Longitudinal assessment of lung clearance index to monitor disease progression in children and adults with cystic fibrosis.

BACKGROUND: Lung clearance index (LCI) is a valuable research tool in cystic fibrosis (CF) but clinical application has been limited by technical challenges and uncertainty about how to interpret longitudinal change. In order to help inform clinical practice, this study aimed to assess feasibility, repeatability and longitudinal LCI change in children and adults with CF with predominantly mild baseline disease. METHODS: Prospective, 3-year, multicentre, observational study of repeated LCI measurement at time of clinical review in patients with CF >5 years, delivered using a rapid wash-in system. RESULTS: 112 patients completed at least one LCI assessment and 98 (90%) were still under follow-up at study end. The median (IQR) age was 14.7 (8.6-22.2) years and the mean (SD) FEV1 z-score was -1.2 (1.3). Of 81 subjects with normal FEV1 (>-2 z-scores), 63% had raised LCI (indicating worse lung function). For repeat stable measurements within 6 months, the mean (limits of agreement) change in LCI was 0.9% (-18.8% to 20.7%). A latent class growth model analysis identified four discrete clusters with high accuracy, differentiated by baseline LCI and FEV1. Baseline LCI was the strongest factor associated with longitudinal change. The median total test time was under 19 min. CONCLUSIONS: Most patients with CF with well-preserved lung function show stable LCI over time. Cluster behaviours can be identified and baseline LCI is a risk factor for future progression. These results support the use of LCI in clinical practice in identifying patients at risk of lung function decline.

Interventions for preventing distal intestinal obstruction syndrome (DIOS) in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is the most common, life-limiting, genetically inherited disease. It affects multiple organs, particularly the respiratory system. However, gastrointestinal problems such as constipation and distal intestinal obstruction syndrome (DIOS) are also important and well-recognised complications in CF. They share similar symptoms e.g. bloating, abdominal pain, but are distinct conditions. Constipation occurs when there is gradual faecal impaction of the colon, but DIOS occurs when there is an accumulation of faeces and sticky mucus, forming a mass in the distal part of the small intestine. The mass may partially block the intestine (incomplete DIOS) or completely block the intestine (complete DIOS). Symptoms of DIOS can affect quality of life and other aspects of CF health, such as airway clearance, exercise, sleep and nutritional status. Treatment of constipation and prevention of complete bowel obstruction are required for gastrointestinal management in CF. However, many different strategies are used in clinical practice and there is a lack of consensus. The importance of this topic was highlighted in a recent research priority setting exercise by the James Lind Alliance. OBJECTIVES: To evaluate the effectiveness and safety of laxative agents of differing types for preventing DIOS (complete and incomplete) in children and adults with CF. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of search: 09 September 2021. We also searched online trial registries. Date of last search: 12 October 2021. SELECTION CRITERIA: Randomised and quasi-randomised controlled parallel trials comparing laxative therapy for preventing DIOS (including osmotic agents, stimulants, mucolytics and substances with more than one action) at any dose to placebo, no treatment or an alternative laxative therapy, in people of any age with pancreatic sufficient or insufficient CF and any stage of lung disease. Randomised cross-over trials were judged on an individual basis. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion, extracted outcome data and performed a risk of bias assessment for the included data. We judged the certainty of the evidence using GRADE criteria. MAIN RESULTS: We included one cross-over trial (17 participants) with a duration of 12 months, in which participants were randomly allocated to either cisapride (a gastro-prokinetic agent) or placebo for six months each. The trial had an unclear risk of bias for most domains but had a high risk of reporting bias. Radiograph scores revealed no difference in occurrence of DIOS between cisapride and placebo (narrative report, no data provided). There were no adverse effects. Symptom scores were the only secondary outcome within the review that were reported. Total gastrointestinal symptom scores favoured cisapride with a statistically significant mean difference (MD) of -7.60 (95% confidence interval (CI) -14.73 to -0.47). There was no significant difference at six months between cisapride and placebo for abdominal distension, MD -0.90 (95% CI -2.39 to 0.59) or abdominal pain, MD -0.4 (95% CI -2.05 to 1.25). The global symptom scores (whether individuals felt better or worse) were reported in the paper to favour cisapride and be statistically significant (P < 0.05). We assessed the available data to be very low certainty. There was a great deal of missing data from the included trial and the investigators failed to report numerical data for many outcomes. The overall risk of bias of the trial was unclear and it had a high risk for reporting bias. There was also indirectness; the trial drug (cisapride) has since been removed from the market in several countries due to adverse effects, thus it has no current applicability for preventing DIOS. The included trial also had very few participants, which downgraded the certainty a further level for precision. AUTHORS' CONCLUSIONS: There is an absence of evidence for interventions for the prevention of DIOS. As there was only one included trial, we could not perform a meta-analysis of the data. Furthermore, the included trial compared a prokinetic agent (cisapride) that is no longer licensed for use in a number of countries due to the risk of serious cardiac events, a finding that came to light after the trial was conducted. Therefore, the limited findings from the trial are not applicable in current clinical practice. Overall, a great deal more research needs to be undertaken on gastrointestinal complications in CF, as this is a very poorly studied area compared to respiratory complications in CF.

