There is poor agreement on definitions of different phenotypes of preschool wheezing disorders. The present Task Force proposes to use the terms episodic (viral) wheeze to describe children who wheeze intermittently and are well between episodes, and multiple-trigger wheeze for children who wheeze both during and outside discrete episodes. Investigations are only needed when in doubt about the diagnosis.Based on the limited evidence available, inhaled short-acting b 2 -agonists by metered-dose inhaler/spacer combination are recommended for symptomatic relief. Educating parents regarding causative factors and treatment is useful. Exposure to tobacco smoke should be avoided; allergen avoidance may be considered when sensitisation has been established. Maintenance treatment with inhaled corticosteroids is recommended for multiple-trigger wheeze; benefits are often small. Montelukast is recommended for the treatment of episodic (viral) wheeze and can be started when symptoms of a viral cold develop.Given the large overlap in phenotypes, and the fact that patients can move from one phenotype to another, inhaled corticosteroids and montelukast may be considered on a trial basis in almost any preschool child with recurrent wheeze, but should be discontinued if there is no clear clinical benefit.Large well-designed randomised controlled trials with clear descriptions of patients are needed to improve the present recommendations on the treatment of these common syndromes.

Aims-To compare the use of health care resources and associated costs between infants with chronic lung disease (CLD) who had or had not an admission with a proven respiratory syncytial virus (RSV) infection. Methods-Review of community care, outpatient attendances, and readmissions in the first two years after birth. Patients: 235 infants (median gestational age 27 weeks) evaluated in four groups: 45 infants with a proven RSV admission (RSV proven); 24 with a probable bronchiolitis admission; 60 with other respiratory admissions; and 106 with non-respiratory or no admissions. Results-The RSV proven compared to the other groups required more frequent and longer admissions to general paediatric wards and intensive care units, more outpatient attendances and GP consultations for respiratory related disorders, and had a higher total cost of care. Conclusion-RSV hospitalisation in patients with CLD is associated with increased health service utilisation and costs in the first two years after birth.

This study provides proof of principle that HCN is detectable in the breath of children with CF and is elevated compared to children with asthma. Further studies are required to capture data from acutely unwell children and more accurately delineate responses to treatment.

Pseudomonas aeruginosa (PA) is associated with a distinctive smell produced by a combination of volatile compounds (VCs). Selected ion flow tube mass spectrometry (SIFT-MS) provides a novel and rapid methodology for rapid, accurate detection of trace quantities (parts per billion; ppb) of VCs in air. We studied the VCs produced by different isolates of PA cultures in vitro from patients with cystic fibrosis. Twenty-one patients with cystic fibrosis provided sputum and cough swab samples for culture. These were used to inoculate blood agar (BA) and Pseudomonas-selective media (PSM). These plates were incubated for 48 hr at 37 degrees C inside sealed plastic bags. The air surrounding the samples after 48 hr (headspace) was analyzed using SIFT-MS. PA growth was commonly associated with the production of significant quantities of VCs, notably hydrogen cyanide gas (HCN). This was detectable in the headspace of 15/22 of PA-positive samples. In contrast, it was only seen in the headspace of 1/13 control samples (6 sterile plates and 7 plates with only mixed upper respiratory tract flora). The concentration of HCN was significantly higher above PA-positive samples than above other bacterial growth (P < 0.01), and in our study, levels of HCN greater than 100 ppb were a sensitive (68%) and highly specific (100%) biomarker of PA. SIFT-MS can detect a range of VCs from PA in vitro. HCN may be a specific indicator of PA infection in vivo, and offers promise as a biomarker for noninvasive detection of PA infection by breath analysis.

