Recommendations for the management of cough in adults

Efficacy and safety of Qing-Feng-Gan-Ke Granules in patients with postinfectious cough: study protocol of a novel-design phase III placebo-controlled, double-blind randomized trial

BACKGROUND

Postinfectious cough (PIC) is a common condition that affects millions of people worldwide every year. There is Western medicine for this condition but the treatment effect is often incomplete. Traditional Chinese medicine (TCM) has been increasingly prescribed for patients with PIC. Preliminary trials on Qing-Feng-Gan-Ke-Granules (QFGKG) conveyed promising results in treating PIC. This protocol describes an ongoing phase III randomized controlled clinical trial, designed according to a novel methodology of "one study, one primary outcome", with the objective of evaluating the efficacy and safety of QFGKG in patients suffering from PIC.

METHODS/DESIGN

This is a multicenter, phase III, randomized, double-blind, parallel-group, placebo-controlled clinical trial, comprising two simultaneously conducted study parts, part A and part B, intending to investigate two primary outcomes, i.e. time to cough resolution and cough symptom score, respectively. A total of 480 patients, aged 18 to 65 years, who complain of an ongoing persistent cough that has been lasting ≥ 3 weeks, will be recruited from six participating sites and then randomized to receive QFGKG 12.0 g twice daily or placebo 12.0 g twice daily. Each part will enroll 240 patients, with 180 patients being allocated to the QFGKG group and 60 to the placebo group.

DISCUSSION

Although traditional Chinese medicine is a structured intervention that has shown some promise in treating persistent cough, existing unconvincing evidence has noted limitations. This is a rare well-designed and rigorously-controlled, randomized, double-blind trial to evaluate the effects and safety of a Chinese herbal medicine in patients with postinfectious cough, providing tangible benefits for clinical research. Results of this trial are inclined to be conjectured as more truthful by implementing separate study parts that specifically estimate exclusive primary outcome. It will not only provide robust clinical evidence on the efficacy and safety of QFGKG for postinfectious cough, but will also provide a critical piece of information on the availability and superiority of a novel methodology for future clinical trials. The current trial is ongoing with recruitment of the predetermined number of patients being in progress.

TRIAL REGISTRATION

The two parts of this trial were separately registered with the Chinese Clinical Trial Registry: ChiCTR-TRC-13003278 (part A); and ChiCTR-TRC-13003337 (part B).

Neural dysfunction following respiratory viral infection as a cause of chronic cough hypersensitivity

Respiratory viral infections are a common cause of acute coughing, an irritating symptom for the patient and an important mechanism of transmission for the virus. Although poorly described, the inflammatory consequences of infection likely induce coughing by chemical (inflammatory mediator) or mechanical (mucous) activation of the cough-evoking sensory nerves that innervate the airway wall. For some individuals, acute cough can evolve into a chronic condition, in which cough and aberrant airway sensations long outlast the initial viral infection. This suggests that some viruses have the capacity to induce persistent plasticity in the neural pathways mediating cough. In this brief review we present the clinical evidence of acute and chronic neural dysfunction following viral respiratory tract infections and explore possible mechanisms by which the nervous system may undergo activation, sensitization and plasticity.

Bardet Biedl syndrome: motile ciliary phenotype

BACKGROUND

Cilia line the surface of the respiratory tract and beat in a coordinated wave to protect the lungs against infection. Bardet Biedl Syndrome (BBS) is a rare condition attributed to cilia dysfunction. Murine models of BBS suggest a respiratory phenotype; however, no reports have studied the translation of these findings in patients.

METHODS

We assessed the clinical symptoms of motile cilia dysfunction and the histology of ciliated respiratory epithelium in patients with BBS.

RESULTS

We report an increased prevalence of neonatal respiratory distress at birth (12%), general practitioner-diagnosed asthma (21%), otitis media (33%), and rhinitis (36%) in patients with BBS. These symptoms, however, occurred at a significantly reduced prevalence compared with patients with known motile cilia dysfunction (primary ciliary dyskinesia). Respiratory epithelial assessment revealed cellular damage, significant ciliary depletion (on 60% of ciliated cells), and goblet cell hyperplasia in patients with BBS (50% goblet cells). These findings were quantifiably similar to those of patients with asthma (P > .05). Surprisingly, motile cilia function and ultrastructure were grossly normal with the exception of occasional unique inclusions within the ciliary membrane.

CONCLUSIONS

In conclusion, motile ciliary structure and function are essentially normal in patients with BBS.

Natural products for chronic cough: Text mining the East Asian historical literature for future therapeutics

Chronic cough is a significant health burden. Patients experience variable benefits from over the counter and prescribed products, but there is an unmet need to provide more effective treatments. Natural products have been used to treat cough and some plant compounds such as pseudoephedrine from ephedra and codeine from opium poppy have been developed into drugs. Text mining historical literature may offer new insight for future therapeutic development. We identified natural products used in the East Asian historical literature to treat chronic cough. Evaluation of the historical literature revealed 331 natural products used to treat chronic cough. Products included plants, minerals and animal substances. These natural products were found in 75 different books published between AD 363 and 1911. Of the 331 products, the 10 most frequently and continually used products were examined, taking into consideration findings from contemporary experimental studies. The natural products identified are promising and offer new directions in therapeutic development for treating chronic cough.

Effects of quitting cannabis on respiratory symptoms

Smoking cannabis is associated with symptoms of bronchitis. Little is known about the persistence of symptoms after stopping cannabis use. We assessed associations between changes in cannabis use and respiratory symptoms in a population-based cohort of 1037 young adults. Participants were asked about cannabis and tobacco use at ages 18, 21, 26, 32 and 38 years. Symptoms of morning cough, sputum production, wheeze, dyspnoea on exertion and asthma diagnoses were ascertained at the same ages. Frequent cannabis use was defined as ≥52 occasions over the previous year. Associations between frequent cannabis use and respiratory symptoms were analysed using generalised estimating equations with adjustments for tobacco smoking, asthma, sex and age. Frequent cannabis use was associated with morning cough (OR 1.97, p<0.001), sputum production (OR 2.31, p<0.001) and wheeze (OR 1.55, p<0.001). Reducing or quitting cannabis use was associated with reductions in the prevalence of cough, sputum and wheeze to levels similar to nonusers.Frequent cannabis use is associated with symptoms of bronchitis in young adults. Reducing cannabis use often leads to a resolution of these symptoms.

P2X3 receptor antagonist (AF-219) in refractory chronic cough: a randomised, double-blind, placebo-controlled phase 2 study

BACKGROUND

Preclinical studies suggest that P2X3 receptors are expressed by airway vagal afferent nerves and contribute to the hypersensitisation of sensory neurons. P2X3 receptors could mediate sensitisation of the cough reflex, leading to chronic cough. We aimed to investigate the efficacy of a first-in-class oral P2X3 antagonist, AF-219, to reduce cough frequency in patients with refractory chronic cough.