Interventions for treating distal intestinal obstruction syndrome (DIOS) in cystic fibrosis.

BACKGROUND: Cystic fibrosis is the most common life-limiting autosomal recessive genetic disorder in white populations. Distal intestinal obstruction syndrome (DIOS) is an important morbidity in cystic fibrosis. It is the result of the accumulation of viscid faecal material within the bowel which combines with thick, sticky mucus produced in the intestines of people with cystic fibrosis. The intestine may be completely blocked (complete DIOS) or only partially blocked (incomplete DIOS). Once a diagnosis of DIOS has been made, the goal of therapy is to relieve the acute complete or incomplete faecal obstruction and ultimately prevent the need for surgical intervention. OBJECTIVES: This review aimed to evaluate the effectiveness and safety of different treatment regimens for the treatment of DIOS (complete and incomplete) in children and adults with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of search: 09 September 2021. We also searched online trial registries. Date of last search: 12 October 2021. SELECTION CRITERIA: Randomised controlled trials, quasi-randomised controlled trials (including cross-over trials (to be judged on an individual basis)) comparing the use of laxative agents or surgery for treating DIOS in children, young people and adults with cystic fibrosis to each other, placebo or no intervention. DATA COLLECTION AND ANALYSIS: Two authors independently screened papers, extracted trial details and assessed for risk of bias. The authors assessed the quality of evidence using GRADE. MAIN RESULTS: There was one trial with 20 participants (16 females) included in the review. The mean age of participants was 13.1 years. The trial was a double-blinded, randomised cross-over trial which had a duration of 12 months in total and compared high-dose and low-dose pancreatic enzyme therapy. As only the abstract of the trial was available, the overall risk of bias was judged to be unclear. The trial did not address either of our primary outcomes (time until resolution of DIOS and treatment failure rate), but reported episodes of acute DIOS, presence of abdominal mass and abdominal pain. There were no numerical data available for these outcomes, but the authors stated that there was no difference between treatment with high-dose or low-dose pancreatic enzymes. The overall certainty of the evidence was found to be very low. AUTHORS' CONCLUSIONS: There is a clear lack of evidence for the treatment of DIOS in people with cystic fibrosis. The included abstract did not address our primary outcome measures and did not provide numerical data for the two secondary outcomes it did address. Therefore, we cannot justify the use of high-dose pancreatic enzymes for treating DIOS, nor can we comment on the efficacy and safety of other laxative agents. From our findings, it is clear that more randomised controlled trials need to be conducted in this area.

Interventions for treating distal intestinal obstruction syndrome (DIOS) in cystic fibrosis.

