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Hematopoietic stem cell transplantation (HSCT) is undertaken in children with the aim of curing a range of malignant and nonmalignant conditions. Unfortunately, pulmonary complications, especially bronchiolitis obliterans syndrome (BOS), are significant sources of morbidity and mortality post-HSCT. Currently, criteria developed by a National Institutes of Health (NIH) working group are used to diagnose BOS in children post-HSCT. Unfortunately, during the development of a recent American Thoracic Society (ATS) Clinical Practice Guideline on this topic, it became apparent that the NIH criteria have significant limitations in the pediatric population, leading to late diagnosis of BOS. Specific limitations include use of an outdated pulmonary function testing reference equation, a reliance on spirometry, use of a fixed forced expiratory volume in 1 second (FEV 1 ) threshold, focus on obstructive defects defined by FEV 1 /vital capacity, and failure to acknowledge that BOS and infection can coexist. In this review, we summarize the evidence regarding the limitations of the current criteria. We also suggest potential evidence-based ideas for improving these criteria. Finally, we highlight a new proposed criteria for post-HSCT BOS in children that were developed by the authors of the recently published ATS clinical practice guideline, along with a pathway forward for improving timely diagnosis of BOS in children post-HSCT., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Our objective was to update a clinical practice guideline for the prevention and treatment of Clostridioides difficile infection (CDI) in pediatric patients with cancer and hematopoietic cell transplantation recipients. We reconvened an international multi-disciplinary panel. A systematic review of randomized controlled trials (RCTs) for the prevention or treatment of CDI in any population was updated and identified 31 new RCTs. Strong recommendations were made to use either oral metronidazole or oral vancomycin for non-severe CDI treatment, and to use either oral vancomycin or oral fidaxomicin for severe CDI. A strong recommendation that fecal microbiota transplantation should not be routinely used to treat CDI was also made. The panel made two new good practice statements to follow infection control practices including isolation in patients experiencing CDI, and to minimize systemic antibacterial administration where feasible, especially in patients who have experienced CDI., Competing Interests: BTF has served on a data safety monitoring board for Astellas and BTF's institution has received grant support from Allovir and Pfizer as well as CDC, FDA and NIH for research performed. CD has received support from Abramson Cancer Center K12 and a CIHR Fellowship Award. TL's institution has received an unrestricted research grant by Gilead Sciences and TL has received payments or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from: Astra Zeneca, EUSA Pharma, Gilead Sciences, MSD/Merck and Pfizer. TL has received support for attending meetings and/or travel from EUSA Pharma and has served on a data safety monitoring board or advisory board for: EUSA Pharma, Gilead Sciences, Merck/MSD, Mundipharma, Pfizer and Pharming. TL has had a leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid at: Working Party Infection German Society of Pediatric Oncology and Hematology and Working Party Infection German Society of Pediatric Infectious Diseases. LS is supported by the Canada Research Chair in Pediatric Oncology Supportive Care. No other authors declared a conflict of interest., (© 2024 The Author(s).)

Background: Cystic fibrosis (CF) lung disease starts in infancy and can be assessed for structural lung abnormalities using computed tomography or magnetic resonance scans, or for lung function impairment using multiple breath washout (MBW). However, in infancy these two methods are not well correlated. Trajectories of CF lung disease assessed by MBW in infants and toddlers remain poorly described, which is why we aimed to 1) describe the trajectory of lung function, 2) explore risk factors for progression and 3) explore the real-life effect of lumacaftor/ivacaftor., Methods: This was a nationwide observational cohort study (2018-2021) using data collected as part of the routine clinical surveillance programme (including MBW and monthly endo-laryngeal suction sampling for bacterial pathogens) in children born after implementation of newborn screening for CF (May 2016). Lumacaftor/ivacaftor commenced from age 2 years in children homozygous for F508del. Ventilation distribution efficiency (VDE), recently described to have advantages over lung clearance index (LCI), was reported as the primary MBW outcome after z-score calculations based on published reference data. Mixed effect linear regression models were the main statistical analyses performed in this study., Results: 59 children, aged 2-45 months, contributed with 211 MBW occasions (median (interquartile range (IQR)) 3 (2-5) MBW occasions per child) with a median (IQR) follow-up time of 10.8 (5.2-22.3) months. An overall mean annual deterioration rate of -0.50 (95% CI -0.78- -0.22) z-VDE was observed, starting from an estimated mean z-VDE of -1.68 (95% CI -2.15- -1.22) at age 0.0 years (intercept). Pseudomonas aeruginosa "ever" (n=14, MBWs 50) had a significantly worse z-VDE trajectory versus P. aeruginosa "never" (mean difference 0.53 (95% CI 0.16-0.89) per year; p=0.0047) and lumacaftor/ivacaftor treatment (n=22, MBWs 46) significantly improved the trajectory of z-VDE (mean difference 1.72 (95% CI 0.79-2.66) per year; p=0.0004), leading to a stable mean z-VDE trajectory after start of treatment., Conclusions: Infants and toddlers with CF demonstrated progressive deterioration in z-VDE over the first years of life. P. aeruginosa isolation "ever" was associated with an accelerated deterioration in lung function, while lumacaftor/ivacaftor therapy significantly improved and stabilised the trajectory., Competing Interests: Conflict of interest: None of the authors have personal financial relationships with any organisations that might have an interest in the submitted work., (Copyright ©The authors 2023.)