METHODS

We did a double-blind, placebo-controlled, two-period, crossover study at one UK centre. With a computer-generated sequence, we randomly assigned patients with refractory chronic cough to AF-219, 600 mg twice a day, or to placebo (1:1), and then, after a 2 week washout, assigned patients to receive the other treatment. Patients, health-care providers, and investigators were masked to sequence assignment. We assessed daytime cough frequency (primary endpoint) at baseline and after 2 weeks of treatment using 24 h ambulatory cough recordings. The primary analysis used a mixed effects model with the intention-to-treat population. This study was registered at ClinicalTrials.gov, number NCT01432730.

FINDINGS

Of 34 individuals assessed between Sept 22, 2011, and Nov 29, 2012, we randomly assigned 24 patients (mean age 54·5 years; SD 11·1). In the observed case analysis, cough frequency was reduced by 75% when patients were allocated to AF-219 compared when allocated to placebo (p=0·0003). Daytime cough frequency fell from a mean 37 coughs per h (SD 32) to 11 (8) coughs per h after AF-219 treatment versus 65 (163) coughs per h to 44 (51) coughs per h after placebo. Six patients withdrew before the end of the study because of taste disturbances, which were reported by all patients taking AF-219.

INTERPRETATION

P2X3 receptors seem to have a key role in mediation of cough neuronal hypersensitivity. Antagonists of P2X3 receptors such as AF-219 are a promising new group of antitussives.

FUNDING

Afferent Pharmaceuticals.

The impact of chronic cough: a cross-sectional European survey

PURPOSE

Studies that investigate the impact of chronic cough have largely focused on patients attending secondary care. Our aim was to investigate the opinions of the wider general population across Europe.

METHODS

An internet survey was made available in 12 languages on the European Lung Foundation website, between January 2012 and April 2013.

RESULTS

Of 1120 respondents from 29 different European countries, 67 % were female, mean age 51 years (SD 15), median cough duration 2-5 years. The majority of respondents reported cough impacted their quality of life, mood and ability to undertake activities. Despite 72 % of respondents having visited their doctor ≥3 times, only 53 % had received a diagnosis. Asthma was the most common diagnosis (23 %). Most respondents reported limited or no effectiveness of medications. 88 % of respondents reported that they would like more information to be available on chronic cough.

CONCLUSIONS

Chronic cough has a negative impact on quality of life. Further work is needed to raise awareness, promote management strategies, develop effective treatments and consider the educational and support needs of patients with chronic cough.

Olodaterol attenuates citric acid-induced cough in naïve and ovalbumin-sensitized and challenged guinea pigs

Excessive coughing is a common feature of airway diseases. Different G-protein coupled receptors, including β2-adrenergic receptors (β2-AR), have been implicated in the molecular mechanisms underlying the cough reflex. However, the potential antitussive property of β2-AR agonists in patients with respiratory disease is a matter of ongoing debate. The aim of our study was to test the efficacy of the long-acting β2-AR agonist olodaterol with regard to its antitussive property in a pre-clinical model of citric acid-induced cough in guinea pigs and to compare the results to different clinically relevant β2-AR agonists. In our study β2-AR agonists were intratracheally administered, as dry powder, into the lungs of naïve or ovalbumin-sensitized guinea pigs 15 minutes prior to induction of cough by exposure to citric acid. Cough events were counted over 15 minutes during the citric acid exposure. Olodaterol dose-dependently inhibited the number of cough events in naïve and even more potently and with a greater maximal efficacy in ovalbumin-sensitized guinea pigs (p < 0.01). Formoterol and salmeterol showed a trend towards reducing cough. On the contrary, indacaterol demonstrated pro-tussive properties as it significantly increased the number of coughs, both in naïve and ovalbumin-sensitized animals (p < 0.001). In conclusion, olodaterol, at doses eliciting bronchodilation, showed antitussive properties in a model of citric acid-induced cough in naïve and ovalbumin-sensitized guinea pigs. This is in agreement with pre-clinical and clinical studies showing antitussive efficacy of β2-AR agonists. Indacaterol increased the number of coughs in this model, which concurs with clinical data where a transient cough has been observed after indacaterol inhalation. While the antitussive properties of β2-AR agonists can be explained by their ability to lead to the cAMP-induced hyperpolarization of the neuron membrane thereby inhibiting sensory nerve activation and the cough reflex, the mechanism underlying the pro-tussive property of indacaterol is not known.

Tools for assessing outcomes in studies of chronic cough: CHEST guideline and expert panel report

BACKGROUND

Since the publication of the 2006 American College of Chest Physicians (CHEST) cough guidelines, a variety of tools has been developed or further refined for assessing cough. The purpose of the present committee was to evaluate instruments used by investigators performing clinical research on chronic cough. The specific aims were to (1) assess the performance of tools designed to measure cough frequency, severity, and impact in adults, adolescents, and children with chronic cough and (2) make recommendations or suggestions related to these findings.

METHODS

By following the CHEST methodologic guidelines, the CHEST Expert Cough Panel based its recommendations and suggestions on a recently published comparative effectiveness review commissioned by the US Agency for Healthcare Research and Quality, a corresponding summary published in CHEST, and an updated systematic review through November 2013. Recommendations or suggestions based on these data were discussed, graded, and voted on during a meeting of the Expert Cough Panel.

RESULTS

We recommend for adults, adolescents (≥ 14 years of age), and children complaining of chronic cough that validated and reliable health-related quality-of-life (QoL) questionnaires be used as the measurement of choice to assess the impact of cough, such as the Leicester Cough Questionnaire and the Cough-Specific Quality-of-Life Questionnaire in adult and adolescent patients and the Parent Cough-Specific Quality of Life Questionnaire in children. We recommend acoustic cough counting to assess cough frequency but not cough severity. Limited data exist regarding the performance of visual analog scales, numeric rating scales, and tussigenic challenges.

CONCLUSIONS

Validated and reliable cough-specific health-related QoL questionnaires are recommended as the measurement of choice to assess the impact of cough on patients. How they compare is yet to be determined. When used, the reporting of cough severity by visual analog or numeric rating scales should be standardized. Previously validated QoL questionnaires or other cough assessments should not be modified unless the new version has been shown to be reliable and valid. Finally, in research settings, tussigenic challenges play a role in understanding mechanisms of cough.

