Keith C. Meyer • Ganesh Raghu
Editors
2013
Considerable advances have been made over the past decade in understanding the physiology and pathophysiology of swallowing and foregut function, and a considerable amount of knowledge has accumulated that links swallowing disorders or gastroesophageal reflux (GER) to a variety of upper and lower respiratory tract syndromes and disease. While the processes of swallowing and breathing go unnoticed under normal physiological and anatomical conditions, aberrant foregut function can allow an excessive amount of gastric contents to reflux into the esophagus and induce a number of reflux-associated syndromes should refluxed secretions reach the larynx, pharynx, and airways. Under conditions of normal foregut function, the esophagus would not serve as an escape passage for gastric/foregut secretions and ingested food and/or fluids to reflux when the proximal gastrointestinal tract is functioning normally with intact upper and lower esophageal sphincter function. Significant retropulsion of gastric or gastroduodenal contents (which are usually acidic with low pH but can be weakly acidic or nonacidic and contain bile acids) into the esophagus places individuals at risk for esophageal disorders (e.g., ulceration, Barrett’s esophagus) and is commonly recognized as gastroesophageal reflux disease (G RD), a term that is also used when GER is linked to a variety of respiratory syndromes and disorders. In addition to the consequences of excessive (abnormal) GER, the lungs are also at risk for aspiration from above due to disorders of deglutition or when food and fluids back up in the esophagus due to esophageal motility disorders that are often associated with connective tissue disorders.
Gastroesophageal Reflux and the Lung
