Assessment of reversibility of airway obstruction in patients with chronic obstructive airways disease.

Spirometry before and after an inhaled beta agonist or a course of oral prednisolone is widely used to detect reversible airflow limitation in patients with chronic obstructive lung disease. How many of these patients have a response and how the response to beta agonists relates to the response to corticosteroids is not clear. In 127 outpatients (mean (SD) FEV1 0.92 (0.38) 1) who had a clinical diagnosis of chronic obstructive lung disease (continuous breathlessness for more than six months and an FEV1/forced vital capacity (FVC) ratio less than 60%) and who appeared to be stable, the change in FEV1 was measured after salbutamol 200 micrograms from a metered dose inhaler and 5 mg from a nebuliser. Symptoms and spirometric values were recorded before and after two weeks of oral prednisolone 30 mg. Reversibility was defined as a response in FEV1 of 15% or more from baseline alone and as a 15% change and a minimum increase of at least 200 ml. The latter gave results that showed greater internal consistency between the drug regimens. On the basis of this criterion 56 patients (44%) had no response to salbutamol or prednisolone, 71 responded to salbutamol (including all 27 steroid responders), and 25 patients had a response to salbutamol 5 mg but not to 200 micrograms. In general, the largest increase in FEV1 after salbutamol occurred in the subjects with greatest improvement after prednisolone. Subjects showing a response in FEV1 after two weeks' prednisolone had a fall in total symptom score, unlike those who had no response to any treatment or a response to salbutamol only. These data show that reversibility in response to beta agonists is common in patients diagnosed on clinical grounds as having stable chronic obstructive lung disease, that it can be substantial, and that it is best detected by using a larger dose of salbutamol. Salbutamol responders were those most likely to improve after a trial of oral prednisolone. Allowance should be made for the variability of FEV1 in the calculation of the percentage response at low baseline values (less than 1 litre).     

Exercise in patients with chronic obstructive pulmonary disease.

Sporadic visits to the local doctor followed sometimes by changes in oral and inhaled bronchodilators and occasionally by the addition of steroids frequently does little to significantly improve symptoms and function in the disabled patient with COPD. As in other chronic diseases, the management of these patients is facilitated by a team approach in conjunction with general rehabilitation principles. The rationale and practical implementation of such a programme has recently been outlined by the American Association of Cardiopulmonary Rehabilitation. These are multifaceted programmes but a key component, as outlined above, is exercise training. In this brief review the various approaches available have been described. Controversy still reigns regarding the optimal modes of training and there are important differences among the several approaches. Two main groups can be delineated. One emphasises the detailed definition of the impaired physiology with therapeutic measures targeted to specific defects. There is good documentation that, conversely, unstructured programmes that use treadmill and free range walking and cycling also improve endurance for walking. Upper extremity training is of additional benefit. Programmes with as little as three sessions per week of 1-2 hours of low intensity activity have achieved success so we know that simple programmes can be helpful. Moreover, without the necessity for complex testing and training methods these programmes can be implemented with relatively low costs. Future investigations to examine the relationship between improved exercise capacity for walking and arm exercise on the one hand, and the ease of performance of activities of daily living on the other, will help to reinforce the effectiveness of exercise programmes.     

Bronchodilator reversibility to low and high doses of terbutaline and ipratropium bromide in patients with chronic obstructive pulmonary disease.

BACKGROUND--There is uncertainty regarding the use of monotherapy or combination therapy with beta 2 agonists and anticholinergic drugs in patients with chronic obstructive pulmonary disease (COPD). The measurement of forced expiratory volume in one second (FEV1) or relaxed vital capacity (RVC) in the assessment of reversibility in these patients has also caused considerable debate. METHODS--Twenty seven patients with COPD were evaluated on two occasions. Patients received the following treatments in sequence: (sequence 1) low dose terbutaline 500 micrograms, high dose terbutaline 5000 micrograms, low dose ipratropium 40 micrograms, high dose ipratropium 200 micrograms; (sequence 2) low dose ipratropium 40 micrograms, high dose ipratropium 200 micrograms, low dose terbutaline 500 micrograms, high dose terbutaline 5000 micrograms. RVC, FEV1 and FVC were measured at baseline and 30 minutes after successive treatments. RESULTS--Values for FEV1 at baseline on the first and second study days were not significantly different: 0.90 (0.87-0.93) 1 v 0.90 (0.87-0.93) 1. Likewise, baseline values for RVC and FVC were not different. The number of patients showing a greater than 330 ml overall improvement in RVC was 20 of 27 for sequence 1 and 22 of 27 for sequence 2; similar trends were observed for FEV1 and FVC. For all three parameters there was a significant difference between mean responses to low and high doses of terbutaline when the latter was given as the first drug in sequence 1. When ipratropium was given first in sequence 2 there was, however, no significant improvement with high dose terbutaline over and above the response to low dose terbutaline. The latter effect was more noticeable with RVC than with either FEV1 or FVC. The total bronchodilator response at the end of each sequence was similar whether ipratropium was given first or second. CONCLUSIONS--The measurement of RVC, FEV1, and FVC were equally effective at picking up those patients who had a significant overall bronchodilator response to combined therapy with inhaled beta 2 agonist and anticholinergic medication. There was no significant benefit of adding a higher dose of terbutaline when ipratropium bromide had been given previously, particularly when using RVC as the parameter of response.     