Weak peristalsis with large breaks in chronic cough: association with poor esophageal clearance

BACKGROUND

Gastroesophageal reflux plays an important role in chronic cough (CC). Whether disturbed esophageal motility contributes to increased esophageal reflux exposure or interferes with swallowed bolus clearance is unclear. This study used high resolution esophageal manometry and impedance (HRIM) together with Chicago Classification, and 24-h impedance pH (MII/pH) to address these questions in patients with CC compared with heartburn (HB).

METHODS

A retrospective review of 32 patients with CC (mean age 57 [95% CI: 52-62] years) and 32 patients with symptoms of HB (55 [52-62] years) referred for HRIM and MII/pH between September 2012 and September 2013 was undertaken.

KEY RESULTS

Weak peristalsis with large breaks (WPLBs) was observed in 34% of CC patients compared with only 12% of HB patients (p = 0.027). Pathological acid exposure time (AET) was identified in 81% of CC patients with WPLBs compared with 29% without (p = 0.011). Increased AET was associated with prolonged clearance time of refluxed events (p = 0.006) rather than increased number of events. AET correlated with the percentage of peristaltic events with large breaks in CC (ρ = 0.467, p = 0.007). Similar data were obtained for total bolus (acid and non-acid) exposure time. Only one of the CC patients with WPLBs exhibited complete bolus transit (CBT) on swallowing compared with 81% without WPLBs (p < 0.001). Moreover, the percentage of peristaltic events associated with CBT negatively correlated with the percentage of peristaltic events with large breaks (r = -0.653, p < 0.001) in CC.

CONCLUSIONS & INFERENCES

One-third of CC patients exhibit WPLBs, which directly impacts on clearance of refluxed events and bolus's swallowed. These observations may have important implications for esophageal-bronchial interaction in CC.

Adult and paediatric cough guidelines: Ready for an overhaul?

Cough is one of the most common reasons that patients seek medical attention. Cough guidelines from numerous countries and societies are available to assist the clinician to investigate and manage patients with cough. We review some of the recent progress in the field of cough that may lead to revision of these guidelines. In adults with chronic cough, new causes such as obstructive sleep apnoea have been identified. A new terminology, cough hypersensitivity syndrome (CHS), has been proposed for patients with chronic cough, which emphasises cough reflex hypersensitivity as a key feature. New therapeutic options are now available, particularly for patients with refractory or idiopathic chronic cough, which include gabapentin, speech pathology management and morphine. There has been great progress in the assessment of cough with the development of validated quality of life questionnaires and cough frequency monitoring tools. In children, common aetiologies differ from adults and those managed according to guidelines have better outcomes compared to usual care. New diagnostic entities such as protracted bacterial bronchitis have been described. Paediatric-specific cough assessment tools such as the Parent/Child Quality of Life Questionnaire will help improve the assessment of patients. Further research is necessary to improve the evidence base for future clinical guideline recommendations. Guidelines in future should also aim to reach a wider audience that includes primary care physicians, non-specialists and patients.

Chronic dry cough: Diagnostic and management approaches

Cough is the most common symptom for which medical treatment is sought in the outpatient setting. Chronic dry cough poses a great diagnostic and management challenge due to myriad etiologies. Chronic cough has been commonly considered to be caused by gastroesophageal reflux, post-nasal drip or asthma. However, recent evidences suggest that many patients with these conditions do not have cough, and in those with cough, the response to specific treatments is unpredictable at best. This raises questions about the concept of a triad of treatable causes for chronic cough. This article discusses the mechanism and etiology of cough, along with recent advances in the field of cough, highlighting some of the diagnostic and management challenges.

Overview of the management of cough: CHEST Guideline and Expert Panel Report

This overview will demonstrate that cough is a common and potentially expensive health-care problem. Improvement in the quality of care of those with cough has been the focus of study for a variety of disciplines in medicine. The purpose of the Cough Guideline and Expert Panel is to synthesize current knowledge in a form that will aid clinical decision-making for the diagnosis and management of cough across disciplines and also identify gaps in knowledge and treatment options.

Anatomy and neurophysiology of cough: CHEST Guideline and Expert Panel report

Bronchopulmonary C-fibers and a subset of mechanically sensitive, acid-sensitive myelinated sensory nerves play essential roles in regulating cough. These vagal sensory nerves terminate primarily in the larynx, trachea, carina, and large intrapulmonary bronchi. Other bronchopulmonary sensory nerves, sensory nerves innervating other viscera, as well as somatosensory nerves innervating the chest wall, diaphragm, and abdominal musculature regulate cough patterning and cough sensitivity. The responsiveness and morphology of the airway vagal sensory nerve subtypes and the extrapulmonary sensory nerves that regulate coughing are described. The brainstem and higher brain control systems that process this sensory information are complex, but our current understanding of them is considerable and increasing. The relevance of these neural systems to clinical phenomena, such as urge to cough and psychologic methods for treatment of dystussia, is high, and modern imaging methods have revealed potential neural substrates for some features of cough in the human.

Chronic cough - assessment of treatment efficacy based on two questionnaires

INTRODUCTION

Efficacy of chronic cough treatment is ambiguous. The aim of the study was to analyze chronic cough alleviation after specific treatment and the relationship between cough etiology and treatment efficacy.

MATERIAL AND METHODS

A stepwise diagnostic approach was used to diagnose cough etiology in non-smoking adults with chronic cough. In all patients specific treatment was applied. Two different questionnaires - a visual analog scale and a 5-degree scale - were used to assess cough severity before and after 4-6 months of treatment.

RESULTS

A significant correlation between pre-treatment and post-treatment results of both questionnaires was found (Spearman coefficient 0.43, p = 0.0003 and 0.73, p < 0.0001, respectively). Baseline questionnaire analysis revealed no differences in cough severity between patients with different cough causes or multiple cough causes. Although specific treatment resulted in a significant decrease of cough severity in the entire group, only partial improvement was noted. According to the visual analogue scale, a decrease of cough severity by at least 50% was achieved only in 54.4% of patients (37/68). Similarly, satisfactory improvement was noted in only 54.4% (37/68) of patients when using the 5-point scale. There were three sub-groups of patients, in whom no relevant decrease of cough severity was observed despite treatment: patients with 1. three coexisting cough causes, 2. non-asthmatic eosinophilic bronchitis, and 3. chronic idiopathic cough.

CONCLUSIONS

Cough severity does not depend on its etiology. Efficacy of chronic cough treatment in non-smoking patients is only moderate.

