Cough and gastroesophageal reflux

[A coughing patients makes a visit to the otorhinolaryngologist's office: the practical aspects of diagnostics and treatment]

This article summarizes the modern concepts of the most common causes and mechanism underlying the development of cough. The significance of pathogenetic cough-suppressant therapy is emphasized with special reference to the following aspects: the importance of reducing the thickness or bronchial secretions, its more efficient removal from the lumen of the respiratory passages, creation of the prerequisites for regression of the inflammatory process, lowering the intensity of cough, improvement of subjective feelings and the quality of life of a given patient. The advantages of the application of the compounded preparations containing synergic components responsible for the high therapeutic effectiveness of these medicines is demonstrated as exemplified by the ingredients of the ascoril expectorant. It is concluded that this medication should be recommended for the treatment of patients suffering from cough of the known nature.

Human Lung Mucous Glands Manifest Evidence of the H+/K+-ATPase Proton Pump

Objectives:

The H+/K+-ATPase proton pump has been demonstrated in human laryngeal submucosal glands, and is not solely present in the parietal cells of the stomach. Although proton secretion is present in the lung, a variety of mechanisms have been elucidated. The hypothesis of this study is that the H+/K+-ATPase proton pump is one additional pathway of proton secretion in the human lung.

Methods:

Fourteen surgical lung specimens from 10 subjects were retrospectively obtained after approval from our Human Subjects Committee. Banked human stomach tissue was used for comparative positive and negative controls. Sections were immunostained with 2 monoclonal antibodies selectively reactive with alpha or beta subunits of the H+/K+-ATPase proton pump.

Results:

In the human lung, consistent staining for both subunits was present in the mucous gland cells and ducts in all specimens in which mucous glands were present (6 specimens from 5 subjects). Overall, weak to strong staining was present in focal areas within the multicellular mucous glands. There was only scant focal staining in the respiratory epithelium in 4 specimens. Stomach parietal cells exhibited strongly positive staining for both subunits of the proton pump. There was no staining in stomach cells that were not morphologically consistent with parietal cells.

Conclusions:

The H+/K+-ATPase proton pump is present in mucous cells and ducts in the human lung, with some variable expression noted. Proton pump inhibitor pharmacotherapy may have a site of action in the human lung, explaining some of the controversies otherwise attributable to interrelatedness of aerodigestive tract disease.

Clinical and neurophysiologic characterization of an European family with hereditary sensory neuropathy, paroxysmal cough and gastroesophageal reflux

In 2002, Spring et al reported a family with an autosomal dominant form of hereditary sensory neuropathy; patients also presented adult onset of gastroesophageal reflux and cough. Since then, no further families have been described. Objective: To study a new Portuguese family with these characteristics. Method: To describe the clinical and neurophysiologic characteristics of one family with features of sensory neuropathy associated with cough and gastroesophageal erflux. Results: Three of five siblings presented a similar history of paroxysmal cough (5th decade). About a decade later they experienced numbness and paraesthesia in the feets and in all cases there was evidence of an axonal sensory neuropathy. A history of gastroesophageal reflux of variable severity and age of onset was also present. Discussion: Molecular genetic studies have demonstrated genetic heterogeneity between the hereditary sensory neuropathy type 1 subtypes. The identification of these families is of major importance because further work is required to identify the underlying genetic defect.

Diagnostic yield of oesophageal pH monitoring in patients with chronic unexplained cough

OBJECTIVE

One of the main causes of persistent cough is gastro-oesophageal reflux. In these patients, excessive oesophageal acid exposure and/or a temporal association between gastro-oesophageal reflux and cough can be demonstrated during 24-h pH monitoring. Impedance pH monitoring may have a higher yield than pH monitoring alone, but this technique is not yet widely available. The aim of this study was to assess the diagnostic yield of ambulatory 24-h oesophageal pH monitoring for the evaluation of chronic unexplained cough.

