Assessment of bronchodilator response in preschoolers: A systematic review.

BACKGROUND: Several techniques can be used to assess bronchodilator response (BDR) in preschool-aged children, including spirometry, respiratory oscillometry, the interrupter technique, and specific airway resistance. However, there has not been a systematic comparison of BDR thresholds across studies yet. METHODS: A systematic review was performed on all studies up to May 2023 measuring a bronchodilator effect in children 2-6 years old using one of these techniques (PROSPERO CRD42021264659). Studies were identified using MEDLINE, Cochrane, EMBASE, CINAHL via EBSCO, Web of Science databases, and reference lists of relevant manuscripts. RESULTS: Of 1224 screened studies, 43 were included. Over 85% were from predominantly European ancestry populations, and only 22 studies (51.2%) calculated a BDR cutoff based on a healthy control group. Five studies included triplicate testing with a placebo to account for the within-subject intrasession repeatability. A relative BDR was most consistently reported by the included studies (95%) but varied widely across all techniques. Various statistical methods were used to define a BDR, with six studies using receiver operating characteristic analyses to measure the discriminative power to distinguish healthy from wheezy and asthmatic children. CONCLUSION: A BDR in 2- to 6-year-olds cannot be universally defined based on the reviewed literature due to inconsistent methodology and cutoff calculations. Further studies incorporating robust methods using either distribution-based or clinical anchor-based approaches to define BDR are required.

Longitudinal tracking of intrabreath respiratory impedance in preschool children.

BACKGROUND: Longitudinal measurements of intrabreath respiratory impedance (Zrs) in preschool-aged children may be able to distinguish abnormal lung function trajectories in children with a history of wheezing compared to healthy ones. METHODS: Children from a prospective, longitudinal community-based cohort performed annual intrabreath oscillometry (IB-OSC) measurements from age 3- to 7-years. IB-OSC was performed using a single 10 Hz sinusoid while clinically asymptomatic. Linear mixed-effects models were developed to explore the effects of wheezing phenotypes, growth, and sex on seven IB-OSC outcome variables over time: resistance at end-expiration (ReE), resistance at end-inspiration (ReI), the tidal change in resistance (∆R=ReE-ReI), reactance at end-expiration (XeE), reactance at end-inspiration (XeI), the tidal change in reactance (∆X=XeE-XeI), and ∆X normalized by tidal volume (∆X/VT). RESULTS: Eighty-five children produced 374 acceptable IB-OSC measurements. Subjects were classified into one of three wheeze groups: never (n = 36), transient (n = 34), or persistent (n = 15). After adjusting for height, children with persistent wheezing, compared to those who never wheezed, had +0.814 hPa s L-1 ReE (95% confidence interval [CI] +0.178 to +1.451, p = 0.015), -0.792 hPa s L-1 XeE (95% CI -1.203 to -0.381, p = 0.003), -0.538 hPa s L-1 ∆X (95% CI -0.834 to -0.242, p = 0.007) and -1.672 hPa s L-2 ∆X/VT (95% CI -2.567 to -0.777, p < 0.001). Increasing height had a significant effect on all IB-OSC resistance and reactance variables when adjusted for the effect of preschool wheezing. CONCLUSIONS: IB-OSC is feasible for tracking lung function growth in preschool-aged children and may allow abnormal lung function to be identified early in asymptomatic preschoolers with a history of persistent wheezing.

Lung parenchymal calcifications in a child with cystic fibrosis.

We describe a 6-year-old girl with homozygous p.Phe508del cystic fibrosis with severe multi-lobar bronchiectasis and obstructive lung disease who was found to have prominent parenchymal calcifications in the right middle lobe on a computed tomography scan of the chest. Histopathology from the calcified area of lung biopsy showed fibrous tissue with chronic inflammation with CD3+ T-lymphocytes and macrophages with no granulomas. Dystrophic calcification was seen within this necrotic debris.

Flexible Bronchoscopy Diagnosis of Uncommon Congenital H-type Tracheoesophageal Fistula, Dual Fistulae, Bronchoesophageal Fistula, and Recurrence of Fistula in Children: A 20-year Experience.

BACKGROUND: Interventional pediatric flexible bronchoscopy has many advantages over radiologic investigations in diagnosing uncommon congenital H-type tracheoesophageal fistula (TEF), dual TEF, bronchoesophageal fistula (BEF) and fistula recurrence including higher rates of identification and anatomic localization with guide wire cannulation. We compare the diagnostic utility of flexible bronchoscopy to radiologic techniques for congenital aerodigestive fistula. METHODS: A single center retrospective review was completed of all cases of pediatric TEF and BEF diagnosed with flexible bronchoscopy between January 2000 and November 2020. RESULTS: Fistulae were diagnosed 21 times in 18 patients at a median age of 1.22 years (interquartile range: 0.50 to 2.99). The median time from diagnosis to repair was 17.5 days (interquartile range: 5.5 to 43). Symptoms commonly related to fistula were found in all patients. Uncommon fistulae included single H-type TEF (n=10, 47.6%), dual H-type TEF (n=2, 9.5%), dual proximal and distal TEF with esophageal atresia (n=5, 23.8%), TEF recurrence (n=2, 14.3%), BEF (n=1, 4.8%), and a BEF recurrence (n=1, 4.8%). Flexible bronchoscopy confirmed the diagnosis in all fistulae using a guide wire cannulation or methylene blue dye injection. A combined procedure with simultaneous bronchoscopy and esophagoscopy was used for 6 fistulae. The positive examination rate was 75% for bronchoscopy compared with 2.6% for contrast swallow studies and 28.6% for tube esophagograms. CONCLUSIONS: Flexible bronchoscopy should be considered as a first line investigation in uncommon aerodigestive fistulae. In the absence of a skilled bronchoscopist, the best radiologic investigation is a pull-back tube esophagogram but may still require endoscopic confirmation at the time of fistula repair.