Exercise-induced airway obstruction in relation to chronic obstructive lung disease

Gimeno, F., Berg, W. Chr., Steenhuis, E. J., de Vries, K., Peset, R., and Sluiter, H. J. (1974).Thorax,29, 16-20. Exercise-induced airway obstruction in relation to chronic obstructive lung disease. Forty-two patients with chronic obstructive lung disease and clinically suspected exercise-induced airway obstruction were studied to ascertain whether those with proven exercise-induced airway obstruction had specific distinguishing features. Exercise-induced airway obstruction (defined as a fall of FEV₁ of at least 10% of the pre-exercise values) was detected in 20 of the 42 patients. These 20 were found to have a lower elastic recoil but were otherwise identical with the remainder as regards clinical and physiological abnormality. It is postulated that exercise-induced airway obstruction can be a manifestation of chronic obstructive lung disease.     

盐酸戊乙奎醚对慢性阻塞性肺病病人呼吸力学参数的影响

目的研究应用盐酸戊乙奎醚对慢性阻塞性肺病(chronic obstructive pulmonary dis-ease,COPD)病人气管内插管应用呼吸机后呼吸力学参数的影响。方法COPD病人66例随机均分为两组:盐酸戊乙奎醚组(Ⅰ组):气管插管应用呼吸机前静注盐酸戊乙奎醚1mg;对照组(Ⅱ组):不给予任何支气管扩张药物。分别观察并监测气管内插管应用呼吸机后1、4和6h的呼吸力学参数(气道压力、气道阻力和胸肺顺应性)。结果Ⅰ组各个时间点的气道峰压、气道平台压以及气道阻力明显低于Ⅱ组(P<0.05),而胸肺顺应性明显高于Ⅱ组(P<0.05)。结论盐酸戊乙奎醚可明显降低COPD病人气管内插管后的气道压力和气道阻力,增加胸肺顺应性。     

Exercise in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) may incur exercise limitation by any one or combination of disturbances in breathing mechanics, oxygen transport, respiratory muscle metabolism or respiratory regulation and sensation. In spite of the increased ventilation demand/capacity ratio in these patients, the relationship between breathing mechanics, respiratory muscle fatigue, the adequacy of alveolar ventilation and the development of exertional dyspnoea is neither clearly defined nor predictable from data obtained with the patient at rest. The issue of oxygen transport during exercise has been complicated by confusion between arterial hypoxia and inadequate volume of oxygen transported to the tissues, which frequently may differ qualitatively and quantitatively. The cardiac output response to exercise in patients with COPD is therefore critical in determining oxygen transport. This response is also impossible to predict from resting lung mechanics, pulmonary arterial blood pressure, arterial oxygen tension or clinical disease profile. Without exercise testing, which includes measurement of all the variables mentioned, it is impossible to define clearly the cause of exercise-induced symptoms in patients with COPD. Exercise training with and without supplemental oxygen has been shown to improve exercise tolerance in these patients, but the precise mechanism of this improvement remains obscure.     

