10%高渗盐水激发试验对哮喘的诊断价值

目的探讨高渗盐水激发试验在哮喘的诊断价值,了解其诊断的敏感性和特异性。方法对已经确诊的稳定期的哮喘患者行乙酰甲胆碱激发试验及高渗盐水激发试验探讨其敏感性;对具有气道高反应性的常见疾病,慢性支气管炎,无哮喘症状的过敏性鼻炎及非慢性咳嗽变异性哮喘的慢性咳嗽患者行两种激发试验了解其特异性。结果对于稳定期的哮喘患者,乙酰甲胆碱激发试验的阳性率较高达到90%(27/0),而在高渗盐水激发试验阳性率为56%(17/30)。无喘息症状的慢性支气管炎患者、无气道症状的过敏性鼻炎患者及非咳嗽变异性哮喘的慢性咳嗽患者的阳性率在乙酰甲胆碱激发试验分别为63%(19/30),53%16/30),36%(11/30),在高渗盐水激发试验分别为13%(4/30)6%(2/30)3%(1/30)。结论乙酰甲胆碱激发试验敏感性高,特异性不足,高渗盐水激发试验特异性高而敏感性不足,高渗盐水激发试验有望作为乙酰甲胆碱激发试验的补充,在哮喘诊断中有望发挥独特作用。     

10%氯化钠和氯化乙酰甲胆碱测定气道反应性结果比较

气道高反应性是支气管哮喘病理特点，其传统测定方法采用定量吸入药物氯化乙酰甲胆碱（Ｍａｔｈ）或组织胺激发气道的反应性。近年来报道非药物高渗盐水作为激发剂进行测定，且方法各异，我们采用呼吸阻力（Ｒｒｓ）测定法，分别用高渗盐水激发及乙酰甲胆碱激发，对二者进行比较。１对象与方法１．１对象１６例拟诊变异性哮喘或喘息性气管炎、６例过敏性鼻炎、２例药物疹、５例哮喘相对缓解期患者，共２９例。采用乙酞甲胆碱做气道反应性测定（ＢＲＭ），其中２１例结果判断为阳性，再将这些患者于吸入乙酰甲胆碱做ＢＲＭ后的７２小时吸入１…     

组胺、乙酰甲胆碱检测气道高反应性不良反应比较

目的 观察组胺与乙酰甲胆碱检测气道高反应性时所出现的不良反应.方法 采用德国耶格(JAEGER)肺功能仪-支气管激发试验检测系统,对60例处于缓解期(肺功能检测正常)的轻度支气管哮喘患者,分别实施组胺与乙酰甲胆碱(乙酰甲胆碱与组胺)支气管激发试验检测.结果 .①60例支气管哮喘患者检测支气管激发试验,激发剂的选择无论是组胺还是乙酰甲胆碱均提示支气管激发试验阳性,支持存在气道高反应性;②支气管激发试验检测过程可见组胺药物不良反应明显大于乙酰甲胆碱.其不良反应程度与随着吸入药物浓度增大、吸人时间延长而增加.结论 药物支气管激发试验激发剂的选择应首选乙酰甲胆碱,组胺应慎选或不选.     

组胺、乙酰甲胆碱检测气道高反应性不良反应比较

目的 观察组胺与乙酰甲胆碱检测气道高反应性时所出现的不良反应.方法 采用德国耶格（JAEGER）肺功能仪-支气管激发试验检测系统,对60例处于缓解期（肺功能检测正常）的轻度支气管哮喘患者,分别实施组胺与乙酰甲胆碱（乙酰甲胆碱与组胺）支气管激发试验检测.结果 ①60例支气管哮喘患者检测支气管激发试验,激发剂的选择无论是组胺还是乙酰甲胆碱均提示支气管激发试验阳性,支持存在气道高反应性;②支气管激发试验检测过程可见组胺药物不良反应明显大于乙酰甲胆碱,其不良反应程度与随着吸入药物浓度增大、吸入时间延长而增加.结论 药物支气管激发试验激发剂的选择应首选乙酰甲胆碱,组胺应慎选或不选.     