Atopic cough and fungal allergy

We have shown that some patients presenting with chronic bronchodilator-resistant non-productive cough have a global atopic tendency and cough hypersensitivity without nonspecific bronchial hyperresponsiveness, abbreviated as atopic cough (AC). The cough can be treated successfully with histamine H1 antagonists and/or glucocorticoids. Eosinophilic tracheobronchitis and cough hypersensitivity are pathological and physiological characteristics of AC. Fungus-associated chronic cough (FACC) is defined as chronic cough associated with basidiomycetous (BM) fungi found in induced sputum, and recognition of FACC has provided the possibility of using antifungal drugs as new treatment strategies. Bjerkandera adusta is a wood decay BM fungus, which has attracted attention because of its potential role in enhancing the severity of cough symptoms in FACC patients by sensitization to this fungus. Before making a diagnosis of "idiopathic cough" in cases of chronic refractory cough, remaining intractable cough-related laryngeal sensations, such as "a sensation of mucus in the throat (SMIT)," which is correlated with fungal colonization, should be evaluated and treated appropriately in each patient. The new findings, i.e., the detection of environmental mushroom spores that should not be present in the human airways in addition to the good clinical response of patients to antifungal drugs, may lead to the development of novel strategies for treatment of chronic cough.

Nonpharmacological interventions for refractory chronic cough patients: systematic review

BACKGROUND

For people with refractory chronic cough, nonpharmacological interventions are emerging as alternatives to antitussive medications. These treatments generally are delivered by physiotherapists and speech and language therapists and consist of education, breathing exercises, cough suppression techniques, and counselling. Although the number of studies investigating these treatment options has increased in recent years there has not been a systematic review of the efficacy of these treatment options.

METHODS

Studies were searched for in EMBASE, AMED, Medline, CINAHL, and PsycINFO databases. Bibliographies of studies and reviews were searched by hand. Critical appraisal was carried out by one reviewer using the SIGN appraisal tools and Cochrane handbook for systematic reviews.

RESULTS

From a total of 184 studies, 5 full-text English language articles were included in the review. Nonpharmacological interventions were found to significantly reduce cough reflex sensitivity, improve quality of life, and lead to reductions in cough severity and frequency. However, few studies used validated and reliable tools to measure cough severity and frequency thereby limiting the robustness of these findings.

CONCLUSION

Present data support the use of two to four sessions of education, cough suppression techniques, breathing exercises, and counselling in order to achieve improvements in cough sensitivity and cough-related quality of life for people with chronic refractory cough. Due to the lack of validated outcome measures, results for other aspects of cough should be interpreted with caution. There is a need for additional larger-powered comparative studies investigating nonpharmacological interventions for refractory chronic cough.

A worldwide survey of chronic cough: a manifestation of enhanced somatosensory response

Reports from individual centres suggest a preponderance of females with chronic cough. Females also have heightened cough reflex sensitivity. Here we have reviewed the age and sex of unselected referrals to 11 cough clinics. To investigate the cause of any observed sex dimorphism, functional magnetic resonance imaging of putative cough centres was analysed in normal volunteers. The demographic profile of consecutive patients presenting with chronic cough was evaluated. Cough challenge with capsaicin was undertaken in normal volunteers to construct a concentration-response curve. Subsequent functional magnetic resonance imaging during repeated inhalation of sub-tussive concentrations of capsaicin observed areas of activation within the brain and differences in the sexes identified. Of the 10,032 patients presenting with chronic cough, two-thirds (6591) were female (mean age 55 years). The patient profile was largely uniform across centres. The most common age for presentation was 60-69 years. The maximum tolerable dose of inhaled capsaicin was lower in females; however, a significantly greater activation of the somatosensory cortex was observed. Patients presenting with chronic cough from diverse racial and geographic backgrounds have a strikingly homogeneous demographic profile, suggesting a distinct clinical entity. The preponderance of females may be explained by sex-related differences in the central processing of cough sensation.

Chronic cough: a herald symptom of thoracic aortic aneurysm in a patient with a bicuspid aortic valve

Chronic cough has a wide differential, of which thoracic aortic aneurysm is a rare but potentially devastating cause. We present a patient with previous aortic valve replacement for a bicuspid valve who had been suffering from a chronic cough for 8 months and who developed subsequent voice hoarseness. This had been initially managed in the community with trials of steroid inhalers, steroid nasal sprays and proton pump inhibitors to no avail. He was referred to cardiology and chest clinics. An urgent CT aortogram was requested given his widened mediastinum on chest radiograph, cardiac history of bicuspid valve and symptoms. This revealed a large aneurysm of the thoracic aorta with chronic dissection that required urgent operative intervention. His cough resolved 6 weeks postoperatively. The purpose of this report is to highlight thoracic aortic aneurysms as a potential rare differential for chronic cough and as a complication of patients with bicuspid aortic valves.

Is opiate action in cough due to sedation?

OBJECTIVES

Opiates have been used for cough suppression for centuries. It is unclear whether this antitussive action is due to their known sedative effects. We aimed to assess correlation between cough suppression and opiate usage.

METHODS

We performed a post hoc analysis of two published trials with three opioids. In study one, patients with chronic cough were treated with 4 weeks of modified release morphine sulphate (5 mg twice daily) or placebo in a double-blinded placebo-controlled fashion. Cough suppression was assessed subjectively by the Leicester Cough Questionnaire and objectively by citric acid aerosol (CAA) induced cough challenge. In study 2, normal volunteers were given single doses of placebo, codeine 30 mg or dextromethorphan 50 mg and cough suppression assessed using the CAA-induced cough challenge. Sedation was contemporaneously assessed by direct questioning.

RESULTS

There were 14 episodes of patient-reported sedation; 2 with modified release morphine sulphate, 9 with codeine and 3 with dextromethorphan. There was no correlation between change in the Leicester Cough Questionnaire or the CAA-induced cough challenge and reported sedation.

CONCLUSION

This observational study suggests that sedation is unlikely to underlie the antitussive properties of these opioids. Eliciting the mechanism of these medications in cough may be a target for future tailored drug development.

Evidence for multiple sensory circuits in the brain arising from the respiratory system: an anterograde viral tract tracing study in rodents

Complex sensations accompany the activation of sensory neurons within the respiratory system, yet little is known about the organization of sensory pathways in the brain that mediate these sensations. In the present study, we employ anterograde viral neuroanatomical tract tracing with isogenic self-reporting recombinants of HSV-1 strain H129 to map the higher brain regions in receipt of vagal sensory neurons arising from the trachea versus the lungs, and single-cell PCR to characterize the phenotype of sensory neurons arising from these two divisions of the respiratory tree. The results suggest that the upper and lower airways are predominantly innervated by sensory neurons derived from the somatic jugular and visceral nodose cranial ganglia, respectively. This coincides with central circuitry that is predominately somatic-like, arising from the trachea, and visceral-like, arising from the lungs. Although some convergence of sensory pathways was noted in preautonomic cell groups, this was notably absent in thalamic and cortical regions. These data support the notion that distinct afferent subtypes, via distinct central circuits, subserve sensations arising from the upper versus lower airways. The findings may explain why sensations arising from different levels of the respiratory tree are qualitatively and quantitatively unique.

