Sleep-disordered breathing symptoms and their association with structural and functional pulmonary changes in children born extremely preterm.

This study aimed to evaluate symptoms of sleep-disordered breathing (SDB) among children born extremely preterm, with and without a history of bronchopulmonary dysplasia (BPD), including associations between sleep and respiratory symptoms, physical activity, pulmonary function, and pulmonary magnetic resonance imaging (MRI). This multi-center cross-sectional study enrolled children aged 7-9 years born extremely preterm with and without BPD. Participants completed the Pediatric Sleep Questionnaire (PSQ), the modified Epworth sleepiness scale, a respiratory symptom questionnaire, pedometer measurements, pulmonary function testing, and pulmonary MRI. Spearman's correlations and univariate and multivariable linear regression modelling were performed. Twenty-eight of 45 children included had a history of moderate-to-severe BPD. The prevalence of sleep-related symptoms was low, with the exception of hyperactivity and inattention. There were no differences in mean (SD) scores on sleep questionnaires in children with and without BPD (PSQ: 0.21 (0.13) vs 0.16 (0.14), p = 0.3; modified Epworth: 2.4 (2.4) vs 1.8 (2.8), p = 0.4). Multiple regression analyses examining difference in sleep scores between groups, adjusting for gestational age and intraventricular hemorrhage, found no statistical difference (p > 0.05). Greater daytime sleepiness was moderately correlated with FEV1%-predicted (r = - 0.52); no other moderate-strong associations were identified.  Conclusions: There was no evidence of clinically important differences in sleep symptoms between children with and without BPD, suggesting that sleep symptoms may be related to prematurity-related factors other than a BPD diagnosis, including airflow limitation. Further research is necessary to explore the relationship between sleep symptoms, airway obstruction, and neurobehavioral symptoms among premature-born children.  Trial registration: NCT02921308. Date of registration: October 3, 2016. What is Known: • Presence of bronchopulmonary dysplasia (BPD) may further contribute to the development of SDB, though its impact is not well-studied. • Premature-born children have a greater risk of lung structural and functional differences, including sleep-disordered breathing (SDB). What is New: • There was no difference in sleep symptoms between children with and without BPD, suggesting that sleep symptoms are related to other prematurity-related factors, such as airflow limitation. • Greater daytime sleepiness was correlated with lower FEV1 in our population, which reflects greater airflow limitation.

Routine lung volume recruitment in boys with Duchenne muscular dystrophy: a randomised clinical trial.

BACKGROUND: Impaired cough results in airway secretion retention, atelectasis and pneumonia in individuals with Duchenne muscular dystrophy (DMD). Lung volume recruitment (LVR) stacks breaths to inflate the lungs to greater volumes than spontaneous effort. LVR is recommended in DMD clinical care guidelines but is not well studied. We aimed to determine whether twice-daily LVR, compared with standard of care alone, attenuates the decline in FVC at 2 years in boys with DMD. METHODS: In this multicentre, assessor-blinded, randomised controlled trial, boys with DMD, aged 6-16 years with FVC >30% predicted, were randomised to receive conventional treatment or conventional treatment plus manual LVR twice daily for 2 years. The primary outcome was FVC % predicted at 2 years, adjusted for baseline FVC % predicted, age and ambulatory status. Secondary outcomes included change in chest wall distensibility (maximal insufflation capacity minus FVC) and peak cough flow. RESULTS: Sixty-six boys (36 in LVR group, 30 in control) were evaluated (median age (IQR): 11.5 years (9.5-13.5), median baseline FVC (IQR): 85% predicted (73-96)). Adjusted mean difference in FVC between groups at 2 years was 1.9% predicted (95% CI -6.9% to 10.7%; p=0.68) in the direction of treatment benefit. We found no differences in secondary outcomes. CONCLUSION: There was no difference in decline in FVC % predicted with use of twice-daily LVR for boys with DMD and relatively normal lung function. The burden associated with routine LVR may outweigh the benefit. Benefits of LVR to maintain lung health in boys with worse baseline lung function still need to be clarified. TRIAL REGISTRATION NUMBER: NCT01999075.