三种乙酰甲胆碱激发试验在成人支气管哮喘诊断中的应用

气道高反应性是支气管哮喘的重要特征。测定气道反应性对支气管哮喘的临床诊断日益重要。潮气吸入法以及定量雾化吸入法乙酰甲胆碱激发试验以第1秒用力呼气容积（FEV1）下降20％时所吸入的乙酰甲胆碱的累计药物浓度（PC20～FEV1）或总量（PD20-FEV1）来评价气道的高反应性;而Astograph法乙酰甲胆碱激发试验是以强迫振荡原理,以连续测定的呼吸阻力作为判断气道高反应性程度的指标。本文就三种激发试验对气道高反应的评价指标及在成人应用中的特点进行综述。     

三种乙酰甲胆碱激发试验在成人支气管哮喘诊断中的应用

气道高反应性是支气管哮喘的重要特征.测定气道反应性对支气管哮喘的临床诊断日益重要.潮气吸人法以及定量雾化吸入法乙酰甲胆碱激发试验以第1秒用力呼气容积(FEV1)下降20%时所吸入的乙酰甲胆碱的累计药物浓度(PC20-FEV1)或总量(PD20-FEV1)来评价气道的高反应性;而Astograph法乙酰甲胆碱激发试验是以强迫振荡原理,以连续测定的呼吸阻力作为判断气道高反应性程度的指标.本文就三种激发试验对气道高反应的评价指标及在成人应用中的特点进行综述.     

吸入皮质激素对哮喘患者血清嗜酸粒细胞和T－淋巴细胞功能的影响

为研究吸入皮质激素倍氯米松对哮喘患合体内嗜酸粒细胞、Ｔ－淋巴细胞功能状态的影响，对治疗前后哮喘患者血清嗜酸性阳离子蛋白（ＥＣＰ）、可溶性白细胞介素－２（ｓＩＬ－２Ｒ）浓度及患者乙酰甲胆碱气道反应性进行检测。结果表明。吸入皮质激素６周后，血清ＥＣＰ、ｓＩＬ－２Ｒ浓度降低，肺功能改善、乙酰甲胆碱－ＰＣ＿（２０）（ＦＥＶ＿１下降２０％时的乙酰甲胆碱激发浓度）值增高。提示：糖皮质激索能抑制嗜酸性粒细胞、Ｔ－淋巴细胞激活。具有抗炎和降低气道高反应性的作用。     

吸入皮质激素对哮喘患者血清嗜酸粒细胞和T—淋巴细胞功能的…

为研究吸入皮质激素倍氯米松对哮喘患者体内嗜酸粒细胞、Ｔ－淋巴细胞功能状态的影响，对治疗前后哮喘患者血清嗜酸性阳离子蛋白（ＥＣＰ）、可溶性白细胞介素－２（ｓＩＬ－２Ｒ）浓度及患者乙酰甲胆碱气道反应性进行检测。结果表明，吸入皮质激素６周后，血清ＥＣＰ、ｓＩＬ－２Ｒ浓度降低，肺功能改善，乙酰甲胆碱－ＰＣ２０（ＦＥＶ１下降２０％时的乙酰甲胆碱激发浓度）值增高。提示：糖皮质激素能抑制嗜酸性粒细胞、Ｔ－淋巴细     

过敏性鼻炎与支气管哮喘的关系

过敏性鼻炎和支气管哮喘常常共同存在于同一患者,过敏性鼻炎常发生在哮喘之前,患者中支气管哮喘的发病率明显高于一般人群,用乙酰甲胆碱或组织胺作支气管激发试验,发现一部分不伴哮喘的过敏性鼻炎患者气道反应性增高,可能是进一步发展为支气管哮喘的高危人群,治疗过敏性鼻炎可以减轻哮喘的症状,改善肺功能,降低气道反应性。鼻－支气管反射,鼻腔阻塞后呼吸方式的改变,后鼻滴漏的炎性分泌物吸入下呼吸道可能是过敏性鼻炎与支     