MATERIAL AND METHODS

Twenty-four-hour pH monitoring studies were analysed in 55 patients with chronic cough. In 14 of these studies concurrent ambulatory pressure monitoring was done. A cough episode was considered to be related to reflux if the cough occurred within two minutes after the onset of the reflux episode ("reflux-cough sequence"). Temporal relationships between cough and reflux were expressed by using the symptom association probability (SAP).

RESULTS

Thirty-seven patients actually coughed during the 24-h study. Eleven patients (20%) had a positive SAP for the reflux-cough sequence. In 5 patients, reflux followed coughing. Pathological oesophageal acid exposure was found in 15 subjects. Interestingly, only a minority (39.2%) of the cough bursts detected manometrically were marked by patients who had undergone both combined 24-h pH and pressure recording.

CONCLUSIONS

This study shows that, in a routine clinical setting, combined 24-h pH and pressure monitoring is useful in the evaluation of patients with chronic unexplained cough, as positive findings are not infrequently found and have diagnostic and therapeutic consequences.

Cough motor mechanisms

Cough is a defensive airway mechanisms which involves the sequential activation of several laryngeal and respiratory muscles in the generation of the typical four-phase motor pattern. Activation of such muscles can be considered to represent the "primary" cough motor mechanism, and its functional significance, although complex, appears to be fairly well established. Nonetheless, the outflows of cough are numerous, and may additionally involve the reflex or mechanical activation of other respiratory and non-respiratory motor systems. These additional, or "secondary", outflows of cough can mainly be regarded as being involved in either enhancing the defensive function of cough, or opposing the possible noxious effects exerted by the mechanical stresses of coughing. In addition, both the primary and secondary cough motor mechanisms are known to play multiple functional roles, thus considerably complicating the cough panorama. Finally, some of the secondary cough motor responses, such as the changes in the pattern of breathing, seem to be devoid of any favourable action and their functional meaning, if any, is not fully understood. Although it is well known that all patterns of cough can be produced voluntarily, the extent to which also volitional cough is accompanied by an array of motor responses similar to that of reflex cough remains to be elucidated.

Autosomal dominant hereditary sensory neuropathy with chronic cough and gastro-oesophageal reflux: clinical features in two families linked to chromosome 3p22-p24

Autosomal dominant hereditary sensory neuropathy (HSN I) is a clinically and genetically heterogeneous group of disorders, and in some families it is due to mutations in the serine palmitoyltransferase (SPTLC1) gene. We have characterized two families with HSN I associated with cough and gastro-oesophageal reflux (GOR). From a large Australian family, 27 individuals and from a smaller family, 11 individuals provided clinical information and blood for genetic analysis. Affected individuals had an adult onset of paroxysmal cough, GOR and distal sensory loss. Cough could be triggered by noxious odours or by pressure in the external auditory canal (Arnold's ear-cough reflex). Other features included throat clearing, hoarse voice, cough syncope and sensorineural hearing loss. Neurophysiological and pathological studies demonstrated a sensory axonal neuropathy. Gastric emptying studies were normal, and autonomic function and sweat tests were either normal or showed distal hypohidrosis. Cough was likely to be due to a combination of denervation hypersensitivity of the upper airways and oesophagus, and prominent GOR. Most affected individuals were shown on 24 h ambulatory oesophageal pH monitoring to have multiple episodes of GOR, closely temporally associated with coughing. Hoarse voice was probably attributable to acid-induced laryngeal damage, and there was no evidence of vocal cord palsy. No other cause for cough was found on most respiratory or otorhinological studies. Linkage to chromosome 3p22-p24 has been found in both families, with no evidence of linkage to loci for known HSN I, autosomal dominant hereditary motor and sensory neuropathy, hereditary GOR or triple A syndrome. These families represent a genetically novel variant of HSN I, with a distinctive cough owing to involvement of the upper aerodigestive tract.

