Cough (London, England)最新文献

Background: Cough in the patients with cough variant asthma is triggered by bronchoconstriction, which responds to bronchodilator therapy. Following airway narrowing induced by inhaled methacholine, deep inspiration (DI) causes dilation of the airways in both asthmatic and non-asthmatic subjects. The aim of the present study was to investigate the relationship between bronchodilator effect of DI and bronchoconstriction-triggered cough.

Methods: We measured airway responsiveness to methacholine using partial and full flow-volume curves in 28 healthy adults. The expiratory flow at 40% above residual volume from the full forced vital capacity (MEF40) was obtained and the volume was used as the reference volume to determine the isovolume flow from the partial curve (PEF40). Coughs were counted for 32 min during and following the inhalation of methacholine at the provocative concentration which produced a 20% fall or more in FEV1from the post-saline value (PC20-FEV1). The bronchodilator effect of DI on bronchoconstriction induced by methacholine at the PC20-FEV1 concentration was expressed as the ratio of (MEF40-PEF40)/PEF40 (DI index).

Results: The number of coughs for 32 min during and following the inhalation of PC20-FEV1 concentration of methacholine was 39.3 +/- 29.7 (mean +/- SD)/32 min. The number of coughs during and following the inhalation was correlated with DI index (r = 0.57, p = 0.0015), but not with PC20-FEV1 or change in FEV1 or PEF40 by inhalation of the PC20-FEV1 concentration of methacholine.

Conclusion: We found that methacholine-induced cough was associated with the bronchodilator effect of DI on methacholine induced-bronchoconstriction in normal subjects.

Background: Chronic cough has negative effects on quality of life. However, the changes in health-related quality of life and clinical implications remain unclear in Chinese patients with chronic cough.

Methods: A standard Chinese version of Leicester cough questionnaire (LCQ) was developed by an established translation procedure and its repeatability was assessed in a preliminary study involving 20 untreated patients with stable chronic cough. The quality of life was measured with the Short form-36 health survey and compared between 110 patients with chronic cough and 90 healthy volunteers. The changes in health-related quality of life were evaluated in the patients with chronic cough with the LCQ just before the specific treatment was initiated and a week after the cough had resolved completely. Cough threshold with inhaled capsaicin, expressed as the lowest concentration of capsaicin required for the induction of > or = 5 coughs, was also measured.

Results: The repeatability of the Chinese version of the LCQ was validated at a four day interval with the intraclass correlation coefficients of 0.89-0.94 for total and domain score (n = 20). The scores of the Short form-36 health survey were significantly lower in patients with chronic cough than those in healthy volunteers. In general, there was no significant difference in overall quality of life between different causes of chronic cough or genders although embarrassment, frustration and sleep disturbance were more common in female patients, as indicated by the LCQ. However, the successful treatment of cough obviously increased the total scores of the LCQ from 14.2 +/- 2.7 to 19.5 +/- 1.9 (t = 13.7, P < 0.0001). There was a significant correlation between the total score of the LCQ and physical (r = 0.39, P < 0.0001) or mental (r = 0.30, P < 0.001) component summary of the Short form-36 health survey but not between the LCQ and capsaicin cough threshold.

Conclusion: The quality of life is significantly impaired in Chinese patients with chronic cough. The Chinese version of the LCQ is a valid measure of cough related quality of life and is repeatable and responsive.

Background: Bronchial challenge tests are used to evaluate bronchial responsiveness in diagnosis and follow-up of asthmatic patients. Challenge induced cough has increasingly been recognized as a valuable diagnostic tool. Various stimuli and protocols have been employed. The aim of this study was to compare cough and dyspnea intensity induced by different stimuli.

Methods: Twenty asthmatic patients underwent challenge tests with methacholine, bradykinin and exercise. Cough was counted during challenge tests. Dyspnea was assessed by modified Borg scale and visual analogue scale. Statistical comparisons were performed by linear mixed-effects model.

Results: For cough evaluation, bradykinin was the most potent trigger (p < 0.01). In terms of dyspnea measured by Borg scale, there were no differences among stimuli (p > 0.05). By visual analogue scale, bradykinin induced more dyspnea than other stimuli (p < or = 0.04).

Conclusion: Bradykinin seems to be the most suitable stimulus for bronchial challenge tests intended for measuring cough in association with bronchoconstriction.

Background: In order to assess severity of cough from patients' perspectives and capture the effects of treatment in clinical trials, a measurement tool must show evidence of validity and reliability. The purpose of this study was to characterize cough severity from patients' perspectives as the initial step in the development of a new patient-reported outcome (PRO) measure for use in clinical trials.