支气管哮喘、咳嗽变异性哮喘及急性支气管炎气道反应性特点及意义

目的探讨支气管哮喘、咳嗽变异性哮喘及急性支气管炎气道反应性特点,以便为临床诊断提供依据。方法采用日本产ＡＳＴＯＧＡＰＨＴＣＫ６０００ＣＶ气道反应测定仪,以乙酰甲胆碱为气道激发剂,观察６０例支气管哮喘、５８例咳嗽变异性哮喘及３７例急性支气管炎患者气道反应性变化。结果支气管哮喘和咳嗽变异性哮喘病人气道激发试验均为阳性,哮喘病人的气道反应阈值（Ｄｍｉｎ）低于咳嗽变异性哮喘病人（Ｐ＜００５）。急性支气管炎病人中,气道激发试验３３例阴性,占８９％,４例阳性,占１１％。４例阳性急性支气管炎患者的气道反应性曲线与哮喘组及咳嗽变异性哮喘组明显不同,其Ｄｍｉｎ也显著高于哮喘组（Ｐ＜００１）及咳嗽变异性哮喘组（Ｐ＜００５）。结论气道反应性测定对于不同类型哮喘及急性支气管炎的鉴别和指导治疗具有很好的临床应用价值。     

对慢性喘息型支气管炎气道反应性特点及其本质的探讨

目的 研究慢性喘息型支气管炎对乙酰甲胆碱和运动激发试验的气道反应性特点,并对其本质进行初步探讨。方法 对诊断明确的支气管哮喘患者,单纯型慢性支气管炎患者及慢性喘息型支气管炎患者分别进行乙酰甲胆碱吸入激发和运动激发试验,观察血嗜酸嗜酸粒细胞计数,血ＩｇＥ水平并测定慢性喘息型支气管炎患者血肖嗜酸细胞阳离子蛋白含量。     

The effect of inhaled corticosteroids on the maximal degree of airway narrowing to methacholine in asthmatic subjects

Airway hyperresponsiveness in asthma is characterized by an increase in sensitivity and in maximal response to airway-narrowing stimuli. Long-term therapy with inhaled corticosteroids is known to reduce airway hypersensitivity in asthmatic patients. To investigate whether these drugs also reduce the maximal degree of airway narrowing we studied the effects of inhaled budesonide on the maximal response plateau of the dose-response curve to inhaled methacholine in mildly asthmatic patients in whom a raised plateau could be measured. Sixteen atopic patients with mild asthma were placed randomly into two parallel treatment groups to receive double-blindly either budesonide (400 micrograms twice daily) or placebo, inhaled via a Turbuhaler, for 4 wk. Before treatment, after 2 and 4 wk of treatment, and after 2 and 4 wk of wash-out, complete dose-response curves to methacholine were obtained using a standardized 2-min tidal breathing method. The response was measured by FEV1, expressed in % fall from baseline. A plateau on the log dose-response curve was considered if three or more data points fell within a 5% response range. The maximal response was obtained by averaging the values on the plateau (MFEV1), and the sensitivity was calculated from the provocative concentration of methacholine, causing a 20% fall in FEV1 (PC20). After 4 wk of budesonide treatment, mean MFEV1 decreased from 41.6 to 33.7% fall (p = 0.0004). The changes in MFEV1 were significantly different between placebo and budesonide (p = 0.03). The geometric mean PC20 increased from 3.4 to 6.3 mg/ml (p = 0.02), but the changes in PC20 were not different between the two groups (p = 0.23).(ABSTRACT TRUNCATED AT 250 WORDS)     

The feasibility of airways hyperresponsiveness as an inclusion criterion for studies on childhood asthma.

The feasibility of moderately severe airway hyperresponsiveness (AH) was examined as an inclusion criterion for clinical trials in asthmatic children. During the baseline period of a long-term clinical trial in asthmatic children, maintenance therapy with fluticasone (200 microg x day(-1)) was stopped for a maximum of 8 weeks and methacholine challenges were performed at 2-week intervals or earlier if the patients' condition deteriorated. Patients were eligible to continue the study if the provocative dose of methacholine causing a 20% fall in forced expired volume in one second (FEV1) (PD20) was <80 microg. Fifty-one per cent of the children did not develop a PD20 < 80 microg after withdrawal of fluticasone. Patients with or without a PD20 <80 microg did not differ in duration of asthma, duration of treatment, or peak flow variation. Patients with a PD20 <80 microg had higher levels of total and specific immunoglobulin-E, and lower levels of FEV1 and mean maximal expiratory flow than patients with a PD20 > or = 80 microg. Forty-four per cent of the patients with a PD20 > or = 80 microg did not have any symptoms during the wash-out period and 39% of these patients remained free from symptoms during one year follow-up. The results of this study suggest that recruiting asthmatic children for clinical trials may be difficult if airways hyperresponsiveness is used as the sole inclusion criterion.     