Capsaicin responsiveness and cough in asthma and chronic obstructive pulmonary disease

BACKGROUND: Chronic cough is associated with an increased sensitivity to inhaled capsaicin in a number of conditions but there are no data for patients with more severe asthma or chronic obstructive pulmonary disease (COPD). Moreover, the relationships between the capsaicin response (expressed as the concentration of capsaicin provoking five coughs, C5), self-reported cough, and routine medication is not known. METHODS: The cough response to capsaicin in 53 subjects with asthma, 56 subjects with COPD, and 96 healthy individuals was recorded and compared with a number of subjective measures of self-reported cough, measures of airway obstruction, and prescribed medication. In asthmatic subjects the relationships between the cough response to capsaicin and mean daily peak flow variability and non-specific bronchial hyperresponsiveness to histamine were also examined. RESULTS: Subjects with asthma (median C5 = 62 mM) and COPD (median C5 = 31 mM) were similarly sensitive to capsaicin and both were more reactive than normal subjects (median C5 >500 mM). Capsaicin sensitivity was related to symptomatic cough as measured by the diary card score in both asthma and COPD (r = -0.38 and r = -0.44, respectively), but only in asthma and not COPD when measured using a visual analogue score (r = -0.32 and r = -0.05, respectively). Capsaicin sensitivity was independent of the degree of airway obstruction and in asthmatics was not related to PEF variability or PC(20) for histamine. The response to capsaicin was not related to treatment with inhaled corticosteroids but was increased in those using anticholinergic agents in both conditions. CONCLUSIONS: These data suggest that an increased cough reflex, as measured by capsaicin responsiveness, is an important contributor to the presence of cough in asthma and COPD, rather than cough being simply secondary to excessive airway secretions. The lack of any relationship between capsaicin responsiveness and airflow limitation as measured by the FEV(1) suggests that the mechanisms producing cough are likely to be different from those causing airways obstruction, at least in patients with COPD.     

Chronic obstructive pulmonary disease. 4: imaging the lungs in patients with chronic obstructive pulmonary disease

The role of chest radiography and computed tomography in the evaluation of pulmonary emphysema and chronic bronchitis is reviewed.     

Haemodynamic effects of terbutaline in chronic obstructive airways disease.

Terbutaline, a cardioselective beta-adrenoceptor agonist, administered intravenously (250 micrograms) to seven patients with chronic obstructive airways disease (mean FEV1 0.99 l) resulted in reduction of mean pulmonary artery pressure (resting 23 +/- 2 to 19 +/- 2 mmHg, p < 0.05; exercise 43 +/- 3 to 35 +/- 3 mmHg, p < 0.05) and calculated pulmonary vascular resistance (resting 168 +/- 27 to 109 +/- 17 dyne s cm-5, p < 0.01; exercise 170 +/- 30 to 119 +/- 18 dyne s cm-5, p < 0.01) accompanied by an increase in heart rate (resting 86 +/- 5 to 96 +/- 4 per min, p < 0.01; exercise 108 +/- 2 to 114 +/- 2 per min, p < 0.01) and cardiac output (resting 3.7 +/- 0.4 to 4.1 +/- 0.4, p < 0.05; exercise 4.9 +/- 0.06 to 6.1 +/- 6 l, min-1 m-2, p < 0.05). The haemodynamic changes were associated with an increase in resting peak expiratory flow rate (184 +/- 20 to 216 +/- 25 l/min, p < 0.01), while the calculated indices of ventilation/perfusion relationship remained essentially unchanged. The reduction in mean pulmonary artery pressure after terbutaline observed in the present studies was probably the result of a combination of simple vasodilator effect, the reduction in airways resistance, and increase in the ventilation.     

Citric acid cough threshold and airway responsiveness in asthmatic patients and smokers with chronic airflow obstruction.

The relation between citric acid cough threshold and airway hyperresponsiveness was investigated in 11 non-smoking patients with allergic asthma (mean FEV1 94% predicted) and 25 non-atopic smokers with chronic airflow obstruction (mean FEV1 65% predicted). Cough threshold was determined on two occasions by administering doubling concentrations of citric acid. Seven of the 11 asthmatic subjects and 14 of 25 smokers with chronic airflow obstruction had a positive cough threshold on both test days. Cough threshold measurements were reproducible in both groups (standard deviation of duplicate measurements 1.2 doubling concentrations in asthma, 1.1 doubling concentrations in chronic airflow obstruction). Citric acid provocation did not cause bronchial obstruction in most patients, though four patients had a fall in FEV1 of more than 20% for a short time on one occasion only. No significant difference in cough threshold was found between the two patient groups despite differences in baseline FEV1 values. There was no significant correlation between cough threshold and the provocative concentration of histamine causing a 20% fall in FEV1 (PC20) histamine in either group. Thus sensory nerves can be activated with a tussive agent in patients with asthma and chronic airflow obstruction without causing bronchial smooth muscle contraction.     

Epidural anesthesia following thoracotomy in patients with chronic obstructive airway disease.

