of different GI, pancreatic, and liver diseases in children, including gastroesophageal reflux disease, inflammatory bowel disease, pancreatitis, alpha1-antitrypsin deficiency, nonalcoholic fatty liver disease, and complications of chronic liver disease (hepatopulmonary syndrome and portopulmonary hypertension).

Use of a non-invasive accelerometric method for diagnosing gastroesophageal reflux in premature infants

OBJECTIVE

To evaluate the clinical usefulness of a non-invasive accelerometric device to diagnose GER in preterm babies.

STUDY DESIGN

An accelerometer was taped over the sub-xiphoid process in 110 preterm (GA 29.6 ± 3.3 wk) infants (133 studies). Low frequency, sub-audible signals were captured via digital recording (sampling rate 200 Hz), then re-sampled (rate = 60 Hz) to create a spectrogram (focused range 0-30 Hz). Mean amplitude in the focused range was calculated.

RESULTS

Of 85 studies with simultaneous pH-metry and accelerometry, 18 had concurrent positive and 23 had concurrent negative scores, 42 had negative pH scores when accelerometry was positive (≥1 µV), consistent with non-acid reflux. Eleven infants at high risk of aspiration received surgical interventions. All but 1 had negative pH scores while 10/11 had positive accelerometry.

CONCLUSIONS

The non-invasiveness of this accelerometric technique allows for GER screening and for repeated testing to assess efficacy of interventions.

T Lymphocytes, Multi-Omic Interactions and Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) remains a significant clinical challenge in neonatal medicine. BPD is clearly a multifactorial disease with numerous antenatal and postnatal components influencing lung development. Extremely immature infants are born in the late canalicular or early saccular stage and usually receive intensive care until the early alveolar stage of lung development, resulting in varying magnitudes of impairment of alveolar septation, lung fibrosis, and abnormal vascular development. The interactions between T lymphocytes, the genome and the epigenome, the microbiome and the metabolome, as well as nutrition and therapeutic interventions such as the exposure to oxygen, volutrauma, antibiotics, corticosteroids, caffeine and omeprazole, play an important role in pathogenesis and disease progression. While our general understanding of these interactions thanks to basic research is improving, this knowledge is yet to be translated into comprehensive prevention and clinical management strategies for the benefit of preterm infants developing BPD and later during infancy and childhood suffering from the disease itself and its sequelae. In this review, we summarise existing evidence on the interplay between T lymphocytes, lung multi-omics and currently used therapeutic interventions in BPD, and highlight avenues for potential future immunology related research in the field.

Oxidative and Proteolytic Inactivation of Alpha-1 Antitrypsin in Bronchopulmonary Dysplasia Pathogenesis: A Top-Down Proteomic Bronchoalveolar Lavage Fluid Analysis

The study investigates the role of the oxidative and proteolytic inactivation of alpha-1 antitrypsin (AAT) in the pathogenesis of bronchopulmonary dysplasia (BPD) in premature infants. Bronchoalveolar lavage fluid (BALF) samples were collected on the 3rd day of life from mechanically ventilated neonates with gestational age ≤ 30 weeks and analyzed without previous treatment (top-down proteomics) by reverse-phase high-performance liquid chromatography-electrospray ionization mass spectrometry. AAT fragments were identified by high-resolution LTQ Orbitrap XL experiments and the relative abundances determined by considering the extracted ion current (XIC) peak area. Forty preterm neonates were studied: 20 (50%) did not develop BPD (no-BPD group), 17 (42.5%) developed mild or moderate new-BPD (mild + moderate BPD group), and 3 (7.5%) developed severe new-BPD (severe BPD group). Eighteen fragments of AAT and a fragment of AAT oxidized at a methionine residue were identified: significantly higher values of AAT fragments 25-57, 375-418, 397-418, 144-171, and 397-418 with oxidized methionine were found in the severe BPD group. The significantly higher levels of several AAT fragments and of the fragment 397-418, oxidized in BALF of preterm infants developing BPD, underlie the central role of an imbalance between proteases and protease inhibitors in exacerbating lung injury and inducing most severe forms of BPD. The study has some limitations, and between them, the small sample size implies the need for further confirmation by larger studies.

Synthetic Surfactant CHF5633 Compared with Poractant Alfa in the Treatment of Neonatal Respiratory Distress Syndrome: A Multicenter, Double-Blind, Randomized, Controlled Clinical Trial

OBJECTIVE

To compare efficacy and safety of a new synthetic surfactant, CHF5633, enriched with surfactant proteins, SP-B and SP-C peptide analogues, with porcine surfactant, poractant alfa, for the treatment of respiratory distress syndrome in infants born preterm.

STUDY DESIGN

Neonates born preterm on respiratory support requiring fraction of inspired oxygen (FiO₂) ≥0.30 from 24^0/7 to 26^6/7 weeks and FiO₂ ≥0.35 from 27^0/7 to 29^6/7 weeks of gestation to maintain 88%-95% oxygen saturation were randomized to receive 200 mg/kg of CHF5633 or poractant alfa. If necessary, redosing was given at 100 mg/kg. Efficacy end points were oxygen requirement (FiO₂, respiratory severity score [FiO₂ × mean airway pressure]) in the first 24 hours, 7 and 28 days, discharge home, and/or 36 weeks of postmenstrual age; mortality and bronchopulmonary dysplasia at 28 days and 36 weeks of PMA. Adverse events and immunogenicity were monitored for safety.

RESULTS

Of the 123 randomized neonates, 113 were treated (56 and 57 in CHF5633 and poractant alfa groups, respectively). In both arms, FiO₂ and respiratory severity score decreased from baseline at all time points (P < .001) with no statistically significant differences between groups. Rescue surfactant use (19 [33.9%] vs 17 [29.8%]), bronchopulmonary dysplasia (31 [55.4%] and 32 [56.1%]), and mortality at day 28 (4 [7.1%] and 3 [5.3%]) were similar in the CHF5633 and poractant alfa groups, respectively. In 2 (3.4%) and 1 (1.7%) neonates, adverse drug reactions were reported in CHF5633 and poractant alfa groups, respectively. No immunogenicity was detected.