Objective was to update a clinical practice guideline (CPG) for the management of fatigue in children and adolescents with cancer or pediatric hematopoietic cell transplant recipients. We reconvened a multi-disciplinary and multi-national panel. While the previous 2018 CPG evaluated adult and pediatric randomized controlled trials (RCTs) to manage fatigue, this 2023 update revised previous recommendations based only on pediatric RCTs. Twenty RCTs were included in the updated systematic review. Physical activity significantly reduced fatigue (standardized mean difference -0.44, 95% confidence interval -0.64 to -0.24; n = 8 RCTs). Using the 2018 recommendations as a basis, the panel continued to make strong recommendations to use physical activity, and to offer relaxation, mindfulness or both, to manage fatigue in pediatric patients. Cognitive or cognitive behavioral therapies may be offered. Pharmacological approaches should not be routinely used. The panel made a new good practice statement to routinely assess for fatigue, ideally using a validated scale., Competing Interests: PSH received grants or research support from NIH; royalties or licenses from Lippincott; consulting fees from MSKCC and participated on the REACH Board at Nemours, Delaware. SNCR received grants from CIHR, CCS and Kids Cancer Care-IMPACT. LS is supported by the Canada Research Chair in Pediatric Oncology Supportive Care. No other authors declared a conflict of interest., (© 2023 The Author(s).)

Mycobacterium abscessus is a nontuberculous mycobacterium (NTM) of particular concern in individuals with obstructive lung diseases such as cystic fibrosis (CF). Treatment requires multiple drugs and is characterised by high rates of relapse; thus, new strategies to limit infection are urgently required. This study sought to determine how Bacille Calmette-Guérin (BCG) vaccination may impact NTM infection, using a murine model of Mycobacterium abscessus infection and observational data from a non-BCG vaccinated CF cohort in Sydney, Australia and a BCG-vaccinated CF cohort in Cape Town, South Africa. In mice, BCG vaccination induced multifunctional antigen-specific CD4 + T cells circulating in the blood and was protective against dissemination of bacteria to the spleen. Prior infection with M. abscessus afforded the highest level of protection against M. abscessus challenge in the lung, and immunity was characterised by a greater frequency of pulmonary cytokine-secreting CD4 + T cells compared to BCG vaccination. In the clinical CF cohorts, the overall rates of NTM sampling during a three-year period were equivalent; however, rates of NTM colonisation were significantly lower in the BCG-vaccinated (Cape Town) cohort, which was most apparent for M. abscessus . This study provides evidence that routine BCG vaccination may reduce M. abscessus colonisation in individuals with CF, which correlates with the ability of BCG to induce multifunctional CD4 + T cells recognising M. abscessus in a murine model. Further research is needed to determine the optimal strategies for limiting NTM infections in individuals with CF.

Pulmonary chronic graft- versus -host disease (cGVHD) is a substantial cause of pulmonary morbidity and mortality post-haematopoietic stem cell transplantation (HSCT). Current spirometry-based monitoring strategies have significant limitations. Understanding the utility of novel peripheral airway function tests - multiple breath washout (MBW) and oscillometry - is critical in efforts to improve detection, facilitate earlier intervention and improve outcomes. In this scoping review, we identified 17 studies investigating MBW or oscillometry, or both, after allogenic HSCT. Despite small study numbers limiting the ability to draw firm conclusions, several themes were evident. Detectable peripheral airway abnormality in MBW occurred in a substantial proportion prior to HSCT. MBW indices post-HSCT were more frequently abnormal than spirometry when reporting group data and among those with extrapulmonary cGVHD and pulmonary cGVHD. Changes in MBW indices over time may be more indicative of pulmonary complications than absolute values at any given time point. Oscillometry indices were often normal at baseline, but more frequently abnormal in those who developed pulmonary cGVHD. Pooling currently available individual participant data across these studies may improve our ability to formally compare their respective sensitivity and specificity at specific time points and assess the trajectory of MBW and oscillometry indices over time., Competing Interests: Conflict of interest: N. Sonneveld has nothing to disclose. Conflict of interest: J.H. Rayment has nothing to disclose. Conflict of interest: J. Usemann has nothing to disclose. Conflict of interest: K.G. Nielsen has nothing to disclose. Conflict of interest: P.D. Robinson has nothing to disclose., (Copyright ©The authors 2023.)

