Bronchodilators in chronic air-flow limitation. Effects on airway function, exercise capacity, and quality of life

Low-dose oral theophylline combined with inhaled corticosteroids for people with chronic obstructive pulmonary disease and high risk of exacerbations: a RCT

BACKGROUND

Despite widespread use of therapies such as inhaled corticosteroids (ICSs), people with chronic obstructive pulmonary disease (COPD) continue to suffer, have reduced life expectancy and utilise considerable NHS resources. Laboratory investigations have demonstrated that at low plasma concentrations (1-5 mg/l) theophylline markedly enhances the anti-inflammatory effects of corticosteroids in COPD.

OBJECTIVE

To determine the clinical effectiveness and cost-effectiveness of adding low-dose theophylline to a drug regimen containing ICSs in people with COPD at high risk of exacerbation.

DESIGN

A multicentre, pragmatic, double-blind, randomised, placebo-controlled clinical trial.

SETTING

The trial was conducted in 121 UK primary and secondary care sites.

PARTICIPANTS

People with COPD [i.e. who have a forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) of < 0.7] currently on a drug regimen including ICSs with a history of two or more exacerbations treated with antibiotics and/or oral corticosteroids (OCSs) in the previous year.

INTERVENTIONS

Participants were randomised (1 : 1) to receive either low-dose theophylline or placebo for 1 year. The dose of theophylline (200 mg once or twice a day) was determined by ideal body weight and smoking status.

PRIMARY OUTCOME

The number of participant-reported exacerbations in the 1-year treatment period that were treated with antibiotics and/or OCSs.

RESULTS

A total of 1578 people were randomised (60% from primary care): 791 to theophylline and 787 to placebo. There were 11 post-randomisation exclusions. Trial medication was prescribed to 1567 participants: 788 in the theophylline arm and 779 in the placebo arm. Participants in the trial arms were well balanced in terms of characteristics. The mean age was 68.4 [standard deviation (SD) 8.4] years, 54% were male, 32% smoked and mean FEV₁ was 51.7% (SD 20.0%) predicted. Primary outcome data were available for 98% of participants: 772 in the theophylline arm and 764 in the placebo arm. There were 1489 person-years of follow-up data. The mean number of exacerbations was 2.24 (SD 1.99) for participants allocated to theophylline and 2.23 (SD 1.97) for participants allocated to placebo [adjusted incidence rate ratio (IRR) 0.99, 95% confidence interval (CI) 0.91 to 1.08]. Low-dose theophylline had no significant effects on lung function (i.e. FEV₁), incidence of pneumonia, mortality, breathlessness or measures of quality of life or disease impact. Hospital admissions due to COPD exacerbation were less frequent with low-dose theophylline (adjusted IRR 0.72, 95% CI 0.55 to 0.94). However, 39 of the 51 excess hospital admissions in the placebo group were accounted for by 10 participants having three or more exacerbations. There were no differences in the reporting of theophylline side effects between the theophylline and placebo arms.

LIMITATIONS

A higher than expected percentage of participants (26%) ceased trial medication; this was balanced between the theophylline and placebo arms and mitigated by over-recruitment (n = 154 additional participants were recruited) and the high rate of follow-up. The limitation of not using documented exacerbations is addressed by evidence that patient recall is highly reliable and the results of a small within-trial validation study.

CONCLUSION

For people with COPD at high risk of exacerbation, the addition of low-dose oral theophylline to a drug regimen that includes ICSs confers no overall clinical or health economic benefit. This result was evident from the intention-to-treat and per-protocol analyses.

FUTURE WORK

To promote consideration of the findings of this trial in national and international COPD guidelines.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN27066620.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 37. See the NIHR Journals Library website for further project information.

Short-term and long-term effects of a self-managed physical activity program using a pedometer for chronic respiratory disease: a randomized controlled trial

[Purpose] The aim of this study was to evaluate the effects of a self-managed physical activity program using a pedometer and diary on physical function, ADL, and QOL in patients with chronic respiratory disease. [Subjects and Methods] 17 outpatients with chronic respiratory disease were assessed for dyspnea, muscle strength, exercise tolerance, ADL, and QOL at baseline, after 3-, and 6-months after the start of the program. Patients were randomly assigned to "Control" or "Diary" group. In the Diary group, the number of steps was counted with a pedometer and recorded in a diary together with self-evaluation of physical activity, while patients assigned to the Control group did not use a pedometer or keep a diary. [Results] The Diary group showed significant improvement in the daily step count over time. The Diary group showed significant improvement of the dyspnea, muscle strength, and exercise tolerance at 3 months, dyspnea and muscle strength at 6 months. Significant differences found between two groups with regard to the extent of change in the muscle strength, exercise tolerance, and QOL at 3 months. [Conclusion] This study suggests that a self-managed physical activity program using a pedometer and diary can increase the level of physical activity.