Effects of specific immunotherapy in allergic rhinitic individuals with bronchial hyperresponsiveness

Allergic rhinitis can be associated with bronchial hyperresponsiveness (BHR), and carries an increased risk for the development of asthma. The aim of this study was to evaluate the ability of specific immunotherapy (SIT) to reduce the progression of allergic rhinitis to asthma and prevent the associated increase in BHR. Forty-four subjects monosensitized to Dermatophagoides pteronyssinus, with perennial rhinitis and BHR to methacholine, were randomly assigned to receive SIT or placebo in a double-blind study conducted over a period of 2 yr. After 1 yr of treatment, a 2.88-fold increase in the provocative dose of methacholine producing a 20% decrease in FEV(1) (PD(20)FEV(1)) was recorded in the SIT-treated group (95% confidence interval [CI]: 3.98- to 2.09-fold; p < 0.001), with a further increase to fourfold at the end of Year 2 (95% CI: 2.9- to 5.7-fold; p < 0.001). At the end of the study, the methacholine PD(20)FEV(1) was within the normal range in 50% of treated subjects (p < 0.0001), and was significantly higher in this group than in the group receiving placebo (p < 0.0001). In contrast, no changes in methacholine PD(20)FEV(1) were found in the placebo group throughout the study. Although 9% of subjects given placebo developed asthma, none of those treated with SIT did. This study suggests that SIT, when administered to carefully selected, monosensitized patients with perennial allergic rhinitis, reduces airway responsiveness in subjects with rhinitis, and may be an appropriate prophylactic treatment for rhinitic patients with hyperreactive airways.     

Do inhaled corticosteroids affect perception of dyspnea during bronchoconstriction in asthma?

BACKGROUND: Some of the disagreements on the perception of dyspnea (PD) during bronchoconstriction in asthma patients could depend on the interrelationships among the following: (1) the influence of baseline airflow obstruction on the patient's ability to detect any further increase in airway resistance; (2) the effect of eosinophilic inflammation on the airway; (3) bronchial hyperresponsiveness (BHR); and (4) the effect of inhaled corticosteroids (ICSs). OBJECTIVE: We hypothesized that if the inflammation of the airway wall influences to some extent and in some way the PD in asthma patients, ICSs reverse the effect of airway inflammation on the PD. METHODS: We studied 100 asthma patients who were divided into the following four groups: patients with obstruction who were either ICS-naive (group I) or were treated with ICSs (group II); and nonobstructed patients who were either ICS-naive (group III) or were treated with ICSs (group IV). PD on the visual analog scale (VAS) was assessed during a methacholine-induced FEV(1) decrease and specifically was quantified as the VAS slope and score at an FEV(1) decrease of 5 to 20%. BHR was assessed in terms of the provocative concentration of methacholine causing a 20% fall in FEV(1) (PC(20)). Eosinophil counts in induced sputum samples also were performed. Regression analysis, univariate analysis of variance, and factor analysis were applied for statistical evaluation. RESULTS: For a 5 to 20% fall in FEV(1) from the lowest point after saline solution induction, VAS score was lowest in group II, slightly higher in group I, slightly higher still in group IV, and the highest in group III. In the patients as a whole, BHR related to PD, but age, clinical score, duration of the disease, and presence of baseline airway obstruction did not. In patients with obstruction who were treated with ICSs, eosinophil counts related to PD negatively. Factor analysis yielded the following four factors that accounted for 70% of the variance in the data: ICS; eosinophil counts; FEV(1); and PC(20) loaded on separated factors with PD loading on the same factors as PC(20). The post hoc analysis carried out dividing the patients into ICS-treated and ICS-naive, showed that in the former group eosinophil counts and BHR proved to be factors negatively associated with PD, while in the latter group eosinophil counts were positively associated with PD. CONCLUSIONS: We have shown that eosinophilic inflammation of the airway wall may increase PD and that the association of eosinophil counts with ICSs may result in lessening the PD.     

