Sleep studies in obese children with obstructive sleep apnea: Pulse oximetry as a diagnostic tool.

Obstructive sleep apnea is associated with many co-morbidities in children and young people. Obesity has long been recognised as an important risk factor associated with obstructive sleep apnea. Currently, polysomnography is regarded as the gold-standard diagnostic tool for obstructive sleep apnea. The validity of oximetry as a screening and diagnostic tool for obstructive sleep apnea has been the subject of several studies in the literature. There is little published evidence on the use of oximetry in children with obesity. This study assesses whether oximetry is a reliable diagnostic tool for obstructive sleep apnea in obese children. We reviewed the medical records of obese children with a suspected diagnosis of obstructive sleep apnea who underwent oximetry and cardiorespiratory polygraphy or full polysomnography at Sheffield Children's Hospital between January 2010 and March 2022. We compared oximetry results with the apnea-hypopnea index from cardiorespiratory polygraphy or full polysomnography for each patient. A total of 60 patient records were included in the analysis. The sensitivity of oximetry in diagnosing obstructive sleep apnea was 70.9%, with a specificity of 65.5% and a positive predictive value of 68.75%. In the subgroup of subjects with severe obstructive sleep apnea (apnea-hypopnea index > 10), oximetry had a sensitivity of 87.5%. We concluded that oximetry could be a helpful initial diagnostic tool for obstructive sleep apnea in obese children, but is not entirely reliable. A negative oximetry result in a symptomatic individual should prompt a referral for more detailed investigations, while a positive result can help in treatment decisions without needing a polysomnography.

Seasonal Azithromycin Use in Paediatric Protracted Bacterial Bronchitis Does Not Promote Antimicrobial Resistance but Does Modulate the Nasopharyngeal Microbiome.

Protracted bacterial bronchitis (PBB) causes chronic wet cough for which seasonal azithromycin is increasingly used to reduce exacerbations. We investigated the impact of seasonal azithromycin on antimicrobial resistance and the nasopharyngeal microbiome. In an observational cohort study, 50 children with PBB were enrolled over two consecutive winters; 25/50 at study entry were designated on clinical grounds to take azithromycin over the winter months and 25/50 were not. Serial nasopharyngeal swabs were collected during the study period (12-20 months) and cultured bacterial isolates were assessed for antimicrobial susceptibility. 16S rRNA-based sequencing was performed on a subset of samples. Irrespective of azithromycin usage, high levels of azithromycin resistance were found; 73% of bacteria from swabs in the azithromycin group vs. 69% in the comparison group. Resistance was predominantly driven by azithromycin-resistant S. pneumoniae, yet these isolates were mostly erythromycin susceptible. Analysis of 16S rRNA-based sequencing revealed a reduction in within-sample diversity in response to azithromycin, but only in samples of children actively taking azithromycin at the time of swab collection. Actively taking azithromycin at the time of swab collection significantly contributed to dissimilarity in bacterial community composition. The discrepancy between laboratory detection of azithromycin and erythromycin resistance in the S. pneumoniae isolates requires further investigation. Seasonal azithromycin for PBB did not promote antimicrobial resistance over the study period, but did perturb the microbiome.

Lung MRI with hyperpolarised gases: current & future clinical perspectives.

The use of pulmonary MRI in a clinical setting has historically been limited. Whilst CT remains the gold-standard for structural lung imaging in many clinical indications, technical developments in ultrashort and zero echo time MRI techniques are beginning to help realise non-ionising structural imaging in certain lung disorders. In this invited review, we discuss a complementary technique - hyperpolarised (HP) gas MRI with inhaled 3He and 129Xe - a method for functional and microstructural imaging of the lung that has great potential as a clinical tool for early detection and improved understanding of pathophysiology in many lung diseases. HP gas MRI now has the potential to make an impact on clinical management by enabling safe, sensitive monitoring of disease progression and response to therapy. With reference to the significant evidence base gathered over the last two decades, we review HP gas MRI studies in patients with a range of pulmonary disorders, including COPD/emphysema, asthma, cystic fibrosis, and interstitial lung disease. We provide several examples of our experience in Sheffield of using these techniques in a diagnostic clinical setting in challenging adult and paediatric lung diseases.

Homozygous GDF2 nonsense mutations result in a loss of circulating BMP9 and BMP10 and are associated with either PAH or an "HHT-like" syndrome in children.

