Cough (London, England)最新文献

Background: Many tussive agents are components of foods, but little is known about the relationship between cough reflex and oral chemesthesis sensitivities. We investigated the relationships between cough reflex and oral chemesthesis in individuals using two transient receptor potential vanilloid 1 (TRPV1) agonists with different potencies: capsaicin and capsiate.

Methods: Twenty-eight healthy never-smokers were allocated to evaluate cough and oral chemesthesis of capsinoids. Cough reflex sensitivities are estimated by the lowest concentrations generating five coughs by each TRPV1 agonist inhalation. Oral chemesthesis sensitivities are estimated by the lowest concentrations which generate a hot sensation when filter paper loaded with each TRPV1 agonist is placed on the tongue.

Results: There were strong correlations between capsaicin- and capsiate-induced cough reflex sensitivities, and between capsaicin- and capsiate-induced oral chemesthesis sensitivities. However, there were no significant correlations between cough reflex and oral chemesthesis sensitivities induced by both capsaicin and capsiate. The cough reflex sensitivities are significantly greater in females than in males whereas there were no gender differences in oral chemesthesis.

Conclusion: The results showed that the sensitivities of sensory afferents were different between cough reflex and oral chemesthesis, suggesting that TRPV1 sensitivities differ between organs within healthy individuals. Capsiate could be a tussigen for the cough challenge test.

Narcotic antitussives such as codeine reveal the antitussive effect primarily via the mu-opioid receptor in the central nervous system (CNS). The kappa-opioid receptor also seems to contribute partly to the production of the antitussive effect of the drugs. There is controversy as to whether delta-receptors are involved in promoting an antitussive effect. Peripheral opioid receptors seem to have certain limited roles. Although narcotic antitussives are the most potent antitussives at present, certain types of coughs, such as chronic cough, are particularly difficult to suppress even with codeine. In guinea pigs, coughs elicited by mechanical stimulation of the bifurcation of the trachea were not able to be suppressed by codeine. In gupigs with sub-acute bronchitis caused by SO2 gas exposure, coughing is difficult to inhibit with centrally acting antitussives such as codeine. Some studies suggest that neurokinins are involved in the development of codeine-resistant coughs. However, evidence supporting this claim is still insufficient. It is very important to characterize opiate-resistant coughs in experimental animals, and to determine which experimentally induced coughs correspond to which types of cough in humans. In this review, we describe the mechanisms of antitussive effects of narcotic antitussives, addressing codeine-sensitive and -resistant coughs, and including our own results.

Chronic cough is a common reason for presentation to both general practice and respiratory clinics. In up to 25% of cases, the cause remains unclear after extensive investigations. We report 4 patients presenting with an isolated chronic cough who were subsequently found to have obstructive sleep apnoea. The cough improved rapidly with nocturnal continuous positive airway pressure therapy. Further studies are required to investigate the prevalence of coexistence of these common conditions.

Exposure to environmental tobacco smoke (ETS) and active tobacco smoking has been shown to increase symptoms of bronchial asthma such as bronchoconstriction but effects on other respiratory symptoms remain poorly assessed. Current levels of exposure to tobacco smoke may also be responsible for the development of chronic cough in both children and adults. The present study analyses the effects of tobacco smoke exposure as potential causes of chronic cough. A panel of PubMed-based searches was performed relating the symptom of cough to various forms of tobacco smoke exposure. It was found that especially prenatal and postnatal exposures to ETS have an important influence on children's respiratory health including the symptom of cough. These effects may be prevented if children and pregnant women are protected from exposure to ETS. Whereas the total number of studies addressing the relationship between cough and ETS exposure is relatively small, the present study demonstrated that there is a critical amount of data pointing to a causative role of environmental ETS exposure for the respiratory symptom of cough. Since research efforts have only targeted this effect to a minor extent, future epidemiological and experimental studies are needed to further unravel the relation between ETS and cough.

Background: Chronic cough is a common symptom which causes significant levels of morbidity. It is becoming increasingly well characterised by research taking place in specialist cough clinics, where successful treatment rates are high. However, there is a paucity of data regarding the symptom complex of chronic cough in the community. This report details the results of a postal questionnaire survey sent to individuals requesting further information on chronic cough.

Methods: 856 chronic cough questionnaires were sent out to members of the public who requested an information sheet following a national UK radio broadcast. Information regarding demography, history of cough, previous treatment and physical, psychological and social effects of the cough was elicited.

Results: 373 completed questionnaires were returned. Mean age was 65.3 years (SD 12.0, range 9-88 years). 73% were female and 2% current smokers. Median duration of cough was 6.5 years. 66% had no other coexisting respiratory diagnosis, whilst 24% reported asthma. Of those who responded, 91% had consulted a general practitioner regarding the cough and of them, 85% had been prescribed some sort of treatment. 61% had seen at least one hospital specialist. Commonly reported associated physical symptoms included breathlessness (55%), wheeze (37%), fatigue (72%) and disturbed sleep (70%). Incontinence occurred in 55% of women. Similarly, the majority reported psychological effects such as anger or frustration (83%), anxiety (69%) and depression (55%). 64% felt that the cough interfered with their social life.

Conclusion: Chronic cough causes a high level of morbidity in the community, which results in a correspondingly high rate of healthcare utilisation. Demography and symptomatology seems to be similar to that reported from specialist centres, but successful treatment of the cough was uncommon, despite a high number of medical consultations in both primary and secondary care. If understanding of this debilitating but eminently treatable condition is enhanced, management of chronic cough will improve and many patients will be helped.

