Management of Belching, Hiccups, and Aerophagia
Management of Belching, Hiccups, and Aerophagia
Belching is the audible escape of air from the esophagus into the pharynx. The medical term for belching is eructation. We distinguish 2 types of belches: the so-called gastric belch and supragastric belch. Gastric belching is the escape of swallowed intragastric air that enters the esophagus during a transient lower-esophageal sphincter relaxation (TLESR). TLESRs are triggered by distention of the proximal stomach and allow venting of air from the stomach, thereby serving as a gastric decompression mechanism and preventing passage of large volumes of gas through the pylorus into the intestines. TLESRs therefore sometimes are referred to as the belch reflex. Once in the esophagus, esophageal distention caused by the refluxed air initiates reflexogenic relaxation of the upper-esophageal sphincter (UES) through which the air can escape the esophagus. Gastric belches occur 25 to 30 times per day and are physiological. Gastric belches are involuntary and are controlled entirely by reflexes.
In supragastric belches the air does not originate from the stomach but is ingested immediately before it is expelled again. Supragastric belches are not a reflex but instead are the result of human behavior. Studies with simultaneous impedance monitoring and high-resolution manometry reveal the underlying mechanism of this behavior. A contraction of the diaphragm creates a negative pressure in the thoracic cavity and the esophagus, subsequent relaxation of the UES, resulting in inflow of air into the esophagus (Figure 1). The air thus is suctioned into the esophagus where it is expelled again immediately in a pharyngeal direction using straining. A minority of subjects that express supragastric belching use a different technique. They inject air into the esophagus by a simultaneous contraction of the muscles of the base of the tongue and the pharynx. The subsequent expulsion of air out of the esophagus in retrograde direction is induced by straining and goes through a similar mechanism as in patients who apply suction to move the air into the esophagus.
(Enlarge Image)
Figure 1.
Combined high-resolution manometry and impedance monitoring showing a supragastric belch. Because of a contraction of the diaphragm, the esophagogastric junction (EGJ) moves distally and a decrease in pressure in the esophagus is observed. Subsequently, relaxation of the UES allows the influx of air from the pharynx into the esophagus seen on the impedance tracing (arrow). The supragastric belch is characterized by an increase in impedance, starting in the proximal impedance channel, and progressing to the most distal impedance channel and followed by a return to baseline, starting in the most distal channel and progressing to the proximal channel. The movement of air out of the esophagus in a retrograde direction is caused by straining, as can be seen as a simultaneous increase in pressure in esophageal and gastric channels.
Many insights gained into belching physiology and pathophysiology over the past 10 years are the results of studies with esophageal electrical impedance monitoring. With impedance monitoring the resistance of a medium to an alternating electrical current is measured and this allows one to measure movement of air in the esophagus. It is thus a very useful tool in the evaluation of belching and air swallowing.
Some patients consult with isolated excessive belching and report that they suffer from episodes of frequent belching in which they may belch up to 20 times a minute. These patients may show spells of excessive belching during consultation with their physician. Patients who complain of isolated excessive belching almost without exception suffer from excessive uncontrolled supragastric belching. A high prevalence of anxiety disorders has been described in these patients and some patients report that their symptoms increase during stressful events. Excessive belching also has been described in patients with obsessive compulsive disorder, bulimia nervosa, and encephalitis. Many patients stop belching during speaking and it has been shown that distraction also reduces the frequency of belching whereas putting attention to their belching behavior usually results in an increase in belching frequency. Supragastric belching is never observed during sleep. Careful history taking is usually enough to establish a diagnosis but sometimes an impedance monitoring test may be required; this can help to distinguish excessive supragastric belching from gastroesophageal reflux disease (GERD) and rumination. The diagnosis is made when spells of supragastric belches are observed during the impedance measurement (Table 1). Patients with excessive supragastric belching usually have no other symptoms besides sometimes some dyspeptic symptoms. The presence of weight loss, pain, dysphagia, heartburn, and regurgitation are not compatible with excessive supragastric belching and are an indication for further diagnostic evaluation.
It is unclear what causes supragastric belching and what causes patients to start this behavior. Some patients report that initially they belched purposefully to relieve a sensation of bloating or abdominal discomfort but that with time they lost control of the belching.
