Prevalence of Forgut Dysfunction in Pulmonary Fibrosis and COPD Patients Undergoing LTx Evaluation

Pulmonary fibrosis (PF) & COPD are progressive and fatal lung diseases that lead to lung transplantation (LTx). However, the respiratory physiology, intrathoracic pressure variation, and chest wall compliance are markedly different. Gastroesophageal reflux (GER) is a significant risk factor for development and/or progression of end-stage lung disease pre-LTx and chronic rejection post-LTx. This study attempts to define the prevalence of forgut dysfunction based on comprehensive GI testing in patients with end-stage PF and COPD undergoing transplant evaluation. From February 2009-March 2012 126 people underwent bilateral lung transplantation. These patients underwent comprehensive pre-transplant GER work-up including EGD, manometry, esophagram pH testing and nuclear medicine gastric emptying studies. Except gastric emptying readings, all foregut function studies were performed by the same transplant surgeons. Tests were analyzed for comparison between groups according to disease states. The association for group by outcome variables were tested using contingency tables and a chi-square test statistics. Complete data was collected in 82 patients with a mean age of 56.5 years +/- 14.4 years. 41(50%) classified as COPD, 41(50%) PF. No significant differences in prevalence of hiatal hernia (HH) (46% vs. 64%), barrett’s (3% vs. 0%) or delayed gastric emptying (17% vs. 13%) between COPD vs. PF respectively. Similarly, no difference noted in manometer LES basal tone and wave amp @ 7cm. Mean DeMeester pH scores significantly higher in PF (40.1) vs. COPD (15.5), p=0.003. Proportion of time with pH < 4 was significantly higher in PF vs. COPD (1.5% vs. 0.5%, p=0.015). The prevalence of forgut dysfunction based on comprehensive GI testing in patients with end-stage lung disease is significant. pH probe assessment demonstrated a significantly higher proportion of time spent at pH< 4 and elevated DeMeester scores in PF compared to COPD. However, no significant difference were noted in the presence of HH or barrett’s, delayed gastric emptying, or manometer assessments between cohorts.