Nebulised bronchodilators, antibiotics and rhDNase for children with cystic fibrosis.

Bronchodilators syndrome occurring in association with ipratropium. Nebulised bronchodilators are used extensively in children with cystic fibrosis, but in many Optimal dosage regimens for b agonists have not been investigated, and doses given to chilinstances this use is not yet based on objective evidence of clinical benefit. dren with cystic fibrosis are usually similar to those used in asthma. It has been suggested that these doses should be calculated according to body weight, but whether this refinement    is of any practical significance in cystic fibrosis The main effect of bronchodilators is probably is unknown. to reduce smooth muscle spasm in the airways If a decision has been made to give inhaled of patients with cystic fibrosis. In addition, bronchodilators to a child with cystic fibrosis, improved mucociliary clearance has been selection of the mode of administration deshown in vivo following subcutaneous adserves careful consideration because the time ministration of terbutaline to adults with cystic and effort taken to deliver nebulised bronchofibrosis and also, theoretically, b agonists might dilators is of critical importance if other reduce inflammatory damage. The relative nebulised treatments such as antibiotics and importance of these mechanisms and their clinrhDNase are prescribed concurrently. Mixing ical relevance are unknown. of antibiotics and rhDNase in the same nebuThe occurrence of reversible airways obliser chamber is not recommended and an struction in children with cystic fibrosis is interval of 30 minutes should be allowed belargely a reflection of the frequency of asthma tween giving these two medications. Such rein the whole paediatric population (perhaps gimens are onerous and to allow children to 15%), as well as an increase in bronchial refollow a near normal lifestyle it is imperative sponsiveness secondary to the complex chronic to avoid giving nebulised bronchodilators when inflammation present in their airways. Over a administration by hand held inhalers would be third of patients with cystic fibrosis will show equally effective. evidence of reversible airways obstruction at some time, but the response in individuals is extremely variable. The interpretation of these results is hampered by poor reAntibiotics producibility of pulmonary function measThe use of nebulised antibiotics is discussed in urements. In view of this variability a detail in the paper by Webb and Dodd on pp therapeutic trial of regular b agonists is apS69–71. Here the use of nebulised antibiotics is propriate in children with cystic fibrosis who considered specifically in relation to paediatric wheeze, or in cases where there is a marked practice. improvement in symptoms or pulmonary funcThe study by Valerius et al demonstrated tion following a test dose. The routine use of that chronic colonisation with Pseudomonas methacholine challenge is not recommended. aeruginosa in patients with cystic fibrosis could It is not known whether the responses to b be delayed by the use of oral ciprofloxacin agonists or anticholinergic agents vary with age. and nebulised colistin. Longer term studies are required to determine the duration of benefit and whether repeated courses of treatment are beneficial or whether P aeruginosa is isolated 