Gastroesophageal reflux (GER) in cystic fibrosis (CF) was first reported in 1975 and has a prevalence between 35% and 81%. Several factors can favor GER in CF, including delayed gastric emptying, low basal lower esophageal sphincter pressure, and an increased number of transient lower esophageal sphincter relaxations. Canadian Blog about HealthCare.
Recently, 24-h impedance-pH monitoring, which makes it possible to measure both acid and non-acid reflux, has become the gold standard for GER detection. With this technique, Blondeau studied 33 adults with CF and found increased acid reflux in 64% and increased weakly acidic reflux in 21%. This group studied 24 children with CF with the same technique and found increased GER in 67%, with GER events being mainly acidic.
The highest concern about increased GER in CF is the alleged occurrence of aspiration of (duodeno)-gastric contents into the lungs, which may result in an exaggerated bronchial inflammatory reaction. Ledson et al9 described tracheal acidification in four of 11 patients with CF, and recently bile acids (BAs) were found in the saliva of almost one-half of adults with CF and in 35% of children with CF.
The impact of increased GER/aspiration on lung function impairment in CF evolution remains unclear. Data from the European Epidemiologic Registry of CF show that patients with CF with GER have lower pulmonary function than those without GER. Limiting factors to assess the relevance of GER and aspiration in CF are the invasiveness of reflux monitoring and lack of sensitive and specific markers to screen for aspiration. Detection of duodenogastric markers in BAL fluid (BALF) is specific but not practical because bronchoscopy is invasive and not routinely performed for patients with CF. Measuring the presence of duodenogastric components in saliva is simple, but, if positive, only indicates regurgitation of gastric contents and suggests a higher risk for aspiration. In contrast, detection of duodenogastric components in sputum is noninvasive and can confirm aspiration into the airways.