Blood pressure variability in children with obesity and sleep-disordered breathing following positive airway pressure treatment.

Obese youth with sleep-disordered breathing are treated with positive airway pressure to improve sleep and cardiovascular status. While improvements in sleep parameters have been confirmed, a study by Katz et al. showed no major improvement in ambulatory blood pressure. The aim of this ancillary study was to analyze short-term blood pressure variability, following positive airway pressure treatment, as a more sensitive marker of cardiovascular health. We analyzed 24-h blood pressure variability data in 17 children, taken at baseline and after 12 months of treatment. These data were derived from an already published prospective, multicenter cohort study conducted in 27 youth (8-16 years) with obesity who were prescribed 1-year of positive airway pressure for moderate-severe sleep-disordered breathing. Significant decreases were found in 24 h systolic blood pressure (p = 0.040) and nighttime diastolic blood pressure (p = 0.041) average real variability, and diastolic blood pressure (p = 0.035) weighted standard deviation. Significant decreases were noted in nighttime diastolic blood pressure time rate variability (p = 0.007). Positive airway pressure treatment resulted in a significant decrease in blood pressure variability, suggesting a clinically significant improvement of sympathetic nerve activity in youth with obesity and sleep-disordered breathing. IMPACT: Cardiovascular variability, as measured by blood pressure variability, is improved in children following positive airway pressure treatment. Our novel findings of improved blood pressure time rate variability are the first described in the pediatric literature. Future studies aimed at analyzing target organ damage in this patient population will allow for a better understanding as to whether alterations in blood pressure variability translate to decreasing target organ damage in children, as seen in adults.

Risk factors for respiratory adverse events after adenoidectomy and tonsillectomy in children with down syndrome: a retrospective cohort study.

Obstructive sleep apnea syndrome is a major cause of morbidity in the Down syndrome population and is commonly treated with adenoidectomy and/or tonsillectomy (AT). However, these children are at increased risk for perioperative respiratory adverse events (PRAEs). The objective of this study was to examine risk factors for major PRAEs requiring intervention in children with Down syndrome undergoing AT and to describe their postoperative monitoring environment. This retrospective study included all children with Down syndrome aged 0-18 years who underwent a preoperative polysomnogram followed by AT at a tertiary pediatric institution. Descriptive statistics were used to summarize baseline demographic and clinical characteristics. A multivariable model for prediction of PRAEs was constructed. A priori, it was decided that minimum oxygen saturation, apnea-hypopnea index, and average oxygen saturation asleep would be included, along with medical comorbidities associated with PRAEs at p < 0.2 in univariable analyses. Fifty-eight children were included in this study; twelve had a PRAE. Cardiac disease was associated with PRAEs on univariable analysis (p = 0.03). In multivariable analysis, average oxygen saturation asleep was associated with PRAEs (OR 1.50; 95% confidence interval 1.00, 2.41; p = 0.05). For all of the remaining variables, p > 0.15. Fifty-six children were admitted for monitoring overnight; four were admitted to the intensive care unit and fifty-two were admitted to the ward. CONCLUSIONS: A multivariable model found evidence that lower average oxygen saturation while asleep was associated with PRAEs requiring intervention in children with Down syndrome. This study highlights the difficulty in predicting complications in this population. WHAT IS KNOWN: • Obstructive sleep apnea syndrome is a major cause of morbidity in the Down syndrome population and is commonly treated with adenoidectomy and/or tonsillectomy. • However, children with Down syndrome are at increased risk for perioperative respiratory adverse events (PRAEs) following adenoidectomy and/or tonsillectomy. WHAT IS NEW: • We found that a lower average oxygen saturation asleep is associated with increased odds of PRAEs, adjusting for age, total apnea-hypopnea index, cardiac comorbidity, and minimum oxygen saturation. • This study highlights the difficulty in predicting complications in this population.