BACKGROUND: Cystic fibrosis is the most common life-limiting autosomal recessive genetic disorder in white populations. Distal intestinal obstruction syndrome (DIOS) is an important morbidity in cystic fibrosis. It is the result of the accumulation of viscid faecal material within the bowel which combines with thick, sticky mucus produced in the intestines of people with cystic fibrosis. The intestine may be completely blocked (complete DIOS) or only partially blocked (incomplete DIOS). Once a diagnosis of DIOS has been made, the goal of therapy is to relieve the acute complete or incomplete faecal obstruction and ultimately prevent the need for surgical intervention. OBJECTIVES: This review aimed to evaluate the effectiveness and safety of different treatment regimens for the treatment of DIOS (complete and incomplete) in children and adults with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews.Date of last search: 24 July 2018.We also searched the following trials registries and other resources: ClinicalTrials.gov; International Standard Randomised Controlled Trial Number (ISRCTN) Registry; the WHO International Clinical Trials Registry; and Open Grey.Date of last searches: 10 June 2018. SELECTION CRITERIA: Randomised controlled trials, quasi-randomised controlled trials (including cross-over trials (to be judged on an individual basis)) comparing the use of laxative agents or surgery for treating DIOS in children, young people and adults with cystic fibrosis to each other, placebo or no intervention. DATA COLLECTION AND ANALYSIS: Two authors independently screened papers, extracted trial details and assessed for risk of bias. The authors assessed the quality of evidence using GRADE. MAIN RESULTS: There was one trial with 20 participants (16 females) included in the review. The mean age of participants was 13.1 years. The trial was a double-blinded, randomised cross-over trial which had a duration of 12 months in total and compared high-dose and low-dose pancreatic enzyme therapy. As only the abstract of the trial was available, the overall risk of bias was judged to be unclear. The trial did not address either of our primary outcomes (time until resolution of DIOS and treatment failure rate), but reported episodes of acute DIOS, presence of abdominal mass and abdominal pain. There were no numerical data available for these outcomes, but the authors stated that there was no difference between treatment with high-dose or low-dose pancreatic enzymes. The overall quality of the evidence was found to be very low. AUTHORS' CONCLUSIONS: There is a clear lack of evidence for the treatment of DIOS in people with cystic fibrosis. The included abstract did not address our primary outcome measures and did not provide numerical data for the two secondary outcomes it did address. Therefore, we cannot justify the use of high-dose pancreatic enzymes for treating DIOS, nor can we comment on the efficacy and safety of other laxative agents. From our findings, it is clear that more randomised controlled trials need to be conducted in this area.

