Previously published studies have indicated that gastroesophageal reflux (GER) disease is common in pediatric patients with cystic fibrosis. The aim of the present study was to get insight into the incidence of GER and to characterize the nature of reflux episodes in children with cystic fibrosis. This was a multicenter, prospective study of children with cystic fibrosis older than 18 months. Forty four consecutive patients (22 boys, mean age 10.4 ± 3.6, range 3.0-17.8 years) were enrolled into the study. All patients underwent 24 h pH-impedance monitoring. GER were classified according to the widely recognized criteria as an acid, weakly acid, weakly alkaline, or proximal. The pH-impedance trace was considered abnormal when acid exposure was >6 %. GER was diagnosed in 24/44 (54.5 %) children. A total of 1585 (median 35, range 7-128) reflux episodes were detected; 1199 (75.6 %) were acidic, 382 (24.1 %) weakly acidic, and 4 (0.3 %) weakly alkaline. Six hundred and ninety-one (43.6 %) reflux episodes reached the proximal esophagus. In 14/44 patients typical GER symptoms were present. We conclude that the incidence of GER in children with cystic fibrosis is very high. In the majority of patients typical GER symptoms are absent. Therefore, diagnostic procedures should be considered, regardless of lacking symptoms. Although acid reflux episodes predominate in children with cystic fibrosis, classical pH-metry may not constitute a sufficient diagnostic method in this population because of a relatively high number of proximal reflux episodes. Such episodes also indicate an increased risk for aspiration. The pH-impedance diagnostic measurement is advocated when suspecting GER in children with cystic fibrosis.
Keywords: Children; Cystic fibrosis; Gastroesophageal reflux; Nonacidic reflux; pH-impedance.