Gastroesophageal reflux disease and pulmonary function: A potential role of the dead space extension

Results: Statistically significant differences between GERD and non-GERD groups in FVC (p=0.034), FEV1 (p=0.002), FEV1/FVC (p=0.001), and PEF (p=0.001) were observed. There were no statistically significant differences in FEF 25% (p=0.859), FEF 50% (p=0.850), and FEF 75% (p=0.058). Values of DLCO (p=0.006) and DLCO/VA (p=0.001) were significantly lower and QS/QT was significantly higher (p=0.001) in the GERD group than in the non-GERD group. However, in both groups the average values of DLCO and DLCO/VA expressed as a percentage of predictive values were within normal range, while the value of QS/QT in the GERD group showed pathological (6.0%) mean value (normal value ≤5.0%). There were no significant differences in respiratory function test re sults between patients with ERD and NERD. Conclusions: Our results suggest that microaspiration of stomach contents may cause surfactant damage, development of microatelectasis, and dead space expansion with consequent increase of intrapulmonary (venous) shunt.