The Saudi Guidelines for the Diagnosis and Management of COPD

The Saudi Thoracic Society (STS) launched the Saudi Initiative for Chronic Airway Diseases (SICAD) to develop a guideline for the diagnosis and management of chronic obstructive pulmonary disease (COPD). This guideline is primarily aimed for internists and general practitioners. Though there is scanty epidemiological data related to COPD, the SICAD panel believes that COPD prevalence is increasing in Saudi Arabia due to increasing prevalence of tobacco smoking among men and women. To overcome the issue of underutilization of spirometry for diagnosing COPD, handheld spirometry is recommended to screen individuals at risk for COPD. A unique feature about this guideline is the simplified practical approach to classify COPD into three classes based on the symptoms as per COPD Assessment Test (CAT) and the risk of exacerbations and hospitalization. Those patients with low risk of exacerbation (<2 in the past year) can be classified as either Class I when they have less symptoms (CAT < 10) or Class II when they have more symptoms (CAT ≥ 10). High-risk COPD patients, as manifested with ≥2 exacerbation or hospitalization in the past year irrespective of the baseline symptoms, are classified as Class III. Class I and II patients require bronchodilators for symptom relief, while Class III patients are recommended to use medications that reduce the risks of exacerbations. The guideline recommends screening for co-morbidities and suggests a comprehensive management approach including pulmonary rehabilitation for those with a CAT score ≥10. The article also discusses the diagnosis and management of acute exacerbations in COPD.

Asthma and Chronic Obstructive Pulmonary Disease (COPD) - Differences and Similarities

Bronchial asthma and COPD (chronic obstructive pulmonary disease) are obstructive pulmonary diseases that affected millions of people all over the world. Asthma is a serious global health problem with an estimated 300 million affected individuals. COPD is one of the major causes of chronic morbidity and mortality and one of the major public health problems worldwide. COPD is the fourth leading cause of death in the world and further increases in its prevalence and mortality can be predicted. Although asthma and COPD have many similarities, they also have many differences. They are two different diseases with differences in etiology, symptoms, type of airway inflammation, inflammatory cells, mediators, consequences of inflammation, response to therapy, course. Some similarities in airway inflammation in severe asthma and COPD and good response to combined therapy in both of these diseases suggest that they have some similar patophysiologic characteristics. The aim of this article is to show similarities and differences between these two diseases. Today asthma and COPD are not fully curable, not identified enough and not treated enough and the therapy is still developing. But in future better understanding of pathology, adequate identifying and treatment, may be and new drugs, will provide a much better quality of life, reduced morbidity and mortality of these patients.

Chronic obstructive pulmonary disease in the elderly: an update on pharmacological management

The prevalence of chronic obstructive pulmonary disease (COPD) continues to rise in association with an aging Western society. While barriers to receiving optimal healthcare exist for aging patients, pharmacotherapy of COPD in the elderly is important because the treatment benefits in this group are comparable to those seen in the younger COPD population. The frequent presence of co-morbidities and reduced clearance capacity make selection of pharmacotherapy in elderly patients with stable COPD challenging. The adverse effects of standard therapy for COPD may also be more pronounced in elderly patients. A careful risk-versus-benefit assessment should always be carried out when prescribing long-term inhaled bronchodilator and corticosteroid therapy to an elderly COPD patient, and when prescribing beta(2)-adrenoceptor agonists and methylxanthines, in particular, to those with cardiovascular co-morbidities. The present review focuses on the special considerations regarding initiation and maintenance of pharmacotherapy in elderly patients with stable COPD.

Health-related quality of life in emphysema

Patients with emphysema may experience reduced health-related quality of life (HRQOL). HRQOL measures have evolved from two different measurement traditions: psychometric theory and decision theory. Psychometric methods typically create a profile of outcomes, whereas decision theory methods offer a summary score on a continuum ranging from 0.0 (for death or worst possible health) to 1.0 (for best possible health). Decision theory methods are better suited for cost-effectiveness studies. Generic HRQOL measures can be applied to any disease population, whereas disease-targeted measures are tailored to a specific clinical condition. Disease-targeted measures are typically more sensitive to clinical change, but cannot offer a comparison basis for different clinical conditions. This article reviews the measurement of HRQOL in patients with emphysema. The National Emphysema Treatment Trial (NETT) offers an example of the application of both generic and disease-targeted, as well as profile and decision theory, methods. The NETT illustrates how HRQOL measures can be used to assess outcomes and estimate cost-effectiveness in a major clinical trial.