CONCLUSIONS

Treatment with CHF5633 showed similar efficacy and safety as poractant alfa in neonates born preterm with moderate-to-severe respiratory distress syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02452476.

Characterization of Disease Phenotype in Very Preterm Infants with Severe Bronchopulmonary Dysplasia

Rationale: Bronchopulmonary dysplasia (BPD) is a heterogenous condition with poorly characterized disease subgroups.Objectives: To define the frequency of three disease components: moderate-severe parenchymal disease, pulmonary hypertension (PH), or large airway disease, in a referral cohort of preterm infants with severe BPD. The association between each component and a primary composite outcome of death before hospital discharge, tracheostomy, or home pulmonary vasodilator therapy was assessed.Methods: This was a retrospective, single-center cohort study of infants born at <32 weeks' gestation with severe BPD who underwent both chest computed tomography with angiography (CTA) and echocardiography between 40 and 50 weeks postmenstrual age between 2011 and 2015. Moderate-severe parenchymal lung disease was defined as an Ochiai score ≥8 on CTA. PH was diagnosed by echocardiogram using standard criteria. Large airway disease was defined as tracheomalacia or bronchomalacia on bronchoscopy and/or tracheoscopy or CTA.Measurements and Main Results: Of 76 evaluated infants, 73 (96%) were classifiable into phenotypic subgroups: 57 with moderate-severe parenchymal disease, 48 with PH, and 44 with large airway disease. The presence of all three disease components was most common (n = 23). Individually, PH and large airway disease, but not moderate-severe parenchymal disease, were associated with increased risk for the primary study outcome. Having more disease components was associated with an incremental increase in the risk for the primary outcome (2 vs. 1: odds ratio, 4.9; 95% confidence interval, 1.4-17.2 and 3 vs. 1: odds ratio, 12.8; 95% confidence interval, 2.4-70.0).Conclusions: Infants with severe BPD are variable in their predominant pathophysiology. Disease phenotyping may enable better risk stratification and targeted therapeutic intervention.

Is α-Amylase an Important Biomarker to Detect Aspiration of Oral Secretions in Ventilated Patients?

Alpha-amylase has emerged as a biomarker of interest in detecting aspiration of oral secretions. In several studies, most ventilated patients have α-amylase values detected in pulmonary secretions. Values of α-amylase are high (as expected) in oral secretions and lowest in bronchoalveolar lavage samples. Around 5-7% of oral α-amylase is detectable in tracheal secretions. Once secretions are aspirated, the duration of detection of α-amylase in pulmonary secretions is unknown. Evidence varies on the relationship between α-amylase and clinical outcomes. Although detection of α-amylase in pulmonary secretions is useful to identify that aspiration has occurred, the lack of standardized reference values, the lack of knowledge regarding duration of detection following aspiration, and mixed findings related to clinical outcomes, limit its usefulness as a measurement tool. If α-amylase is to be used in research and/or clinical practice, additional data are needed to assist in interpretation and application of findings.

Less invasive surfactant administration reduces incidence of severe intraventricular haemorrage in preterms with respiratory distress syndrome: a cohort study

OBJECTIVE

Less invasive surfactant administration (LISA) has proved to safely improve morbidity in extreme preterms with respiratory distress syndrome (RDS). Its effect regarding intraventricular hemorrhage (IVH) remains controversial between most recent systematic reviews. We aimed to evaluate its effect over incidence of severe IVH in this population.

STUDY DESIGN

We compared the incidence of IVH in a prospective cohort of consecutively born preterm infants <34 weeks' gestation receiving LISA (n = 108) with a historical cohort receiving surfactant delivery via tracheal tube and managed with mechanical ventilation (n = 100).

RESULTS

No significant differences regarding perinatal characteristics were observed between both groups. There was a significant reduction in the incidence of severe IVH in LISA group as compared with the historical group [OR = 0.054 (95% CI 0.01-0.2) p = 0.000. NNT 5]. In addition, a significant trend towards decreased mortality was also observed in the study group [OR = 0.2 (95% CI 0.04-0.9) p = 0.027, NNT 9]. Intervention group infants also showed lower oxygenation requirements during the first 72 h post surfactant administration and a reduced incidence of pneumothorax. They were less frequently intubated [31 infants (28.4%) vs. 100 [100%]; P < 0.001] and required fewer days of mechanical ventilation. However, no significant difference in bronchopulmonary dysplasia incidence was observed between both groups.

CONCLUSIONS

LISA approach effectively reduces severe IVH in very low and low birth weight (BW) preterms with RDS. In addition we observe a significant trend towards reduction in both need and duration of MV support, air leak, and overall mortality in the intervention group.

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.

Pepsin and oropharyngeal pH monitoring to diagnose patients with laryngopharyngeal reflux

Objectives

The aim of this study was to compare the diagnostic accuracy of salivary pepsin with oropharyngeal pH monitoring using the Restech measurement system (Dx‐pH) for the diagnosis of laryngopharyngeal reflux (LPR).

Study Design

Prospective cohort study.

Methods

Seventy patients with primary symptoms related to LPR underwent gastroscopy, high‐resolution manometry, pH throughout 24‐hour monitoring (MII‐pH), and barium esophagography between October 2015 and May 2018. In addition, an ear, nose, and throat examination was performed, including assessment of Belafsky Reflux Finding Score (RFS). Clinical symptoms were evaluated with the Belafsky Reflux Symptom Index (RSI) and the Gastrointestinal Quality of Life Index (GIQLI). Simultaneous to MII‐pH, pepsin determination and Dx‐pH were performed.

