6.8. Recurrent Pneumonia Recurrent pneumonia and interstitial lung disease may be complications of reflux, presumably as a result of the failure of airway protective mechanisms to protect the lungs against aspirated gastric contents (513). Reflux causing recurrent pneumonia has been reported in otherwise healthy infants and children (96,514,515). In a retrospective series reviewing the causes of recurrent pneumonia in a heterogenous group of 238 children, the primary cause was aspiration during swallowing in 48%, immunologic disorders in 14%, congenital heart disease in 9%, asthma in 8%, respiratory tract anatomic abnormalities in 8%, unknown in 8%, and reflux in only 6% (516). Small case series suggest that reflux may cause or exacerbate interstitial lung disorders such as idiopathic pulmonary fibrosis (517,518), cystic fibrosis (CF) (519,520), or lung transplant (520,521). No test can determine whether reflux is causing recurrent pneumonia. An abnormal esophageal pH test may increase the probability that reflux is a cause of recurrent pneumonia but is not proof thereof. A normal esophageal pH test cannot exclude reflux as a cause of pneumonia because if airway protection mechanisms are compromised, even brief reflux episodes that are within the normal range may be associated with aspiration. Aspiration during swallowing is much more common than aspiration of refluxed material (522). Upper esophageal and pharyngeal pH recordings and combined pH/MII studies have similar limitations and do not improve the ability to predict GER-related pneumonia (523). Lipid-laden alveolar macrophages have been used as an indicator of aspiration but the sensitivity and specificity as an indicator of GER-related lung disease is poor (187,524–529). Pepsin content of pulmonary lavage fluid has also been used to document aspiration of gastric contents. Pepsin concentration is elevated in pulmonary lavage from patients with reflux (185,186) but there is substantial overlap with controls (187). Nuclear scintigraphy can detect aspirated gastric contents when images are obtained for 24 hours after enteral administration of a labeled meal. One study reporting that 50% of patients with a variety of respiratory symptoms had aspiration on scintigraphy (169) has not been replicated. It is important to recognize that aspiration also occurs in healthy subjects, especially during sleep (171,172) so the threshold for pathologic aspiration of saliva or gastric contents is not established. No data are available regarding the predictive value of any diagnostic test for determining which patients will respond to either medical or surgical therapy for GERD. Both medical (530) and surgical (97,531) therapy of GERD have been reported to reduce pulmonary symptoms in certain populations of children with recurrent pneumonia. However, in one study of children older than 4 years of age, the number of hospitalizations for respiratory-related events increased after antireflux surgery (397). Gastrojejunal feeding provides an alternative approach to prevent reflux-related pneumonia in children with severe NI (532). A recent review of children with severe NI and GERD reported that surgical therapy improved several complications but did not alter the risk of pneumonia (533). The potential benefits of antisecretory therapy for neurologically impaired children with recurrent pneumonia must be balanced against the risk that PPI therapy may increase the incidence of community-acquired pneumonia in these patients, as it does in well children (322). A large double-blind placebo-controlled study to determine the role of PPI therapy in the child with NI is lacking. In many cases the clinician must make management decisions based on inconclusive diagnostic studies with no certainty regarding outcome. In patients with severely impaired lung function, it may be necessary to proceed with antireflux surgery in an attempt to prevent further pulmonary damage, despite lack of definitive proof that reflux is a cause of pulmonary disease. Alternatively, if minimal pulmonary disease is present, consideration of medical therapy with careful follow-up of pulmonary function may be instituted, although the potential benefits versus risks of PPI are unclear. The efficacy of therapies such as lifestyle changes and prokinetics has not been well studied. A trial of nasogastric feeding may be used to exclude aspiration during swallowing as a potential cause of recurrent disease (532). A trial of nasojejunal therapy may help determine whether surgical antireflux therapy is likely to be beneficial.