Oesophageal function, acid reflux and bronchopulmonary disease : A study on children and adolescents with asthma or cystic fibrosis

Sammanfattning: This thesis comprises a literature review of gastro-ocsophageal reflux (GOR) and six studies which aim to determine the prevalence of oesophageal dysfunction (OD) and pathological GOR and their significance concerning the bronchopulmonary disease in children and adolescents with bronchial asthma or cystic fibrosis (CF). Oesophageal function was assessed by manomctry combined with oesophageal provocation tests. 24-hour two-level oesophageal pH monitoring was used to quantify GOR, to study the temporal relationship between acid reflux and asthma symptoms, and to assess the propensity to aspirate. Symptoms of OD and asthma were evaluated by interview and by the use of questionnaires. Severity of bronchopulmonary disease in the CF patients was assessed by radiography and spirometry. A double-blind placebo-controlled trial of ranitidine 150/300 mg per day over four weeks was performed in the asthma group to see if a reduction in acid reflux improved asthma. The relative significance of reflux symptoms and atopic allergy, regarding lung function and bronchial histamine reactivity in asthma, was evaluated. Pathological GOR and OD were significantly more common in asthma and CF patients than in controls. Episodes of acid reflux seemed to provoke asthma symptoms in a few patients. Ranitidine produced a significant but modest reduction in nocturnal/morning asthma symptoms in patients with pathological GOR, when compared to those with normal GOR. Asthma patients with reflux symptoms more frequently experienced asthma attacks initiated by non-specifictrigger factors than patients without such symptoms. The presence of atopic allergy was related to impaired lung function and increased bronchial hyperreactivity. Severity of OD and bronchopulmonarydisease correlated well in CF patients.OD or pathological GOR are found in the majority of children and adolescents with asthma or CF. In CF subjects OD and GOR may be parts of a vicious circle including malnutrition and progressive lung damage. In asthma acid reflux is, on the whole, a mild trigger or a modulatory factor, and appears to influence the airways via oesophago-bronchial reflexes rather than by aspiration. Atopic allergy is still more important than GOR in childhood asthma.