Night-time gastro-oesophageal reflux disease: prevalence, hazards, and management

Patients who complain of symptoms of gastro-oesophageal reflux disease (GORD) that occur at night require special attention. Night-time GORD can profoundly impair quality of life by causing pain, disturbing sleep, and interfering with next-day mental and physical functioning. Sleep impairs oesophageal acid clearance resulting in a prolongation of acid mucosal contact, and nocturnal reflux portends a greater risk of erosive oesophagitis and other significant complications of gastro-oesophageal reflux. Lifestyle changes such as elevating the head of the bed and adjusting the sleeping position can relieve night-time heartburn, and instituting some dietary changes along with occasional use of histamine H2 blockers can also be helpful. Relief of night-time reflux and its attendant symptoms usually requires a medication with acid-suppressing properties that extend into the sleeping interval. In most instances, more powerful acid suppression in the form of proton-pump inhibitors will be required. Clinical studies have shown that 40 mg esomeprazole provides better control of night-time GORD symptoms than 20 mg omeprazole or 30 mg lansoprazole. Furthermore, 40 mg pantoprazole offers even faster relief than 40 mg esomeprazole for night-time GORD symptoms. Of the several proton-pump inhibitors available on the market, esomeprazole and pantoprazole appear to have some advantages, which have been documented in recent studies. Esomeprazole has been shown to be more effective than lansoprazole in relieving GORD symptoms, and esomeprazole and pantoprazole appear to be equally effective in resolving GORD symptoms in a comparative study. Pantoprazole has pharmacokinetic properties that document a longer half-life compared with the other proton-pump inhibitors, and pantoprazole has the slowest inhibition recovery rate. These properties lend credence to pantoprazole as an effective treatment for associated symptoms of night-time reflux.

Supra-oesophageal manifestations of gastro-oesophageal reflux disease

Since the early 1960s, many studies have been published that consider the possible relationship between gastro-oesophageal (acid) reflux (GORD) and various other complaints, including dental erosions, ear, nose and throat problems, chronic cough and asthma. Although a high coincidence of GORD and these supra-oesophageal complaints have been noted, there is no consensus on the pathophysiology and management of such complications. In this article we review the literature published between 1966 and 2000 on this subject. We also analyse the available information on the incidence, pathophysiological mechanisms, diagnostic approach and therapeutic options in the various subgroups of disorders.

Gastroesophageal Reflux Disease: Symptoms Versus pH Monitoring Results

OBJECTIVES: The reason why some patients with gastroesophageal reflux disease (GERD) have symptoms of upper aerodigestive system irritation, while others mainly have gastroenterologic symptoms, is not well established. This retrospective case series study was designed to examine the existence of a correlation between symptoms and reflux characteristics, based on data obtained from esophageal pH monitoring.

METHODS: The study population consisted of 139 patients; 97 patients presented with laryngopharyngeal symptoms of GERD, including unexplained hoarseness, throat clearing, chronic cough, laryngospasm, globus, throat pain, and 42 patients presented with gastroenterologic symptoms, including heartburn and regurgitation. The results of 24-hour, double-channel ambulatory esophageal pH monitoring were analyzed comparing 2 symptom groups. The incidence of abnormal acid reflux at the upper and lower esophageal segments and the effects of upright and supine positions on reflux parameters were evaluated.

RESULTS: The incidence of laryngopharyngeal reflux was significantly higher in the laryngopharyngeal symptom group than in the other (52% versus 38%). The patients with laryngopharyngeal reflux from both groups showed no significant differences in terms of number of acid reflux episodes, percentage of times pH was <4, and esophageal acid clearance. Upright and supine parameters did not show significant differences between the patient groups. Upright acid reflux episodes were, however, common in both groups at the lower esophageal and laryngopharyngeal segments.

CONCLUSION: Recent studies suggesting that otolaryngologic patients commonly show upright, daytime reflux with normal esophageal clearance and that typical GERD patients commonly have supine, nocturnal reflux with prolonged esophageal clearance are not supported by this study. This study indicates that acid reflux parameters and positional changes are not sufficient to explain why patients with GERD experience different symptoms. The regional symptoms of GERD may be attributed to the impairment of epithelial resistance, motor activity, and buffering systems for the esophageal antireflux barrier.