Methods: This focus groups study included patients with clinician confirmed chronic cough recruited from a large internal medicine clinic in the US. A semi-structured focus group guide was designed to elicit information about patients' experiences with cough severity and their characterization of symptoms. The focus group data were coded to identify concepts and terminology of cough severity.

Results: Three focus groups were conducted [n = 22; 6 male; mean age 66.1 (+/- 12.9)]. Etiology included GERD, asthma, bronchitis, post-nasal drip, and other. Three domains of cough severity were identified: frequency, intensity, and disruption. In addition to a single cough, participants in all focus groups described coughing in uncontrollable paroxysms they called "fits," "bouts," "spells," or "episodes." The urge to cough, described as an important sign of impending cough, was considered a component of cough frequency. Participants also described daytime activity and nighttime sleep disruption as an indication of cough severity. Finally, participants described variability in cough severity.

Conclusion: Results suggest that patients describe cough severity in terms of frequency, intensity, and disruptiveness, indicating these 3 domains should be addressed when evaluating cough severity and outcomes of treatment.

Rationale: Chronic persistent cough can be associated with laryngeal dysfunction that leads to symptoms such as dysphonia, sensory hyperresponsiveness to capsaicin, and motor dysfunction with paradoxical vocal fold movement and variable extrathoracic airflow obstruction (reduced inspiratory airflow). Successful therapy of chronic persistent cough improves symptoms and sensory hyperresponsiveness. The effects of treatment for chronic cough on laryngeal dysfunction are not known.

Objective: The aim of this study was to investigate effects of therapy for chronic cough and paradoxical vocal fold movement.

Methods: Adults with chronic cough (n = 24) were assessed before and after treatment for chronic persistent cough by measuring quality of life, extrathoracic airway hyperresponsiveness to hypertonic saline provocation, capsaicin cough reflex hypersensitivity and fibreoptic laryngoscopy to observe paradoxical vocal fold movement. Subjects with chronic cough were classified into those with (n = 14) or without (n = 10) paradoxical vocal fold movement based on direct observation at laryngoscopy.

Results: Following treatment there was a significant improvement in cough related quality of life and cough reflex sensitivity in both groups. Subjects with chronic cough and paradoxical vocal fold movement also had additional improvements in extrathoracic airway hyperresponsiveness and paradoxical vocal fold movement. The degree of improvement in cough reflex sensitivity correlated with the improvement in extrathoracic airway hyperresponsiveness.

Conclusion: Laryngeal dysfunction is common in chronic persistent cough, where it is manifest as paradoxical vocal fold movement and extrathoracic airway hyperresponsiveness. Successful treatment for chronic persistent cough leads to improvements in these features of laryngeal dysfunction.

Background: Little is known regarding mechanistic and phenotypic differences between cough variant asthma (CVA), presenting with a chronic cough as the sole symptom that responds to bronchodilators, and classic asthma with wheezing during methacholine inhalation. Here we reported airway sensitivity, airway reactivity, and as the main concern, the appearance of cough and wheezes during methacholine inhalation in patients with CVA or classic asthma.

Methods: We cross-sectionally examined the degrees of airway sensitivity, the point where resistance started to increase, and reactivity, the slope of the methacholine-resistance curve, and the appearance of cough and wheezes in steroid-naïve adult patients with classic asthma (n = 58) or CVA (n = 55) while they were continuously inhaling methacholine during simultaneous measurement of respiratory resistance.

Results: Patients with CVA were less sensitive and less reactive to inhaled methacholine and wheezed less frequently but coughed more frequently during methacholine-induced bronchoconstriction than did patients with classic asthma. Multivariate analysis revealed that airway hypersensitivity and lower baseline FEV1/FVC were associated with the appearance of wheezes, whereas a diagnosis of CVA was associated with coughing.

Conclusion: There are mechanistic and phenotypic differences between CVA and classic asthma during methacholine inhalation. Frequent coughing during bronchoconstriction may be a distinctive feature of CVA.

Background: Childhood habit cough has been treated successfully by making suggestions that it can be stopped, desensitization techniques, use of distractors, provision of rewards, and self-hypnosis. All of these techniques have involved personal contact between a health care provider and a patient.

Case presentation: A 5-year-old with cystic fibrosis was diagnosed with habit cough following evaluation by a pediatric pulmonologist and otolaryngologist. An expert in the treatment of habit cough provided instruction by telephone to the patient's mother regarding use of hypnotic techniques in this setting, which was associated with resolution of the cough within a week.

Conclusion: As this report describes a single patient, it is possible that his improvement was unrelated to the given advice. Therefore, it remains to be seen whether therapy by telephone for habit cough is applicable widely.