Results

Of 70 patients, 41 (58.6%) subjects with a pathological DeMeester score showed higher mean values of pepsin (mean value: 216 ng/mL, 95% confidence interval [CI]: 172 to 260), compared to patients with a normal DeMeester score (mean value: 161 ng/mL, 95% CI: 115 to 207). Salivary pepsin showed a specificity of 86.2% and sensitivity of 41.5% for diagnosing LPR using the optimal cutoff value of 216 ng/mL. Furthermore, a significant correlation between the values of salivary pepsin and the RSI score was seen in patients with pathological results in MII‐pH (r = 0.344; P = 0.046).

However, elevated Dx‐pH measurements showed no significant correlation with either MII‐pH, RSI score, RFS score, or GIQLI score, or with the results of pepsin measurement.

Conclusion

Pepsin measurement in saliva could be an alternative tool to assist office‐based diagnosis of LPR, whereas Dx‐pH does not seem to be an adequate test.

Level of Evidence

2B Laryngoscope, 130:1780–1786, 2020

Early transpyloric vs gastric feeding in preterm infants: a retrospective cohort study

BACKGROUND

Neonatal transpyloric feeding (TPF) has not been rigorously studied since the 1980s. Our objective was to evaluate early TPF, defined as TPF initiated within the first week after birth, among preterm infants in the setting of modern neonatal practice.

STUDY DESIGN

A retrospective cohort study was conducted between 2013 and 2017 for all extremely low birth weight (ELBW) infants born in a tertiary neonatal intensive care unit where early TPF is a common practice. Infants were excluded if they did not receive enteral feeding within the first week after birth or if they died prior to initiation of enteral feeding. The primary outcome was death or bronchopulmonary dysplasia (BPD). The association between early TPF and the primary outcome was assessed using multivariable logistic regression, with adjustment for gestational age, birth weight, and intubation status.

RESULT

The study sample included 368 ELBW infants. Twenty-seven percent received early TPF. Death or BPD occurred in 58% of infants who received early TPF compared with 67% of infants who received gastric feeding, adjusted odds ratio 0.6, 95% confidence interval 0.3-0.9. Growth and adverse gastrointestinal outcomes did not differ between the two groups.

CONCLUSION

Early TPF is associated with reduced risk of death or BPD among ELBW infants. Further investigation in the form of a randomized controlled trial is required to confirm a causal association between early TPF and improved clinical outcomes.

Pepsin promotes IL-8 signaling-induced epithelial-mesenchymal transition in laryngeal carcinoma

Background

Laryngopharyngeal reflux (LPR), with its increasing morbidity, is attracting considerable attention. In recent years, the causal role between LPR and laryngeal carcinoma has been debated. The main harmful component of LPR is pepsin, which has been shown to induce mucosal inflammation by damaging the mucous membrane. Thus, pepsin is linked to an increased risk of laryngeal carcinoma, although the potential mechanism remains largely unknown.

Methods

The human laryngeal carcinoma cell lines Hep-2 and Tu212 were exposed to different pepsin concentrations and the morphology, proliferation, migration, secretion of inflammatory cytokines, and epithelial–mesenchymal transition (EMT) of the cells were assessed. To evaluate whether interleukin-8 (IL-8) had a causal relationship with pepsin and EMT, an IL-8 inhibitor was used to suppress IL-8 secretion during pepsin exposure and the expression of EMT markers, cell proliferation, and migration were analyzed.

Results

Pepsin promoted proliferation, colony formation, migration, and IL-8 secretion of Hep-2 and Tu212 cells in vitro. Furthermore, increased pepsin concentrations changed the morphology of Hep-2 and Tu212 cells; levels of the epithelial marker E-cadherin were reduced and those of mesenchymal markers vimentin and β-catenin and the transcription factors snail and slug were elevated. A similar effect was observed in laryngeal carcinoma tissues using immunohistochemistry. IL-8 level was reduced and EMT was restored when pepsin was inhibited by pepstatin. EMT was weakened after exposure to the IL-8 inhibitor, with significant reduction in pepsin-induced cell proliferation and migration.

Conclusions

Pepsin may induce EMT in laryngeal carcinoma through the IL-8 signaling pathway, which indicates that it has potential role in enhancing cell proliferation and metastasis of laryngeal carcinoma.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0772-7) contains supplementary material, which is available to authorized users.

Diagnosis and Management of Gastroesophageal Reflux in Preterm Infants

Gastroesophageal reflux (GER), generally defined as the passage of gastric contents into the esophagus, is an almost universal phenomenon in preterm infants. It is a common diagnosis in the NICU; however, there is large variation in its treatment across NICU sites. In this clinical report, the physiology, diagnosis, and symptomatology in preterm infants as well as currently used treatment strategies in the NICU are examined. Conservative measures to control reflux, such as left lateral body position, head elevation, and feeding regimen manipulation, have not been shown to reduce clinically assessed signs of GER in the preterm infant. In addition, preterm infants with clinically diagnosed GER are often treated with pharmacologic agents; however, a lack of evidence of efficacy together with emerging evidence of significant harm (particularly with gastric acid blockade) strongly suggest that these agents should be used sparingly, if at all, in preterm infants.

Gastroesophageal Reflux Disease and Aerodigestive Disorders

This relationship between gastroesophageal reflux and airway disorders is complex, possibly bidirectional, and not clearly defined. The tools used to investigate gastroesophageal reflux are mostly informative about involvement of gastroesophageal reflux within the gastrointestinal tract, although they are often utilized to study the relationship between gastroesophageal reflux and airway issues with are suspected to occur in relation to reflux. These modalities often lack specificity for reflux-related airway disorders. Co-incidence of gastroesophageal reflux and airway disorders does not necessarily infer causality. While much of our focus has been on managing acidity, controlling refluxate is an area that has not been traditionally aggressively pursued. Our management approach is based on some of the evidence presented, but also often from a lack of adequate study to provide further guidance.