Effects of esophageal acid perfusion on airway hyperresponsiveness in patients with bronchial asthma

STUDY OBJECTIVES: The effects of gastroesophageal reflux on airway hyperresponsiveness in patients with bronchial asthma have yet to be studied in significant detail. The purpose of the present study was to determine how esophageal acid perfusion could change airway responsiveness in patients with bronchial asthma. PATIENTS AND INTERVENTIONS: In seven patients with bronchial asthma (mean +/- SD age, 55.1 +/- 6.4 years; four women and three men), esophageal pH was monitored by a pH meter and airway responsiveness was evaluated by aerosol inhalation of methacholine, during esophageal perfusion through an esophageal tube filled with either saline solution or 0. 1N hydrochloric acid (HCl), the order of which was selected at random, in 1-week intervals. Spirometry was also performed during esophageal pH monitoring. RESULTS: A significant decrease in the geometric mean of airway sensitivity or the concentration of methacholine causing a 35% fall in respiratory conductance was observed during esophageal HCl perfusion compared with that of saline solution perfusion (p < 0.01 or p < 0.003), although no significant changes were observed in vital capacity, FEV(1), peak expiratory flow, respiratory resistance, or slope of respiratory conductance during the periods of saline solution and HCl perfusion. CONCLUSION: We concluded that an increase in airway hyperresponsiveness was induced when HCl stimulated the esophagus in patients with bronchial asthma. These results suggest that esophageal reflux is one of the important factors that aggravate asthmatic status.     

Changes in FVC during methacholine-induced bronchoconstriction in elderly patients with asthma: bronchial hyperresponsiveness and aging

STUDY OBJECTIVE: We evaluated whether aging may produce changes in bronchial hyperresponsiveness, risk of enhanced bronchoconstriction, and changes of bronchoconstriction perception. SETTING: Each subject underwent a methacholine bronchial challenge. Methacholine challenge was stopped when one of the following conditions occurred: (1) plateau of bronchoconstriction; (2) decrease of FEV(1) > 40%; (3) FEV(1) drop below 1 L; or (4) excessive respiratory discomfort. Methacholine dose-response curves were plotted both for FVC and FEV(1). The provocative dose of methacholine causing a 20% decrease in FEV(1) with respect to baseline (PD(20)) and the fall in FVC (DeltaFVC) at PD(20) were computed. The Borg scale was used for scoring the perception of respiratory discomfort. PATIENTS: We compared 17 young asthmatic patients (aged 22 to 45 years) with 17 older asthmatic patients (aged 63 to 78 years) selected on the basis of similar baseline pulmonary function and disease duration. RESULTS: No significant between-group difference was found in PD(20) and in plateau development. Conversely, DeltaFVC was significantly higher in the older group (mean +/- SD, 15.5 +/- 3.9% vs 11.6 +/- 5.5% in younger patients). In addition, DeltaFVC showed a positive linear relationship with age (p = 0.0026). Elderly subjects were less aware of bronchoconstriction during the methacholine challenge (p = 0.04). CONCLUSIONS: In elderly patients with asthma having comparable pulmonary function and disease duration, bronchial responsiveness is not different from that observed in younger asthmatic patients. Nevertheless, in such patients, an age-related tendency to an enhanced bronchoconstriction and a reduced perception of the degree of bronchoconstriction exist.     