Endobronchial vasculitis in childhood granulomatosis with polyangiitis.

Laryngo-tracheo-bronchial disease in childhood granulomatosis with polyangiitis may acutely present with endobronchial small vessel vasculitis without airway stenosis. Treatment should not be delayed in the presence of haemoptysis as it may indicate acute pulmonary capillaritis which can lead to fatal respiratory failure from diffuse alveolar haemorrhage.

Predictors of home oxygen duration in chronic neonatal lung disease.

AIMS: In infants with chronic neonatal lung disease (CNLD), we aimed to identify predictors of home oxygen duration, predictors of discharge oxygen flow rates, and the association of oxygen flow rates with respiratory outcomes. METHODS: Infants with CNLD requiring home oxygen in 2016 and 2017 were retrospectively reviewed. Hazard ratios (HR) were estimated from Cox proportional hazards regression models in the cohort. A multinomial logistic regression model examined the effects of maternal and infant variables on discharge oxygen flow rates. Kruskal-Wallis test with univariate linear regression and Fisher's exact test with binomial univariate logistic regression were used to examine associations between oxygen flow groups and post-discharge clinical variables. RESULTS: One hundred and forty-nine infants were included. Median corrected gestational age (CGA) at oxygen cessation was 6.8 months (interquartile range, 4.4) with 87.2% of infants weaned by 12 months CGA. Shorter initial neonatal intensive care unit (NICU) stay predicted faster oxygen weaning at 9 months (HR, 0.99; 95% confidence interval [CI], 0.98-1.00, p = .02) and 12 months (HR, 0.99; 95% CI, 0.98-1.00, p = .02). Infants with hypercarbia at discharge or discharged from NICU at higher CGA had higher odds of requiring ≥ 200 ml/min relative to ≤ 125 ml/min oxygen. Infants discharged with > 250 ml/min oxygen were more likely to have a respiratory-related admission before 2 years chronological age. CONCLUSION: Shorter initial NICU stay was the best predictor of earlier home oxygen cessation. At NICU discharge, infants with hypercarbia or a higher CGA may require more home oxygen and experience more respiratory-related hospital admission in the first 2 years of chronological age.

Flexible bronchoscopy in diagnosis and management of dual tracheoesophageal fistula: A case series.

Dual and H-type tracheoesophageal fistulae can present major diagnostic and management difficulties. A methodological approach with flexible bronchoscopy and a guide wire cannulation technique was used to diagnose, localize, and aid operative surgical management in five children with dual and H-type tracheoesophageal fistulae. All children had successful outcomes.

Using continuous overnight pulse oximetry to guide home oxygen therapy in chronic neonatal lung disease.

AIM: The aims of this study are: (i) to survey the knowledge of paediatric clinicians using overnight continuous pulse oximetry data to guide management of infants with chronic neonatal lung disease (CNLD); (ii) to assess the ability of paediatric clinicians to interpret overnight continuous pulse oximetry data; and (iii) to describe the overnight oximetry interpretation practices of paediatric respiratory specialists. METHODS: Paediatric clinicians from three tertiary teaching hospitals completed an anonymous survey regarding overnight continuous pulse oximetry in chronic neonatal lung disease. Using a modified Delphi technique, paediatric respiratory specialists participated in a concordance exercise and discussions to establish consensus interpretations for 25 oximetry studies. Paediatric clinicians were invited to complete the same exercise as a comparison. RESULTS: Self-rated knowledge from 74 surveyed clinicians was proportional to clinical experience. Twenty paediatric clinicians and nine paediatric respiratory specialists completed the oximetry exercise with scores of 64% (κ = 0.25) and 80% (κ = 0.45), respectively. Individual parameters like a mean peripheral arterial haemoglobin saturation (SpO2 ) below 93% and percentage time spent below SpO2 93% correlated poorly with the consensus interpretations. Paediatric respiratory specialists instead relied on visual analysis of SpO2 waveforms, utilising the frequency and depth of desaturations to guide management. CONCLUSION: Interpretation of overnight oximetry data is variable amongst both paediatric clinicians and respiratory specialists. This likely reflects inadequate evidence defining clinically significant intermittent hypoxaemia, whether in terms of desaturation duration, frequency or nadir.