Sensor errors resulting in elevated values of N 2 concentration [N 2 ] in commercial multiple-breath washout (MBW) devices have been shown to prolong the washout and result in erroneously high functional residual capacity (FRC) and lung clearance index (LCI) values. The errors also affect the indices of conductive and acinar ventilatory heterogeneity ( S cond and S acin ) although the mechanism by which this change in values occurs remains unclear. Exploring these effects also provides a timely opportunity to examine the appropriateness of the algorithm used to calculate these indices. Using a two-compartment model with differing specific ventilation (SV) such that the lower SV unit empties late, noise-free MBW were simulated both corrected and uncorrected for the recent sensor error. S cond was calculated using regression of normalized phase III slope (Sn III ) against lung turnover (TO) from a TO range starting at 1.5 and ending at an upper turnover (TO upper ) between 4 and 8 (default 6) over a range of simulated values. The principal effect of the sensor error was that as the MBW proceeded the phase III slope of successive breaths was normalized by an increasingly overestimated [N 2 ], resulting in Sn III values that fell precipitously at high TO, greatly reducing S cond . Reanalysis of previously published data and of simulated data showed a large proportional bias in S cond , whereas S acin was only minimally affected. In adult subject data, reducing TO upper below 5.5 was associated with a large drop of up to ∼60% in S cond calculated from data corrected for sensor error. Raising the upper TO limit elevated S cond by ∼20% but with a large concomitant increase in variability. In contrast to S cond , S acin was relatively unaffected by changes in TO upper with changes of <3%. This work serves to emphasize that the upper limit of TO of 6 represents an appropriate upper limit for the calculation of S cond . NEW & NOTEWORTHY Sensor errors that elevated values of N 2 concentration in commercial multiple-breath washout (MBW) devices resulted in errors in calculated parameters including S cond and S acin . We examined the mechanism of the change in values produced by these errors and explored the appropriateness of the calculation of S cond and S acin . This work serves to emphasize that the current algorithm in use is appropriate for the calculation of S cond and S acin .

Previous studies suggest that infants with Robin sequence show a pattern of steady improvement in the severity of airway obstruction, and of their treatment requirements, during infancy., Methods: Three infants with Robin sequence and severe obstructive sleep apnea were managed with nasal continuous positive airways pressure (CPAP). Multiple measures of airway obstruction were made during infancy, including CPAP pressure evaluations and sleep studies (screening and polysomnography studies). Parameters reported include obstructive apnea-hypopnea index, oxygen desaturation parameters, and CPAP pressures required for effective airway management., Results: CPAP pressure requirements increased in all three infants during their first weeks of life. Apnea indices on polysomnography did not track with the CPAP pressure requirements. Peak pressure requirements were at 5 and 7 weeks for two patients, with subsequent gradual decline and cessation of therapy CPAP at 39 and 74 weeks, respectively. The third patient had a complicated course, jaw distraction at 17 weeks, and biphasic CPAP pressure requirement (first peak at 3 weeks, but maximum pressure at 74 weeks), with cessation of CPAP at 75 weeks., Conclusions: The observed pattern of early increases in CPAP pressure requirements for infants with Robin sequence adds to the complexities of managing this disorder. Factors that may lead to this pattern of change in airway obstruction are discussed., (Copyright © 2023 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons.)

Objective: To develop a summary format of clinical practice guideline (CPG) recommendations to improve understandability among health care professionals., Methods: We developed a summary format based on current research and used the "Think Aloud" technique in one-on-one cognitive interviews to iteratively improve it. Interviews of health care professionals from Children's Oncology Group-member, National Cancer Institute Community Oncology Research Program sites were conducted. After every five interviews (a round), responses were reviewed, and changes made to the format until it was well understood and no new, substantive suggestions for revision were raised. We took a directed (deductive) approach to content analysis of the interview notes to identify concerns related to recommendation summary usability, understandability, validity, applicability and visual appeal., Results: During seven rounds of interviews with 33 health care professionals, we identified important factors that influenced understandability. Participants found understanding weak recommendations more challenging than strong recommendations. Understanding was improved when the term 'conditional' recommendation was used instead of 'weak' recommendation. Participants found a Rationale section to be very helpful but desired more information when a recommendation entailed a practice change. In the final format, the recommendation strength is clearly indicated in the title, highlighted, and defined within a text box. The rationale for the recommendation is in a column on the left, with supporting evidence on the right. In a bulleted list, the Rationale section describes the benefits and harms and additional factors, such as implementation, that were considered by the CPG developers. Each bullet under the supporting evidence section indicates the level of evidence with an explanation and the supporting studies with hyperlinks when applicable., Conclusions: A summary format to present strong and conditional recommendations was created through an iterative interview process. The format is straightforward, making it easy for organizations and CPG developers to use it to communicate recommendations clearly to intended users., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Santesso et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Pneumonia is the number one cause of disease and deaths in children under five years old, outside the neonatal period, with the greatest number of cases reported from resource-limited settings. The etiology is variable, with not much information on the local etiology drug resistance profile in many countries. Recent studies suggest an increasing contribution from respiratory viruses, also in children with severe pneumonia, with an increased relative contribution in settings that have good vaccine coverage against common bacterial pathogens. Respiratory virus circulation was greatly reduced during highly restrictive measures to contain the spread of COVID-19 but rebounded once COVID-19 restrictions were relaxed. We conducted a comprehensive literature review of the disease burden, pathogens, case management and current available prevention of community acquired childhood pneumonia, with a focus on rational antibiotic use, since the treatment of respiratory infections is the leading cause of antibiotic use in children. Consistent application of revised World Health Organisation (WHO) guidance that children presenting with coryzal symptoms or wheeze can be managed without antibiotics in the absence of fever, will help to reduce unnecessary antibiotic use, as will increased availability and use of bedside inflammatory marker tests, such as C-reactive protein (CRP) in children with respiratory symptoms and fever., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Nguyen, Robinson, Fitzgerald and Marais.)