Chronic cough: a respiratory viewpoint

PURPOSE OF REVIEW

This article reviews the common causes and investigation of chronic cough and explores unexplained cough and its relationship to cough hypersensitivity.

RECENT FINDINGS

Cough plays a critical role in airway protection and clearance of secretions. Chronic cough, however, is a debilitating symptom that can significantly interfere with quality of life. Despite their limitations cough guidelines have raised the awareness of chronic cough as an important problem and provided a framework for a logical care pathway. The use of a systematic approach to diagnosis and management in a specialist clinic can result in successful identification as to the cause, with subsequent relief of symptoms. In a proportion of patients no diagnosis is reached or treatment fails. A common finding among these patients is cough reflex hypersensitivity and this is an important feature irrespective of the underlying diagnosis. The majority of patients referred to tertiary cough clinics are females. Women appear to have an intrinsically heightened cough response with augmented cough challenge and a high frequency of ACE-inhibitor cough.

SUMMARY

The way in which we review cough has undergone radical change in the last decade. A distinct population of patients with chronic idiopathic cough is emerging in whom cough reflex hypersensitivity is a feature. Extended co-operation between clinicians, scientists and the pharmaceutical industry is required to better understand the pathophysiology of the enhanced cough reflex and the development of more effective antitussive therapies.

Surface-evoked laryngeal sensory action potential evaluation in neurogenic chronic cough

OBJECTIVES

Neurogenic chronic cough is currently a diagnosis of exclusion. We hypothesized that surface-evoked laryngeal sensory action potential (SELSAP) testing could be used to help establish a diagnosis of laryngeal sensory neuropathy as a cause of chronic cough, based on altered SELSAP waveform morphology.

STUDY DESIGN

Retrospective cohort study.

METHODS

Laryngeal electromyographic (EMG) data including SELSAP waveform testing from patients with chronic cough were directly compared with a control population without significant laryngeal symptoms, and statistical analysis of unilateral and bilateral neuropathy injury subgroups was performed.

RESULTS

Thirty patients with a chief complaint of chronic cough underwent laryngeal EMG testing since January 2000 with needle EMG and surface nerve conduction studies. SELSAP waveform analysis of unilateral and bilateral laryngeal neuropathy demonstrated significantly lowered median SELSAP peak amplitude compared with controls (P < 0.01).

CONCLUSIONS

Patients with suspected neurogenic chronic cough demonstrate statistically significant alterations in SELSAP waveform that can support a diagnosis of laryngeal sensory neuropathy.

On the definition of chronic cough and current treatment pathways: an international qualitative study

BACKGROUND

The pathogenesis of chronic cough is not well understood and treatment options are limited. In this study we sought to explore the current understanding and management of chronic cough across an international group of specialists.

METHODS

This was an international study of cross sectional qualitative design. In depth interviews were carried out with "Respiratory Specialists" experienced in treating treating Chronic Obstructive Pulmonary Disease (COPD), idiopathic pulmonary fibrosis (IPF), idiopathic chronic cough (ICC) and/or lung cancer patients and with "Disease Experts" in the field of Chronic Cough. Participants in the study were recruited from the USA, UK, Germany, Ireland, Australia and Japan. Interviews with specialists were held at research facilities and with DEs over the telephone. These were preceded by the specialists completing case records of patients recently seen. All interviews were conducted by native speaking trained moderators using a semi-structured interview guide script. This was designed to elicit the definition of chronic cough, explore the unmet needs for each disease state, define therapy goals, identify patient phenotypes and give an overview of the treatment pathway.

RESULTS

76 specialists and 10 experts took part in the study. Over two thirds (70%) of respondents defined chronic cough as "cough lasting more than 8/12 weeks" (range 2 weeks to 2 years). Physicians emphasised three interdependent aspects of clinical assessment: impact on quality of life, type of cough (productive versus non-productive) and the underlying pathology. Specialists emphasised treating the underlying cause rather than the cough, this being most prominent in Japan. Experts as a group focussed on chronic cough independently. Evaluation of the respiratory system, GI tract and upper airway (ENT) for establishing an underlying cause was recommended. Type of cough (productive vs non-productive) and impact on quality of life influenced treatment initiation. 33% of patients with ICC were prescribed anti-tussives. With associated diagnoses of COPD, IPF or lung cancer the emphasis was on treating the underlying condition. Alternatives to pharmacological treatments were frequently considered.

CONCLUSION

There is significant international variation in our understanding and management of chronic cough. Further work is required to bring forth clear guidance and effective medicines for these patients.

An evaluation of an intervention designed to improve the evidence-based supply of non-prescription medicines from community pharmacies

OBJECTIVES

The aims of this study were to conduct the proof of concept study and to develop and evaluate an educational intervention that promotes the evidence-based supply of non-prescription medicines (NPMs).

METHOD

An educational intervention was delivered to pharmacy assistants and pharmacists in three pharmacies in England. The intervention included the provision of summaries of evidence for the treatment of four minor ailments and resulted in the preparation of evidence-based portfolios for the treatment of the following ailments: athlete's foot, cough, nasal congestion and period pain. The effect of the intervention was evaluated using a combination of direct overt observation, vignettes, self-reported behaviour and interviews.

KEY FINDINGS

Evaluation data were collected from the three pharmacies. Data were derived from 3 pharmacists and 13 assistants, of whom 10 (3 pharmacists; 7 assistants) attended the training event. Comparing pre- and post-intervention practice, 8/11 (pre-) versus 5/6 (post-) observed, 46/80 versus 62/80 vignette and 25/30 versus 39/40 self-reported recommendations were evidence based. Prior to the intervention, 3/16 participants understood the role of evidence regarding the supply of NPMs compared with 16/16 post-intervention. Participants reported relying upon experiential knowledge to inform their decision making prior to the educational intervention. Thereafter, the participants reported using evidence to a greater extent. Barriers and facilitators for evidence-based practice were also identified.

CONCLUSION

A one-off educational intervention increased participants' self-reported awareness and potential application of evidence to inform their supply of NPMs. Further research is needed to assess the effectiveness, long-term impact, generalisability and cost-effectiveness of this intervention for a wider range of common conditions.

The diagnosis and treatment of acute cough in adults

BACKGROUND

Cough is the most common complaint for which patients visit their primary care physician, being present in about 8% of consultations. A profusion of new evidence has made it necessary to produce a comprehensively updated version of the guideline on cough of the German College of General Practitioners and Family Physicians (Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin, DEGAM), which was last issued in 2008.