Interventions for preventing distal intestinal obstruction syndrome (DIOS) in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is the most common, life-limiting, genetically inherited disease. It affects multiple organs, particularly the respiratory system. However, gastrointestinal problems such as constipation and distal intestinal obstruction syndrome (DIOS) are also important and well-recognised complications in CF. They share similar symptoms e.g. bloating, abdominal pain, but are distinct conditions. Constipation occurs when there is gradual faecal impaction of the colon, but DIOS occurs when there is an accumulation of faeces and sticky mucus, forming a mass in the distal part of the small intestine. The mass may partially block the intestine (incomplete DIOS) or completely block the intestine (complete DIOS). Symptoms of DIOS can affect quality of life and other aspects of CF health, such as airway clearance, exercise, sleep and nutritional status. Treatment of constipation and prevention of complete bowel obstruction are required for gastrointestinal management in CF. However, many different strategies are used in clinical practice and there is a lack of consensus. The importance of this topic was highlighted in a recent research priority setting exercise by the James Lind Alliance. OBJECTIVES: To evaluate the effectiveness and safety of laxative agents of differing types for preventing DIOS (complete and incomplete) in children and adults with CF. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of search: 22 May 2018.We also searched online trial registries. Date of last search: 10 June 2018. SELECTION CRITERIA: Randomised and quasi-randomised controlled parallel trials comparing laxative therapy for preventing DIOS (including osmotic agents, stimulants, mucolytics and substances with more than one action) at any dose to placebo, no treatment or an alternative laxative therapy, in people of any age with pancreatic sufficient or insufficient CF and any stage of lung disease. Randomised cross-over trials were judged on an individual basis. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion, extracted outcome data and performed a risk of bias assessment for the included data. We judged the quality of the evidence using GRADE criteria. MAIN RESULTS: We included one cross-over trial (17 participants) with a duration of 12 months, in which participants were randomly allocated to either cisapride (a gastro-prokinetic agent) or placebo for six months each. The trial had an unclear risk of bias for most domains but had a high risk of reporting bias.Radiograph scores revealed no difference in occurrence of DIOS between cisapride and placebo (narrative report, no data provided). There were no adverse effects. Symptom scores were the only secondary outcome within the review that were reported. Total gastrointestinal symptom scores favoured cisapride with a statistically significant mean difference (MD) of -7.60 (95% confidence interval (CI) -14.73 to -0.47). There was no significant difference at six months between cisapride and placebo for abdominal distension, MD -0.90 (95% CI -2.39 to 0.59) or abdominal pain, MD -0.4 (95% CI -2.05 to 1.25). The global symptom scores (whether individuals felt better or worse) were reported in the paper to favour cisapride and be statistically significant (P < 0.05).We assessed the available data to be very low quality. There was a great deal of missing data from the included trial and the investigators failed to report numerical data for many outcomes. The overall risk of bias of the trial was unclear and it had a high risk for reporting bias. There was also indirectness; the trial drug (cisapride) has since been removed from the market in several countries due to adverse effects, thus it has no current applicability for preventing DIOS. The included trial also had very few participants, which downgraded the quality a further level for precision. AUTHORS' CONCLUSIONS: There is an absence of evidence for interventions for the prevention of DIOS. As there was only one included trial, we could not perform a meta-analysis of the data. Furthermore, the included trial compared a prokinetic agent (cisapride) that is no longer licensed for use in a number of countries due to the risk of serious cardiac events, a finding that came to light after the trial was conducted. Therefore, the limited findings from the trial are not applicable in current clinical practice.Overall, a great deal more research needs to be undertaken on gastrointestinal complications in CF, as this is a very poorly studied area compared to respiratory complications in CF.

Research is the Future, the Future is .

Over the past two decades, Professor Lenney has established the Paediatric Respiratory Department at the Royal Stoke University Hospital as a centre recognised for high quality research. A broad portfolio of clinical and laboratory based research is in progress. Four research areas are discussed that are likely to contribute to the continued academic output from the unit. These are the use of selected ion flow tube mass spectrometry for the detection of biomarkers associated with pulmonary pathogens, the measurement of lung clearance index in preschool children, structured light plethysmography in children and the use of oral prednisolone for asthma exacerbations in children.

A review of prednisolone prescribing for children with acute asthma in the UK.

INTRODUCTION: Worldwide asthma guidelines recommend short courses of oral prednisolone in children with acute exacerbations generating high prescription numbers. There is a paucity of evidence to inform the optimal dose and course duration. This has led to a variation in the recommendations for prednisolone prescribing. Our objective was to assess prednisolone prescribing practise for children with acute asthma in a representative sample of UK prescribers. METHODS: We developed an online questionnaire asking prescribers the prednisolone dosage, course duration and formulation used, whether they discussed oral prednisolone side effects with the family and at what child's age they changed from prescribing soluble to non-soluble formulations. This was sent to 1006 UK prescribers including Paediatric Respiratory Consultants, doctors in training, asthma nurses and General Practitioners. RESULTS: 200 complete responses were received (response rate 20%). The majority of surveyed prescribers follow the British National Formulary for Children recommendations on dosage rather than those included in the British Thoracic Society and the Scottish Intercollegiate Guidelines Network. Despite this, we highlighted a 4-fold variation in prednisolone dosages for acute asthma. The majority of prescribers chose 3 days as the course duration. High use of soluble formulations was highlighted. CONCLUSIONS: There is wide variation in the dose of prednisolone prescribed for children with acute asthma in the UK. This reflects a relative lack of evidence that needs addressing.