Effect of add-on therapy of tiotropium in COPD treated with theophylline

BACKGROUND

Although combination therapy with bronchodilators is recommended for chronic obstructive pulmonary disease (COPD), there is insufficient evidence for the efficacy of some combinations of long-acting bronchodilators.

OBJECTIVE

We investigated the effects of a combination therapy with tiotropium and theophylline in COPD patients.

METHODS

In a 12-week, open-labeled, parallel-group randomized study, pulmonary functions and dyspnea scores were compared between the combination and theophylline alone therapy at baseline, and 4 and 8 weeks after randomization in COPD.

RESULTS

Sixty-one COPD patients completed the trial (31 combination therapy, 30 theophylline alone; mean age 70 years; 58 males; mean dyspnea score 2.0 and forced expiratory volume in one second (FEV1) 1.5 L [62.5% predicted]). FEV1 in the combination group, but not in the theophylline alone, was significantly increased at 4 (1.56 +/- 0.13 L, p < 0.001) and 8 weeks (1.60 +/- 0.13 L, p < 0.001) from the baseline (1.40 +/- 0.12 L). In the combination group, but not the theophylline alone group, the dyspnea score was significantly improved after 4 (p < 0.01) and 8 weeks (p <0.05) compared with baseline. In 17 patients who did not receive theophylline at screening, treatment with 4 or 8 weeks of theophylline alone did not improve dyspnea score or FEV1.

CONCLUSION

Addition of tiotropium therapy to theophylline treatment can improve dyspnea and pulmonary function in COPD. Although this study did not assess whether there was any benefit of adding theophylline to patients treated with tiotropium, tiotropium can be a useful addition in COPD already treated with theophylline.

A meta-analysis on the efficacy of oral theophylline in patients with stable COPD

Background

Theophylline is a nonspecific inhibitor of phosphodiesterases that, despite exerting bronchodilator and anti-inflammatory effects, is a third-line therapy rarely used to treat chronic airflow limitation. We wished to evaluate the efficacy of oral theophylline as measured by improvements in trough (pre-dose) or peak (post-dose) FEV₁ and FVC in patients with clinically stable COPD.

Design

Meta-analysis of randomized, placebo-controlled trials reported as of June 2005 in which theophylline was orally administered to stable COPD patients and the functional evaluations included pre- and post-theophylline values for FEV₁ and FVC.

Results

A total of 18 trials were included in the meta-analysis. The weighted mean differences (WMD) with 95% confidence intervals (95% CI) for improvement over placebo in trough FEV₁ and FVC were 0.108L (0.053–0.163) and 0.186L (0.036–0.336), respectively, while peak FEV₁ and FVC improved by 0.096L (0.044–0.147) and 0.242L (0.11–0.374), respectively.

Conclusions

Treatment with oral theophylline improves both trough and peak FEV₁ and FVC in clinically stable COPD patients. These results support previously reported benefits of theophylline in COPD.

Is combination therapy with inhaled anticholinergics and beta2-adrenoceptor agonists justified for chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) is a debilitating condition characterised by progressive, irreversible airflow limitation. The economic and social burden of the disease is enormous. The treatment of COPD is guided by the stage of the disease and is aimed primarily at control of symptoms. Bronchodilators are the cornerstone of pharmacological management of COPD. Short-acting bronchodilators (beta(2)-adrenoceptor agonists and anticholinergics) have been available for many years and have been extensively studied as individual agents and in combination. When administered in combination, short-acting bronchodilators provide superior bronchodilation compared with individual agents given alone. However, the improvement in bronchodilation does not translate into an improvement in quality-of-life (QOL) indices. More recently, long-acting beta(2)-adrenoceptor agonists (LABAs) and anticholinergics have been introduced, and current guidelines recommend regular use of these agents in COPD of Global initiative for chronic Obstructive Lung Disease (GOLD) stage II or more. Combining short-acting anticholinergics with LABAs for daily use has been evaluated, but this combination does not confer any advantage in terms of subjective improvement or prevention of exacerbations. Combining the long-acting anticholinergic tiotropium bromide with formoterol given once or twice daily improves airway obstruction and hyperinflation. However, the effects of combinations of long-acting bronchodilators on patients' symptom scores, QOL and exacerbations remain to be studied. Ultra-LABAs, which are in development, may enable use of a combination of long-acting bronchodilators in a single inhaler for once-daily use, thus simplifying the regimen. This article discusses the results of various clinical trials comparing the efficacy of bronchodilators given alone or in combination to patients with COPD, with emphasis on the effects of these agents on bronchodilation, symptomatic and objective improvements in QOL and prevention of exacerbations.