Improvement of respiratory symptoms following laparoscopic Nissen fundoplication

BACKGROUND

Laparoscopic fundoplication has become the standard of care for the management of symptomatic gastro-oesophageal reflux disease (GORD). Although atypical and respiratory symptoms are frequently described in standard texts in association with reflux, the response of respiratory symptoms to management of GORD has not been extensively studied.

METHODS

Herein is reported a prospective series of 29 patients who presented with predominantly respiratory symptoms. Typical and respiratory symptoms were graded according to a standard scale. All patients had preoperative investigations confirming GORD. These patients were treated by a laparoscopic Nissen fundoplication and followed up for a minimum of 14 months (range: 14-48 months). Patients were contacted and interviewed by an independent observer.

RESULTS

Conversion to open surgery was necessary in three patients. There were four significant complications. Ultimately control of typical reflux symptoms was achieved in 88%. Cough was completely relieved in 81% and improved in a further 13%. Wheeze and nocturnal bronchospasm was completely relieved in 50% and improved in the balance. Dysphagia remains a significant problem, with only 42% of patients completely free of trouble.

CONCLUSIONS

Overall the respiratory symptoms were improved in the majority of patients, with cough responding somewhat better than wheeze. Appropriate patient selection remains the greatest challenge when a patient with cough or wheeze that is considered to be due to GORD is referred for surgery.

Epidemiology of cough

Patients with cough may be conveniently divided into those with acute, usually viral, illness and those with chronic cough. Acute cough represents the largest single cause of consultation in primary care, whereas chronic cough is one of the commonest presentations in respiratory medicine. The world-wide market in cough treatments is several billion dollars. In both syndromes, cough sensitivity is upregulated, but the inflammation giving rise to cough is localised to the larynx and large airways in acute cough. Whilst this is also true of cough-predominant asthma, the origin of cough in chronic disease may also lie in the oesophagus, nose or sinuses leading to errors in diagnosis and treatment.

Chronic cough due to gastroesophageal reflux disease: efficacy of antireflux surgery

BACKGROUND

Gastroesophageal reflux disease (GERD) can be overlooked as the cause of chronic cough (CC) when typical gastrointestinal symptoms are absent or minimal. We analyzed the outcomes of Nissen fundoplication (NF) for patients who failed medical therapy for CC attributable only to GERD (G-CC). We performed a prospective outcome evaluation of 21 consecutive patients with G-CC undergoing NF from 1997 to 2000 at a tertiary care university hospital.

MATERIALS AND METHODS

Twenty-one patients without prior antireflux surgeries had G-CC diagnosed by a clinical profile and 24-h pH monitoring showing a cough-reflux correlation. Respiratory symptoms alone were present in 53% of patients. NF was performed when G-CC persisted despite intensive medical therapy, including an antireflux diet. Preoperatively, all patients underwent 24-h pH monitoring, esophageal manometry, barium swallow, gastric emptying study, bronchoscopy, and upper endoscopy. NF was utilized in all cases, laparoscopically in 18. Before and after surgery, patients graded their cough severity using the Adverse Cough Outcome Survey (ACOS). Quality of life was measured using the Sickness Impact Profile (SIP).

RESULTS

Postoperatively, 18 patients (86%) reported an improvement of their cough. G-CC considerably improved in 16/21 patients (76%), with complete resolution in 13 patients (62%). Mild to moderate improvement was found in 2 patients (10%). Patient-reported cough severity (ACOS) and quality of life (SIP) both significantly improved early (6-12 weeks) postoperatively and persisted during the long-term (1 year) follow-up. The average hospital length of stay was 1.78 +/- 0.2 (l-4) days for the laparoscopic (n = 18) and 6.3 +/- 1.2 (4-8) days for the open surgery (n = 3) groups.