Outcome data from 15 years of cystic fibrosis newborn screening in a large UK region.

BACKGROUND: The West Midlands Newborn Bloodspot Screening Laboratory is one of 16 in the UK and serves two tertiary paediatric cystic fibrosis (CF) centres (Staffordshire Children's Hospital at Royal Stoke and Birmingham Children's Hospital). CF newborn bloodspot screening (NBS) in this region started in November 2006 prior to the UK national roll-out in 2007. It uses an immunoreactive trypsinogen (IRT)/DNA/IRT protocol. We report the outcomes from 15 years of CF screening. METHODS: The West Midlands CF NBS outcomes from 1 November 2006 to 31 October 2021 were reviewed. Clinical data were also obtained for babies referred to the CF centres as 'CF suspected'. RESULTS: 1 075 161 babies were screened, with 402 referred as 'CF suspected' and 205 identified as CF carriers. Of the 'CF suspected' babies, 268 were diagnosed with CF, 33 with CF screen positive, inconclusive diagnosis (CFSPID) and 17 as a CF carrier. Any CF-related diagnosis was excluded in 67. Outcome data were not available for 17, of whom 14 had died. Eighteen children with a negative CF NBS have subsequently been diagnosed with CF, 10 had meconium ileus and 8 were true 'affected not detected', presenting with respiratory symptoms or failure to thrive. This gives the West Midlands a CF birth prevalence of 1 in 4012 live births and the NBS protocol a sensitivity of 97.1% and a positive predictive value of 66.7%. CONCLUSIONS: This large regional data set has excellent case ascertainment and demonstrates successful performance of the CF NBS protocol, with low numbers identified as CFSPID or CF carriers.

ALPINE2: Efficacy and safety of 14-day vs 28-day inhaled aztreonam for Pa eradication in children with cystic fibrosis.

BACKGROUND: Antibiotic eradication therapies recommended for newly isolated Pseudomonas aeruginosa (Pa) in people with cystic fibrosis (pwCF) can be burdensome. ALPINE2 compared the efficacy and safety of a shortened 14-day course of aztreonam for inhalation solution (AZLI) with 28-day AZLI in paediatric pwCF. METHODS: ALPINE2 (a double-blind, phase 3b study) included children aged 3 months to <18 years with CF and new-onset Pa infection. Participants were randomized to receive 75 mg AZLI three times daily for either 28 or 14 days followed by 14 days' matched placebo. The primary endpoint was rate of primary Pa eradication (no Pa detected during the 4 weeks post AZLI treatment). Non-inferiority was achieved if the lower 95% CI bound of the treatment difference between the two arms was above -20%. Secondary endpoints included assessments of Pa recurrence during 108 weeks of follow-up after primary eradication. Safety endpoints included treatment-emergent adverse events (TEAEs). RESULTS: In total, 149 participants were randomized (14-day AZLI, n = 74; 28-day AZLI, n = 75) and 142 (95.3%) completed treatment. Median age: 6.0 years (range: 0.3-17.0). Baseline characteristics were similar between treatment arms. Primary Pa eradication rates: 14-day AZLI, 55.9%; 28-day AZLI, 63.4%; treatment difference (CI), -8.0% (-24.6, 8.6%). Pa recurrence rates at follow-up end: 14-day AZLI, 54.1% (n = 20/37); 28-day AZLI, 41.9% (n = 18/43). TEAEs were similar between treatment arms. No new safety signals were observed. CONCLUSIONS: Non-inferiority of 14-day AZLI versus 28-day AZLI was not demonstrated. Both courses were well tolerated, further supporting AZLI short-term safety in paediatric and adolescent pwCF. CLINICALTRIALS: GOV: NCT03219164.

Is hydrogen cyanide a marker of Burkholderia cepacia complex?