Cystic fibrosis (CF) lung disease is characterized by increased ventilation inhomogeneity (VI), as measured by multiple-breath washout (MBW). Lung clearance index (LCI) is the most reported VI outcome. This study aimed to evaluate historically published reference equations for sulfur hexafluoride (SF 6 ) MBW outcomes, to data collected using updated commercial SF 6 MBW equipment, and to produce device-specific equations if necessary. SF 6 MBW was performed in 327 healthy children aged 0.1-18.4 yr [151 (46%) girls], 191 (58.4%) <3 yr. z-Scores were calculated from published reference equations (FRC and LCI) and multivariate linear regression was performed to produce device-specific reference equations. Due to increasing residual standard deviations with increasing LCI values, investigation of methods for improvement were investigated, based on the relationship between VI and dead space ventilation (VD/VT; dead space volume/tidal volume) in a cohort of 59 healthy children, 26 children with CF ( n = 138 test occasions), and 49 adults with lung disease. Historical SF 6 MBW reference equations were unsuitable for EXHALYZER D data. In contrast to LCI and log 10 (LCI), 1/LCI (ventilation distribution efficiency; VDE) was linearly related to VD/VT, with z-scores linearly related to its absolute values. Reference equations were reported for VDE and log 10 (FRC). Significant predictors for VDE and log 10 (FRC), respectively, were log 10 (age) and sex, and log 10 (height), sex, and posture. VDE is potentially a better index of VI than LCI, particularly in more advanced CF lung disease and also for longitudinal monitoring. Further confirmatory clinical studies, particularly longitudinal imaging studies of structural or ventilatory changes, are warranted. NEW & NOTEWORTHY Lung clearance index (LCI) is the most used outcome from the multiple-breath washout test. As known for decades, the LCI is not linearly related to dead space ventilation, giving difficulties interpreting changes over time and in clinical trials. We present a new and improved outcome based on LCI, the ventilation distribution efficiency (VDE), which solves this problem by being linearly related to dead space ventilation. A pediatric age range reference equation for VDE is presented.

The small size and large surface area of ultrafine particles (UFP) enhance their ability to deposit in the lung periphery and their reactivity. The Ultrafine Particles from Traffic Emissions and Children's Health (UPTECH) cross-sectional study was conducted in 8-11-year-old schoolchildren attending 25 primary (elementary) schools, randomly selected from the Brisbane Metropolitan Area, Queensland, Australia. Main study findings outlined indirect evidence of distal airway deposition (raised C reactive protein) but as yet, there is no direct evidence in the literature of effects of UFP exposure on peripheral airway function. We present further UPTECH study data from two sensitive peripheral airway function tests, Oscillometry and Multiple Breath Nitrogen Washout (MBNW), performed in 577 and 627 children (88% and 96% of UPTECH study cohort) respectively: mean(SD) age 10.1(0.9) years, 46% male, with 50% atopy and 14% current asthma. Bayesian generalised linear mixed effects regression models were used to estimate the effect of UFP particle number count (PNC) exposure on key oscillometry (airway resistance, (Rrs), and reactance, (Xrs)) and MBNW (lung clearance index, (LCI) and functional residual capacity, (FRC)) indices. We adjusted for age, sex, and height, and potential confounders including socio-economic disadvantage, PM 2.5 and NO 2 exposure. All models contained an interaction term between UFP PNC exposure and atopy, allowing estimation of the effect of exposure on non-atopic and atopic students. Increasing UFP PNC was associated with greater lung stiffness as evidenced by a decrease in Xrs [mean (95% credible interval) -1.63 (-3.36 to -0.05)%] per 1000#.cm -3 ]. It was also associated with greater lung stiffness (decrease in Xrs) in atopic subjects across all models [mean change ranging from -2.06 to -2.40% per 1000#.cm -3 ]. A paradoxical positive effect was observed for Rrs across all models [mean change ranging from -1.55 to -1.70% per 1000#.cm -3 ] (decreases in Rrs indicating an increase in airway calibre), which was present for both atopic and non-atopic subjects. No effects on MBNW indices were observed. In conclusion, a modest detrimental effect of UFP on peripheral airway function among atopic subjects, as assessed by respiratory system reactance, was observed extending the main UPTECH study findings which reported a positive association with a biomarker for systemic inflammation, C-reactive protein (CRP). Further studies are warranted to explore the pathophysiological mechanisms underlying increased respiratory stiffness, and whether it persists through to adolescence and adulthood., (Copyright © 2022. Published by Elsevier Inc.)

