No abstract

In the largest cohort of school-aged children (born very preterm in the 1990s) to undergo extensive lung function and fitness assessments, we demonstrated significant impairment in exercise capacity despite evidence of only mild small-airway obstruction and gas trapping. Additional studies are required to evaluate the cause of this exercise limitation and whether it can be improved with a training program.

Shuttle tests are simple, inexpensive field tests that have been used to estimate the cardiorespiratory status of children. It has yet to be validated in children with CF. The aim of this study was to assess the reproducibility and criterion validity of shuttle tests in children with cystic fibrosis (CF). Ninety-three CF patients aged 6 to 16 years of age with a wide range of disease severity performed the study. The 10-m shuttle test was used for children 7 years of age and younger and those deemed too chronically ill by their physicians to perform the longer test (n = 35.) All other children performed the 20-m shuttle test (n = 58). Reproducibility and criterion validity were assessed for each child over a two week period. Gas analysis was performed throughout testing using a polargraphic gas analyzer. The 10-m shuttle tests were reproducible (mean difference between tests VO(2) 2.41 mL/kg/min, CI 3.46,-0.18) and the difference from treadmill testing was not statistically significant (mean difference VO(2) 5.30 mL/kg/min, CI-7.46, 1.18). The 20-m shuttle tests were reproducible (mean difference between tests VO(2) 2.07 mL/kg/min, CI-3.90,0.60) and the difference from treadmill testing was not statistically significant (mean difference VO(2) 3.50 mL/kg/min, CI-4.90, 1.60). We conclude that when formal exercise testing with treadmill or cycle ergometer cannot be performed, the shuttle tests provide a reproducible and valid alternative.

ABSTRACT. Objective. Although dornase alfa is a widely used, aerosolized, mucolytic agent in patients with cystic fibrosis (CF), its efficacy in relation to the timing of physiotherapy has not been tested. We sought to determine whether dornase alfa is more efficacious when it is administered 30 minutes before versus 30 minutes after physiotherapy/positive expiratory pressure (PEP) therapy in clinically stable children.Methods. Using a crossover, randomized, doubleblind, and placebo-controlled trial, we undertook a 6-week study of the efficacy of dornase alfa in relation to the timing of physiotherapy at home. There were 2 treatment orders. Dornase alfa before ؉ placebo after physiotherapy/PEP for 2 weeks was followed by a 2-week washout and then the reverse order placebo before and dornase alfa after physiotherapy/PEP for the final 2 weeks. The second treatment order reversed the placebo and dornase alfa therapy for the first and last 2-week blocks. The main outcome measures used included the change in predicted percentage of forced expiratory volume in 1 second (FEV 1 ), a composite quality of wellbeing score (QWB), and a measure of aerobic fitness (maximal oxygen consumption, [VO 2max ]), determined using shuttle testing.Results. Fifty-two patients who had CF (27 female) with mild to moderate suppurative lung disease, were a mean ؎ SD age of 10.7 ؎ 3.2 years, had Shwachman scores of 86 ؎ 11.8, had predicted FEV 1 of 83% ؎ 18%, had quality of well-being score of 0.76 ؎ 0.08, and had VO 2max of 42.6 ؎ 6.3 ml/kg per min were enrolled. Fifty patients completed the study. Intention-to-treat analysis was used. Nonsignificant mean (95% confidence interval) differences in FEV 1 ABBREVIATIONS. CF, cystic fibrosis; FEV 1 , forced expiratory volume in 1 second; PEP, positive expiratory pressure; VO 2max , maximal oxygen consumption; QWB, quality of well-being score; CI, confidence interval; FEF , mid expiratory flow rate. P hysiotherapy and systemic and nebulized antibiotics have been the cornerstones of treatment in cystic fibrosis (CF) for many years. [1][2][3] The introduction of the nebulized mucolytic agent dornase alfa (Pulmozyme [Hoffman-La Roche, Dee Why, Sydney, Australia]) in the 1990s proved to be an innovative adjunct to the management of lung disease in terms of reduced pulmonary exacerbations, improved lung function, and quality-of-life measures. 3-5 Dornase alfa use varies from country to country, on the basis of patient preference, physician prescribing practices, measured benefit in an individual, and health funding arrangements. In Australia, most recent figures indicate that dornase alfa is used by 22.1% of school-aged children (5-18 years), all of whom have demonstrated a Ͼ10% improvement in forced expiratory volume in 1 second (FEV 1 ) after 4 weeks of therapy. 6 However, despite the evaluation of dornase alfa in Ͼ15 years of clinical trials, there is no evidence as to whether dornase alfa is more efficacious when delivered before or after physiotherapy. As has been shown in adults who are prescri...