BACKGROUND: Disrupted endothelial BMP9/10 signaling may contribute to the pathophysiology of both hereditary hemorrhagic telangiectasia (HHT) and pulmonary arterial hypertension (PAH), yet loss of circulating BMP9 has not been confirmed in individuals with ultra-rare homozygous GDF2 (BMP9 gene) nonsense mutations. We studied two pediatric patients homozygous for GDF2 (BMP9 gene) nonsense mutations: one with PAH (c.[76C>T];[76C>T] or p.[Gln26Ter];[Gln26Ter] and a new individual with pulmonary arteriovenous malformations (PAVMs; c.[835G>T];[835G>T] or p.[Glu279Ter];[Glu279Ter]); both with facial telangiectases. METHODS: Plasma samples were assayed for BMP9 and BMP10 by ELISA. In parallel, serum BMP activity was assayed using an endothelial BRE-luciferase reporter cell line (HMEC1-BRE). Proteins were expressed for assessment of secretion and processing. RESULTS: Plasma levels of both BMP9 and BMP10 were undetectable in the two homozygous index cases and this corresponded to low serum-derived endothelial BMP activity in the patients. Measured BMP9 and BMP10 levels were reduced in the asymptomatic heterozygous p.[Glu279Ter] parents, but serum activity was normal. Although expression studies suggested alternate translation can be initiated at Met57 in the p.[Gln26Ter] mutant, this does not result in secretion of functional BMP9. CONCLUSION: Collectively, these data show that homozygous GDF2 mutations, leading to a loss of circulating BMP9 and BMP10, can cause either pediatric PAH and/or "HHT-like" telangiectases and PAVMs. Although patients reported to date have manifestations that overlap with those of HHT, none meet the Curaçao criteria for HHT and seem distinct from HHT in terms of the location and appearance of telangiectases, and a tendency for tiny, diffuse PAVMs.

Parental experience of prophylactic antibiotics.

BACKGROUND AND OBJECTIVES: Long-term prophylactic antibiotics are often used to prevent bacterial infections. However, supporting evidence for this is not always robust. Including parents in decisions relating to medication is key to medicines optimisation. Parental concern regarding medication is a major determinant of poor adherence. This study explores parental experiences of having a child prescribed prophylactic antibiotics and how that affects their antibiotic use behaviour. METHODS: We conducted a prospective, single-centre, exploratory, qualitative study at Sheffield Children's Hospital. Through 15 interviews, involving 18 participants, we explored parental 'lived experiences' and attitudes towards azithromycin prophylaxis prescribed for various respiratory conditions. Thematic analysis was conducted. RESULTS: The overriding factor influencing parental decisions about the uptake of antibiotic prophylaxis is wanting their child to be well now. The main concern voiced by parents is that of antibiotic resistance given their children are high users of antibiotics. This is however seen as a problem for the future, not the present. Preparing families adequately helps prevent practical difficulties relating to medication. Facilitating 'normalisation' of prophylaxis through daily routines and minimising disruption to the family environment may reduce parental anxiety, promote adherence and result in easing of potential restrictions to the child's daily activities. CONCLUSION: Grounded in our deeper understanding, we propose a behavioural model that describes phases parents go through while having a child on prophylactic antibiotics. Time invested in holistically addressing the parental experience and having an awareness of potential issues parents face, may facilitate medication adherence, reduce anxieties and improve doctor-parent relationships.

Chronic Lung Disease in Patients With Perinatally Acquired HIV in England: A Retrospective Case-Note Review.

Chronic lung disease (CLD) is common in individuals living with perinatally acquired HIV (PA-HIV) in southern/eastern Africa. Most of the UK PA-HIV population are African. We conducted a case-note review of CLD in 3 UK PA-HIV cohorts (n = 98). Bronchiectasis or obliterative bronchiolitis occurred in 8.1% of patients and ring/tramline opacities occurred in 19.2% of patients on chest radiograph. There may be unrecognized and underdiagnosed CLD among PA-HIV in the UK.

Pediatric Dysfunctional Breathing: Proposed Components, Mechanisms, Diagnosis, and Management.

