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.

Infant Pulmonary Function Testing and Phenotypes in Severe Bronchopulmonary Dysplasia.

BACKGROUND: The definition of severe bronchopulmonary dysplasia (sBPD) is based on respiratory support needs. The management of a patient with sBPD remains empirical and is highly variable among providers. Our objective in this study was to test the hypothesis that infant pulmonary function testing (iPFT) would reveal distinct phenotypes in patients with established sBPD during the initial NICU stay. METHODS: A prospective cohort study with data prospectively collected on infants with sBPD from May 1, 2003, to June 30, 2016. iPFT data were used to classify the patients as obstructive, restrictive, or mixed. RESULTS: The median gestational age at birth was 25 weeks (interquartile range [IQR], 24-27 weeks) and the median birth weight was 707 g (IQR, 581-925 g). At the time of iPFT, the median postmenstrual age was 52 weeks (IQR, 45-63 weeks), and the median weight was 4.4 kg (IQR, 3.7-6.0 kg). There were 56 (51%) patients with obstructive, 44 (40%) with mixed, and 10 (9%) with restrictive phenotypes. Moderate or severe obstruction was seen in 86% of the obstructive group and 78% of the mixed group. Of the restrictive patients, 70% had moderate and 30% had mild restriction. Bronchodilator response was seen in 74% of obstructive, 63% of mixed, and 25% of restrictive patients. CONCLUSIONS: Our findings reveal that sBPD as it is currently defined includes distinct phenotypes. Future researchers of diagnostic approaches to this population should consider the development of bedside tests to define phenotypes, and researchers in future therapeutic trials should consider the use of pulmonary function phenotyping in patient recruitment.

Systematic Review of Inhaled Bronchodilator and Corticosteroid Therapies in Infants with Bronchopulmonary Dysplasia: Implications and Future Directions.

BACKGROUND: There is much debate surrounding the use of inhaled bronchodilators and corticosteroids for infants with bronchopulmonary dysplasia (BPD). OBJECTIVE: The objective of this systematic review was to identify strengths and knowledge gaps in the literature regarding inhaled therapies in BPD and guide future research to improve long-termoutcomes. METHODS: The databases of Academic Search Complete, CINAHL, PUBMED/MEDLINE, and Scopus were searched for studies that evaluated both acute and long-term clinical outcomes related to the delivery and therapeutic efficacy of inhaled beta-agonists, anticholinergics and corticosteroids in infants with developing and/or established BPD. RESULTS: Of 181 articles, 22 met inclusion criteria for review. Five evaluated beta-agonist therapies (n = 84, weighted gestational age (GA) of 27.1(26-30) weeks, weighted birth weight (BW) of 974(843-1310) grams, weighted post menstrual age (PMA) of 34.8(28-39) weeks, and weighted age of 53(15-86) days old at the time of evaluation). Fourteen evaluated inhaled corticosteroids (n = 2383, GA 26.2(26-29) weeks, weighted BW of 853(760-1114) grams, weighted PMA of 27.0(26-31) weeks, and weighted age of 6(0-45) days old at time of evaluation). Three evaluated combination therapies (n = 198, weighted GA of 27.8(27-29) weeks, weighted BW of 1057(898-1247) grams, weighted PMA of 30.7(29-45) weeks, and age 20(10-111) days old at time of evaluation). CONCLUSION: Whether inhaled bronchodilators and inhaled corticosteroids improve long-term outcomes in BPD remains unclear. Literature regarding these therapies mostly addresses evolving BPD. There appears to be heterogeneity in treatment responses, and may be related to varying modes of administration. Further research is needed to evaluate inhaled therapies in infants with severe BPD. Such investigations should focus on appropriate definitions of disease and subject selection, timing of therapies, and new drugs, devices and delivery methods as compared to traditional methods across all modalities of respiratory support, in addition to the assessment of long-term outcomes of initial responders.