Introduction: The multiple breath nitrogen washout (MBNW) test provides important clinical information in obstructive airways diseases. Recently, a significant cross-sensitivity error in the O 2 and CO 2 sensors of a widely used commercial MBNW device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) was detected, which leads to overestimation of N 2 concentrations. Significant errors in functional residual capacity (FRC) and lung clearance index (LCI) have been reported in infants and children. This study investigated the impact in adults, and on additional important indices reflecting conductive ( S cond ) and acinar ( S acin ) ventilation heterogeneity, in health and disease., Methods: Existing MBNW measurements of 27 healthy volunteers, 20 participants with asthma and 16 smokers were reanalysed using SPIROWARE V 3.3.1, which incorporates an error correction algorithm. Uncorrected and corrected indices were compared using paired t-tests and Bland-Altman plots., Results: Correction of the sensor error significantly lowered FRC (mean difference 9%) and LCI (8-10%) across all three groups. S cond was higher following correction (11%, 14% and 36% in health, asthma and smokers, respectively) with significant proportional bias. S acin was significantly lower following correction in the asthma and smoker groups, but the effect was small (2-5%) and with no proportional bias., Discussion: The O 2 and CO 2 cross-sensitivity sensor error significantly overestimated FRC and LCI in adults, consistent with data in infants and children. There was a high degree of underestimation of S cond but minimal impact on S acin . The presence of significant proportional bias indicates that previous studies will require reanalysis to confirm previous findings and to allow comparability with future studies., Competing Interests: Conflict of interest: No conflicts of interest, financial or otherwise, relating to this study are declared by the authors., (Copyright ©The authors 2022.)

Competing Interests: Declaration of Competing Interest Ms Jensen, Mr Seeto, Dr Stanojevic and Dr Ratjen report other from Vertex Pharmaceuticals and grants (#SHIP14K0) from the CF Foundation during the conduct of the study. Ms Saunders and Mr Short report other from Vertex Pharmaceuticals and ECFS CTN during the conduct of the study. Dr. Robinson reports other from Vertex Pharmaceuticals Ltd during the conduct of the study. Dr. Davies reports other from Algipharma AS, other from Bayer AG, other from Boehringer Ingelheim Pharma GmbH & Co. KG, other from Galapagos NV, other from ImevaX GmbH, other from Nivalis Therapeutics, Inc., other from ProQR Therapeutics III B.V., other from Proteostasis Therapeutics, INC., other from Raptor Pharmaceuticals, Inc, other from Vertex Pharmaceuticals (Europe) Limited, other from Enterprise, other from Novartis, other from Pulmocide, other from Flatley, other from Nivalis Therapeutics Inc., grants from CF Trust, other from Teva, outside the submitted work.