Dysfunctional breathing (DB) is an overarching term describing deviations in the normal biomechanical patterns of breathing which have a significant impact on quality of life, performance and functioning. Whilst it occurs in both children and adults, this article focuses specifically on children. DB can be viewed as having two components; breathing pattern disorder (BPD) and inducible laryngeal obstruction (ILO). They can be considered in isolation, however, are intricately related and often co-exist. When both are suspected, we propose both BPD and ILO be investigated within an all-encompassing multi-disciplinary dysfunctional breathing clinic. The MDT clinic can diagnose DB through expert history taking and a choice of appropriate tests/examinations which may include spirometry, breathing pattern analysis, exercise testing and laryngoscopic examination. Use of the proposed algorithm presented in this article will aid decision making regarding choosing the most appropriate tests and understanding the diagnostic implications of these tests. The most common symptoms of DB are shortness of breath and chest discomfort, often during exercise. Patients with DB typically present with normal spirometry and an altered breathing pattern at rest which is amplified during exercise. In pediatric ILO, abnormalities of the upper airway such as cobblestoning are commonly seen followed by abnormal activity of the upper airway structures provoked by exercise. This may be associated with a varying degree of stridor. The symptoms, however, are often misdiagnosed as asthma and the picture can be further complicated by the common co-presentation of DB and asthma. Associated conditions such as asthma, extra-esophageal reflux, rhinitis, and allergy must be treated appropriately and well controlled before any directed therapy for DB can be started if therapy is to be successful. DB in pediatrics is commonly treated with a course of non-pharmaceutical therapy. The therapy is provided by an experienced physiotherapist, speech and language therapist or psychologist depending on the dominant features of the DB presentation (i.e., BPD or ILO in combination or in isolation) and some patients will benefit from input from more than one of these disciplines. An individualized treatment program based on expert assessment and personalized goals will result in a return to normal function with reoccurrence being rare.

Fifteen-minute consultation: approach to management of respiratory problems in children with neurodisability.

Children with neurodisability have an increased prevalence of respiratory symptoms and morbidity. Several underlying physiological impairments and coexistent problems, like aspiration, make these children vulnerable to respiratory difficulties. The management of these respiratory problems is aimed at improving the quality of life, reducing the risk of exacerbations and further lung damage. This is based on identifying and, where possible, modifying physiological impairments, managing any exacerbating factors and proactive treatment of any complications. Even though increased life expectancy is now possible, an ever-increasing dependence on technology can interfere with quality of life and decisions to escalate to these treatments should be individualised.

Cytokine responses in primary and secondary respiratory syncytial virus infections.

BACKGROUND: Primary respiratory syncytial virus (RSV) infections are characterized by high levels of IL-8 and an intense neutrophilia. Little is known about the cytokine responses in secondary infections. Preschool children experiencing RSV secondary infections were recruited from the siblings of infants admitted to hospital with RSV acute bronchiolitis. METHODS: Fifty-one infants with acute bronchiolitis (39 RSV positive, 12 RSV negative) and 20 age-matched control infants were recruited. In addition, seven older siblings of infants from the RSV-positive cohort and confirmed RSV infection were recruited. Samples of nasal secretions were obtained using a flocked swab, and secretions extracted using centrifugation. Cytokine bead array was used to obtain levels of interleukin (IL)-17A, IL-8, IL-6, IL-21, and tumor necrosis factor-α. RESULTS: Levels of IL-8 and IL-6 were significantly lower in the RSV-positive siblings compared with the RSV-positive infants. There were no significant differences between levels of the other cytokines in the primary and secondary infections. CONCLUSION: The very high levels of IL-8 and IL-6 response characteristic of the primary RSV infection was not observed in secondary RSV-positive infections and this did not appear to be due to a global reduction in cytokine production.

Saline in acute bronchiolitis RCT and economic evaluation: hypertonic saline in acute bronchiolitis - randomised controlled trial and systematic review.