Creating enriched training sets of eligible studies for large systematic reviews: the utility of PubMed's Best Match algorithm.

INTRODUCTION: Solutions like crowd screening and machine learning can assist systematic reviewers with heavy screening burdens but require training sets containing a mix of eligible and ineligible studies. This study explores using PubMed's Best Match algorithm to create small training sets containing at least five relevant studies. METHODS: Six systematic reviews were examined retrospectively. MEDLINE searches were converted and run in PubMed. The ranking of included studies was studied under both Best Match and Most Recent sort conditions. RESULTS: Retrieval sizes for the systematic reviews ranged from 151 to 5,406 records and the numbers of relevant records ranged from 8 to 763. The median ranking of relevant records was higher in Best Match for all six reviews, when compared with Most Recent sort. Best Match placed a total of thirty relevant records in the first fifty, at least one for each systematic review. Most Recent sorting placed only ten relevant records in the first fifty. Best Match sorting outperformed Most Recent in all cases and placed five or more relevant records in the first fifty in three of six cases. DISCUSSION: Using a predetermined set size such as fifty may not provide enough true positives for an effective systematic review training set. However, screening PubMed records ranked by Best Match and continuing until the desired number of true positives are identified is efficient and effective. CONCLUSIONS: The Best Match sort in PubMed improves the ranking and increases the proportion of relevant records in the first fifty records relative to sorting by recency.

Effect of oxygen saturation targets on the incidence of bronchopulmonary dysplasia and duration of respiratory supports in extremely preterm infants.

BACKGROUND: Recent clinical practice changes in neonatal care resulted in higher, narrower oxygen saturation target ranges for preterm infants. The effect of targeting higher or lower oxygen saturations on respiratory outcomes of preterm infants and duration of hospitalization has not been extensively reviewed in the context of current care, but could have significant implications. METHODS: A multicentre retrospective cohort of 145 preterm infants was conducted; 105 had lower oxygen saturation targets (88 to 92%), 40 had higher targets (90 to 95%). The primary outcome was bronchopulmonary dysplasia (BPD). Secondary outcomes included duration of invasive/noninvasive respiratory support, oxygen therapy, and hospitalization. The primary outcome was compared using Fisher's exact test. Secondary outcomes were evaluated with survival analysis and Wilcoxon rank sum test. RESULTS: The difference in incidence of BPD in the lower (N=56, 53.3%) and higher saturation groups (N=14, 35.0%) was not statistically significant (relative risk [RR]=0.66 [0.41, 1.04], P=0.06). The difference in duration of mechanical ventilation in the lower (median 7.8 days, interquartile range [IQR] 3.7 to 15.9) and higher saturation groups (median 4.5, IQR 1.9 to 12.3) approached statistical significance (P=0.05). There were no statistically significant differences in the durations of other respiratory supports or hospital stay between the two groups. CONCLUSIONS: The results of this study approached statistical significance and suggest that higher, narrower oxygen saturation targets may result in a clinically important reduction in BPD incidence and duration of mechanical ventilation. These results require validation in a larger sample to refine optimal targets.

Healthcare utilisation and costs of home mechanical ventilation.