Canadian Thoracic Society recommendations for management of chronic obstructive pulmonary disease - 2007 update

Chronic obstructive pulmonary disease (COPD) is a major respiratory illness in Canada that is both preventable and treatable. Our understanding of the pathophysiology of this complex condition continues to grow and our ability to offer effective treatment to those who suffer from it has improved considerably. The purpose of the present educational initiative of the Canadian Thoracic Society (CTS) is to provide up to date information on new developments in the field so that patients with this condition will receive optimal care that is firmly based on scientific evidence. Since the previous CTS management recommendations were published in 2003, a wealth of new scientific information has become available. The implications of this new knowledge with respect to optimal clinical care have been carefully considered by the CTS Panel and the conclusions are presented in the current document. Highlights of this update include new epidemiological information on mortality and prevalence of COPD, which charts its emergence as a major health problem for women; a new section on common comorbidities in COPD; an increased emphasis on the meaningful benefits of combined pharmacological and nonpharmacological therapies; and a new discussion on the prevention of acute exacerbations. A revised stratification system for severity of airway obstruction is proposed, together with other suggestions on how best to clinically evaluate individual patients with this complex disease. The results of the largest randomized clinical trial ever undertaken in COPD have recently been published, enabling the Panel to make evidence-based recommendations on the role of modern pharmacotherapy. The Panel hopes that these new practice guidelines, which reflect a rigorous analysis of the recent literature, will assist caregivers in the diagnosis and management of this common condition.

Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty

Background

Physical performance measures play an important role in the measurement of outcome in patients undergoing hip and knee arthroplasty. However, many of the commonly used measures lack information on their psychometric properties in this population. The purposes of this study were to examine the reliability and sensitivity to change of the six minute walk test (6MWT), timed up and go test (TUG), stair measure (ST), and a fast self-paced walk test (SPWT) in patients with hip or knee osteoarthritis (OA) who subsequently underwent total joint arthroplasty.

Methods

A sample of convenience of 150 eligible patients, part of an ongoing, larger observational study, was selected. This included 69 subjects who had a diagnosis of hip OA and 81 diagnosed with knee OA with an overall mean age of 63.7 ± 10.7 years. Test-retest reliability, using Shrout and Fleiss Type 2,1 intraclass correlations (ICCs), was assessed preoperatively in a sub-sample of 21 patients at 3 time points during the waiting period prior to surgery. Error associated with the measures' scores and the minimal detectable change at the 90% confidence level was determined. A construct validation process was applied to evaluate the measures' abilities to detect deterioration and improvement at two different time points post-operatively. The standardized response mean (SRM) was used to quantify change for all measures for the two change intervals. Bootstrapping was used to estimate the 95% confidence intervals (CI) for the SRMs.

Results

The ICCs (95% CI) were as follows: 6MWT 0.94 (0.88,0.98), TUG 0.75 (0.51, 0.89), ST 0.90 (0.79, 0.96), and the SPWT 0.91 (0.81, 0.97). Standardized response means varied from .79 to 1.98, being greatest for the ST and 6MWT over the studied time intervals.

Conclusions

The test-retest estimates of the 6MWT, ST, and the SPWT met the requisite standards for making decisions at the individual patient level. All measures were responsive to detecting deterioration and improvement in the early postoperative period.

Oral theophylline for chronic obstructive pulmonary disease

BACKGROUND

Oral theophylline has, for many years, been used as a bronchodilator in patients with COPD. Despite the introduction of new drugs, and its narrow therapeutic index, theophylline is still recommended for COPD treatment.

OBJECTIVES

To determine the effectiveness of oral theophylline when compared to placebo in patients with stable COPD.

SEARCH STRATEGY

The Cochrane Airways Review Group and Cochrane Controlled Clinical Registers were searched.

SELECTION CRITERIA

All studies were randomised controlled trials (RCTs).

DATA COLLECTION AND ANALYSIS

Data were independently abstracted and the methodological quality assessed by two reviewers.

MAIN RESULTS

Twenty RCTs met the inclusion criteria. Concomitant therapy varied from none to any other bronchodilator plus corticosteroid (oral and inhaled). The following outcomes were significantly different when compared to placebo. FEV1 improved with treatment: Weighted Mean Difference (WMD) 100 ml; 95% Confidence Interval (95%CI) 40, 160 ml. Similarly for FVC: WMD 210 ml 95%CI 100, 320. Two studies reported an improvement in VO2max; WMD 195 ml/min, 95%CI 113,27). At rest, PaO2 and PaCO2 both improved with treatment (WMD 3.2 mmHg; 95%CI = 1.2, 5., and WMD -2.4 mmHg; 95%CI = -3.5, -1.2, respectively). Walking distance tests did not improve (4 studies, Standardised Mean Difference 0.30, 95%CI -0.01, 0.62), neither did Visual Analogue Score for breathlessness isn two small studies (WMD 3.6, 95%CI -4.6, 11.8). The Relative Risk (RR) of nausea was greater with theophylline (RR 7.7; 95%CI 1.5, 39.9). However, patients' preference for theophylline was greater than that for placebo (RR 2.27; 95%CI = 1.26, 4.11). Very few patient withdrew from these studies for any reason.

