Bronchial provocation testing with dry powder mannitol in children with cystic fibrosis.

BACKGROUND/AIM: There has been recent interest in dry powder inhaled mannitol as a therapeutic agent in patients with cystic fibrosis (CF). It is has been shown to increase mucociliary clearance (MCC) by rehydrating the airway. To date there have been no studies exclusively in children with CF examining the effect of dry powder mannitol on the airways. The aim of this study was to determine acute tolerability of inhaled mannitol in children with CF. METHODS: Thirty-nine children (aged 8-18 years) with CF underwent a bronchial provocation challenge with incrementally increasing doses of dry powder mannitol (up to a maximum cumulative dose of 475 mg). A positive challenge was defined as a drop in FEV(1) of >or=15% from baseline. RESULTS: Nine out of 38 subjects (24%; 95% confidence interval 10-38%) had a positive challenge. Only two of these nine subjects had a PD(15) (dose of mannitol required to cause a 15% reduction in FEV(1)) prior to the 315 mg dose, the remaining seven children dropping their FEV(1) by >or=15% on the 315 or 475 mg (final) cumulative dose. We found no association between patient characteristics and a positive challenge. Although cough was common during the challenge, other adverse events were infrequent. CONCLUSIONS: We report that 24% of children with CF had a positive airway challenge with inhaled mannitol. This compares with a previously reported 12% of subjects in a study including both adults and children. We could not identify factors predictive of a positive mannitol challenge in our children.

Randomised controlled trial of nasal continuous positive airways pressure (CPAP) in bronchiolitis.

AIMS: To compare continuous positive airways pressure (CPAP) with standard treatment (ST) in the management of bronchiolitis. METHODS: Children <1 year of age with bronchiolitis and capillary PCO2 >6 kPa were recruited and randomised to CPAP or ST and then crossed over to the alternative treatment after 12 h. ST was intravenous fluids and supplemental oxygen by nasal prongs or face mask. The change in PCO2 was compared between the groups after 12 and 24 h. Secondary outcomes were change in capillary pH, respiratory rate, pulse rate and the need for invasive ventilatory support. RESULTS: 29 of 31 children completed the study. PCO2 after 12 h fell by 0.92 kPa in children treated with CPAP compared with a rise of 0.04 kPa in those on ST (p<0.015). If CPAP was used first, there was a significantly better reduction in PCO2 than if it was used second. There were no differences in secondary outcome measures. CPAP was well tolerated with no complications identified. CONCLUSIONS: This study suggests that CPAP compared with ST improves ventilation in children with bronchiolitis and hypercapnoea.

Cystic fibrosis in neonates and infants.

Cystic fibrosis (CF) is a common autosomal recessive disorder, characterized by chronic bronchopulmonary infection, pancreatic insufficiency, and subsequently, other multisystem complications. Most children are diagnosed before school age. Here we review the pathophysiology of the condition, the age-related presentations of CF up until school age, and the appropriate use of diagnostic tests. A specialist centre should supervise treatment. There are exciting new advances in monitoring techniques in the preschool years, including CT scanning, bronchoscopy and gas mixing indices. Recent advances in the knowledge of the molecular biology of CF hold out the hope of specific therapies which can reverse the underlying defect causing death from CF lung disease.