BACKGROUND: Acute bronchiolitis is the most common cause of hospitalisation in infancy. Supportive care and oxygen are the cornerstones of management. A Cochrane review concluded that the use of nebulised 3% hypertonic saline (HS) may significantly reduce the duration of hospitalisation. OBJECTIVE: To test the hypothesis that HS reduces the time to when infants were assessed as being fit for discharge, defined as in air with saturations of > 92% for 6 hours, by 25%. DESIGN: Parallel-group, pragmatic randomised controlled trial, cost-utility analysis and systematic review. SETTING: Ten UK hospitals. PARTICIPANTS: Infants with acute bronchiolitis requiring oxygen therapy were allocated within 4 hours of admission. INTERVENTIONS: Supportive care with oxygen as required, minimal handling and fluid administration as appropriate to the severity of the disease, 3% nebulised HS every ± 6 hours. MAIN OUTCOME MEASURES: The trial primary outcome was time until the infant met objective discharge criteria. Secondary end points included time to discharge and adverse events. The costs analysed related to length of stay (LoS), readmissions, nebulised saline and other NHS resource use. Quality-adjusted life-years (QALYs) were estimated using an existing utility decrement derived for hospitalisation in children, together with the time spent in hospital in the trial. DATA SOURCES: We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and other databases from inception or from 2010 onwards, searched ClinicalTrials.gov and other registries and hand-searched Chest, Paediatrics and Journal of Paediatrics to January 2015. REVIEW METHODS: We included randomised/quasi-randomised trials which compared HS versus saline (± adjunct treatment) or no treatment. We used a fixed-effects model to combine mean differences for LoS and assessed statistical heterogeneity using the I (2) statistic. RESULTS: The trial randomised 158 infants to HS (n = 141 analysed) and 159 to standard care (n = 149 analysed). There was no difference between the two arms in the time to being declared fit for discharge [median 76.6 vs. 75.9 hours, hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.75 to 1.20] or to actual discharge (median 88.5 vs. 88.7 hours, HR 0.97, 95% CI 0.76 to 1.23). There was no difference in adverse events. One infant developed bradycardia with desaturation associated with HS. Mean hospital costs were £2595 and £2727 for the control and intervention groups, respectively (p = 0.657). Incremental QALYs were 0.0000175 (p = 0.757). An incremental cost-effectiveness ratio of £7.6M per QALY gained was not appreciably altered by sensitivity analyses. The systematic review comprised 15 trials (n = 1922) including our own. HS reduced the mean LoS by -0.36 days (95% CI -0.50 to -0.22 days). High levels of heterogeneity (I (2) = 78%) indicate that the result should be treated cautiously. CONCLUSIONS: In this trial, HS had no clinical benefit on LoS or readiness for discharge and was not a cost-effective treatment for acute bronchiolitis. Claims that HS achieves small reductions in LoS must be treated with scepticism. FUTURE WORK: Well-powered randomised controlled trials of high-flow oxygen are needed. STUDY REGISTRATION: This study is registered as NCT01469845 and CRD42014007569. FUNDING DETAILS: This project was funded by the NIHR Health Technology Assessment (HTA) programme and will be published in full in Health Technology Assessment; Vol. 19, No. 66. See the HTA programme website for further project information.

SABRE: a multicentre randomised control trial of nebulised hypertonic saline in infants hospitalised with acute bronchiolitis.

AIM: Acute bronchiolitis is the commonest cause for hospitalisation in infancy. Supportive care remains the cornerstone of current management and no other therapy has been shown to influence the course of the disease. It has been suggested that adding nebulised hypertonic saline to usual care may shorten the duration of hospitalisation. To determine whether hypertonic saline does have beneficial effects we undertook an open, multi-centre parallel-group, pragmatic RCT in ten UK hospitals. METHODS: Infants admitted to hospital with a clinical diagnosis of acute bronchiolitis and requiring oxygen therapy were randomised to receive usual care alone or nebulised 3% hypertonic saline (HS) administered 6-hourly. Randomisation was within 4 h of admission. The primary outcome was time to being assessed as 'fit' for discharge with secondary outcomes including time to discharge, incidence of adverse events together with follow up to 28 days assessing patient centred health related outcomes. RESULTS: A total of 317 infants were recruited to the study. 158 infants were randomised to HS (141 analysed) and 159 to standard care (149 analysed). There was no difference between the two arms in time to being declared fit for discharge (hazard ratio: 0-95, 95% CI: 0.75-1.20) nor to actual discharge (hazard ratio: 0.97, 95% CI: 0.76-1.23). There was no difference in adverse events. One infant in the HS group developed bradycardia with desaturation. CONCLUSION: This study does not support the use of nebulised HS in the treatment of acute bronchiolitis over usual care with minimal handlings. CLINICALTRIALSGOV REGISTRATION NUMBER: NCT01469845.

Macrophages are required for dendritic cell uptake of respiratory syncytial virus from an infected epithelium.

We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells.

Pneumothorax from subpleural blebs-a new association of sotos syndrome?

We describe two unrelated patients with molecularly confirmed Sotos syndrome with multiple subpleural blebs and pneumothorax. We propose this as a new association. Patient 1 is a 3-year-old boy with a 1.9 Mb interstitial deletion of the long arm of chromosome 5, with breakpoints at q35.2 and q35.3, encompassing NSD1 and Patient 2 is a 9-year-old girl with a de novo truncating mutation within NSD1. Both patients presented with sudden onset dyspnea due to a unilateral pneumothorax: Patient 1 at the age of 18 months and Patient 2 at 9 years. In both, the pneumothorax recurred following removal of the chest drain and, on further investigations, multiple subpleural blebs were identified necessitating a pleurodesis and tissue resection. This is the first report of multiple subpleural blebs leading to pneumothorax in association with Sotos syndrome. Given the similar and unusual presentation in the two affected patients, we suggest that this may be a real association, albeit a rare one. While screening would not be advocated for such a rare association, we recommend that clinicians consider pneumothorax in patients with Sotos syndrome and sudden onset of dyspnea and are aware that it may be refractory to first line treatment.