Recently, "Technical standards for respiratory oscillometry" was published, which reviewed the physiological basis of oscillometric measures and detailed the technical factors related to equipment and test performance, quality assurance and reporting of results. Here we present a review of the clinical significance and applications of oscillometry. We briefly review the physiological principles of oscillometry and the basics of oscillometry interpretation, and then describe what is currently known about oscillometry in its role as a sensitive measure of airway resistance, bronchodilator responsiveness and bronchial challenge testing, and response to medical therapy, particularly in asthma and COPD. The technique may have unique advantages in situations where spirometry and other lung function tests are not suitable, such as in infants, neuromuscular disease, sleep apnoea and critical care. Other potential applications include detection of bronchiolitis obliterans, vocal cord dysfunction and the effects of environmental exposures. However, despite great promise as a useful clinical tool, we identify a number of areas in which more evidence of clinical utility is needed before oscillometry becomes routinely used for diagnosing or monitoring respiratory disease., Competing Interests: Conflict of interest: D.A. Kaminsky reports personal payments made as faculty speaker for Cardiorespiratory Diagnostics Seminar from MGC Diagnostics, Inc. outside the submitted work. Past Chair of ATS Proficiency Standards for Pulmonary Function Laboratories Committee, unpaid. Conflict of interest: S.J. Simpson has nothing to disclose. Conflict of interest: K.I. Berger has nothing to disclose. Conflict of interest: P. Calverley reports receiving consulting fees paid by Phillips Respironics for advisory work on a novel COPD ventilator. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from Phillips Respironics, outside the submitted work. Conflict of interest: P.L. de Melo reports patent 28727 issued. Conflict of interest: R.J. Dandurand reports grants or contracts paid to the institution from AstraZeneca, Boehringer-Ingelheim, Covis Pharma, Grifols, MGC Diagnostics, Teva Pharma, Thorasys, and Vyaire, outside the submitted work. Speaking payment from Novartis for L'oscillométrie en clinique: qu'ajoute-t-elle aux évaluations pulmonaires?, 18 September 2019, Boehringer-Ingelheim for L'oscillométrie: vieille physiologie avec un avenir brilliant, 17 November 2020, and Latin American Respiratory Physiology Society for Oscillometry in Asthma and COPD: Interpretation Strategies, 14 November 2020, outside the submitted work. Chairman, Oscillometry Harmonisation Study Group, an international committee academic and industry experts working to standardise oscillometry devices, and Chairman, Respiratory Effectiveness Group Technologies Working Group, Cambridge, U.K. (https://www.regresearchnetwork.org). Conflict of interest: R.L. Dellacà reports royalties or licenses from Restech, Philips and Vyaire. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from Restech and Philips, outside the submitted work. Support for attending meetings from Philips and Vyaire. Patent issued, owned and licensed from Politecnico di Milano University. Member of the Board of Directors for Restech. Stocks owned for Restech. Free loan of equipment for studies received from Vyaire and Restech. Conflict of interest: C.S. Farah has nothing to disclose. Conflict of interest: R. Farré has nothing to disclose. Conflict of interest: G.L. Hall has nothing to disclose. Conflict of interest: I. Ioan has nothing to disclose. Conflict of interest: C.G. Irvin received consulting fees from Medical Graphics Corporation, outside the submitted work. Conflict of interest: D.W. Kaczka reports support for the present manuscript from University of Iowa. Grants or contracts from Dept of Defence and NIH, outside the submitted work. Consulting fees received from ZOLL Medical, Inc. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from CHEST, ASME, Medical Society of New Zealand, and Johns Hopkins University, outside the submitted work. US patent 10,675,423 B2 (patent on MFOV technique, inventor) and PCT patent pending, patent on MFOV technique pending. Stock or stock options held for OscillaVent, Inc. Loan of ventilator for other projects from ZOLL Medical Inc. Conflict of interest: G.G. King reports grants or contracts from Restech Italy, NHMRC, Boehringer Ingelheim, CycloPharm, GlaxoSmithKline, Menarini, MundiPharma, Philanthropic individuals and societies, outside the submitted work. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from AstraZeneca, Boehringer Ingelheim, Chiesi, Cipla, CycloPharm, GlaxoSmithKline, Menarini, MundiPharma and Novartis, outside the submitted work. Leadership or fiduciary role in other board, society, committee or advocacy group for ERS Technical Standards for Respiratory Oscillometry. Conflict of interest: H. Kurosawa reports receiving a grant from CHEST Co. Ltd. Royalties or licence for CHEST Co. Ltd. Payment or honoraria for lectures received from CHEST Co. Ltd. Nippon, Boehringer Ingelheim, Novartis, and Teijin Pharma, outside the submitted work. Conflict of interest: E. Lombardi reports grants or contracts from Restech and Sanofi, outside the submitted work. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from Angelini, Chiesi, GSK, Novartis and Sanofi, outside the submitted work. Participation on a Data Safety Monitoring Board or Advisory Board for GSK and Novartis. Conflict of interest: G.N. Maksym reports grants or contracts from National Research Council of Canada, Cyclomedica Inc. Australia, and Lung Association of Nova Scotia, outside the submitted work. Accommodation Expenses received from Thorasys, Thoracic Medical Systems Inc. for attending European Society Meeting 2019. Patents planned, issued or pending for Method and system to acquire oscillometry measurements, owned by Thorasys, Thoracic Medical Systems Inc. Stock or stock options held for Thorasys, Thoracic Medical Systems Inc. Conflict of interest: F. Marchal has nothing to disclose. Conflict of interest: E. Oostveen has nothing to disclose. Conflict of interest: B.W. Oppenheimer has nothing to disclose. Conflict of interest: P.D. Robinson has nothing to disclose. Conflict of interest: M. van den Berge reports grants or contracts from GlaxoSmithKline, Novartis, Astra Zeneca, Roche, and Genentech, outside the submitted work. Conflict of interest: C. Thamrin report grants or contracts from Restech SRL and THORASYS Thoracic. Equipment on loan for research studies from Restech SRL and THORASYS Thoracic, outside the submitted work., (Copyright ©The authors 2022.)