Epidural analgesia for control of postoperative thoracotomy pain in patients with carcinoma of the lung and chronic obstructive airway disease is described. The rationale and procedure for its use are presented. Epidural analgesia used in 8 patients requiring pulmonary resection who had chronic obstructive airway disease resulted in an improved postoperative course and avoided use of narcotics or a respirator in 7 of the 8 patients.     

Reduced baroreceptor sensitivity in patients with chronic obstructive pulmonary disease.

Baroreceptor sensitivity, reflected by the slope of the linear regression of the electrocardiographic R-R interval on the rise of systolic blood pressure after injection of phenylephrine, was significantly lower in 27 patients with chronic obstructive pulmonary disease (4.67 +/- 2.67) than in 10 normal subjects (12.07 +/- 3.3) of comparable age (p less than 0.001). In 20 patients in whom right heart catheterisation was performed, pulmonary artery pressure was inversely related to baroreflex sensitivity (r = - 0.603, p less than 0.01). Independent variables such as arterial Po2, Pco2, and mean pulmonary artery pressure were examined in order to assess their ability to predict baroreflex sensitivity. The independent variable that made the most significant contribution was mean pulmonary artery pressure. It seems that the attenuation of baroreflex response in patients with chronic obstructive pulmonary disease is caused mainly by pulmonary hypertension and partly by the central effects of hypoxia and hypercapnia.     

Effects of nedocromil sodium in the treatment of non-allergic subjects with chronic obstructive pulmonary disease.

BACKGROUND--Nedocromil sodium, a nonsteroidal anti-inflammatory drug, is effective in the treatment of asthma. Its efficacy in the treatment of chronic obstructive pulmonary disease (COPD) has not been investigated. METHODS--Fifty four non-allergic patients with COPD were randomised to 10 weeks of treatment with placebo or nedocromil sodium (4 x 8 mg/day) in a double blind study. RESULTS--Nedocromil sodium treatment had no effect on airway responsiveness to histamine, methacholine, and adenosine-5'-monophosphate, pulmonary function, and symptom scores. Both patients and clinicians favoured treatment with nedocromil sodium, however, and the number of dropouts (because of exacerbations) was fewer during treatment with the drug. CONCLUSIONS--Longer trials will be necessary to assess if nedocromil sodium can reduce the frequency of exacerbations and the decrease in pulmonary function, eventually leading to a better quality of life in patients with COPD.     

慢性阻塞性肺疾病患者术后肺炎的预防与处理

术后肺炎(postoperative pneumonia,PP)属医院感染性肺炎(院内肺炎),是术后常见的肺部并发症。慢性阻塞性肺疾病(chronic obstructive pul monary disease,COPD)是一种以气流受限为特征的肺部疾病,通常呈进行性发展,不完全可逆,多与肺部对有害颗粒物或有害气体的异常炎症反应有关。由于阻塞性通气功能障碍,合并全小叶肺气肿时尚有弥散量降低,因此,对心肺功能有影响的麻醉和手术均可导致呼吸功能的恶化而使病情加重。由于心肺功能的改变,使麻醉、术前、术后的管理与一般患者不同,应加强围手术期的管理,以减少PP的发生。一、COPD的特点与…     

Cough threshold in patients with chronic obstructive pulmonary disease

BACKGROUND: Cough is an important symptom of patients with chronic obstructive pulmonary disease (COPD). The cough threshold to citric acid and capsaicin in patients with COPD and in normal volunteers was measured, as well as bronchial hyperresponsiveness to methacholine. METHODS: Nineteen patients with COPD and 22 controls were recruited. Subjects underwent a methacholine bronchoprovocation test and a cough challenge to citric acid and capsaicin. RESULTS: The log citric acid cough threshold D2 (concentration causing two coughs) was significantly lower in patients with COPD (mean 2.17 versus 2.56, mean difference (95% CI) 0.39 (0.04 to 0.74), p = 0.02) but not for capsaicin cough D2 (0.66 versus 0.8, p = 0.41). Sixteen patients with COPD had bronchial hyperresponsiveness which was correlated with baseline FEV1 (r = 0.6, p = 0.01, 95% CI 0.15 to 0.84). CONCLUSIONS: Patients with COPD have a lower cough threshold to citric acid, possibly due to a differential effect of cigarette smoke on citric acid sensitive cough receptors.     

Bronchial responsiveness and acute bronchodilator response in chronic obstructive pulmonary disease and diffuse panbronchiolitis.