CONCLUSION

Twenty-four-hour esophageal pH monitoring is a valuable tool for preoperative cough-reflux correlation. Antireflux surgery is effective in carefully selected patients whose refractory CC is attributable only to GERD. NF controls the severity of cough while improving the quality of life. Outcomes are further enhanced using laparoscopic procedures with shorter hospital stays.

Chronic cough, asthma, and gastroesophageal reflux

Gastroesophageal reflux disease (GERD) causes chronic cough and triggers asthma. Mechanisms of reflux-associated chronic cough include micro- and macroaspiration, laryngeal injury, and a vagally mediated reflex. An empiric trial of a proton pump inhibitor in patients without other etiologies of cough found through diagnostic testing may be an effective diagnostic strategy for GERD-associated cough. In GERD-associated asthma, there is evidence of neurogenic inflammation. Medical or surgical therapy of GERD results in asthma symptom improvement in about 70% of patients. A 3-month empiric trial of omeprazole, 20 mg daily, followed by esophageal pH testing in drug nonresponders, is the most cost-effective way of diagnosing asthma triggered by GERD.

Supraesophageal complications of gastroesophageal reflux

Supraesophageal complications of GERD have become more commonly recognized or suspected by physicians. However, the direct association between these complications and GERD has often been difficult, if not impossible, to establish. Furthermore, the majority of patients with suspected supraesophageal complications of GERD do not have either the characteristic symptoms of heartburn and regurgitation or the definitive findings of esophageal inflammation, which would help reinforce the suspicion of a connection between the supraesophageal complications and GERD. Frequent acid reflux has been shown in patients with various bron-chopulmonary, laryngopharyngeal, or oral cavity disorders. GERD is one of the most common gastrointestinal complaints in the population. It is possible that the supraesophageal problems and acid reflux are mutually independent disorders that occur in the same person. The suspected mechanisms of GERD-related supraesophageal complications appear to be directed through two pathways: by a vagal reflex between the esophagus and tracheobronchial tree triggered by acid reflux or by microaspiration that causes contact damage to mucosal surfaces. The most useful diagnostic modality available to the clinician to aid in the diagnosis of supraesophageal GERD complications is the ambulatory pH recording technique. However, the sensitivity and specificity of this test for recording esophageal or pharyngeal acid reflux events has been critically challenged. Despite the many clinical studies that support the theory that GER has a role in suspected supraesophageal complications, only 1 long-term prospective controlled study of a large group of patients with asthma has shown the positive effects of the elimination of acid reflux. With the focus now on "outcomes medicine," there is a serious need for appropriately designed, controlled studies to answer the many questions surrounding a cause-and-effect association between acid reflux and supraesophageal disorders. Because of the lack of convincing proof between acid reflux and suspected supraesophageal complications, the physician must resort to an intent-to-treat strategy as both a primary therapy and a diagnostic trial. High-dose PPI therapy for prolonged periods is the recognized conservative therapy. Operative therapy (i.e., fundoplication operation) is the procedure of choice when overt regurgitation occurs or when medical therapy, although successful, is not practical for long periods. Controlled, well-designed clinical trials and more sophisticated techniques to measure and quantify acid reflux are crucial in the future to help determine which patients with suspected supraesophageal complications actually have acid reflux as a primary cause. The medical community needs to be alerted to the possibility of an association between GERD and supra-esophageal complications so that patients with a GERD-related complication will be recognized and effectively treated.

Respiratory complications of gastrointestinal diseases

Further advances in the ability to diagnose GER disease by use of ambulatory pH monitoring have unveiled a host of extraesophageal manifestations of GERD. These include pulmonary symptoms of asthma, recurrent pneumonia, cough or bronchitis, and infant apnea. Many of these symptoms may be the sole presentations of GER in these patients. It is important that the clinician is aware of these atypical presentations of GERD. The expanding use of ambulatory pH monitoring is helping to clarify the underlying pathophysiology of these disorders as well as to improve the ability to diagnose the atypical manifestations of GERD.