Biofilm cultures of Burkholderia cepacia complex (BCC) infection have been found to generate the nonvolatile cyanide ion. We investigated if gaseous hydrogen cyanide (HCN) was a marker of BCC infection. Selected ion flow tube mass spectrometry analysis showed HCN was not elevated in the headspace of planktonic or biofilm cultures or in the exhaled breath of adult cystic fibrosis patients with chronic BCC infection. HCN is therefore not an in vitro or in vivo marker of BCC.

Implementation of a primary care asthma management quality improvement programme across 68 general practice sites.

Despite national and international guidelines, asthma is frequently misdiagnosed, control is poor and unnecessary deaths are far too common. Large scale asthma management programme such as that undertaken in Finland, can improve asthma outcomes. A primary care asthma management quality improvement programme was developed with the support of the British Lung Foundation (now Asthma + Lung UK) and Optimum Patient Care (OPC) Limited. It was delivered and cascaded to all relevant staff at participating practices in three Clinical Commissioning Groups. The programme focussed on improving diagnostic accuracy, management of risk and control, patient self-management and overall asthma control. Patient data were extracted by OPC for the 12 months before (baseline) and after (outcome) the intervention. In the three CCGs, 68 GP practices participated in the programme. Uptake from practices was higher in the CCG that included asthma in its incentivised quality improvement programme. Asthma outcome data were successfully extracted from 64 practices caring for 673,593 patients. Primary outcome (Royal College of Physicians Three Questions [RCP3Q]) data were available in both the baseline and outcome periods for 10,328 patients in whom good asthma control (RCP3Q = 0) increased from 36.0% to 39.2% (p < 0.001) after the intervention. The odds ratio of reporting good asthma control following the intervention was 1.15 (95% CI 1.09-1.22), p < 0.0001. This asthma management programme produced modest but highly statistically significant improvements in asthma outcomes. Key lessons learnt from this small-scale implementation will enable the methodology to be improved to maximise benefit in a larger scale role out.

How do children and their caregivers perceive the benefits of inhaled asthma therapy?

OBJECTIVE: Although well reported in adults, there is relatively little data on how children with asthma and their parents describe their attitudes to the disease, expectations of therapy, and perception of treatment benefit. We investigated this to determine if they differed from reports by adults with asthma. METHODS: We recruited families with an asthmatic child (4-11 years) who had recently been prescribed a change in treatment [starting inhaled corticosteroid monotherapy (ICS) or changing from ICS to inhaled corticosteroid/long-acting ß(2)-agonist combination therapy (ICS/LABA)]. Semi-structured interviews were conducted with the parents and the children if aged 7-11 years. RESULTS: We interviewed 28 parents and 13 children. All children on ICS/LABA had been changed from ICS monotherapy because of poor asthma control. Pediatric asthma had a significant impact on the whole family and both parents and children hoped the new medication would improve symptoms, increase their participation in physical activities, and decrease unscheduled visits to the GP (General Practitioner)/hospital. Positive effects of treatment change were reported by both parents and children, particularly in those changing from ICS to ICS/LABA. The most commonly reported benefits were reduced cough and wheeze, increased participation in sport or play activities, and reduced rescue medication use. These effects resulted in fewer visits to the GP/hospital and better attendance at school. CONCLUSIONS: While asthma symptoms prevent adults and children from participating in different types of activities (e.g., school, employment), children and their parents report the same benefits as previously reported in adults with asthma.

Why are children with asthma bullied? A risk factor analysis.

The links between bullying and asthma have not been explored in children. We wanted to determine the child/parent factors and attitudes associated with asthma-related bullying. Individual child/parent responses of children with asthma (N=943) from the Room to Breathe survey were analysed. 1 in 10 children reported asthma-related bullying/teasing (n=93). Children with well-controlled asthma were less likely to report being a victim of asthma-related bullying/teasing (OR 0.51, 95% CI 0.23 to 0.84, p=0.006). Being a victim of bullying/teasing was more common in children reporting activity restriction (OR 1.74, 95% CI 1.11 to 2.75, p=0.010), who described their asthma as 'bad' (OR 3.02, 95% CI 1.86 to 4.85, p<0.001) and those whose parents reported ongoing asthma-related health worries (OR 1.64, 95% CI 1.04 to 2.58, p=0.024). Asthma consultations should incorporate specific questions about bullying and be child-focused in order to gain a representative appreciation of asthma control and its impact on the child's life.