Gastric Aspiration and Its Role in Airway Inflammation

Gastro-Oesophageal Reflux (GOR) has been associated with chronic airway diseases while the passage of foreign matter into airways and lungs through aspiration has the potential to initiate a wide spectrum of pulmonary disorders. The clinical syndrome resulting from such aspiration will depend both on the quantity and nature of the aspirate as well as the individual host response. Aspiration of gastric fluids may cause damage to airway epithelium, not only because acidity is toxic to bronchial epithelial cells but also due to the effect of digestive enzymes such as pepsin and bile salts. Experimental models have shown that direct instillation of these factors to airways epithelia cause damage with a consequential inflammatory response. The pathophysiology of these responses is gradually being dissected, with better understanding of acute gastric aspiration injury, a major cause of acute lung injury, providing opportunities for therapeutic intervention and potentially, ultimately, improved understanding of the chronic airway response to aspiration. Ultimately, clarification of the inflammatory pathways which are related to micro-aspiration via pepsin and bile acid salts may eventually progress to pharmacological intervention and surgical studies to assess the clinical benefits of such therapies in driving symptom improvement or reducing disease progression.

Pilot feasibility study to detect mesenchymal stem cell biomarkers of bronchopulmonary dysplasia in the tracheal aspirate fluid of preterm infants

OBJECTIVE

This study aimed to detect novel mesenchymal stem cell peptides/biomarkers of bronchopulmonary dysplasia (BPD) in the tracheal aspirate fluid (TAF) of preterm infants.

STUDY DESIGN

Participants included infants less than 32 weeks' gestational age or birth weight under 1500 grams who required endotracheal intubation and mechanical ventilation within first 24 hours of life. TAF sample collection was performed at the time of the first clinically indicated routine suctioning. Standardization curves for human levels of osteopontin (Opn), macrophage colony stimulating factor 1 (Csf1), transforming growth factor beta 1 (TGF-β1), and secretory immunoglobulin A (sIgA) were generated for 15 enrolled participants.

RESULTS

We demonstrated that stem cell biomarkers are secreted into the TAF of preterm infants and their concentrations can be easily measured during the first week of life.

CONCLUSIONS

Further studies are warranted to determine a causal relationship between these biomarkers and BPD development and severity.

Sep70/Pepsin expression in hypopharynx combined with hypopharyngeal multichannel intraluminal impedance increases diagnostic sensitivity of laryngopharyngeal reflux

BACKGROUND

Improved methods of diagnosis of laryngopharyngeal reflux (LPR) would enable surgeons to better identify patients who may benefit from antireflux surgery (ARS). The objective of the present study was to assess if hypopharyngeal Pepsin and Sep70 expression combined with hypopharyngeal multichannel intraluminal impedance (HMII) has the potential to increase diagnostic sensitivity of LPR.

METHODS

This study was performed on patients who underwent unsedated transnasal endoscopy with hypopharyngeal biopsy and 24-h HMII to determine abnormal proximal exposure (APE) and DeMeester score (DMS) from 2013 to 2016. Pepsin and Sep70 protein expression was assessed by Western blots of biopsy specimens. The outcomes of ARS were assessed using reflux symptom index (RSI). HMII APE classification, Sep 70, and Pepsin protein levels were compared in normative and symptomatic LPR patients and further analyzed alongside quality of life changes following ARS.

RESULTS

Of 30 subjects enrolled, 23 were excluded for abnormal HMII results or endoscopic evidence of esophagitis. Seven subjects and 105 patients were included in the normative and symptomatic groups, respectively. Compared to the normative group, only Pepsin expression was significantly higher in the symptomatic group [APE+/LPR+ (p = 0.000), APE+/LPR- (p = 0.001), and APE- (p = 0.047)]. Further, the ratio of Sep70/Pepsin was significantly lower in the symptomatic group [APE+/LPR+ (p = 0.008), APE+/LPR- (p = 0.000), and APE- (p = 0.050)], and a cutoff ratio for a diagnosis of LPR was established as < 158. Of 105 symptomatic patients, 48 patients underwent ARS. Of these, 17 patients had complete pre- and post-RSI questionnaires. LPR symptoms improved in 15 (88%), of whom 2 were APE- but met criteria for a diagnosis of LPR based on the Sep70/Pepsin cutoff.

CONCLUSIONS

The identified Sep70/Pepsin ratio may serve as a reliable biomarker for the diagnosis of LPR. As a result, this may help identify additional patients who have a false-negative HMII result due to the 24-h testing window.

The diagnostic value of pepsin detection in saliva for gastro-esophageal reflux disease: a preliminary study from China

Background

None of current diagnostic methods has been proven to be a reliable tool for gastro-esophageal reflux disease (GERD). Pepsin in saliva has been proposed as a promising diagnostic biomarker for gastro-esophageal reflux. We aimed to determine the diagnostic value of salivary pepsin detection for GERD.

Methods

Two hundred and fifty patients with symptoms suggestive of GERD and 35 asymptomatic healthy volunteers provided saliva on morning waking, after lunch and dinner for pepsin determination using the Peptest lateral flow device. All patients underwent 24-h multichannel intraluminal impedance pH (24-h MII-pH) monitoring and upper gastrointestinal endoscopy. Based on 24-h MII-pH and endoscopy study, patients were defined as GERD (abnormal MII-pH results and/or reflux esophagitis) and non-GERD otherwise.

Results

Patients with GERD had a higher prevalence of pepsin in saliva and higher pepsin concentration than patients with non-GERD and healthy controls (P < 0.001 for all). The pepsin test had a sensitivity of 73% and a specificity of 88.3% for diagnosing GERD using the optimal cut-off value of 76 ng/mL. Postprandial saliva samples collected when the symptoms occurred had a more powerful ability to identify GERD.

Conclusions

Salivary pepsin test had moderate diagnostic value for GERD. It may be a promising tool to replace the use of currently invasive tools with advantages of non-invasive, easy to perform and cost effective.

Trial registration

ChiCTR-DDD-16009506 (date of registration: October 20, 2016).