Background: Adding a slow vital capacity (SVC) to multiple breath washout (MBW) allows quantification of otherwise overlooked signal from under/un-ventilated lung units (UVLU) and may provide a more comprehensive assessment of airway disease than conventional lung clearance index (LCI 2.5 )., Methods: We conducted a pilot study on people undergoing MBW tests: 10 healthy controls (HC) and 43 cystic fibrosis (CF) subjects performed an SVC after the standard end of test. We term the new outcome LCI with Short extension (LCI ShX ). We assessed (i) CF/ HC differences, (ii) variability (iii) effect of pulmonary exacerbation (PEx)/treatment and (iv) relationship with CF computed tomography (CFCT) scores., Results: HC/ CF group differences were larger with LCI ShX than LCI 2.5 (P<0.001). Within the CF group UVLU was highly variable and when abnormal it did not correlate with corresponding LCI 2.5 . Signal showed little variability during clinical stability (n = 11 CF; 2 visits; median inter-test variability 2.6% LCI ShX, 2.5% LCI 2.5 ). PEx signal was significantly greater for LCI ShX both for onset and resolution. Both MBW parameters correlated significantly with total lung CT scores and hyperinflation but only LCI ShX correlated with mucus plugging., Conclusions: UVLU captured within the LCI ShX varies between individuals; the lack of relationship with LCI 2.5 demonstrates that new, additional information is being captured. LCI ShX repeatability during clinical stability combined with its larger signal around episodes of PEx may lend it superior sensitivity as an outcome measure. Further studies will build on this pilot data to fully establish its utility in monitoring disease status., Competing Interests: Declaration of Competing Interest Christopher Short, Clare Saunders, Dominic Hughes, Samantha Irving, Laura Gardener, Mark Rosenthal and Paul Robinson report no conflicts of interest. Thomas Semple reports speakers fees - Vertex Pharmaceuticals. Research grants – Chiesi Pharmaceuticals. Consultancy fees - Boehringer-Ingelheim and Calyx. Prof. Jane Davies has performed clinical trial leadership roles, educational and/ or advisory activities for the following: Abbvie, Algipharma AS, Bayer AG, Boehringer Ingelheim Pharma GmbH & Co. KG, Eloxx, Enterprise, Galapagos NV, ImevaX GmbH, Ionis, Nivalis Therapeutics, Inc., Novartis, ProQR Therapeutics III B.V., Proteostasis Therapeutics, INC., Pulmocide Raptor Pharmaceuticals, Inc, Vertex Pharmaceuticals., (Copyright © 2021. Published by Elsevier B.V.)

The lack of comparability in indices of ventilation heterogeneity between free- and controlled-breathing MBNW protocols is confirmed in asthma https://bit.ly/3lmri4A., Competing Interests: Provenance: Submitted article, peer reviewed. Conflicts of interest: B.M. Handley has nothing to disclose. Conflicts of interest: J. Bozier has nothing to disclose. Conflicts of interest: E. Jeagal has nothing to disclose. Conflicts of interest: S. Rutting has nothing to disclose. Conflicts of interest: R.E. Schoeffel has nothing to disclose. Conflicts of interest: P.D. Robinson has nothing to disclose. Conflicts of interest: G.G. King reports fees for consultancy services, conference attendance support and unrestricted research grants from AstraZeneca, Boehringer Ingelheim, CycloPharm, GlaxoSmithKline, Novartis, Menarini, MundiPharma. G.G. King also reports NHMRC research grants and fellowships. Conflicts of interest: S. Milne has nothing to disclose. Conflicts of interest: C. Thamrin reports supply of equipment for an unrelated study from Restech SRL. C. Thamrin also reports funded research collaboration for an unrelated project., (Copyright ©The authors 2021.)

Background: Clinical practice guideline (CPG)-consistent care improves patient outcomes, but CPG implementation is poor. Little is known about CPG implementation in pediatric oncology. This study aimed to understand supportive care CPG implementation facilitators and barriers at pediatric oncology National Cancer Institute (NCI) Community Oncology Research Program (NCORP) institutions., Methods: Healthcare professionals at 26 pediatric, Children's Oncology Group-member, NCORP institutions were invited to participate in face-to-face focus groups. Serial focus groups were held until saturation of ideas was reached. Supportive care CPG implementation facilitators and barriers were solicited using nominal group technique (NGT), and implementation of specific supportive care CPG recommendations was discussed. Notes from each focus group were analyzed using a directed content analysis. The top five themes arising from an analysis of NGT items were identified, first from each focus group and then across all focus groups., Results: Saturation of ideas was reached after seven focus groups involving 35 participants from 18 institutions. The top five facilitators of CPG implementation identified across all focus groups were organizational factors including charging teams with CPG implementation, individual factors including willingness to standardize care, user needs and values including mentorship, system factors including implementation structure, and implementation strategies including a basis in science. The top five barriers of CPG implementation identified were organizational factors including tolerance for inconsistencies, individual factors including lack of trust, system factors including administrative hurdles, user needs and values including lack of inclusivity, and professional including knowledge gaps., Conclusions: Healthcare professionals at pediatric NCORP institutions believe that organizational factors are the most important determinants of supportive care CPG implementation. They believe that CPG-consistent supportive care is most likely to be delivered in organizations that prioritize evidence-based care, provide structure and resources to implement CPGs, and eliminate implementation barriers., Trial Registration: ClinicalTrials.gov Identifier: NCT02847130. Date of registration: July 28, 2016., (© 2021. The Author(s).)