It is important to realize that supragastric belching is not the same as air swallowing or aerophagia (Greek for "air eating"). With every swallow a certain volume of air is ingested and this is transported by the peristaltic contraction wave to the stomach; this is what we call air swallowing. During supragastric belching peristaltic contractions in the esophagus are not seen, the air is injected by pharyngeal muscle contraction or through suction created by a negative intrathoracic pressure. Aerophagia is a disorder in which there is a true increase in ingested volume of air as a result of air swallowing, and thus this is distinct from excessive supragastric belching.
Patients with excessive belching often complain of social isolation as a result of the excessive belching and it is important to take their symptoms seriously because these patients often suffer from a decreased health-related quality of life. Little evidence exists on the optimal treatment of patients with supragastric belching. In our institution we always start with explaining the mechanism of belching to the patient; this can be difficult because some patients are convinced of the presence of a gas-producing mechanism in the stomach or intestines and find it difficult to accept that it is a behavior disorder that is causing the excessive belching. Some physicians show the patient that they are able to belch intentionally themselves, to convince the patient that this is learned behavior. When there is a suspicion that excessive belching is secondary to a psychiatric disorder, the patient is referred for an evaluation by a psychiatrist first.
The only evidence for treatment of supragastric belching is provided by an open-label study by Hemmink et al. In that study 11 patients with excessive supragastric belching were referred to a speech therapist with experience in treatment of these patients. It is important to mention that this therapist was well informed of the mechanisms of supragastric belching. The therapy focused on explanation and on creating awareness of the belching mechanism. The first step consisted of a description of the behavior that caused the injection or suctioning of air and was accompanied by glottis training and conventional breathing and vocal exercises. Early in the therapy, attention on belching was moved to attention on the periods of tight glottal and mouth closure. Symptom intensity and frequency, as scored with a visual analogue scale, improved significantly after 10 treatment sessions. Only 1 patient showed no response and stopped treatment early. It can be argued that this was an open-label study and that its results were a reflection of the natural cause of the symptoms, but the patients had a mean symptom duration of 2.1 years at presentation, which makes a spontaneous symptom regression less likely. The effects of speech therapy thus seem encouraging, although more evidence is most welcome.
Given that excessive supragastric belching is a behavior disorder, cognitive behavior therapy seems a reasonable alternative approach. The observation that distraction and stimulation influence the occurrence of belching supports this. The key is to provide the patient insight into the fact that supragastric belching is a learned behavior and, thus, it may be possible to unlearn this as well.
Both a speech therapist and a behavior therapist seem equipped for treatment of these patients. The choice of treatment depends on the available facilities. Hospitals with large Ear, Nose, and Throat departments where total laryngectomy is performed usually have well-trained speech therapists. After a laryngectomy with vocal cord resection, patients are taught to speak with the esophagus using supragastric belching. The speech therapists that train laryngectomized patients to perform esophageal speech may unlearn the same behavior in the patients with excessive supragastric belching. Alternatively, when there is local experience with behavior therapy, this seems most sensible. For both speech therapy and behavior therapy, it is of the utmost importance that the therapist has knowledge of the mechanism of supragastric belching and that therapy is aimed at reducing this. Therapists who are unaware of the mechanisms of supragastric belching still may think that excessive belching is the result of air swallowing and their therapy will not be very effective.
For the same reason, drugs that reduce surface tension such as dimethicone and simethicone are not useful in patients with excessive supragastric belching. A small study with baclofen, a γ-aminobutyric acid-B receptor agonist that reduces the frequency of TLESRs, showed that this drug reduced the number of supragastric belches. Anecdotally, successful treatment of excessive belching has been reported in a few cases using hypnosis and biofeedback.
One of the most reported symptoms in patients with GERD next to heartburn and regurgitation is belching. Excessive belching in patients with GERD can be caused by a high frequency of gastric belching; however, supragastric belching also has been observed in patients with GERD. Patients with GERD swallow air more often and subsequently have more gastric belches than healthy subjects. Acid-suppressive therapy reduces the frequency of air swallowing in patients with GERD in contrast to healthy subjects, which suggests that the unpleasant sensation of heartburn stimulates patients to take larger gulps and swallow more air. As expected, acid-suppressive therapy indeed reduces belching. Symptoms of belching also respond to treatment with the TLESR-inhibitor baclofen.
As mentioned previously, in a subset of patients with GERD, supragastric belching is seen on an impedance measurement; this can be asymptomatic. In the GERD patients with severe belching symptoms, however, supragastric belches are usually the main determinant of these symptoms.