Pepsin as a Marker of Extraesophageal Reflux

Diagnosis of extraesophageal reflux (EER) currently relies on tools designed for diagnosis of gastroesophageal reflux. Such tools lack the sensitivity and reproducibility to detect the less frequent and mildly acidic reflux associated with upper airway disease. Pepsin has been posited to be a reliable biological marker of EER. Our aim was to present a comprehensive literature review of the use of pepsin as a diagnostic marker of EER. Two methods are typically used for detection of pepsin in the airways: enzymatic and immunologic. The limitations, advantages, and examples of use of each are discussed. Pepsin assay has been used to identify refluxate in trachea, lung, sinus, middle ear, combined sputum and saliva, and breath condensate. An immunologic pepsin assay of combined sputum and saliva was determined to be 100% sensitive and 89% specific for detection of EER (based on pH-metry), and an enzymatic test of nasal lavage fluid (100% sensitivity and 92.5% specificity) demonstrated an increased incidence of EER in patients with chronic rhinosinusitis. Pepsin assay identified tracheal pepsin to be an indicator of bronchopulmonary dysplasia and related mortality risk in ventilated preterm infants. Pepsin assay is a useful tool for correlation of reflux with airway disease and is a reliable diagnostic marker of EER.

Idiopathic Pulmonary Fibrosis: Novel Concepts of Proton Pump Inhibitors as Antifibrotic Drugs

The prevalence of abnormal acid gastroesophageal reflux (GER) is higher in patients with idiopathic pulmonary fibrosis (IPF) than in matched control subjects. Several studies demonstrated that more than one-third of patients with IPF have abnormal esophageal acid exposures. In addition, many of these studies indicate that the majority of patients with IPF have silent reflux with no symptoms of GER. Findings of abnormal reflux persist in a large proportion of patients with IPF placed on antacid therapy such as proton pump inhibitors (PPIs). This seemingly paradoxical observation suggests that either patients with IPF are somehow resistant to PPI-based intervention or PPIs are inherently unable to suppress acid GER. By contrast, patients with IPF who undergo Nissen fundoplication surgery are effectively relieved from the complications of GER, and retrospective studies suggest improved lung function. Retrospective, anecdotal data suggest a beneficial role of PPIs in IPF including stabilization of lung function, reduction in episodes of acute exacerbation, and enhanced longevity. The recent evidence-based guidelines for treatment of IPF approved conditional recommendation of PPIs for all patients with IPF regardless of their GER status. Recently, we have reported that PPIs possess antiinflammatory and antifibrotic activities by directly suppressing proinflammatory cytokines, profibrotic proteins, and proliferation of lung fibroblasts. Our study provides an alternative explanation for the beneficial effect of PPIs in IPF. In this Perspective, we reviewed emerging progress on antifibrotic effect of PPIs using IPF as a disease model. In addition, we summarized surgical and pharmacological interventions for GER and their downstream effect on lung physiology.

Pepsin as a biomarker for laryngopharyngeal reflux in children with laryngomalacia

OBJECTIVES/HYPOTHESIS

Laryngomalacia is a common cause of newborn stridor. Laryngopharyngeal reflux (LPR) has been associated with laryngomalacia. Although pepsin, a component of LPR, has been associated with inflammatory diseases of the aerodigestive tract, its presence in the airways of laryngomalacia patients is unknown.

STUDY DESIGN

Prospective case-control study comparing patients under age 3 years with laryngomalacia to children without laryngomalacia.

METHODS

Children less than 3 years old undergoing supraglottoplasty for laryngomalacia or surgery unrelated to the airway, without a history of laryngomalacia, reflux, or respiratory disease, were offered enrollment. Supraglottic lavage samples (3 mL) were obtained from all subjects. Two-millimeter arytenoid biopsies were collected from laryngomalacia patients. Pepsin Western blot and enzyme-linked immunosorbent assay were performed.

RESULTS

Ten laryngomalacia and five control subjects were enrolled. Pepsin was detected in lavages of laryngomalacia patients (8/10) but absent in controls (0/5; P = .007). Pepsin was observed more frequently in lavages (8/10) than biopsies (4/10; P = .046) of laryngomalacia subjects. Higher median pepsin concentration was observed in laryngomalacia than control lavages (P = .025).

CONCLUSIONS

Pepsin in supraglottic specimens demonstrated an association with laryngomalacia, supporting a role for refluxed pepsin in laryngomalacia. These data corroborate previous work implicating pepsin in inflammatory diseases of the upper airways. Further studies are warranted to investigate the contribution of pepsin to the pathophysiology of laryngomalacia.

LEVEL OF EVIDENCE

3b. Laryngoscope, 127:2413-2417, 2017.

Pepsin in saliva as a biomarker for oropharyngeal reflux compared with 24-hour esophageal impedance/pH monitoring in pediatric patients

BACKGROUND

Pepsin in saliva is a proposed biomarker for oropharyngeal reflux. Pepsin may be prevalent in saliva from subjects with gastro-esophageal reflux and may correlate with proximal reflux by intraluminal impedance/pH monitoring (MII/pH).

METHODS

Patients (3 days to 17.6 years, n=90) undergoing 24-hour MII/pH monitoring and asymptomatic controls (2 months to 13.7 years, n=43) were included. Salivary pepsin was determined using a pepsin enzyme-linked immunosorbent assay. Eight saliva samples were collected from patients undergoing 24-hr MII/pH: (i) before catheter placement, (ii) before and 30 minutes after each of three meals, and (iii) upon awakening. One sample was collected from each control.

KEY RESULTS

In MII/pH subjects, 85.6% (77/90) had at least one pepsin-positive sample compared with 9.3% (4/43) in controls. The range of pepsin observed in individual subjects varied widely over 24 hours. The average pepsin concentration in all samples obtained within 2 hours following the most recent reflux event was 30.7±135 ng/mL, decreasing to 16.5±39.1 ng/mL in samples collected more than 2 hours later. The frequency of pepsin-positive samples correlated significantly with symptom index (r_S =0.332, P=.0014), proximal (r_S =0.340, P=.0010), and distal (r_S =0.272, P=.0095) MII events.

