A long list of respiratory symptoms may be associated with GE reflux, however, it is often difficult to know whether the reflux causes the lung problems or the other way around. Since the windpipe (trachea) and the esophagus are very close together, many people have assumed that aspiration of refluxed stomach contents leads to respiratory symptoms.
Reflux of stomach contents up into the upper esophagus occurs in some patients with recurrent respiratory symptoms, but this appears to be very uncommon and is probably extremely rare among children who are neurologically normal.
While children with neurological abnormalities may aspirate refluxed stomach contents, more often, these children aspirate while they are eating. This is called laryngeal penetration and it occurs when swallow-breathe patterns are not well coordinated. Normally, with the initiation of a swallow, there is a pause in breathing and the larynx closes to protect the airway. In children who show no swallowing difficulties, it is reasonable to assume that these protective reflexes will function during an episode of reflux.
There are reports describing children who suffer from chronic congestion and chronic hoarseness having GE reflux. It is thought that aspiration of refluxed stomach contents causes inflammation and swelling of the upper airways and results in noisy breathing (stridor) or spasms of the vocal cords (laryngospasm). If evaluation of the upper airway shows chronic inflammation, it is reasonable to consider GE reflux as a potential source of the symptoms.
The role of GE reflux in apnea (stopping breathing) and bradycardia (slowing of the heart rate) has been of great interest because of the potentially life-threatening nature of these symptoms. Although many studies have shown that infants with apnea may have reflux, there is usually little or no correlation between apneic episodes and reflux episodes. Instances in which apnea and reflux have been directly associated in a cause-and-effect manner are extremely uncommon.
Both children and adults with chronic asthma have an increased incidence of GE reflux. However, it is extremely difficult to know whether reflux causes asthma or asthma causes reflux. Chronic asthma may precipitate reflux because chronic coughing and increased respiratory efforts increase abdominal pressure which tends to force stomach contents upwards. Among children with chronic asthma, the incidence of reflux has been reported to range from 46-75%. In one study, 82% of adult asthmatics had evidence of reflux! Relatively few children with chronic asthma experience significant improvement in their asthma when they are treated for reflux, so while reflux should be considered as a possible cause of uncontrolled chronic respiratory symptoms in children, it is important to remember that many of the trigger factors for wheezing also trigger reflux.