Frequent belching is reported by 80% of the patients with functional dyspepsia. Studies using impedance monitoring show that patients with functional dyspepsia swallow air more frequently than healthy subjects and have more gastric belches. The presence of supragastric belches has not been studied in patients with functional dyspepsia. Frequent air swallowing in patients with functional dyspepsia is probably a response of the patient to unpleasant abdominal sensations. Frequent belching also has been reported in patients with organic disorders that cause abdominal discomfort or pain, such as peptic ulcer disease, pancreatitis, angina pectoris, and symptomatic cholecystolithiasis; however, in those conditions other symptoms usually are predominant.
The physiologic importance of belching is illustrated by those patients who have an acquired inability to belch. After antireflux surgery, the newly made wrap around the LES prevents reflux by reducing the number of TLESRs and increasing the sphincter pressure during TLESRs. Besides a large reduction in reflux episodes, the number of gastric belches is also greatly reduced and in some patients no belching is observed at all. The loss of the venting capacity of the stomach can lead to accumulation of air in the stomach and intestines and this results in bloating and increased flatulence. These symptoms can be very severe and sometimes are the reason for a second surgery in which the normal anatomy is restored. We recently described that some patients start with supragastric belching after antireflux surgery in a futile attempt to vent gastric air to reduce symptoms of gas bloat. The fact that a patient reports that he still is capable of belching after antireflux surgery thus cannot be taken as an indication that the venting capacity of the stomach is intact because the belching also can be caused by supragastric belching. The reduction in belching has been shown to be smaller after a partial fundoplication (270°, Toupet) than after a complete fundoplication (360°, Nissen).
Very rarely, an inability to belch has been reported by patients with achalasia. In achalasia the neurons that control motility of the esophageal smooth muscles are involved in a degenerative process. This generally results in aperistalsis and failure of the LES to relax. Very rarely, however, dysrelaxation of the UES also occurs, which makes it impossible for intraesophageal air to escape and, hence, belching has become impossible. Dilatation of the esophagus with air occurs and patients will experience thoracic pain; even airway obstruction has been described.
In a similar way, a high threshold of the UES to relax can cause chest pain and it has been suggested that belching disorders play a role in some of the patients with noncardiac chest pain. (Table 1).
Belching
Gastric and Supragastric Belching
Belching is the audible escape of air from the esophagus into the pharynx. The medical term for belching is eructation. We distinguish 2 types of belches: the so-called gastric belch and supragastric belch. Gastric belching is the escape of swallowed intragastric air that enters the esophagus during a transient lower-esophageal sphincter relaxation (TLESR). TLESRs are triggered by distention of the proximal stomach and allow venting of air from the stomach, thereby serving as a gastric decompression mechanism and preventing passage of large volumes of gas through the pylorus into the intestines. TLESRs therefore sometimes are referred to as the belch reflex. Once in the esophagus, esophageal distention caused by the refluxed air initiates reflexogenic relaxation of the upper-esophageal sphincter (UES) through which the air can escape the esophagus. Gastric belches occur 25 to 30 times per day and are physiological. Gastric belches are involuntary and are controlled entirely by reflexes.
In supragastric belches the air does not originate from the stomach but is ingested immediately before it is expelled again. Supragastric belches are not a reflex but instead are the result of human behavior. Studies with simultaneous impedance monitoring and high-resolution manometry reveal the underlying mechanism of this behavior. A contraction of the diaphragm creates a negative pressure in the thoracic cavity and the esophagus, subsequent relaxation of the UES, resulting in inflow of air into the esophagus (Figure 1). The air thus is suctioned into the esophagus where it is expelled again immediately in a pharyngeal direction using straining. A minority of subjects that express supragastric belching use a different technique. They inject air into the esophagus by a simultaneous contraction of the muscles of the base of the tongue and the pharynx. The subsequent expulsion of air out of the esophagus in retrograde direction is induced by straining and goes through a similar mechanism as in patients who apply suction to move the air into the esophagus.
(Enlarge Image)
Figure 1.
Combined high-resolution manometry and impedance monitoring showing a supragastric belch. Because of a contraction of the diaphragm, the esophagogastric junction (EGJ) moves distally and a decrease in pressure in the esophagus is observed. Subsequently, relaxation of the UES allows the influx of air from the pharynx into the esophagus seen on the impedance tracing (arrow). The supragastric belch is characterized by an increase in impedance, starting in the proximal impedance channel, and progressing to the most distal impedance channel and followed by a return to baseline, starting in the most distal channel and progressing to the proximal channel. The movement of air out of the esophagus in a retrograde direction is caused by straining, as can be seen as a simultaneous increase in pressure in esophageal and gastric channels.