REVIEWER'S CONCLUSIONS

Theophylline has a modest effect on FEV1 and FVC and slightly improves arterial blood gas tensions in moderate to severe COPD. These benefits were seen in patients receiving a variety of different concomitant therapies. Improvement in exercise performance depended on the method of testing. There was a very low dropout rate in the studies that could be included in this review, which suggests that recruited patients may have been known by the investigators to be theophylline tolerant. This may limit the generalisability of these studies.

The incremental shuttle walking test in elderly people with chronic airflow limitation

BACKGROUND

There is a concern that comorbidity or frailty in older people could limit the usefulness of currently available exercise tests for chronic lung disease. This study evaluated the feasibility and reproducibility of the incremental shuttle walking test (SWT) in people aged 70 years or over, compared exercise tolerance with other disability markers, and assessed whether the SWT is responsive to change after bronchodilators.

METHODS

Fifty elderly patients with chronic airflow limitation (CAL) and 32 controls without airflow limitation attempted the SWT before and after combined nebulised salbutamol/ipratropium bromide. Subjects also completed the Nottingham Extended Activities of Daily Living index (NEADL) and the London Handicap score (LHS).

RESULTS

Forty four subjects with CAL (88%) and 29 controls (84%) completed the SWT, including many with co-morbidities. Two week repeatability was good and the SWT was strongly associated with EADL (r=0.51, p<0.001) and LHS (r=0.43, p<0.004), but only weakly with forced expiratory volume in 1 second (FEV1) (r=0.31, p=0.05). Subjects with CAL walked a mean distance of 177.7 m compared with 243.3 m in controls (p<0.001); following bronchodilator therapy the distance walked increased in the CAL group by 13.2% (p=0.009).

CONCLUSION

The SWT is a feasible and reproducible measure of exercise tolerance in elderly people with and without airflow obstruction and correlates with other markers of disability. It is sensitive to change following bronchodilation in subjects with CAL, although the change correlates less well with improvements in FEV1. Overall, these results suggest that the SWT might be an appropriate measure to assess interventions in elderly people.

Subjective outcome measurement--a primer

There is a growing recognition within both the practice and research communities in pharmacy that serious attention must be given to the systematic study of the outcomes of pharmacy services, especially those outcomes that are focused on the patient. Research has tended to focus too strongly on the measurement of structure and process, with the unspoken assumption that if these are of good quality, the outcome will automatically be similar. However, the literature on outcome measurement instruments is vast and practitioners moving into this area for the first time may find themselves lost in a morass of conflicting definitions and different methods of measurement. This review considers the outcome measures or 'measurement instruments' that are used to assess subjective health status. Two commonly used taxonomies are described that concern the conceptual content (functional status, general health perceptions, quality of life and health-related quality of life) and the breadth of coverage of the instruments (generic, disease specific, domain or dimensions specific and patient-centred instruments). Specific attention is paid to the newest of these groups, the patient-centred instruments, which are very different in style and content to the other three and reflect a change in direction in instrument development, to address limitations of commonly used 'fixed' outcome instruments. Detail is given on what makes a quality instrument in particular circumstances (validity, reliability, sensitivity to change, multidimensional construct, practicality and applicability), to help pharmacists develop the necessary skills to select appropriate instruments in the burgeoning field of outcomes measurement.

Effects of theophylline and ipratropium bromide on exercise performance in patients with stable chronic obstructive pulmonary disease

BACKGROUND

The effects of theophylline or anticholinergic agents on exercise capacity in patients with chronic obstructive pulmonary disease (COPD) remain controversial. The aim of the present study was to compare the effect of an oral theophylline with an inhaled anticholinergic agent and to examine the effects of combined therapy on exercise performance using progressive cycle ergometry.

METHODS

Twenty one men with stable COPD and a mean (SD) forced expiratory volume in one second (FEV1) of 1.00 (0.40) 1 were studied. Theophylline (600 or 800 mg daily), ipratropium bromide (160 micrograms), a combination of both drugs, and placebo were given in a randomised, double blind, four period crossover design study. Spirometric data, pulse rate, and blood pressure were assessed before and at 90 and 120 minutes after inhalation. Symptom limited progressive cycle ergometer exercise tests (20 watts/min) were performed 90 minutes after each inhalation, and dyspnoea was measured during exercise using the Borg scale.