The common co-existence of cough and gastroesophageal reflux disease (GORD) is well established. However, ascertaining cause and effect is more difficult for many reasons that include occurrence by chance of two common symptoms, the changing definition of GORD, equipment limitations and the lack of randomised controlled trials. Given these difficulties, it is not surprising that there is disparity of opinion between respiratory and gastroenterology society guidelines on the link between GORD and chronic cough. This commentary explores of these issues.

Background: Chronic cough is a common condition with a significant impact on quality of life. Currently, no health status measure specific for chronic cough exists in the Netherlands. Thus we developed a Dutch version of the Leicester Cough Questionnaire (LCQ) and tested its scaling and clinical properties.

Methods: The LCQ was adapted for Dutch conditions following a forward-backward translation procedure. All patients referred to our cough clinic between May 2004 and February 2005 completed five questionnaires, the LCQ, the modified Borg score for cough, the Short-Form 36 (SF-36), the Hospital Anxiety and Depression Scale (HADS) and the Global Rating of Change (GRC) upon presentation, after two weeks and after 6 months. Concurrent validation, internal consistency, repeatability and responsiveness were determined.

Results: For the concurrent validation the correlation coefficients (n = 152 patients) between the LCQ and the other outcome measures varied between 0.22 and 0.61. The internal consistency of the LCQ (n = 58) was high for each of the domains with a Crohnbach's alpha coefficient between 0.77 and 0.91. The two week repeatability of the LCQ in patients with no change in cough (n = 48) was high with intraclass correlation coefficients varying between 0.86 and 0.93. Patients who reported an improvement in cough (n = 140) after 6 months demonstrated significant improvement on each of the domains of the LCQ.

Conclusion: The Dutch version of the LCQ is a valid and reliable questionnaire to measure (changes of) health status in patients with chronic cough.

Inflammatory mediators are involved in the pathogenesis of airway inflammation, but the role of prostaglandin I2 (PGI2) remains obscure. This study was designed to investigate the role of PGI2 in cough reflex sensitivity of the asthmatic airway, which is characterized by chronic eosinophilic airway inflammation. The effect of beraprost, a chemically and biologically stable analogue of PGI2, on cough response to inhaled capsaicin was examined in 21 patients with stable asthma in a randomized, placebo-controlled cross over study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity. The cough threshold was significantly (p < 0.05) decreased after two weeks of treatment with beraprost [17.8 (GSEM 1.20) microM] compared with placebo [30.3 (GSEM 1.21) microM]. PGI2 increases cough reflex sensitivity of the asthmatic airway, suggesting that inhibition of PGI2 may be a novel therapeutic option for patients with asthma, especially cough predominant asthma.

Gastro-oesophageal reflux (GOR) is one of the most common causes of chronic cough in Western countries, responsible for 10 to 40% of cases. In Japan, however, GOR-associated chronic cough (GOR-CC) has been rarely reported and its clinical manifestation including frequency of concomitant reflux laryngitis is poorly known. We have analyzed prevalence and clinical characteristics of patients who were diagnosed as having GOR-CC among adult patients with chronic cough (>or= 8 weeks) who visited our asthma and cough clinic over a period of 19 months. Diagnosis of GOR-CC was based on the response of coughing to a proton-pump inhibitor (lansoprazole) and/or positive results of 24 h ambulatory esophageal pH monitoring. Laryngeal involvement was based on symptoms or objective diagnosis by specialists.GOR-associated chronic cough was diagnosed in 7.1% (8 of 112) of chronic cough patients. In addition to the demographic data which were consistent with the characteristics of patients with GOR-CC in the Western populations, including gender (6 females), age (mean +/- SE, 56.9 +/- 5.8 years), duration of cough (9.9 +/- 3.3 months), lack of gastrointestinal symptoms (3 of 8) and complication with other causes of cough (5 of 8), we found the standard range of body mass index (23.9 +/- 1.5 kg/m2) and high incidence of concomitant reflux laryngitis (5 of 8) in the present 8 patients. Among 4 patients who could stop treatment with temporal resolution of cough, cough recurred in 3 patients, 1 week to 8 months after the discontinuation. In conclusion, GOR-CC is a less frequent cause of chronic cough in Japan than in Western countries. Signs or symptoms of laryngitis may be important as clues to suspicion of GOR-CC.

Background: The relationships between chronic productive cough (CPC), environmental tobacco smoke (ETS) exposure, and asthma are not clearly established in children. Therefore, we wished to determine the prevalence of CPC and examine the relationships between CPC, ETS exposure, and asthma in young teenagers.

Methods: We performed a cross sectional survey of 2397 Seattle middle school students, 11-15 years old, using written and video respiratory-symptom questionnaires. We defined CPC as--daily cough productive of phlegm for at least 3 months out of the year; current asthma as--yes to "Have you had wheezing or whistling in your chest in the past 12 months?" and yes in the past year to any of the four video wheezing/asthma video scenarios; and ETS exposure as exposed to tobacco smoke at least several hours each day. We used multilogistic regression to examine relationships between CPC, asthma, and ETS exposure and included in the model the potentially confounding variables race, gender, and allergic rhinitis.

Results: The prevalence of CPC was 7.2%. Forty-seven percent (82/173) of children with CPC met criteria for current asthma, while only 10% (214/2224) of those without CPC had current asthma. Current asthma had the strongest associated with CPC, odds ratio (OR) 6.4 [95% CI 4.5-9.0], and ETS was independently associated with both CPC, OR 2.7 [1.8-4.1] and asthma, OR 2.7 [1.5-4.7].

Conclusion: In a population of young teenagers, CPC was strongly associated with report of current asthma symptoms and also with ETS exposure. This suggests that asthma and ETS exposure may contribute to CPC in children. However, this study was not designed to determine whether asthma was the actual cause of CPC in this population of children.