Effects of inhaled corticosteroids on cough threshold in patients with bronchial asthma

In asthmatic subjects cough can be related to the degree of airway inflammation. The aim of this study was to evaluate the effect of treatment with high dose inhaled beclomethasone dipropionate (BDP) on cough threshold in asthmatic subjects. Cough threshold to inhaled capsaicin (one breath of 10(-8)-10(-4)M solution) and to citric acid (one breath of 10(-4)-1 M), expressed as provocative concentration of two (PC2) and four coughs (PC4), was measured in 16 normal and 36 asthmatic subjects. After baseline evaluation, asthmatic subjects were randomized in two groups: (a) Group A, n=20: treated with salbutamol (200 microg t.i.d.) plus BDP (500 microg t.i.d.); (b) Group B, n=16: treated with salbutamol plus placebo in the same doses. After 1 month, cough threshold and clinical and functional evaluation were repeated. After treatment, asthmatics of group A showed a significant improvement in PC4 citric acid, in total symptom and cough scores, and in PD20FEV1 methacholine. In asthmatics of group B, treatment caused no improvement in symptoms, PD20FEV1 methacoline and cough threshold. In addition, cough threshold was not different between normal and asthmatic subjects and, in asthmatics, cough threshold did not correlate with PD20FEV1 methacholine. These data confirm that cough in asthma can be partially related to airway inflammation.     

Long-term follow-up of toluene diisocyanate-induced asthma.

Eighty-seven cases of occupational asthma induced by toluene diisocyanate (TDI) were diagnosed by an inhalation challenge with TDI and methacholine. After an average follow-up interval of 11 yrs, all subjects were re-examined. Of the 87 subjects examined, 13 (15%) had remained in the same job, 44 (50.5%) had been removed from exposure for <10 yrs and 30 (34.5%) had been removed for >10 yrs. The proportion of subjects who experienced symptoms of asthma and those who were hyperresponsive to methacholine was significantly lower. Of the patients, 59% used short-acting bronchodilators, 8% long-acting bronchodilators and 18% were on regular inhaled glucocorticoids. Thus, multiple regression analysis showed a positive correlation between forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) at follow-up and FVC and FEV1 at diagnosis, and a negative correlation with smoking and with therapy with bronchodilators. Stepwise logistic regression showed that the follow-up provocative dose causing a 20% fall in the FEV1 (PD20) could be predicted from baseline PD20. These results indicate that respiratory symptoms and airway hyperresponsiveness to methacholine persist in subjects removed from exposure to TDI for >10 yrs. A more favourable prognosis was associated with a better lung function and a lower degree of airway hyperresponsiveness to methacholine at diagnosis.     

Association of airway responsiveness with asthma and persistent wheeze in a Chinese population

STUDY OBJECTIVES: Data from a cross-sectional study were analyzed to examine the association of increased airway responsiveness with physician-diagnosed asthma and persistent wheeze. DESIGN: Two methods for calculating the provocative dose that decreases the airflow rate by 20% (PD(20)) were used as indexes for increased airway responsiveness: (1) a 20% drop in FEV(1) calculated from baseline FEV(1) (PD(20)b), and (2) a 20% drop in FEV(1) from FEV(1) measurements after inhalation of saline solution (PD(20)s). Both PD(20)b and PD(20)s were measured through induction by varying doses of methacholine. SETTING: Anqing, Anhui Province, China. PARTICIPANTS: Study subjects were 8 to 74 years of age and were classified into four groups: children (< 15 years old), young adults (15 to 29 years old), adults (30 to 44 years old), and older adults (> or 5 years old). INTERVENTIONS: The differences in estimated odds ratios of airway hyperresponsiveness with asthma and wheeze, sensitivity and specificity, and coefficients of variation were compared between PD(20)b and PD(20)s. The sample for analysis consisted of 10,284 subjects from 2,663 nuclear families with complete data on wheeze, asthma, and major potential confounding factors. MEASUREMENTS AND RESULTS: The prevalence of asthma in this sample was lowest in subjects with no demonstrable PD(20) and had a reverse dose-response relationship with PD(20) across all age groups. Using the receiver operating characteristic, the sensitivity and specificity of the PD(20)s or PD(20)b were found to be almost identical. A similar trend was found for persistent wheeze, although the estimated odds ratios for persistent wheeze appeared slightly smaller than those for physician-diagnosed asthma. CONCLUSIONS: This study demonstrates a dose-response relationship between increased airway responsiveness and asthma and wheeze in this Chinese population. PD(20)s or PD(20)b yielded virtually indistinguishable results, which indicated that either of the two tests could serve as an index of airway hyperresponsiveness.