BACKGROUND--Diffuse panbronchiolitis (DPB) is characterised clinically by chronic airflow limitation and respiratory tract infection, and pathologically by chronic bronchiolar inflammation. To elucidate the functional differences between chronic obstructive pulmonary disease (COPD) and DPB the bronchial responsiveness to methacholine was compared in 64 patients with COPD and 32 patients with DPB, and the bronchodilator response was compared in 72 patients with COPD and 49 with DPB. METHODS--Bronchial responsiveness to methacholine was determined by the dosimeter method and expressed as PD20FEV1, and bronchodilator response was measured as the change in percentage predicted response with 5 mg nebulised salbutamol. RESULTS--Baseline FEV1 was similar in the two groups of patients. Patients with COPD were more responsive to methacholine than were those with DPB (geometric mean PD20FEV1 8.87 v 48.0 cumulative units). Reversibility of air flow obstruction, expressed as the difference between the percentage predicted postbronchodilator FEV1 and prebronchodilator FEV1, was significantly larger in patients with COPD than in those with DPB (7.87 (6.52)% v 4.16 (4.43)%). CONCLUSIONS--The observation that patients with DPB differ substantially in bronchial responsiveness from those with COPD is thought to reflect the difference in the mechanisms of these two diseases--that is, airway disease in DPB and more parenchymal disease in the group of patients with COPD. The nature of bronchiolar inflammation in COPD and DPB is also different, possibly explaining the difference in bronchial responsiveness. More fixed airflow limitation as a result of structural bronchiolar lesions in DPB will explain the smaller reversibility of airflow obstruction.     

Effects of inhaled budesonide on spirometric values, reversibility, airway responsiveness, and cough threshold in smokers with chronic obstructive lung disease.

Inhaled corticosteroids are known to reduce respiratory symptoms and airway responsiveness in allergic patients with asthma. The aim of the present randomised, double blind study was to assess the effect of eight weeks' treatment with inhaled budesonide in non-allergic smokers with chronic obstructive lung disease. Twenty four subjects (23 male) entered the study. Their ages ranged from 40 to 70 (mean 57) years, with a mean of 35 (range 9-80) pack years of smoking; the mean FEV1 was 53% (range 32-74%) predicted and geometric mean PC20 (histamine concentration causing a 20% fall in FEV1) 0.96 (range 0.07-7.82) mg/ml. After a two week washout, single blind, placebo period, 12 patients were allocated to treatment with budesonide 1600 microgram/day and 12 to placebo for eight weeks. The only additional drug to be taken was ipratropium bromide "if needed." Twenty one patients completed the study, 10 in the budesonide group and 11 in the placebo group. The standard deviation of the difference between duplicate measurements of PC20 histamine and citric acid cough threshold made two weeks apart was below one doubling dose step. There was a significant reduction in dyspnoea in the budesonide group, but otherwise no change in symptom scores or use of ipratropium bromide over the eight weeks of treatment within or between the two groups. No significant differences in spirometric values, peak expiratory flow, PC20 histamine, or citric acid cough threshold were found between the groups. Although differences were not significant, some of the changes showed a trend in favour of budesonide. Whether a longer observation period would show a significant influence of inhaled corticosteroids in patients with chronic obstructive lung disease remains to be determined.     

Body composition and exercise performance in patients with chronic obstructive pulmonary disease.

To investigate whether a compromised nutritional state may limit exercise performance in patients with chronic obstructive pulmonary disease we studied 54 such patients (FEV1 less than 50% and arterial oxygen tension (PaO2) greater than 7.3 kPa) whose clinical condition was stable and who were admitted to a pulmonary rehabilitation centre. Fat free mass was assessed anthropometrically (from skinfold measurements at four sites) and by bioelectrical impedance; creatinine height index and arm muscle circumference were also assessed. The mean (SD) distance walked in 12 minutes was 845 (178) m. No association was established between the distance walked and spirometric measures. A good correlation was found between the distance walked and fat free mass in the whole group (r = 0.73 for impedance measurements and 0.65 for skinfold thickness) and in a subgroup of 23 lean patients (body weight less than 90% of ideal weight; r = 0.66 for impedance measurements and 0.46 for skinfold thickness). Body weight correlated with the distance walked only in the whole group (r = 0.61). On stepwise regression analysis fat free mass measured by bioelectrical impedance, maximal inspiratory mouth pressure, and PaO2 accounted for 60% of the variation in the distance walked in 12 minutes. We conclude that fat free mass, independently of airflow obstruction, is an important determinant of exercise performance in patients with severe chronic obstructive pulmonary disease.