BACKGROUND: Individuals using home mechanical ventilation (HMV) frequently choose to live at home for quality of life, despite financial burden. Previous studies of healthcare utilisation and costs do not consider public and private expenditures, including caregiver time. OBJECTIVES: To determine public and private healthcare utilisation and costs for HMV users living at home in two Canadian provinces, and examine factors associated with higher costs. METHODS: Longitudinal, prospective observational cost analysis study (April 2012 to August 2015) collecting data on public and private (out-of-pocket, third-party insurance, caregiving) costs every 2 weeks for 6 months using the Ambulatory and Home Care Record. Functional Independence Measure (FIM) was used at baseline and study completion. Regression models examined variables associated with total monthly costs selected a priori using Andersen and Newman's framework for healthcare utilisation, relevant literature, and clinical expertise. Data are reported in 2015 Canadian dollars ($C1=US$0.78=£0.51=€0.71). RESULTS: We enrolled 134 HMV users; 95 with family caregivers. Overall median (IQR) monthly healthcare cost was $5275 ($2291-$10 181) with $2410 (58%) publicly funded; $1609 (39%) family caregiving; and $141 (3%) out-of-pocket (<1% third-party insurance). Median healthcare costs were $8733 ($5868-$15 274) for those invasively ventilated and $3925 ($1212-$7390) for non-invasive ventilation. Variables associated with highest monthly costs were amyotrophic lateral sclerosis (1.88, 95% CI 1.09 to 3.26, P<0.03) and lower FIM quintiles (higher dependency) (up to 6.98, 95% CI 3.88 to 12.55, P<0.0001) adjusting for age, sex, tracheostomy and ventilation duration. CONCLUSIONS: For HMV users, most healthcare costs were publicly supported or associated with family caregiving. Highest costs were incurred by the most dependent users. Understanding healthcare costs for HMV users will inform policy decisions to optimise resource allocation, helping individuals live at home while minimising caregiver burden.

Research Needs Assessment for Children With Obstructive Sleep Apnea Undergoing Diagnostic or Surgical Procedures.

Recent concerns have been raised about the quality and safety of adenotonsillectomy, a common surgery performed to treat obstructive sleep apnea (OSA) in children. OSA is a risk factor for opioid-related perioperative respiratory complications including those associated with anoxic brain injury or death. Our objective was to identify controversial issues related to the care of children with OSA. A standardized Delphi consensus technique involving an interdisciplinary group of 24 pediatric OSA experts identified 3 key issues: "postoperative disposition, preoperative screening, and pain management." These topics are prime candidates for future systematic reviews and will guide Society of Anesthesia and Sleep Medicine-related research endeavors.

Pediatric tonsillectomy is a resource-intensive procedure: a study of Canadian health administrative data.

BACKGROUND: The majority of pediatric surgeries are performed in a day surgery setting. The rate of adverse postoperative outcomes and the factors that influence them are poorly described in the Canadian setting. Concerns about the safety of adenotonsillectomy (AT) have been raised. The objective of this Ontario-based study was to determine the rates and risks of hospital readmission, emergency department (ED) visits, or deaths within 30 days following common pediatric surgeries, with an emphasis on AT. METHODS: Inpatient and day surgery children who were < 18 yr of age and undergoing one of the ten most common surgeries in Ontario from 2002-2013 were identified by linking four provincial health administrative databases. Risk of each outcome was determined separately for all surgeries. Cox regression was used to measure the association of demographics, clinical factors, Ontario drug benefit (ODB) status, and prescribed opioids with adverse outcomes. RESULTS: Among 364,629 children, AT accounted for 30.5% of all surgeries. The AT patient rates of readmission and ED visits compared with the full study cohort were 2.7% vs 1.5% and 12.4% vs 9.2%, respectively. The study cohort postoperative death rate was 0.27 per 10,000 children (95% confidence interval [CI], 0.18 to 0.39). For the study cohort, an increased risk of readmission was associated with previous urgent admission (hazard ratio [HR], 2.15; 95% CI, 1.75 to 2.63), length-of-stay ≥ four days (HR, 2.04; 95% CI, 1.57 to 2.65), Charlson comorbidity score ≥ 1 (HR, 1.61; 95% CI, 1.17 to 2.22), and age ≥ 14 yr (HR, 1.15; 95% CI, 1.02 to 1.19) or ≤ 3 yr (HR, 1.16; 95% CI, 1.15 to 1.17). Similar factors were associated with an increased risk of ED visits. Patients covered by ODB (11.8%), particularly those prescribed opioids, had an increased risk for readmission and ED visit. CONCLUSIONS: Post-discharge readmissions and ED visits are relatively common after pediatric surgery, particularly for AT. Perioperative treatment algorithms that consider risk factors for hospital revisits are required in children.