Many insights gained into belching physiology and pathophysiology over the past 10 years are the results of studies with esophageal electrical impedance monitoring. With impedance monitoring the resistance of a medium to an alternating electrical current is measured and this allows one to measure movement of air in the esophagus. It is thus a very useful tool in the evaluation of belching and air swallowing.
Excessive Supragastric Belching
Some patients consult with isolated excessive belching and report that they suffer from episodes of frequent belching in which they may belch up to 20 times a minute. These patients may show spells of excessive belching during consultation with their physician. Patients who complain of isolated excessive belching almost without exception suffer from excessive uncontrolled supragastric belching. A high prevalence of anxiety disorders has been described in these patients and some patients report that their symptoms increase during stressful events. Excessive belching also has been described in patients with obsessive compulsive disorder, bulimia nervosa, and encephalitis. Many patients stop belching during speaking and it has been shown that distraction also reduces the frequency of belching whereas putting attention to their belching behavior usually results in an increase in belching frequency. Supragastric belching is never observed during sleep. Careful history taking is usually enough to establish a diagnosis but sometimes an impedance monitoring test may be required; this can help to distinguish excessive supragastric belching from gastroesophageal reflux disease (GERD) and rumination. The diagnosis is made when spells of supragastric belches are observed during the impedance measurement (Table 1). Patients with excessive supragastric belching usually have no other symptoms besides sometimes some dyspeptic symptoms. The presence of weight loss, pain, dysphagia, heartburn, and regurgitation are not compatible with excessive supragastric belching and are an indication for further diagnostic evaluation.
It is unclear what causes supragastric belching and what causes patients to start this behavior. Some patients report that initially they belched purposefully to relieve a sensation of bloating or abdominal discomfort but that with time they lost control of the belching.
It is important to realize that supragastric belching is not the same as air swallowing or aerophagia (Greek for "air eating"). With every swallow a certain volume of air is ingested and this is transported by the peristaltic contraction wave to the stomach; this is what we call air swallowing. During supragastric belching peristaltic contractions in the esophagus are not seen, the air is injected by pharyngeal muscle contraction or through suction created by a negative intrathoracic pressure. Aerophagia is a disorder in which there is a true increase in ingested volume of air as a result of air swallowing, and thus this is distinct from excessive supragastric belching.
Management of Supragastric Belching
Patients with excessive belching often complain of social isolation as a result of the excessive belching and it is important to take their symptoms seriously because these patients often suffer from a decreased health-related quality of life. Little evidence exists on the optimal treatment of patients with supragastric belching. In our institution we always start with explaining the mechanism of belching to the patient; this can be difficult because some patients are convinced of the presence of a gas-producing mechanism in the stomach or intestines and find it difficult to accept that it is a behavior disorder that is causing the excessive belching. Some physicians show the patient that they are able to belch intentionally themselves, to convince the patient that this is learned behavior. When there is a suspicion that excessive belching is secondary to a psychiatric disorder, the patient is referred for an evaluation by a psychiatrist first.
The only evidence for treatment of supragastric belching is provided by an open-label study by Hemmink et al. In that study 11 patients with excessive supragastric belching were referred to a speech therapist with experience in treatment of these patients. It is important to mention that this therapist was well informed of the mechanisms of supragastric belching. The therapy focused on explanation and on creating awareness of the belching mechanism. The first step consisted of a description of the behavior that caused the injection or suctioning of air and was accompanied by glottis training and conventional breathing and vocal exercises. Early in the therapy, attention on belching was moved to attention on the periods of tight glottal and mouth closure. Symptom intensity and frequency, as scored with a visual analogue scale, improved significantly after 10 treatment sessions. Only 1 patient showed no response and stopped treatment early. It can be argued that this was an open-label study and that its results were a reflection of the natural cause of the symptoms, but the patients had a mean symptom duration of 2.1 years at presentation, which makes a spontaneous symptom regression less likely. The effects of speech therapy thus seem encouraging, although more evidence is most welcome.
Given that excessive supragastric belching is a behavior disorder, cognitive behavior therapy seems a reasonable alternative approach. The observation that distraction and stimulation influence the occurrence of belching supports this. The key is to provide the patient insight into the fact that supragastric belching is a learned behavior and, thus, it may be possible to unlearn this as well.