CONCLUSIONS & INFERENCES

Concentration of salivary pepsin may not be an accurate measure of severity of reflux because of the wide range observed in individuals over 24 hours. Saliva samples must be obtained soon after a reflux event. Defining a regimen for optimal saliva collection may help to achieve the goal of using salivary pepsin as a biomarker for oropharyngeal reflux.

CLINICAL TRIAL REGISTRY

NCT01091805.

Salivary Pepsin Lacks Sensitivity as a Diagnostic Tool to Evaluate Extraesophageal Reflux Disease

OBJECTIVES

To determine the sensitivity of salivary pepsin compared with multichannel intraluminal impedance with pH testing (pH-MII), endoscopy, and gastroesophageal reflux disease (GERD) questionnaires.

STUDY DESIGN

We prospectively recruited 50 children from Boston Children's Hospital who were undergoing pH-MII to evaluate for GERD. The patients completed 24-hour pH-MII testing, completed symptom and quality of life questionnaires, and provided a saliva specimen that was analyzed using the PepTest lateral flow test. A subset of patients also underwent bronchoscopy and esophagogastroduodenoscopy. Receiver operating characteristic curve analyses were performed to determine the sensitivity of salivary pepsin compared with each reference standard.

RESULTS

Twenty-one of the 50 patients (42%) were salivary pepsin-positive, with a median salivary pepsin concentration of 10 ng/mL (IQR, 10-55 ng/mL). There was no significant difference in the distributions of acid, nonacid, total reflux episodes, full column reflux, or any other reflux variable in patients who were pepsin-positive compared with those who were pepsin-negative (P > .50). There was no significant correlation between the number of reflux episodes and pepsin concentration (P > .10). There was no positive relationship between salivary pepsin positivity, any extraesophageal symptoms or quality of life scores, or inflammation on bronchoscopy or esophagogastroduodenoscopy (P > .30).

CONCLUSION

Salivary pepsin measurement has a low sensitivity for predicting pathological gastroesophageal reflux in children.

Airway reflux

An ever-increasing number of adult and pediatric disorders have been shown to be influenced or caused by airway reflux. This has become a controversial and complicated aspect of medicine that requires a multidisciplinary approach. Evidence indicates that it is not only the acidic components of gastric refluxate that injure extraesophageal tissues but also the nonacidic components, such as pepsin and bile. There is a realization that proton pump inhibitors will not be effective when nonacidic components of refluxate are causing the problem. New in vitro and in vivo models for the study of airway reflux and new therapeutic and surgical approaches are discussed in this review article.

Applying Adult Ventilator-associated Pneumonia Bundle Evidence to the Ventilated Neonate

BACKGROUND

Ventilator-associated pneumonia (VAP) in neonates can be reduced by implementing preventive care practices. Implementation of a group, or bundle, of evidence-based practices that improve processes of care has been shown to be cost-effective and to have better outcomes than implementation of individual single practices.

PURPOSE

The purpose of this article is to describe a safe, effective, and efficient neonatal VAP prevention protocol developed for caregivers in the neonatal intensive care unit (NICU). Improved understanding of VAP causes, effects of care practices, and rationale for interventions can help reduce VAP risk to neonatal patients.

METHOD

In order to improve care practices to affect VAP rates, initial and annual education occurred on improved protocol components after surveying staff practices and auditing documentation compliance.

FINDINGS/RESULTS

In 2009, a tertiary care level III NICU in the Midwestern United States had 14 VAP cases. Lacking evidence-based VAP prevention practices for neonates, effective adult strategies were modified to meet the complex needs of the ventilated neonate. A protocol was developed over time and resulted in an annual decrease in VAP until rates were zero for 20 consecutive months from October 2012 to May 2014.

IMPLICATIONS FOR PRACTICE

This article describes a VAP prevention protocol developed to address care practices surrounding hand hygiene, intubation, feeding, suctioning, positioning, oral care, and respiratory equipment in the NICU.

IMPLICATIONS FOR RESEARCH

Implementation of this VAP prevention protocol in other facilities with appropriate monitoring and tracking would provide broader support for standardization of care. Individual components of this VAP protocol could be studied to strengthen the inclusion of each; however, bundled interventions are often considered stronger when implemented as a whole.

Acid and Weakly Acidic Gastroesophageal Reflux and Pepsin Isoforms (A and C) in Tracheal Secretions of Critically Ill Children

BACKGROUND

Gastroesophageal reflux (GER) and pulmonary aspiration are frequent in patients in the ICU. The presence of pepsin in airways seems to be the link between them. However, pepsin isoforms A (gastric specific) and C (pneumocyte potentially derived) need to be distinguished. This study aimed to evaluate GER patterns and to determine the presence of pepsin A and C in tracheal secretions of critically ill children receiving mechanical ventilation.

METHODS

All patients underwent combined multichannel intraluminal impedance-pH (MII-pH) monitoring. Tracheal secretion samples were collected to determine the presence of pepsin. Pepsin A and C were evaluated by Western blot. MII-pH parameters analyzed were number of total GER episodes (NGER); acid, weakly acidic, and weakly alkaline GER episodes; and proximal and distal GER episodes.

RESULTS

Thirty-four patients (median age, 4 months; range, 1-174 months) were included. MII-pH monitoring detected 2,172 GER episodes (77.0% were weakly acidic; 71.7% were proximal). The median NGER episodes per patient was 59.5 (25th-75th percentile, 20.3-85.3). Weakly acidic GER episodes per patient were significantly more frequent than acid GER episodes per patient (median [25th-75th percentile], 43.5 [20.3-68.3] vs 1.0 [0-13.8], respectively; P < .001). Only three patients had an altered acid reflux index (44.9%, 12.7%, and 13.6%) while not taking antacid drugs. Pepsin A was found in 100% of samples and pepsin C in 76.5%.

