title: Aspiration of gastric fluid in pulmonary allografts: effect of pH.
abstract: BACKGROUND
  Chronic aspiration of gastric fluid potentially plays a central role in the pathogenesis of obliterative bronchiolitis, which is often associated with chronic pulmonary allograft failure. It remains unknown whether pharmaceutical-induced increases in gastric pH might effectively prevent any putative pulmonary injury associated with chronic aspiration.
  
  
  METHODS
  To test the hypothesis that neutralization of gastric fluid would affect the development of aspiration-associated obliterative bronchiolitis, an established rat lung transplant model (WKY-to-F344) was utilized. Pulmonary allograft recipients were subjected to eight weekly aspirations of gastric fluid at pH 2.5 (low-pH), gastric fluid at pH 7.4 (neutralized-pH), or saline as a control.
  
  
  RESULTS
  Histologic analysis revealed that the fraction of airways affected with lesions consistent with obliterative bronchiolitis was 0.55 ± 0.08 (mean ± SEM) in rats receiving aspiration with low-pH gastric fluid, 0.49 ± 0.07 in animals receiving neutralized-pH gastric fluid, and 0.07 ± 0.05 in rats receiving normal saline only. The difference between groups receiving gastric fluid, regardless of pH, was significantly different from the saline control (P < 0.0001), whereas the difference between the groups receiving low-pH gastric fluid and neutralized-pH gastric fluid was not significant (P = 0.75).
  
  
  CONCLUSIONS
  Effective management of gastroesophageal reflux disease in lung transplant recipients should probably include more than neutralization of gastric fluid.
authors: Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA.
authors: Tao
authors: T
authors: Tang
authors: Jui-Chih
authors: JC
authors: Chang
authors: Amy
authors: A
authors: Xie
authors: R Duane
authors: RD
authors: Davis
authors: William
authors: W
authors: Parker
authors: Shu S
authors: SS
authors: Lin
mesh_terms: D000818:Animals; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000209:etiology; D006863:Hydrogen-Ion Concentration; D008168:Lung / Q000473:pathology; D008170:Lung Compliance; D016040:Lung Transplantation / Q000009:adverse effects*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D011921:Rats, Inbred WKY; D063466:Respiratory Aspiration of Gastric Contents / Q000209:etiology*; D014184:Transplantation, Homologous