Protocol for CLASSIC PBB: comparison of lower airway sampling strategies in children with protracted bacterial bronchitis.

BACKGROUND: Protracted bacterial bronchitis (PBB) is an endobronchial infection and a the most common cause of chronic wet cough in young children. It is treated with antibiotics, which can only be targeted if the causative organism is known. As most affected children do not expectorate sputum, lower airway samples can only be obtained by bronchoalveolar lavage (BAL) samples taken during flexible bronchoscopy (FB-BAL). This is invasive and is therefore reserved for children with severe or relapsing cases. Most children with PBB are treated empirically with broad spectrum antibiotics. CLASSIC PBB will compare the pathogen yield from two less invasive strategies with that from FB-BAL to see if they are comparable. METHODS: 131 children with PBB from four UK centres referred FB-BAL will be recruited. When attending for FB-BAL, they will have a cough swab and an induced sputum sample obtained. The primary outcome will be the discordance of the pathogen yield from the cough swab and the induced sputum when compared with FB-BAL. Secondary outcomes will be the sensitivity of each sampling strategy, the success rate of the induced sputum in producing a usable sample and the tolerability of each of the three sampling strategies. DISCUSSION: If either or both of the two less invasive airway sampling strategies are shown to be a useful alternative to FB-BAL, this will lead to more children with PBB having lower airway samples enabling targeted antibiotic prescribing. It would also reduce the need for FB, which is known to be burdensome for children and their families. TRIAL REGISTRATION NUMBER: ISRCTN79883982.

Single-centre survey of parents regarding the hidden burden of paediatric flexible bronchoscopy.

Although paediatric flexible bronchoscopy is safe with relatively few side effects, parents frequently report an associated burden. To assess this, we undertook 25 semi-structured interviews with the parents of children who had recently undergone this procedure. Despite reporting the procedure was well explained, parental worry about procedure was common. The procedure resulted in children missing a median of 2 days from nursery/school and the parents having to take a median of 2 days carers leave. There was an additional financial burden related to sibling childcare, travel costs and car parking. Clinicians should address these issues in pre-procedure counselling.

Duration of initial antibiotic course is associated with recurrent relapse in protracted bacterial bronchitis.

Protracted bacterial bronchitis (PBB) is the leading cause of chronic wet cough in young children from developed countries. Despite its high prevalence there is a paucity of evidence to inform the optimal duration of treatment leading to variation in practice. Relapse of chronic cough is common and recurrent PBB (>3 episodes in 12 months) is associated with a future diagnosis of bronchiectasis. We investigated the factors associated with any relapse (≥1 episode in 12 months) and recurrent PBB in 66 children. No factor was significantly associated with any relapse. Duration of initial antibiotic treatment was the only factor significantly associated with recurrent PBB. Those who received antibiotics for 6 weeks antibiotics were less likely to develop recurrent PBB than those who received for 2 weeks (p=0.046). This is the first study to show an association between duration of initial antibiotic course and therefore future bronchiectasis. Prospective studies are needed to investigate this association.

Developing a core outcome set for children with protracted bacterial bronchitis.