METHOD

The interdisciplinary evidence and consensus based S3 guideline on cough of the DEGAM was updated on the basis of a systematic review of the relevant literature published from 2003 to July 2012 (MEDLINE, Cochrane Library, EMBASE, Web of Science). Evidence levels were assessed and consensus procedures were followed as prescribed by AWMF standards, with the participation of 7 medical societies.

RESULTS

182 publications were used to update the guideline, including 45 systematic reviews (26 of which included a meta-analysis) and 17 randomized controlled trials (RCTs). 11 recommendations for acute cough were approved by consensus in a nominal group process. The history and physical examination are the basis of diagnostic evaluation. When the clinical diagnosis is that of an acute, uncomplicated bronchitis, no laboratory tests, sputum evaluation, or chest x-rays should be performed, and antibiotics should not be given. There is inadequate evidence for the efficacy of antitussive or expectorant drugs against acute cough. The state of the evidence for phytotherapeutic agents is heterogeneous. Persons with community-acquired pneumonia should receive empirical antibiotic treatment for 5 to 7 days; specific risk factors can influence the choice of drug to be used. It is recommended that laboratory tests should not be performed and neuraminidase inhibitors should not be given in the routine management of influenza.

CONCLUSION

A specifically intended effect of these recommendations is to reduce the use of antibiotics to treat colds and acute bronchitis, for which they are not indicated. Further clinical trials of treatments for cough should be performed in order to extend the evidence base, which is now fragmentary.

Leicester Cough Questionnaire: translation to Portuguese and cross-cultural adaptation for use in Brazil

OBJECTIVE

To translate the Leicester Cough Questionnaire (LCQ) to Portuguese and adapt it for use in Brazil.

METHODS

Cross-cultural adaptation of a quality of life questionnaire requires a translated version that is conceptually equivalent to the original version and culturally acceptable in the target country. The protocol used consisted of the translation of the LCQ to Portuguese by three Brazilian translators who were fluent in English and its back-translation to English by another translator who was a native speaker of English and fluent in Portuguese. The back-translated version was evaluated by one of the authors of the original questionnaire in order to verify its equivalence. Later in the process, a provisional Portuguese-language version was thoroughly reviewed by an expert committee. In 10 patients with chronic cough, cognitive debriefing was carried out in order to test the understandability, clarity, and acceptability of the translated questionnaire in the target population. On that basis, the final Portuguese-language version of the LCQ was produced and approved by the committee.

RESULTS

Few items were questioned by the source author and revised by the committee of experts. During the cognitive debriefing phase, the Portuguese-language version of the LCQ proved to be well accepted and understood by all of the respondents, which demonstrates the robustness of the process of translation and cross-cultural adaptation.

CONCLUSIONS

The final version of the LCQ adapted for use in Brazil was found to be easy to understand and easily applied.

Evaluation and treatment of chronic cough

Chronic cough is a frustrating and common problem, resulting in significant psychological and physical sequelae as well as enormous financial costs in terms of health care expense and time lost from work. Decreased QoL and depression are common. However, using a systematic approach, including assessing whether the patient uses ACE-I and cigarettes, excluding the presence of red flags and risk factors for life-threatening diseases, and obtaining and normal chest radiograph, more than 90% of cases of chronic cough are diagnosed as being caused by UACS, asthma, or GERD. It is recommended to address these conditions sequentially, starting with UACS. Nonasthmatic eosinophilic bronchitis and pertussis infections are unrecognized by primary care providers and should be considered after UACS, asthma, and GERD have been addressed. Finally, cough hypersensitivity syndrome is a new area of research and has been hypothesized to be the underlying factor in many cases of chronic cough, regardless of the inciting factor. More clinical research is needed to further elucidate the cough reflex pathway and the factors involved in modulating its sensitivity, which may eventually lead to new antitussive therapeutics.

Effect of acid suppression therapy on gastroesophageal reflux and cough in idiopathic pulmonary fibrosis: an intervention study

Background

Chronic cough affects more than 70 percent of patients with Idiopathic Pulmonary Fibrosis and causes significant morbidity. Gastroesophageal reflux is the cause of some cases of chronic cough; and also has a postulated role in the aetiology of Idiopathic Pulmonary Fibrosis. A high prevalence of acid; and more recently non-acid, reflux has been observed in Idiopathic Pulmonary Fibrosis cohorts. Therefore, gastroesophageal reflux may be implicated in the pathogenesis of cough in Idiopathic Pulmonary Fibrosis.

Methods

Eighteen subjects with Idiopathic Pulmonary Fibrosis underwent 24-hour oesophageal impedance and cough count monitoring after the careful exclusion of causes of chronic cough other than gastroesophageal reflux. All 18 were then treated with high dose acid suppression therapies. Fourteen subjects underwent repeat 24-hour oesophageal impedance and cough count monitoring after eight weeks.

Results

Total reflux and acid reflux frequencies were within the normal range in the majority of this cohort. The frequencies of non-acid and proximal reflux events were above the normal range. Following high dose acid suppression therapy there was a significant decrease in the number of acid reflux events (p = 0.02), but an increase in the number of non-acid reflux events (p = 0.01). There was no change in cough frequency (p = 0.70).

Conclusions

This study confirms that non-acid reflux is prevalent; and that proximal oesophageal reflux occurs in the majority, of subjects with Idiopathic Pulmonary Fibrosis. It is the first study to investigate the effect of acid suppression therapy on gastroesophageal reflux and cough in patients with Idiopathic Pulmonary Fibrosis. The observation that cough frequency does not improve despite verifiable reductions in oesophageal acid exposure challenges the role of acid reflux in Idiopathic Pulmonary Fibrosis associated cough. The finding that non-acid reflux is increased following the use of acid suppression therapies cautions against the widespread use of acid suppression in patients with Idiopathic Pulmonary Fibrosis given the potential role for non-acid reflux in the pathogenesis of cough and Idiopathic Pulmonary Fibrosis itself.

Study registration

The study was registered with the Cardiff and Vale University Local Health Board Research and Development Committee (09/CMC/4619) and the South East Wales Ethics Committee (09/WSE04/57).

[Acute cough in infants: impact of national guidelines on medical practices in a French department]

CONTEXT AND AIM

Guidelines have been published regularly since 2010 by the ANSM (the Health Products Safety Agency) advising against antitussive drugs for infants because of their inefficacy and their side effects (convulsions, respiratory congestion). Antihistamines, mucolytics, and terpene-based suppositories have theoretically disappeared from infant pharmacopoeia. We assessed the degree of compliance with these guidelines on the part of health professionals.