RESULTS

The mean (SD) serum theophylline concentration was 18.3 (6.3) micrograms/ml, and seven patients had side effects during treatment with theophylline. Theophylline and ipratropium bromide produced greater increases in FEV1, maximal oxygen consumption, maximal minute ventilation, and several dyspnoea ratios than placebo. There were no differences between theophylline and ipratropium bromide except in maximal heart rate. A combination of both drugs produced greater improvements in pulmonary function and exercise capacity than either drug alone.

CONCLUSIONS

Both high dose theophylline and high dose ipratropium bromide improved exercise capacity in patients with stable COPD. Although data based on short term effects cannot be directly applied to long term therapy, theophylline added to an inhaled anticholinergic agent may have beneficial effects on exercise capacity in patients with COPD.

Effects of regular salmeterol on lung function and exercise capacity in patients with chronic obstructive airways disease

BACKGROUND

The aim of this study was to evaluate the effects of single and chronic dosing with salmeterol on exercise capacity and lung function in patients with chronic obstructive pulmonary disease.

METHODS

Twenty nine patients of mean (SE) age 64 (1.5) years, forced expiratory volume in one second (FEV1) 42(3)% of predicted, and 5-15% reversibility to salbutamol 200 micrograms were randomised to receive four weeks treatment with salmeterol 50 micrograms twice daily or placebo in a double blind crossover fashion with a one week washout period in between. Measurements of spirometric parameters, static lung volumes, and exercise capacity were made one and six hours after a single dose, and six hours after the final dose of salmeterol or placebo.

RESULTS

Salmeterol produced a small increase in FEV1 at one and six hours after a single dose, and this was maintained after chronic dosing (mean difference and 95% CI versus placebo): single dosing at one hour 0.07 (95% CI 0.02 to 0.11) 1, single dosing at six hours 0.16 (95% CI 0.09 to 0.22) 1, chronic dosing at six hours 0.11 (95% CI 0.03 to 0.19) 1. The increase in forced vital capacity (FVC) was greater with salmeterol than with placebo six hours after single but not chronic dosing: single dosing at six hours 0.17 (95% CI 0.04 to 0.29) 1, chronic dosing at six hours 0.02 (95% CI -0.18 to 0.22) 1. Slow vital capacity was increased after treatment with salmeterol compared with placebo one and six hours after single but not after chronic dosing. There were no significant differences in static lung volumes or exercise capacity after single or chronic dosing with salmeterol compared with placebo. Patients reported a significantly lower Borg score for perceived exertion following the six minute walk after chronic treatment with salmeterol compared with placebo.

CONCLUSIONS

Salmeterol produced a small improvement in spirometric values compared with placebo consistent with the degree of reversibility originally shown by the subjects to salbutamol 200 micrograms. This was not associated with improvements in static lung volumes or exercise capacity, but there was some symptomatic benefit in that patients were able to walk the same distance in six minutes with less perceived exertion.

Randomised study of n of 1 trials versus standard practice

OBJECTIVE

To compare outcomes between groups of patients with irreversible chronic airflow limitation given theophylline by n of 1 trials or standard practice.

DESIGN

Randomised controlled study of n of 1 trials versus standard practice.

SETTING

Tertiary care center outpatient department.

SUBJECTS

31 patients with irreversible chronic airflow limitation who were unsure that theophylline was helpful after an open trial.

INTERVENTIONS

n Of 1 trials (single patient randomised multiple crossover comparisons of theophylline against placebo) followed published guidelines. For standard practice patients theophylline was stopped and resumed if their dyspnoea worsened; if their dyspnoea then improved theophylline was continued. For both groups a decision to continue or stop the drug was made within three months of randomisation.

MAIN OUTCOME MEASURES

Exercise capacity as measured by six minute walking distance, quality of life as measured by the chronic respiratory disease questionnaire at baseline and six months after randomisation, and proportions of patients taking theophylline at six months.

RESULTS

26 patients completed follow up. 47% fewer n of 1 trial patients than standard practice patients were taking theophylline at six months (5/14 versus 10/12; 95% confidence interval of difference 14% to 80%) without differences in exercise capacity or quality of life.

CONCLUSIONS

n Of 1 trials led to less theophylline use without adverse effects on exercise capacity or quality of life in patients with irreversible chronic airflow limitation. These data directly support the presence of a clinically important bias towards unnecessary treatment during open prescription of theophylline for irreversible chronic airflow limitation. Confirmation in a larger study and similar studies for other problems appropriate for n of 1 trials are needed before widespread use of n of 1 trials can be advocated in routine clinical practice.