Creation of a reference dataset of neck sizes in children: standardizing a potential new tool for prediction of obesity-associated diseases?

BACKGROUND: Neck circumference (NC), is an emerging marker of obesity and associated disease risk, but is challenging to use as a screening tool in children, as age and sex standardized cutoffs have not been determined. A population-based sample of NC in Canadian children was collected, and age- and sex-specific reference curves for NC were developed. METHODS: NC, waist circumference (WC), weight and height were measured on participants aged 6-17 years in cycle 2 of the Canadian Health Measures Survey. Quantile regression of NC versus age in males and females was used to obtain NC percentiles. Linear regression was used to examine association between NC, body mass index (BMI) and WC. NC was compared in healthy weight (BMI < 85th percentile) and overweight/obese (BMI > 85th percentile) subjects. RESULTS: The sample included 936 females and 977 males. For all age and sex groups, NC was larger in overweight/obese children (p < 0.0001). For each additional unit of BMI, average NC in males was 0.49 cm higher and in females, 0.43 cm higher. For each additional cm of WC, average NC in males was 0.18 cm higher and in females, 0.17 cm higher. CONCLUSION: This study presents the first reference data on Canadian children's NC. The reference curves may have future clinical applicability in identifying children at risk of central obesity-associated conditions and thresholds associated with disease risk.

Behavioral and emotional characteristics of Canadian children with obesity and moderate-severe sleep-disordered breathing treated with positive airway pressure: longitudinal changes and associations with adherence.

STUDY OBJECTIVES: Behavioral characteristics and outcomes of positive airway pressure (PAP) therapy in children with obesity and moderate-severe sleep-disordered breathing (SDB) have not been reported. Our aims were to 1) determine baseline behavioral/emotional symptoms of this population and characterize changes over time with PAP, and 2) examine associations between baseline behavioral/emotional symptoms and PAP adherence. METHODS: This multicenter prospective cohort study of children with obesity prescribed PAP for moderate-severe SDB assessed PAP adherence (≥ 4 h/night, >50% of nights, usage diaries, downloads) and compared behavioral/emotional characteristics with parent- and child-reported Conners Rating Scale (Conners) and the Child Behavior Checklist (CBCL) at baseline and 1 year after PAP prescription between adherent and nonadherent participants; scores at baseline were compared retrospectively between adherence groups. RESULTS: Twenty-four children were included (median 14.1 years [IQR:12.4,16.0]; 87.5% males). Baseline Conners and CBCL scores were elevated (parent- and child-reported Conners inattention and hyperactivity subscales and CBCL subscales [total, internalizing, externalizing]). Baseline parent-reported Conners scores were significantly more elevated in the nonadherent than adherent group (inattention: 73.3 ± 8.5 vs 60.5 ± 14.6, P = .01; hyperactivity: 70.9 ± 11.1 vs 59.1 ± 16.0, P = .05). This difference was present 1 year later for inattention (P = .01) but not for hyperactivity (P = .09). Parent-reported CBCL scores improved over 1 year in adherent but not nonadherent participants. CONCLUSIONS: We found that children with obesity and moderate-severe SDB have elevated symptoms of behavioral/emotional concerns on standardized testing. Parent-reported emotional characteristics improved in the adherent but not in the nonadherent group. Children with greater inattention/hyperactivity at baseline were less adherent to PAP, suggesting this may contribute to PAP nonadherence. CITATION: Constantin E, MacLean JE, Barrowman N, et al. Behavioral and emotional characteristics of Canadian children with obesity and moderate-severe sleep-disordered breathing treated with positive airway pressure: longitudinal changes and associations with adherence. J Clin Sleep Med. 2023;19(3):555-562.

Understanding the experiences of lung volume recruitment among boys with Duchenne muscular dystrophy: A multicenter qualitative study.