MATERIALS AND METHODS

From June 2012 to August 2012, 198 general practitioners and 44 pediatricians were assessed in the Alpes-Maritimes department of France by means of questionnaires. At the same time, an analysis of medical prescriptions was sought from the Regional Directorate of Medical Services (RDMS) of the PACA-Corse region Health Insurance.

RESULTS

The rate of noncompliance with the contraindications was 14.9% (17.7% general practitioners and 2.3% pediatricians). The RDMS study showed a slight decrease in prescriptions for antitussives not recommended from 2011 to 2012: -21% for pediatricians, -15.5% for generalist physicians.

CONCLUSION

Continued educational and informative campaigns are therefore needed to stop medical prescriptions of cough medicines for infants, which should also involve parents.

Antitussive drugs--past, present, and future

Cough remains a serious unmet clinical problem, both as a symptom of a range of other conditions such as asthma, chronic obstructive pulmonary disease, gastroesophageal reflux, and as a problem in its own right in patients with chronic cough of unknown origin. This article reviews our current understanding of the pathogenesis of cough and the hypertussive state characterizing a number of diseases as well as reviewing the evidence for the different classes of antitussive drug currently in clinical use. For completeness, the review also discusses a number of major drug classes often clinically used to treat cough but that are not generally classified as antitussive drugs. We also reviewed a number of drug classes in various stages of development as antitussive drugs. Perhaps surprising for drugs used to treat such a common symptom, there is a paucity of well-controlled clinical studies documenting evidence for the use of many of the drug classes in use today, particularly those available over the counter. Nonetheless, there has been a considerable increase in our understanding of the cough reflex over the last decade that has led to a number of promising new targets for antitussive drugs being identified and thus giving some hope of new drugs being available in the not too distant future for the treatment of this often debilitating symptom.

EAACI Position Paper on assessment of cough in the workplace

Cough is a nonspecific and relatively common symptom that can present difficulties in diagnosis and management, particularly when it is reported to be associated with the workplace. The present consensus document, prepared by a taskforce of the Interest Group on Occupational Allergy of the European Academy of Allergy and Clinical Immunology by means of a nonsystematic review of the current literature, is intended to provide a definition and classification of work-related chronic cough (WRCC) to assist the daily practice of physicians facing with this symptom. The review demonstrates that several upper and lower airway work-related diseases may present with chronic cough; hence, the possible link with the workplace should always be considered. Due to the broad spectrum of underlying diseases, a multidisciplinary approach is necessary to achieve a definite diagnosis. Nevertheless, more epidemiological studies are necessary to estimate the real prevalence and risk factors for WRCC, the role of exposure to environmental and occupational sensitizers and irritants in its pathogenesis and the interaction with both upper and lower airways. Finally, the best management option should be evaluated in order to achieve the best outcome without adverse social and financial consequences for the worker.

Airway oxidative stress in chronic cough

BACKGROUND

The mechanisms of chronic cough are unclear. Many reactive oxygen species affect airway sensory C-fibres which are capable to induce cough. Several chronic lung diseases are characterised by cough and oxidative stress. In asthma, an association between the cough severity and airway oxidative stress has been demonstrated. The present study was conducted to investigate whether airway oxidative stress is associated with chronic cough in subjects without chronic lung diseases.

METHODS

Exhaled breath condensate samples were obtained in 43 non-smoking patients with chronic cough and 15 healthy subjects. Exclusion criteria included a doctor's diagnosis of any lung disorders and any abnormality in lung x-ray. The concentration of 8-isoprostane was measured. In addition, the patients filled in Leicester Cough Questionnaire and underwent hypertonic saline cough provocation test, spirometry, ambulatory peak flow monitoring, nitric oxide measurement, and histamine airway challenge. In a subgroup of patients the measurements were repeated during 12 weeks' treatment with inhaled budesonide, 800 ug/day.

RESULTS

The 8-isoprostane concentrations were higher in the cough patients than in the healthy subjects (24.6 ± 1.2 pg/ml vs. 10.1 ± 1.7 pg/ml, p = 0.045). The 8-isoprostane concentration was associated with the Leicester Cough Questionnaire total score (p = 0.044) but not with the cough sensitivity to saline or other tests. Budesonide treatment did not affect the 8-isoprostane concentrations.

CONCLUSIONS

Chronic cough seems to be associated with airway oxidative stress in subjects with chronic cough but without chronic lung diseases. This finding may help to develop novel antitussive drugs.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov database (KUH5801112), identifier NCT00859274.

Chronic cough: an update

Cough persisting beyond 8 weeks (ie, chronic cough) is one of the most common reasons for an outpatient visit. A protracted cough can negatively affect one's quality of life by causing anxiety, physical discomfort, social isolation, and personal embarrassment. Herein, the anatomy and physiology of the cough reflex are reviewed. Upper airway cough syndrome, asthma, eosinophilic bronchitis, and gastroesophageal reflux disease account for most chronic cough after excluding smoking, angiotensin-converting enzyme inhibitor use, and chronic bronchitis. Many patients have more than one reason for chronic cough. Treating the underlying cause(s) resolves cough in most instances. There are some coughs that seem refractory despite an extensive work-up. The possibility of a hypersensitive cough reflex response has been proposed to explain these cases. Several clinical algorithms to evaluate chronic cough are presented.

Honey plus coffee versus systemic steroid in the treatment of persistent post-infectious cough: a randomised controlled trial

BACKGROUND

Persistent post-infectious cough (PPC) is a cough that remains after a common cold or an upper respiratory tract infection for more than three weeks or perhaps for many months. Two of the suggested treatments for PPC are systemic steroid and honey plus coffee.

AIMS

The aim of this study was to evaluate and compare scientifically the therapeutic effects of these two regimens.

METHODS

A double-blind randomised controlled trial was conducted from 2008 to 2011 at the Baqiyatallah University Hospital, Tehran, Iran. Included in the study were 97 adults who had experienced PPC for more than three weeks. Patients with other causes of chronic cough, systemic disease, or abnormal routine laboratory tests were excluded. The participants were distributed into three groups. A jam like paste was prepared which consisted of honey plus coffee for the first group ('HC'), prednisolone for the second group (steroid, 'S'), and guaifenesin for the third group (control, 'C'). The participants were told to dissolve a specified amount of their product in warm water and to drink the solution every eight hours for one week. All the participants were evaluated before treatment and one week after completion of treatment to measure the severity of their cough. The main outcome measure was the mean cough frequency before and after one week's treatment calculated by a validated visual analogue cough questionnaire score.