The published results of breath isoprene studies, to date largely involving adults, are briefly reviewed with special attention given to the work done on this topic during the last 10 years using selected ion flow tube mass spectrometry, SIFT-MS. Then the new data recently obtained on isoprene levels in the exhaled breath of some 200 healthy children and young adults (pupils) with ages ranging from 7 to 18 years measured using SIFT-MS are presented in detail. A concentration distribution has been constructed from the data obtained and compared to that for healthy adults also obtained from SIFT-MS data. Although there is overlap between the two distributions, which are close to log normal in both cases, the median level for the young cohort is much lower at 37 parts-per-billion, pbb, geometric standard deviation, GSD, 2.5, compared to that for the adult cohort of 106 ppb with a GSD of 1.65. Further to this, there is a clear increase in the mean breath isoprene concentration with age for the young cohort with a doubling of the level about every 5-6 years until it reaches the age-invariant mean level of that for adult cohort. Should this trend be extrapolated downwards in age it would indicate a near-zero breath isoprene in the newborn that was indicated by a previous study. Indeed, in the present study isoprene was not detected on the breath of two young children. The results reveal mean breath isoprene levels (±SD) for pupils within the given age ranges as 7-10 years (28 ± 24 ppb), 10-13 years (40 ± 21 ppb), 13-16 years (60 ± 41 ppb) and 16-19 years (54 ± 31 ppb). The more rapid increase that occurs between the second and third age ranges is statistically highly significant (p = 0.001) and we attribute this phenomenon to the onset of puberty and the spurt in growth that occurs during this phase of development. There is no significant difference in mean breath isoprene between males and females for both the adult cohort and the younger cohort.

No abstract

Since we first recognized the regular presence of gaseous hydrogen cyanide, HCN, in the headspace of plate cultures of the bacterium Pseudomonas aeruginosa, PA, derived from sputum of cystic fibrosis, CF, patients, and following crucial ion chemistry research that allowed accurate quantification of gaseous HCN by selected ion flow tube mass spectrometry, we have carried out many further in vitro and in vivo studies. We have measured HCN in the headspace of various PA culture types, planktonic and biofilm, significant numbers of genetically identified PA strains together with studies of HCN in the mouth-exhaled and nose-exhaled breath of healthy children and adults and those with CF. The major findings are: (i) virtually all strains of PA release HCN when cultured in vitro, as shown by the investigation of more than 150 genetically differentiated strains, both mucoid and non-mucoid. (ii) HCN is present in the mouth-exhaled breath of adults and children, but is at lower concentrations in children. Its concentration is below the detection limit in nose-exhaled breath of healthy people. (iii) HCN is present in both mouth-exhaled and nose-exhaled breath of patients with CF, suggesting the presence of PA in the lower airways as indicated by clinical microbiological cultures. With confirmation of these findings by further research and clinical trials, nose-exhaled breath HCN measurements could be an additional diagnostic tool to detect the early presence of PA in the lower airways and a non-invasive monitor to enhance the likelihood of its eradication.

Background: In prematurely born infants with chronic lung disease (CLD), RSV hospitalisation is associated with increased health service utilisation and costs in the first two years after birth. Aims: To determine whether RSV hospitalisation in the first two years was associated with chronic respiratory morbidity during the preschool years in prematurely born children who had had CLD. Methods: Retrospective review of readmissions, outpatient attendances, and community care in years 2-4 and, at age 5 years, assessment of the children's respiratory status and their health related quality of life. Comparison was made of the results of children who had had at least one hospitalisation in the first two years after birth for RSV infection (RSV group) to those of the rest of the cohort. Participants were 190 of an original cohort of 235 infants with CLD and a median gestational age 27 (range 22-33) weeks. Results: The 33 children in the RSV group, compared to the rest of the cohort, had a greater duration of hospital stay and more outpatient appointments. The RSV group had required more prescriptions for all treatments and respiratory medications, and more had used an inhaler. The cost of care of the RSV group was higher (median £2630 [J4000, US$4800], range £124-18 091 versus £1360 [J2500, US$3000], range £5-18 929) and their health related quality of life was lower. Conclusion: In prematurely born children who had developed CLD, RSV hospitalisation in the first two years was associated with chronic respiratory morbidity and increased cost of care.