CONCLUSIONS

The majority of GER episodes of children in the ICU were proximal and weakly acidic. All patients had aspiration of gastric contents as detected by pepsin A in tracheal fluid. A specific pepsin assay should be performed to establish gastropulmonary aspiration because pepsin C was found in > 70% of samples.

Anti-gastroesophageal reflux surgery in infants with severe bronchopulmonary dysplasia

Gastroesophageal reflux may exacerbate lung disease in infants with bronchopulmonary dysplasia (BPD). Anti-reflux surgery may therefore reduce the severity of this disease in some infants. We report a retrospective series of 22 infants with severe BPD who underwent anti-reflux surgery. Our experience indicates that these procedures can be safely performed in this population and that early post-operative initiation of gastric feeds is well tolerated. Modest post-operative reductions in required oxygen and median respiratory rate were observed.

Does positioning affect tracheal aspiration of gastric content in ventilated infants?

OBJECTIVES

Gastroesophageal reflux and aspiration can occur in premature infants who are supported with mechanical ventilation. The relation between physical positioning and gastric aspiration in ventilated infants has not been studied. Pepsin measured in tracheal aspirate (TA) emerged as a specific marker for aspiration. The objective of our study was to assess pepsin in TA of ventilated infants at 2 different positions: supine and right lateral.

METHODS

We conducted a randomized controlled trial on premature infants who were enterally fed and supported with mechanical ventilation. Patients were randomized into intervention and control groups. In the intervention group, infants were placed supine for 6 hours before a sample of TA was obtained. A second sample was collected 6 hours later while lying in the right lateral position. In the control group, the 2 samples of TA were obtained while infants remained in the supine position during the entire study time. Pepsin in TA was measured while blinded to the group assignment.

RESULTS

A total of 34 patients were enrolled and randomized to intervention (n = 17) and control (n = 17) groups. Gestational age was 32.7 ± 2.7 weeks, and birth weight was 1617 ± 526 g; both groups had similar demographic and clinical characteristics. Pepsin concentration did not differ between groups at baseline. In the intervention group, pepsin concentration significantly declined from 13 ng/mL (interquartile range [IQR] 11.9-38.7) to 10 ng/mL (IQR 7-12; P < 0.001), whereas it did not change in the control group (P = 0.42).

CONCLUSIONS

The right lateral positioning is associated with decreased TA pepsin. The implications of the present study on hospital practice and clinical outcomes need further investigations.

Pepsin in saliva for the diagnosis of gastro-oesophageal reflux disease

OBJECTIVE

Current diagnostic methods for gastro-oesophageal reflux disease (GORD) have moderate sensitivity/specificity and can be invasive and expensive. Pepsin detection in saliva has been proposed as an 'office-based' method for GORD diagnosis. The aims of this study were to establish normal values of salivary pepsin in healthy asymptomatic subjects and to determine its value to discriminate patients with reflux-related symptoms (GORD, hypersensitive oesophagus (HO)) from functional heartburn (FH).

DESIGN

100 asymptomatic controls and 111 patients with heartburn underwent MII-pH monitoring and simultaneous salivary pepsin determination on waking, after lunch and dinner. Cut-off value for pepsin positivity was 16 ng/mL. Patients were divided into GORD (increased acid exposure time (AET), n=58); HO (normal AET and + Symptom Association Probability (SAP), n=26) and FH (normal AET and-SAP, n=27).

RESULTS

1/3 of asymptomatic subjects had pepsin in saliva at low concentration (0(0-59)ng/mL). Patients with GORD and HO had higher prevalence and pepsin concentration than controls (HO, 237(52-311)ng/mL and GORD, 121(29-252)ng/mL)(p<0.05). Patients with FH had low prevalence and concentration of pepsin in saliva (0(0-40) ng/mL). A positive test had 78.6% sensitivity and 64.9% specificity for diagnosis of GORD+HO (likelihood ratio: 2.23). However, one positive sample with >210 ng/mL pepsin suggested presence of GORD+HO with 98.2% specificity (likelihood ratio: 25.1). Only 18/84 (21.4%) of GORD+HO patients had 3 negative samples.

CONCLUSION

In patients with symptoms suggestive of GORD, salivary pepsin testing may complement questionnaires to assist office-based diagnosis. This may lessen the use of unnecessary antireflux therapy and the need for further invasive and expensive diagnostic methods.

Managing gastroesophageal reflux symptoms in the very low-birth-weight infant postdischarge

Gastroesophageal reflux and gastroesophageal reflux disease symptoms are common challenges for very low-birth-weight infants (<1500 g). These symptoms frequently result in feeding difficulties and family stress. Management of symptoms across healthcare disciplines may not be based on current evidence, and inconsistency can result in confusion for families and delayed interventions. The feeding relationship between infant and caregivers may be impaired when symptoms are persistent and poorly managed. An algorithm for managing gastroesophageal reflux-like symptoms in very low-birth-weight infants (from hospital discharge to 12 months corrected age) was developed through the formation of a multidisciplinary community of practice and critical appraisal of the literature. A case study demonstrates how the algorithm results in a consistent approach for identifying symptoms, applying appropriate management strategies, and facilitating appropriate timing of medical consultation. Application to managing gastroesophageal reflux symptoms in the neonatal intensive care unit will be briefly addressed.

Epidemiology of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is among the most common and serious sequelae of preterm birth. BPD affects at least one-quarter of infants born with birth weights less than 1500 g. The incidence of BPD increases with decreasing gestational age and birth weight. Additional important risk factors include intrauterine growth restriction, sepsis, and prolonged exposure to mechanical ventilation and supplemental oxygen. The diagnosis of BPD predicts multiple adverse outcomes including chronic respiratory impairment and neurodevelopmental delay. This review summarizes the diagnostic criteria, incidence, risk factors, and long-term outcomes of BPD.

