[Gastroesophageal reflux and pulmonary disease].

Gastroesophageal reflux (GER) is a functional entity which is defined as "the involuntary reflux of the gastric contents in the oesophagus, without vomiting and without the involvement of either the gastric, abdominal or diaphragmatic muscles". It is therefore a question of a syndrome which is independent of the anatomical abnormalities in the cardio-tuberositic region (i.e. hiatal hernia). It may also show itself through digestive symptoms, thoracic pains, ENT symptoms and breathing complications. The presence of the latter has been clearly established in certain circumstances: --in infants, GER can cause obstructive apneas, which are responsible for sudden inexplicable deaths (SID): GER and SID have very similar epidemiological characteristics; polygraphic recordings showed that a reflux may immediately precede the onset of obstructive apnea; the instillation of 0.1 N hydrochloric acid in the oesophagus of children with GER causes an apnea. Medical or surgical treatment of the reflux prevents the recurrence of these accidents; --in adults, and older children, GER is responsible for coughs, recurring bronchopneumopathies and asthma; long-term recordings of the oesophageal pH have proved that there is a time-relationship between the two events. Scintigraphic studies have shown the pulmonary contamination by a radioactive isotope placed in the stomach the previous evening. GER has been equally suspected for conditions such as lung abscess, bronchiectasis and hemoptysis, but here it is more difficult to prove. With certain pulmonary fibroses, histological lesions have been compared with those observed during inhalation bronchopneumopathies, but it is difficult to establish a link with a reflux; --functional respiratory studies have not produced a specific functional entity for patients with GER; --careful medical treatment or surgical correction of GER lead to the sedation of respiratory symptoms (RS) in the majority of cases; --the association frequency of a GER and of RS is difficult to establish because of the diversity of the means of diagnosis employed in the past and also because of the heterogeneity of the studied populations, but the frequency is nevertheless high, indeed significantly higher than the prevalence of GER in the general population. The mechanisms which link GER and RS are not well known: first of all, there is the failure of normal antireflux mechanisms and also certain hormonal, alimentary (coffee, alcohol, tobacco, etc.) and therapeutic (theophylline, betamimetics) factors, which facilitate the reflux.(ABSTRACT TRUNCATED AT 400 WORDS)