Assessing quality of life in chronic non-specific lung disease--a review of empirical studies published between 1980 and 1994

Chronic non-specific lung disease (CNSLD), a chronic disease with considerable prevalence and mortality rates, is not only a medical problem, it also has significant psychological and social consequences for the patients concerned. Quality of life research on CNSLD has been rather underdeveloped for quite a long period of time, but has recently become an important topic in research as well as in patient care. In order to get insight into the state of the art of empirical research on quality of life (QOL) in CNSLD, a review of the literature between 1980-1994 on this topic is presented. Special attention is paid to definitions and operationalizations of the QOL concept as well as on questionnaires used to assess QOL and the aims of QOL research. Analysis reveals that QOL is seldom defined clearly and is operationalized in a variety of ways. Most studies have a descriptive nature or pertain to clinical trials. The negative impact of CNSLD on QOL is well-documented and shows the importance of incorporating assessment of QOL in research as well as in patient care. Future research is called for, which should be theory-driven, taking into account recent developments concerning disease-specific measures of QOL.

Efficacy of inhaled salmeterol in the management of smokers with chronic obstructive pulmonary disease: a single centre randomised, double blind, placebo controlled, crossover study

BACKGROUND

The acute response to bronchodilators in patients with chronic obstructive pulmonary disease (COPD) is modest; it has, however, been suggested that these patients may benefit from long term treatment.

METHODS

To investigate the efficacy of salmeterol in smokers with moderate to severe COPD a double blind, randomised, crossover comparison was performed between salmeterol (50 micrograms twice daily) and placebo in 63 patients with stable COPD (mean age 65 years). Prior to inclusion, all patients had a forced expiratory volume in one second (FEV1) of < 60% of predicted and an improvement in FEV1 of < 15% following 400 micrograms inhaled salbutamol. Patients received four weeks of therapy with each of the treatment regimens. Assessment of efficacy was made with recording of morning and evening peak expiratory flow rates (PEF), respiratory symptoms, and use of rescue salbutamol. FEV1 was measured before and after nebulised salbutamol prior to randomisation and at the end of each treatment period.

RESULTS

Morning PEF values were higher during the salmeterol than during the placebo period, although the mean treatment difference was small (12 l/min (95% confidence limits 6 to 17)). No difference in mean evening PEF values was found. Diurnal variation in PEF, assessed as the difference between the morning PEF and that of the previous evening, was more pronounced during the placebo than during the salmeterol period. The mean spirometric values (including reversibility in FEV1) obtained at the end of the two treatment periods were similar. Compared with placebo, treatment with salmeterol was associated with lower daytime and night time symptom scores and less use of rescue salbutamol both during the day and the night. The patients rated the treatment with salmeterol better than treatment with placebo.

CONCLUSIONS

This study shows that, compared with placebo, treatment with salmeterol produces an improvement in respiratory symptoms and morning PEF values in patients with moderate to severe COPD. Treatment with long acting beta agonists may therefore result in an improvement in functional status, even in patients suffering from apparently nonreversible obstructive pulmonary disease.

Effect of increasing doses of beta agonists on spirometric parameters, exercise capacity, and quality of life in patients with chronic airflow limitation

BACKGROUND

A study was undertaken to determine the impact of different doses of inhaled terbutaline on peak flow rates, spirometric parameters, functional exercise capacity, and quality of life in patients with chronic airflow limitation.

METHODS

A double blind, randomised, placebo controlled, multiple crossover trial was conducted with treatment periods of one week. Patients with a clinical diagnosis of chronic airflow limitation and FEV1 below 70% predicted after administration of bronchodilator were recruited from secondary care respiratory practices, and the effect of 500, 1000, and 1500 micrograms inhaled terbutaline four times daily on spirometric parameters (FEV1, FVC), maximum inspiratory pressures, six minute walking distance, and health-related quality of life (Chronic Respiratory Disease Questionnaire, Quality of Well Being, Standard Gamble) was measured.

RESULTS

Twenty five patients completed the trial. Peak flow rates and FEV1 showed statistically significant but clinically trivial improvement on the higher drug doses. Results of maximum inspiratory pressure measurements, walk test distance, and quality of life measures showed minimal differences on the different dosages, and none of the differences approached conventional statistical significance.

CONCLUSIONS

Regular use of beta agonists in doses higher than two puffs four times a day is very unlikely to provide additional functional or symptomatic benefit to patients with chronic airflow limitation.

Effects of high dose inhaled beclomethasone dipropionate, 750 micrograms and 1500 micrograms twice daily, and 40 mg per day oral prednisolone on lung function, symptoms, and bronchial hyperresponsiveness in patients with non-asthmatic chronic airflow obstruction

BACKGROUND

The effect of treatment with inhaled corticosteroids in patients with non-asthmatic chronic airflow obstruction is still disputed. Whether any physiological improvements seen are accompanied by changes in bronchial responsiveness and symptoms and quality of life is also still unclear.