Objective: Offspring born to mothers with asthma in pregnancy are known to have lower lung function which tracks with age. Human group 2 innate lymphoid cells (ILC2) accumulate in foetal lungs, at 10-fold higher levels compared to adult lungs. However, there are no data on foetal ILC2 numbers and the association with respiratory health outcomes such as lung function in early life. We aimed to investigate cord blood immune cell populations from babies born to mothers with asthma in pregnancy., Methods: Cord blood from babies born to asthmatic mothers was collected, and cells were stained in whole cord blood. Analyses were done using traditional gating approaches and computational methodologies (t-distributed stochastic neighbour embedding and PhenoGraph algorithms). At 6 weeks of age, the time to peak tidal expiratory flow as a percentage of total expiratory flow time (tPTEF/tE%) was determined as well as Lung Clearance Index (LCI), during quiet natural sleep., Results: Of 110 eligible infants (March 2017 to November 2019), 91 were successfully immunophenotyped (82.7%). Lung function was attempted in 61 infants (67.0%), and 43 of those infants (70.5% of attempted) had technically acceptable tPTEF/tE% measurements. Thirty-four infants (55.7% of attempted) had acceptable LCI measurements. Foetal ILC2 numbers with increased expression of chemoattractant receptor-homologous molecule (CRTh2), characterised by two distinct analysis methodologies, were associated with poorer infant lung function at 6 weeks of age.", Conclusion: Foetal immune responses may be a surrogate variable for or directly influence lung function outcomes in early life., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors. Clinical & Translational Immunology published by John Wiley & Sons Australia, Ltd on behalf of Australian and New Zealand Society for Immunology, Inc.)

Due to climate change, bushfires are becoming a more frequent and more severe phenomenon which contributes to poor health effects associated with air pollution. In pregnancy, environmental exposures can have lifelong consequences for the fetus, but little is known about these consequences in the context of bushfire smoke exposure. In this review we summarise the current knowledge in this area, and propose a potential mechanism linking bushfire smoke exposure in utero to poor perinatal and respiratory outcomes in the offspring. Bushfire smoke exposure is associated with poor pregnancy outcomes including reduced birth weight and an increased risk of prematurity. Some publications have outlined the adverse health effects on young children, particularly in relation to emergency department presentations and hospital admissions for respiratory problems, but there are no studies in children who were exposed to bushfire smoke in utero. Prenatal stress is likely to occur as a result of catastrophic bushfire events, and stress is known to be associated with poor perinatal and respiratory outcomes. Changes to DNA methylation are potential epigenetic mechanisms linking both smoke particulate exposure and prenatal stress to poor childhood respiratory health outcomes. More research is needed in large pregnancy cohorts exposed to bushfire events to explore this further, and to design appropriate mitigation interventions, in this area of global public health importance.

Recent studies indicate limited utility of nitrogen multiple-breath washout (N 2 MBW) in infancy and advocate for using sulfur hexafluoride (SF 6 ) MBW in this age-group. Modern N 2 MBW systems, such as EXHALYZER D (ECO MEDICS AG, Duernten, Switzerland), use O 2 and CO 2 sensors to calculate N 2 concentrations (in principle, N 2 % = 100 - CO 2 % - O 2 %). High O 2 and CO 2 concentrations have now been shown to significantly suppress signal output from the other sensor, raising apparent N 2 concentrations. We examined whether improved EXHALYZER D N 2 signal, accomplished after thorough examination of this CO 2 and O 2 interaction on gas sensors and its correction, leads to better agreement between N 2 MBW and SF 6 MBW in healthy infants and toddlers. Within the same session, 52 healthy children aged 1-36 mo [mean = 1.30 (SD = 0.72) yr] completed SF 6 MBW and N 2 MBW recordings (EXHALYZER D, SPIROWARE version 3.2.1) during supine quiet sleep. SF 6 and N 2 SPIROWARE files were reanalyzed offline with in-house software using identical algorithms as in SPIROWARE with or without application of the new correction factors for N 2 MBW provided by ECO MEDICS AG. Applying the improved N 2 signal significantly reduced mean [95% confidence interval (CI)] differences between N 2 MBW and SF 6 MBW recorded functional residual capacity (FRC) and lung clearance index (LCI): for FRC, from 26.1 (21.0, 31.2) mL, P < 0.0001, to 1.18 (-2.3, 4.5) mL, P = 0.5, and for LCI, from 1.86 (1.68, 2.02), P < 0.001, to 0.44 (0.33, 0.55), P < 0.001. Correction of N 2 signal for CO 2 and O 2 interactions on gas sensors resulted in markedly closer agreement between N 2 MBW and SF 6 MBW outcomes in healthy infants and toddlers. NEW & NOTEWORTHY Modern nitrogen multiple-breath washout (N 2 MBW) systems such as EXHALYZER D use O 2 and CO 2 sensors to calculate N 2 concentrations. New corrections for interactions between high O 2 and CO 2 concentrations on the gas sensors now provide accurate N 2 signals. The correct N 2 signal led to much improved agreement between N 2 MBW and sulfur hexafluoride (SF 6 ) MBW functional residual capacity (FRC) and lung clearance index (LCI) in 52 sleeping healthy infants and toddlers, suggesting a role for N 2 MBW in this age-group.