RESULTS

There were 97 adult patients (55 men) enrolled in this study with the mean of age of 40.1 years. The mean (+/- SD) cough scores pre- and post-treatment were: HC group 2.9 (0.3) pre-treatment and 0.2 (0.5) post-treatment (p < 0.001); steroid ('S') group 3.0 (0.0) pre-treatment and 2.4 (0.6) post-treatment (p < 0.05); control ('C') group 2.8 (0.4) pre-treatment and 2.7 (0.5) post-treatment (p > 0.05). Analysis of variance showed a significant difference between the mean cough frequency before and after treatment in the HC group versus the S group (p< 0.001). Honey plus coffee was found to be the most effective treatment modality for PPC.

CONCLUSIONS

A combination of honey and coffee can be used as an alternative medicine in the treatment of PPC.

Cough variant and cough-predominant asthma are major causes of persistent cough: a multicenter study in Japan

OBJECTIVE

Persistent cough is a frequent cause of doctor and hospital visits, and its incidence may be increasing. However, diagnosis of the cause of cough remains difficult. Because different causes of cough have different treatments, accurate diagnosis of the cause of cough is critical. To gain a better understanding of the causes of cough in Japan, we performed a multicenter epidemiological study of Japanese patients.

METHODS

The study involved seven institutions in five different areas of Japan, and was conducted over 1 year from March 2009. Patients aged ≥16 years attending the participating centers for the first time complaining of cough persisting for ≥3 weeks were eligible. Patients with chest X-ray abnormalities responsible for cough, fever or blood-stained sputum were excluded, while those with wheeze or shortness of breath were included. Frequency and severity of cough were assessed using questionnaires, and laboratory tests were performed to enable differential diagnoses.

RESULTS

Among the 313 patients evaluated, mean duration of cough symptoms was 192.1 ± 558.4 days. Cough variant asthma (CVA) was the most common cause of prolonged/chronic cough (42.2%), followed by cough-predominant asthma (CPA) (28.4%), atopic cough (7.3%) and chronic obstructive pulmonary disease (6.7%). Patients with an unclear diagnosis were treated with tulobuterol, a transdermal β2-agonist preparation, for 1-2 weeks. Transdermal tulobuterol improved assessments of cough in patients with CVA or CPA, enabling rapid diagnosis of these diseases.

CONCLUSIONS

These findings show that CVA and CPA are the main causes of cough persisting for ≥3 weeks.

Chronic cough: relationship between microaspiration, gastroesophageal reflux, and cough frequency

BACKGROUND

Microaspiration is often considered a potential cause of cough. The aim of this study was to investigate the relationship between microaspiration, the degree and type of gastroesophageal reflux, and the frequency of coughing in patients with chronic cough.

METHODS

One hundred patients with chronic cough (mean [± SD] age, 55.8 years [± 11.0 years]; 65 women) and 32 healthy volunteers (median age, 43.5 years [interquartile range (IQR), 30-50.8 years]; 16 women) were recruited. Patients with chronic cough performed 24-h objective cough frequency with simultaneous esophageal impedance/pH monitoring and measurement of pepsin concentrations in sputum and BAL. Twelve healthy volunteers underwent bronchoscopy/BAL, and 20 underwent impedance/pH monitoring.

RESULTS

Patients with chronic cough had significantly more reflux episodes than healthy volunteers (median, 63.5 reflux episodes [IQR, 52.5-80.0] vs 59.0 [IQR, 41.8-66.0]; P = .03), although the absolute difference was small, and there was no difference in numbers of events extending into the proximal esophagus (median, 17.2% [IQR, 8.0%-26.0%] vs 20.3% [IQR, 5.1%-32.1%]; P = .36). BAL pepsin levels were also similar in chronic cough to control subjects (median, 18.2 ng/mL [range, 0-56.4 ng/mL] vs 9.25 ng/mL [range, 0-46.9 ng/mL]; P = .27). Sputum but not BAL pepsin weakly correlated with the number of proximally occurring reflux events (r = 0.33, P = .045) but was inversely related to cough frequency (r = −0.52, P = .04). Sputum pepsin was, therefore, best predicted by combining the opposing influences of cough and proximal reflux (r = 0.50, P = .004).

CONCLUSIONS

Proximal gastroesophageal reflux and microaspiration into the airways have limited roles in provoking chronic cough. Indeed, coughing appears to be protective, reducing pepsin concentration in the larger airways of patients with chronic cough.

Feasibility study: honey for treatment of cough in children

Respiratory tract infections are an important health problem because of high incidence and economic costs. The World Health Organization identifies honey as a potential demulcent treatment for cough. The aim of this study is to determine: i) patient public perceptions towards a proposed randomized controlled trial (RCT) comparing the effects of honey to placebo for treatment of cough in children; ii) potential participation rates for proposed trial; iii) whether age and gender of parent or child impacts on proposed cough assessment tools. Forty adult participants with children age 1-6 years presenting with an upper respiratory tract infection were enrolled. They underwent a structured interview regarding the proposed trial and assessed their child's cough using two validated questionnaires. Eighty-eight percent of those recruited were willing to participate in the proposed trial. The two independently validated cough scores correlated well. A relationship between age and gender of child or parent with cough assessment score was not found. We conclude that a RCT to determine the effects of honey versus placebo is feasible. The public find the outcome measures and trial design acceptable.

The larynx in cough

About 40% of the population will experience chronic cough at some point during their lives and it tends to be more common in women (Thorax 58:901-7, 2003). Post-nasal drip (or upper airway cough syndrome), gastro-esophageal reflux disease and asthma are considered the most common causes. Yet only a small percentage of patients with these common conditions experience chronic cough. Also there is no agreed measure of post-nasal drip and controversy exists about the diagnosis of reflux above the upper esophageal sphincter (laryngopharyngeal reflux) based on observable changes to the larynx. The approach of the otolaryngologist is to consider the upper and lower airways as a continuum and that a common pathology can have an impact on all these anatomical sites.A multidisciplinary approach is advocated, utilising the skills of the respiratory physician, otolaryngologist, gastroenterologist and speech pathologist.

Approach to the patient with presumed extraoesophageal GERD

Reflux related cough, asthma and laryngitis are frequently encountered and are considered part of extraoesophageal syndromes. The diagnosis of extraoesophageal reflux is difficult due to the lack of gold standard diagnostic criteria. Esophagogastroduodenoscopy and esophageal pH monitoring are inadequate diagnostic tools for due to poor sensitivity and specificity. For this reason, empirical PPI therapy is recommended as an initial approach to diagnose and treat the potential underlying cause of these symptoms in patients without alarm symptoms. Diagnostic testing with esophageal pH and/or impedance monitoring and esophageal motility testing is usually reserved for those who continue to be symptomatic despite a trial of therapy with PPIs. Recent developments have increased our understanding of this difficult to treat group of patients but more research into reflux related extraoesophageal symptoms are needed to better diagnose and treat this group.