Biomarkers in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a complex disorder secondary to gene-environment interactions, and is the commonest chronic lung disease in infancy. There is no specific or effective treatment available to date for BPD. Since the aetiopathogenesis of BPD is multifactorial, involving diverse molecular signaling pathways, a variety of biomarkers detected in biological fluids have been proposed for early identification of infants predisposed to BPD. This review will be restricted to biomarker studies in human infants, conducted mostly in the last decade. The majority of the studies have been conducted using blood, urine or tracheal aspirate samples. Despite the multitude of biomarkers proposed, most studies have been conducted in small numbers of infants, with few being replicated by independent investigators. Confirmatory studies with adequate sample sizes and assessment of the role of putative biomarkers in the aetiology of BPD in developmentally appropriate animal models and human lungs with BPD will enhance the potential for therapeutic interventions. Genomic and proteomic approaches have the greatest potential to significantly advance the field of biomarkers in BPD.

Nonpharmacological management of gastroesophageal reflux in preterm infants

Gastroesophageal reflux (GOR) is very common among preterm infants, due to several physiological mechanisms. Although GOR should not be usually considered a pathological condition, its therapeutic management still represents a controversial issue among neonatologists; pharmacological overtreatment, often unuseful and potentially harmful, is increasingly widespread. Hence, a stepwise approach, firstly promoting conservative strategies such as body positioning, milk thickening, or changes of feeding modalities, should be considered the most advisable choice in preterm infants with GOR. This review focuses on the conservative management of GOR in the preterm population, aiming to provide a complete overview, based on currently available evidence, on potential benefits and adverse effects of nonpharmacological measures. Nonpharmacological management of GOR might represent a useful tool for neonatologists to reduce the use of antireflux medications, which should be limited to selected cases of symptomatic babies.

Pharmacological therapy of gastroesophageal reflux in preterm infants

Although gastroesophageal reflux (GER) is a very common phenomenon among preterm infants, its therapeutic management is still an issue of debate among neonatologists. A step-wise approach should be advisable, firstly promoting nonpharmacological interventions and limiting drugs to selected infants unresponsive to the conservative measures or who are suffering from severe GER with clinical complications. Despite of this, a concerning pharmacological overtreatment has been increasingly reported. Most of the antireflux drugs, however, have not been specifically assessed in preterm infants; moreover, serious adverse effects have been noticed in association to their administration. This review mainly aims to draw the state of the art regarding the pharmacological management of GER in preterm infants, analyzing the best piecies of evidence currently available on the most prescribed anti-reflux drugs. Although further trials are required, sodium alginate-based formulations might be considered promising; however, data regarding their safety are still limited. Few piecies of evidence on the efficacy of histamine-2 receptor blockers and proton pump inhibitors in preterm infants with GER are currently available. Nevertheless, a significantly increased risk of necrotizing enterocolitis and infections has been largely reported in association with their use, thereby leading to an unfavorable risk-benefit ratio. The efficacy of metoclopramide in GER's improvement still needs to be clarified. Other prokinetic agents, such as domperidone and erythromycin, have been reported to be ineffective, whereas cisapride has been withdrawn due to its remarkable cardiac adverse effects.

Detection of pepsin in mouth swab: correlation with clinical gastroesophageal reflux in preterm infants

OBJECTIVE

To study the relationship between pepsinogen/pepsin in a mouth swab and clinical gastroesophageal reflux (GER) in preterm infants.

METHODS

Preterm infants (birth weight ≤ 2000 g) on full enteral feeds were enrolled. Mouth swabs from cheek and below the tongue were collected one, two and three hours after feeding. An enzymatic assay with substrate fluorescein isothiocyanate-casein was used to detect pepsin A and C activities with further confirmation by western blot. Blinded investigators reviewed the infant's medical record to clinically diagnose GER.

RESULTS

A total of 101 premature infants were enrolled. Pepsinogen/pepsin was detected in 45/101 (44.5%) infants in at least one sample. A clinical diagnosis of GER was made in 36/101 (35.6%) infants. Mouth swabs were positive in 26/36 (72%) infants with clinical GER and only 19/65 (29%) infants without GER (p < 0.001). Similarly, the levels of pepsinogen/pepsin A and C were higher in the mouth swabs of infants with clinical GER.

CONCLUSION

The detection of pepsinogen/pepsin in a mouth swab correlates with clinical GER in premature infants.

Preliminary study in to the incidence of gastroesophageal reflux (GER) in high risk neonates admitted to NICU

OBJECTIVE

To find out the incidence of Gastro-esophageal reflux (GER) in neonates at risk for it and compare this with the incidence in the controls.

METHODS

This prospective case control study was conducted on 34 neonates. Twenty-four test high risk neonates comprised of preterms, neonates on mechanical ventilation neonates with ALTE(Acute Life Threatening Episode) and post-operative neonates (Tracheo-esophageal fistula, congenital diaphragmatic hernia). There were ten matched controls. Esophageal pHmetry was done using double sensor antimony pH probe and the two groups were compared. Significant reflux was defined as any reflux on pharyngeal sensor (grade 4 reflux) or a Reflux Index or RI (amount of time the esophageal pH remained <4) >20%.Analysis were done using Fisher Exact t test and Chi square test.

RESULTS

Mean gestational age was 34.87(3.86) wk and 33.7(3.29) wk in the test and control groups respectively, while mean BW was 2186.02(814.57) g and 1851.2(592.93) g in each respective group. In the test group 10 were symptomatic, 5 were on mechanical ventilation, 8 were on CPAP and one was post-operation case. Difference in the incidence of significant RI in test and control group was not statistically significant. Incidence between various group of neonates in test group showed no statistical significance either. However, the incidence of grade IV reflux in test group was 8/24 and control 0/10 and this difference was statistically significant. Reflux did increase when period of gestation decreased and the difference was statistically significant.

CONCLUSIONS

Clinically significant grade IV GER was more in high risk (test) neonates than control.