BACKGROUND: Despite recommendations for regular lung volume recruitment (LVR) use in clinical practice guidelines for children with neuromuscular disease, adherence to LVR is poor. We aimed to describe the experience of LVR by boys with Duchenne muscular dystrophy (DMD), their families, and healthcare providers (HCPs), as well as to identify the barriers and facilitators to LVR use. METHODS: This multicenter, qualitative study evaluated boys with DMD (n = 11) who used twice-daily LVR as part of a randomized controlled trial, as well as their parents (n = 11), and HCPs involved in the clinical use of LVR (n = 9). Semistructured interviews were conducted to identify participants' understanding of LVR therapy and their beliefs, barriers and facilitators to its use. Thematic analysis was conducted using an inductive approach. A subanalysis compared adherent and nonadherent children. RESULTS: Seven themes were identified related to participants' beliefs and experiences with LVR: emotional impact, adaptation to LVR, perceived benefits of LVR, routine, family engagement, clinical resources, and equipment-related factors. Strategies to improve adherence were also identified, including education, reinforcement and demonstration of LVR benefit, as well as clinician support. There were no thematic differences between adherent and nonadherent children. DISCUSSION: Despite the benefits of LVR and positive experiences with it by many families, there remain barriers to adherence to treatment. HCPs need to balance the need for early introduction to give families time to adapt to LVR while ensuring that the benefit of LVR outweighs the burden. Clinician support is important for family engagement.

Physical activity levels, pulmonary function, and MRI in children born extremely preterm: A comparison between children with and without bronchopulmonary dysplasia.

INTRODUCTION: Children with a history of bronchopulmonary dysplasia (BPD) may have lower physical activity levels, but evidence to date is mixed. This study compared physical activity levels between children born extremely preterm with and without history of BPD, and examined their associations with pulmonary magnetic resonance imaging (MRI) and pulmonary function test (PFT) indices. METHODS: This multicentre cross-sectional study included children aged 7-9 years born extremely preterm, with and without BPD. Children wore a pedometer for 1 week, then completed the Physical Activity Questionnaire (PAQ), pulmonary MRI, and PFT. Spearman correlations and multivariable linear regression modeling were performed. RESULTS: Of 45 children, 28 had a history of moderate-severe BPD. There were no differences in any physical activity outcomes by BPD status. Higher average daily step count and higher average daily moderate-to-vigorous physical activity (MVPA) were each correlated with greater forced vital capacity (r = 0.41 and 0.58), greater MRI lung proton density at full expiration (r = 0.42 and 0.49), and lower lung clearance index (r = -0.50 and -0.41). After adjusting for MRI total proton density and BPD status, a 5% increase in forced expiratory volume at 1 s was associated with 738 (95% CI: 208, 1268) more steps per day and 0.1 (0.0, 0.2) more hours of MVPA, respectively. CONCLUSION: School-aged children born extremely preterm have similar physical activity levels to their peers, regardless of history of BPD. MRI and PFT measures suggestive of gas trapping and/or airflow obstruction are associated with lower physical activity levels.

Chronic tracheostomy care of ventilator-dependent and -independent children: Clinical practice patterns of pediatric respirologists in a publicly funded (Canadian) healthcare system.

OBJECTIVES: To describe the current clinical practice patterns of Canadian pediatric respirologists at pediatric tertiary care institutions regarding chronic tracheostomy tube care and management of home invasive ventilation. METHODS: A pediatric respirologist/pediatrician with expertise in tracheostomy tube care and home ventilation was identified at each Canadian pediatric tertiary care center to complete a 59-item survey of multiple choice and short answer questions. Domains assessed included tracheostomy tube care, caregiver competency and home monitoring, speaking valves, medical management of tracheostomy complications, decannulation, and long-term follow-up. RESULTS: The response rate was 100% (17/17) with all Canadian tertiary care pediatric centers represented and heterogeneity of practice was observed in all domains assessed. For example, though most centers employ Bivona™ (17/17) and Shiley™ (15/17) tracheostomy tubes, variability was observed around tube change, re-use, and cleaning practices. Most centers require two trained caregivers (14/17) and recommend 24/7 eyes on care and oxygen saturation monitoring. Discharge with an emergency tracheostomy kit was universal (17/17). Considerable heterogeneity was observed in the timing and use of speaking valves and speech-language assessment. Inhaled anti-pseudomonal antibiotics are employed by most centers (16/17) though the indication, agent, and protocol varied by center. Though decannulation practices varied considerably, the requirement of upper airway patency was universally required to proceed with decannulation (17/17) independent of ongoing ventilatory support requirements. CONCLUSION: Considerable variability in pediatric tracheostomy tube care practice exists across Canada. These results will serve as a starting point to standardize and evaluate tracheostomy tube care nationally.

