Pulmonary function and exercise capacity in survivors of congenital diaphragmatic hernia

Abstract

Congenital diaphragmatic hernia (CDH) is associated with pulmonary hypoplasia and pulmonary hypertension. The objective of this study was to assess pulmonary function and exercise capacity and its early determinants in children and adolescents born with high-risk CDH (CDH-associated respiratory distress within the first 24 h) and to explore the relationship of these findings with CDH severity.

Of 159 patients born with high-risk CDH, 84 survived. Of the 69 eligible patients, 53 children (mean±sd age 11.9±3.5 yrs) underwent spirometry, lung volume measurements and maximal cardiopulmonary exercise testing (CPET). Results of the pulmonary function tests were compared with those from a healthy control group matched for sex, age and height.

CDH survivors had a significantly lower forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), FEV₁/FVC, maximum mid-expiratory flow and peak expiratory flow when compared with healthy controls. The residual volume/total lung capacity ratio was significantly higher. Linear regression analysis showed that gastro-oesophageal reflux disease was an independent determinant of reduced FEV₁ and FVC. CPET results were normal in those tested.

High-risk CDH survivors have mild to moderate pulmonary function abnormalities when compared with a healthy matched control group, which may be related to gastro-oesophageal reflux disease in early life. Exercise capacity and gas exchange parameters were normal in those tested, indicating that the majority of patients do not have physical impairment.