BACKGROUND: Protracted bacterial bronchitis (PBB) is a chronic endobrochial infection and a leading cause of chronic wet cough in children. There is an urgent need for a randomised controlled trial to investigate the optimal treatment but there is no core outcome set (COS) to inform choice of outcomes. A COS is a standardised set of outcomes representing the minimum that should be measured and reported in clinical trials of a specific condition. We have developed a COS for PBB. METHODS: Potential core outcomes were collated from a systematic review, interviews with parents and a clinician survey. A two-round Delphi survey of healthcare professionals identified which outcomes had consensus for inclusion. The final COS was agreed at a consensus meeting of parent representatives and clinicians. RESULTS: 20 outcomes were identified for the Delphi survey. After two rounds, 10 reached consensus. These were combined and edited at the consensus meeting into the final six: 1) Resolution of cough assessed using a cough score/diary recorded daily by parent(s) during treatment; 2) relapse of chronic wet cough and/or cumulative antibiotic treatment during ≥12 months follow-up; 3) change in child's quality of life (parent-proxy reporting for young children); 4) emergence of antibiotic resistance; 5) development of bronchiectasis diagnosed on clinically indicated computed tomography scans; and 6) microbiological clearance of identified respiratory pathogen if samples readily available. CONCLUSIONS: We have developed a COS for PBB which will reduce the outcome heterogeneity and bias of future clinical trials, as well as promoting comparison between studies.

Lung clearance index in healthy volunteers, measured using a novel portable system with a closed circuit wash-in.

INTRODUCTION: Lung clearance index (LCI) is a sensitive measure of early lung disease, but adoption into clinical practice has been slow. Challenges include the time taken to perform each test. We recently described a closed-circuit inert gas wash-in method that reduces overall testing time by decreasing the time to equilibration. The aim of this study was to define a normative range of LCI in healthy adults and children derived using this method. We were also interested in the feasibility of using this system to measure LCI in a community setting. METHODS: LCI was assessed in healthy volunteers at three hospital sites and in two local primary schools. Volunteers completed three washout repeats at a single visit using the closed circuit wash-in method (0.2% SF6 wash-in tracer gas to equilibrium, room air washout). RESULTS: 160 adult and paediatric subjects successfully completed LCI assessment (95%) (100 in hospital, 60 in primary schools). Median coefficient of variation was 3.4% for LCI repeats and 4.3% for FRC. Mean (SD) LCI for the analysis cohort (n = 53, age 5-39 years) was 6.10 (0.42), making the upper limit of normal LCI 6.8. There was no relationship between LCI and multiple demographic variables. Median (interquartile range) total test time was 18.7 (16.0-22.5) minutes. CONCLUSION: The closed circuit method of LCI measurement can be successfully and reproducibly measured in healthy volunteers, including in out-of-hospital settings. Normal range appears stable up to 39 years. With few subjects older than 40 years, further work is required to define the normal limits above this age.

Healthcare utilisation in children with SMA type 1 treated with nusinersen: a single centre retrospective review.

BACKGROUND: Nusinersen has been used to treat spinal muscular atrophy type 1 (SMA1) in the UK since 2017. While initial trials showed neuromuscular benefit from treating SMA1, there is little information on the respiratory effects of nusinersen. We aimed to look at the respiratory care, hospital utilisation and associated costs in newly treated SMA1. METHODS: We reviewed the medical records of all children within the West Midlands with SMA1 treated with nusinersen at Royal Stoke University Hospital. Baseline demographics and hospital admission data were collected including: the reason for admission, total hospital days, days of critical care, days intubated, discharge diagnosis, doses of nusinersen and treatment complications. RESULTS: 11 children (six girls) received nusinersen between May 2017 and April 2019. Their median (range) age was 29 (7-97) months. The median (range) number of nusinersen doses per child was 6 (4-8). All children were receiving long-term ventilatory support; this was mask ventilation in nine and tracheostomy ventilation in two. The total number of hospital days since diagnosis was 1101 with a median (range) of 118 (7-235) days per child. This included general paediatric ward days 0 (0-63), High Dependency Unit 79 (7-173) days and Paediatric Intensive Care Unit 13 (0-109) days per child. This equated to a median (range) of 20 (2-72) % of their life in hospital. The estimated cost of this care was £2.2M. CONCLUSION: Patients with SMA1 treated with nusinersen initially spend a considerable proportion of their early life in hospital. Parents should be counselled accordingly. These data suggest that for every 10 children started on nusinersen an extra HDU bed is required. This has a significant cost implication.