Lung volume recruitment slows pulmonary function decline in Duchenne muscular dystrophy.

OBJECTIVE: To evaluate the long-term effect on measures of forced vital capacity (FVC) before and after the introduction of regular lung volume recruitment (LVR) maneuvers (breath-stacking) in individuals with Duchenne muscular dystrophy (DMD). DESIGN: Retrospective cohort study of pulmonary function data, including FVC, cough peak flow (CPF), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP). Data were collected for 33 months prior to and 45 months after LVR introduction. SETTING: Ambulatory care in a tertiary level regional rehabilitation center in Canada. PARTICIPANTS: All individuals (N=22) with DMD (mean age ± SD, 19.6±2.4y), who were prescribed LVR and reported adherence with therapy. INTERVENTIONS: Introduction of regular LVR (breath-stacking); 3 to 5 maximal lung inflations (maximum insufflation capacity [MIC]) using a hand-held resuscitation bag and mouthpiece, twice daily. MAIN OUTCOME MEASURES: Measures included the rate of decline of FVC in percent-predicted, before and after the introduction of regular LVR. Changes in maximum pressures (MIP, MEP), MIC, and cough peak flows were also measured. RESULTS: At LVR initiation, FVC was 21.8±16.9 percent-predicted, and cough peak flows were <270L/min (144.8±106.9L/min). Annual decline of FVC was 4.7 percent-predicted a year before LVR and 0.5 percent-predicted a year after LVR initiation. The difference, 4.2 percent-predicted a year (95% confidence interval, 3.5-4.9; P<.000), represents an 89% improvement in the annual rate of FVC decline. CONCLUSIONS: The rate of FVC decline in DMD patients improves dramatically with initiation of regular LVR.

Predictors of sleep disordered breathing in children with Down syndrome: a systematic review and meta-analysis.

Children with Down syndrome are at increased risk of sleep disordered breathing (SDB). SDB is associated with significant morbidity including neurocognitive impairment, cardiometabolic disease and systemic inflammation. The identification of clinical markers that may predict SDB is critical in facilitating early diagnosis and treatment, and ultimately, preventing morbidity. The objective of this systematic review was to identify predictors of SDB in patients with Down syndrome. A search was conducted using MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Cumulative Index to Nursing and Allied Health Literature. A meta-analysis was performed according to the Meta-analyses of Observational Studies in Epidemiology checklist. Our review of the literature identified inconsistent associations between a variety of variables and SDB in children with Down syndrome, although the quality of evidence was poor. Meta-analysis of age and sex identified that children with OSA were older than those without OSA, and there was a similar risk of OSA in males and females, although risk favoured males. Currently, the American Academy of Pediatrics guidelines recommend that children with Down syndrome undergo polysomnography by the age of 4 years. Our review supports the recommendation for routine screening of children with Down syndrome. However, results from our meta-analysis suggest a need for longitudinal screening to diagnose children who may develop SDB as they get older.

Opioid dose and postoperative respiratory adverse events after adenotonsillectomy in medically complex children.