Background: Gastroesophageal reflux is one of the most common causes of chronic cough in the general population. Reflux occurs frequently in patients with cystic fibrosis (CF). We undertook laparoscopic Nissen fundoplication in adult CF patients with a clinical diagnosis of reflux cough who had failed conventional medical therapies.

Objective: We determined the response to the surgical route in the treatment of intractable reflux cough in CF.

Method: Patients with refractory cough were assessed by 24 h pH monitoring and oesophageal manometry. Pre-and post-operation cough, lung function and exacerbation frequency were compared. Cough was assessed by the Leicester Cough Questionnaire (LCQ), lung function by spirometry and exacerbation frequency was defined by comparing the postoperative epoch with a similar preoperatively.

Results: Significant abnormalities of oesophageal function were seen in all patients studied. 6 patients (2 females), with the mean age of 34.5 years consented to surgery. Their mean number of reflux episodes was 144.4, mean DeMeester score was 39.2, and mean lower oesophageal sphincter pressure 12.4 mmHg. There was a small change in the FEV1 from 1.03 L to 1.17 (P = 0.04), and FVC improved from 2.62 to 2.87 (P = 0.05). Fundoplication lead to a marked fall in cough with the total LCQ score increasing from 11.9 to 18.3 (P = 0.01). Exacerbation events were reduced by 50% post operatively.

Conclusion: Whilst there is an obvious attention to respiratory causes of cough in CF, reflux is also a common cause. Fundoplication is highly effective in the control of reflux cough in CF. Significant reduction in exacerbation frequency may indicate that reflux with possible aspiration is a major unrecognised contributor to airway disease.

Background: The down-regulation of the cough reflex in patients with aspiration pneumonia can involve both cortical facilitatory pathways for cough and medullary reflex pathways. In order to study the possible involvement of the supramedullary system in the down-regulation of cough reflex, we evaluated the urge-to-cough in patients with aspiration pneumonia.

Methods: Cough reflex sensitivity and the urge-to-cough to inhaled citric acid were evaluated in patients with at least a history of aspiration pneumonia and age-matched healthy elderly people. The cough reflex sensitivities were defined as the lowest concentration of citric acid that elicited two or more coughs (C2) and five or more coughs (C5). The urge-to-cough scores at the concentration of C2 and C5, and at the concentration of two times dilution of C2 (C2/2) and C5 (C5/2) were estimated for each subject.

Results: Both C2 and C5 in the control subjects were significantly greater than those for patients with aspiration pneumonia. There were no significant differences in the urge-to-cough at C2 and C5 between control subjects and patients with aspiration pneumonia. However, the urge-to-cough scores at both C2/2 and C5/2 in patients with aspiration pneumonia were significantly lower than those in control subjects. The number of coughs at C5/2 was significantly greater in the control subjects than those in the patients with aspiration pneumonia whereas the number of coughs at C2/2 did not show a significant difference between the control subjects and the patients with aspiration pneumonia.

Conclusion: The study suggests the involvement of supramedullary dysfunction in the etiology of aspiration pneumonia in the elderly. Therefore, restoration of the cough motivation system could be a new strategy to prevent aspiration pneumonia in the elderly.

There is a need for more objective outcome measures for chronic cough. In this pilot study we sought to investigate the utility of the mannitol challenge as a cough-provocation test in non-asthmatic chronic cough. We studied 16 healthy controls and 13 subjects with chronic cough. We assessed cough severity using a visual analogue score, capsaicin cough sensitivity, health status using the Leicester Cough Questionnaire and the dose of mannitol to cause 2 (C2) or 5 (C5) coughs. In all of the subjects with chronic cough and 6 of the controls we assessed the 1-week repeatability of the mannitol challenge. We found that in those subjects with chronic cough the geometric mean (logSEM) mannitol C2 and C5 was heightened compared to controls (C2: 4 (0.2) versus 16 (0.1); p = 0.04 and C5: 63 (0.1) versus 251 (0.1); p = 0.04). Cough visual analogue score, capsacin-induced cough sensitivity and health status were also altered in chronic cough compared to healthy controls, but in those subjects with chronic cough none of these outcomes was correlated with the mannitol C2 or C5. The repeatability of the mannitol challenge assessed by intraclass correlation was C2 = 0.53 and C5 = 0.59. A cut-off in the dose of mannitol of 62 mg/ml for C2 and 550 mg/ml for C5 had a sensitivity of 69 and 62% and specificity of 69 and 81% respectively to distinguish chronic coughers from healthy controls. In conclusion, the mannitol challenge my have potential as a novel cough challenge test and further work is required to extend our findings and to assess whether it has utility in different causes of chronic cough.