Both a speech therapist and a behavior therapist seem equipped for treatment of these patients. The choice of treatment depends on the available facilities. Hospitals with large Ear, Nose, and Throat departments where total laryngectomy is performed usually have well-trained speech therapists. After a laryngectomy with vocal cord resection, patients are taught to speak with the esophagus using supragastric belching. The speech therapists that train laryngectomized patients to perform esophageal speech may unlearn the same behavior in the patients with excessive supragastric belching. Alternatively, when there is local experience with behavior therapy, this seems most sensible. For both speech therapy and behavior therapy, it is of the utmost importance that the therapist has knowledge of the mechanism of supragastric belching and that therapy is aimed at reducing this. Therapists who are unaware of the mechanisms of supragastric belching still may think that excessive belching is the result of air swallowing and their therapy will not be very effective.
For the same reason, drugs that reduce surface tension such as dimethicone and simethicone are not useful in patients with excessive supragastric belching. A small study with baclofen, a γ-aminobutyric acid-B receptor agonist that reduces the frequency of TLESRs, showed that this drug reduced the number of supragastric belches. Anecdotally, successful treatment of excessive belching has been reported in a few cases using hypnosis and biofeedback.
Excessive Belching in Gastroesophageal Reflux Disease and Functional Dyspepsia
One of the most reported symptoms in patients with GERD next to heartburn and regurgitation is belching. Excessive belching in patients with GERD can be caused by a high frequency of gastric belching; however, supragastric belching also has been observed in patients with GERD. Patients with GERD swallow air more often and subsequently have more gastric belches than healthy subjects. Acid-suppressive therapy reduces the frequency of air swallowing in patients with GERD in contrast to healthy subjects, which suggests that the unpleasant sensation of heartburn stimulates patients to take larger gulps and swallow more air. As expected, acid-suppressive therapy indeed reduces belching. Symptoms of belching also respond to treatment with the TLESR-inhibitor baclofen.
As mentioned previously, in a subset of patients with GERD, supragastric belching is seen on an impedance measurement; this can be asymptomatic. In the GERD patients with severe belching symptoms, however, supragastric belches are usually the main determinant of these symptoms.
Frequent belching is reported by 80% of the patients with functional dyspepsia. Studies using impedance monitoring show that patients with functional dyspepsia swallow air more frequently than healthy subjects and have more gastric belches. The presence of supragastric belches has not been studied in patients with functional dyspepsia. Frequent air swallowing in patients with functional dyspepsia is probably a response of the patient to unpleasant abdominal sensations. Frequent belching also has been reported in patients with organic disorders that cause abdominal discomfort or pain, such as peptic ulcer disease, pancreatitis, angina pectoris, and symptomatic cholecystolithiasis; however, in those conditions other symptoms usually are predominant.
Inability to Belch
The physiologic importance of belching is illustrated by those patients who have an acquired inability to belch. After antireflux surgery, the newly made wrap around the LES prevents reflux by reducing the number of TLESRs and increasing the sphincter pressure during TLESRs. Besides a large reduction in reflux episodes, the number of gastric belches is also greatly reduced and in some patients no belching is observed at all. The loss of the venting capacity of the stomach can lead to accumulation of air in the stomach and intestines and this results in bloating and increased flatulence. These symptoms can be very severe and sometimes are the reason for a second surgery in which the normal anatomy is restored. We recently described that some patients start with supragastric belching after antireflux surgery in a futile attempt to vent gastric air to reduce symptoms of gas bloat. The fact that a patient reports that he still is capable of belching after antireflux surgery thus cannot be taken as an indication that the venting capacity of the stomach is intact because the belching also can be caused by supragastric belching. The reduction in belching has been shown to be smaller after a partial fundoplication (270°, Toupet) than after a complete fundoplication (360°, Nissen).
Very rarely, an inability to belch has been reported by patients with achalasia. In achalasia the neurons that control motility of the esophageal smooth muscles are involved in a degenerative process. This generally results in aperistalsis and failure of the LES to relax. Very rarely, however, dysrelaxation of the UES also occurs, which makes it impossible for intraesophageal air to escape and, hence, belching has become impossible. Dilatation of the esophagus with air occurs and patients will experience thoracic pain; even airway obstruction has been described.
In a similar way, a high threshold of the UES to relax can cause chest pain and it has been suggested that belching disorders play a role in some of the patients with noncardiac chest pain. (Table 1).