STUDY OBJECTIVES: Obstructive sleep-disordered breathing is commonly treated with adenotonsillectomy. Our study objective was to describe perioperative opioid dosing in children with a range of medical complexity evaluated for obstructive sleep-disordered breathing undergoing adenotonsillectomy and to investigate its association with postoperative respiratory adverse events (PRAEs). METHODS: A retrospective chart review of children who underwent adenotonsillectomy and had preoperative polysomnography performed was conducted. PRAEs included requiring oxygen, jaw thrust, positive airway pressure, or mechanical ventilation. Multivariable logistic regression was performed to examine for associations between covariates and PRAEs. RESULTS: The cohort included 374 children with obstructive sleep-disordered breathing, median (interquartile range) age 6.1 (3.9, 9.3) years; 344 (92%) had obstructive sleep apnea (apnea-hypopnea index > 1 events/h) while 30 (8%) had a normal polysomnogram (apnea-hypopnea index < 1 events/h). The median (interquartile range) postoperative morphine-equivalent dose administered was 0.17 (0.09, 0.25) mg/kg. Sixty-six (17.6%) experienced at least 1 PRAE. Multivariable modeling identified the following predictors of PRAE: younger age at surgery (odds ratio 0.90, 95% confidence interval 0.83, 0.98), presence of cardiac comorbidity (odds ratio 2.07, 95% confidence interval 1.09, 3.89), and presence of airway anomaly (odds ratio 3.48, 95% confidence interval 1.30, 8.94). Higher total apnea-hypopnea index and morphine-equivalent dose were associated with PRAE risk, and an interaction between these variables was detected (P = .01). CONCLUSIONS: This study identified opioid dose in morphine equivalents to be a strong predictor of PRAE. Additionally, severity of obstructive sleep apnea and postoperative morphine-equivalent dose contributed together and independently to the occurrence of PRAEs. Attention to opioid dosing, particularly among medically complex children with obstructive sleep-disordered breathing, is required to mitigate risk of PRAEs. CITATION: Tsampalieros A, Murto K, Barrowman N, et al. Opioid dose and postoperative respiratory adverse events after adenotonsillectomy in medically complex children. J Clin Sleep Med. 2022;18(10):2405-2413.

Pulmonary Magnetic Resonance Imaging of Ex-Preterm Children with and without Bronchopulmonary Dysplasia.

Rationale: Children born prematurely, particularly those with bronchopulmonary dysplasia, have persisting lung abnormalities requiring longitudinal monitoring. Pulmonary ultrashort echo time magnetic resonance imaging (MRI) measurements may provide sensitive markers of persisting lung abnormalities and have not been evaluated in school-aged children born prematurely. Objectives: To compare pulmonary MRI and pulmonary function test measurements in preterm-born school-aged children with and without bronchopulmonary dysplasia. Methods: Children aged 7-9 years, born extremely preterm, with and without bronchopulmonary dysplasia, were recruited from three centers. Participants underwent pulmonary ultrashort echo time MRI and pulmonary function tests. Primary outcomes included total proton density and proton density at full expiration, measured using MRI. Multiple linear regression analysis was performed, adjusting for gestational age and bronchopulmonary dysplasia. Associations between MRI and pulmonary function were tested. Results: Thirty-five children were included in the primary analysis (24 with bronchopulmonary dysplasia, 11 without); 29 completed pulmonary function tests, of whom 11 (38%) had airflow limitation. Children with bronchopulmonary dysplasia had 44% (95% confidence interval [CI], 10-66%) lower mean total proton density (mean ± standard deviation, 3.6 ± 2.6) than those without (6.1 ± 4.0). Those with bronchopulmonary dysplasia had 25% (95% CI, 3-42%) lower proton density at full expiration than those without. Lower total proton density and proton density at full expiration were moderately correlated with greater residual volume, residual volume/total lung capacity, and lung clearance index (Spearman correlations for total proton density: -0.42, -0.57, and -0.53, respectively. Spearman correlations for proton density at full expiration: -0.28, -0.57, and -0.45, respectively). Conclusions: School-aged preterm-born children with bronchopulmonary dysplasia have parenchymal tissue abnormalities measured using ultrashort MRI proton density, compared with those without. MRI proton density correlated with pulmonary function measures indicative of gas trapping. Clinical trial registered with www.clinicaltrials.gov (NCT02921308).