METHODS

A sequential placebo controlled, blinded parallel group study investigating the effect of three weeks of treatment with inhaled beclomethasone dipropionate (BDP), 750 micrograms or 1500 micrograms twice daily, and oral prednisolone, 40 mg per day, was carried out in 105 patients with severe non-asthmatic chronic airflow obstruction (mean age 66 years, mean forced expiratory volume in one second (FEV1) 1.05 litres [40% predicted], geometric mean PD20 0.52 mumol). End points assessed were FEV1, forced vital capacity (FVC), and peak expiratory flow (PEF), bronchial responsiveness to inhaled histamine, and quality of life as measured by a formal quality of life questionnaire.

RESULTS

Both doses of BDP produced equivalent, small, but significant improvements in FEV1 (mean 48 ml), FVC (mean 120 ml), and PEF (mean 12.4 l/min). The addition of oral prednisolone to the treatment regime in two thirds of the patients did not produce any further improvement in these parameters. Inhaled BDP produced a treatment response in individual patients (defined as an improvement in FEV1, FVC, or mean PEF of at least 20% compared with baseline values) more commonly than placebo (34% v 15%). The two doses of BDP were equally effective in this respect and again no further benefit of treatment with oral prednisolone was noted. Treatment with BDP for up to six weeks did not affect bronchial responsiveness to histamine. Small but significant improvements were seen in dyspnoea during daily activities, and the feeling of mastery over the disease.

CONCLUSIONS

High dose inhaled BDP is an effective treatment for patients with chronic airflow obstruction not caused by asthma. Both objective and subjective measures show improvement. Unlike asthma, no improvement in bronchial responsiveness was detected after six weeks of treatment.

Value of theophylline treatment in patients handicapped by chronic obstructive lung disease

BACKGROUND

It is still not certain whether it is worth using theophylline in addition to inhaled bronchodilators and corticosteroids to treat obstructive airways disease. This trial was designed to test whether the addition of prescribed theophylline in doses sufficient for sustained optimal steady state plasma concentrations would produce any detectable additional advantage in spirometric or functional variables in these handicapped patients.

METHODS

A randomised, double blind, placebo controlled, crossover study of added theophylline treatment was aimed at steady state plasma concentrations of 10 and 17 mg/l, the dose being calculated individually by Bayesian parameter estimation and maintained for six weeks along with the patient's previously prescribed bronchodilators and steroids. Of 20 patients sequentially recruited, 15 provided data that could be analysed. All had chronic obstructive lung disease with a mean forced expiratory volume in the first second (FEV1) up to about 30% of the predicted value and gave no history of being treated with theophylline. The protocol included spirometry, whole body plethysmography, and treadmill exercise. Measurements also included steady state plasma theophylline concentrations and trapped gas volume. Quality of life was assessed by an established questionnaire method covering breathlessness in everyday activities, fatigue, emotional function, and control over the disease.

RESULTS

Both target plasma concentrations were achieved. Improvements in peak flow (PEF; mean 20%), trapped gas volumes (38%), two stage vital capacity (15%), distances walked (48%), breathlessness in everyday activities (32%), and fatigue (18%) were found at the higher plasma concentration only. FEV1, forced vital capacity (FVC), emotional function, and control did not change.

CONCLUSION

Theophylline treatment with sustained steady state concentrations about 17 mg/l provides worthwhile objective and subjective further benefits for patients handicapped by chronic obstructive lung disease when it is added to bronchodilators and corticosteroids.

Diagnosis of obstructive airways disease from the clinical examination

OBJECTIVE

To determine the operating characteristics of history and physical examination items for pulmonary airflow obstruction.

DESIGN

Prospective observational study.

SETTING

Medical Preoperative Evaluation Clinic at the Durham Veterans Affairs Medical Center.

PATIENTS/PARTICIPANTS

Consecutive patients referred for outpatient medical preoperative risk assessment.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Number of years the patient had smoked cigarettes, patient-reported wheezing [LR+ (likelihood ratio for finding present) = 3.1; LR- (likelihood ratio for finding absent) = 0.58], and auscultated wheezing (LR+ = 12; LR- = 0.87) were independent predictors of obstructive airways disease from the history and physical examination. Forced expiratory time and peak expiratory flow rate, both measured by the clinician at the bedside, were additional independent predictors of airflow obstruction. A nomogram using patient-reported wheezing, number of years the patient had smoked, and auscultated wheezing was developed and validated (area under receiver operating characteristic curve = 0.78; p = 0.0001) for the bedside prediction of obstructive airways disease. Peak expiratory flow rate can be substituted for auscultated wheezing with similar predictive ability.

CONCLUSIONS

The results of bedside clinical examinations predict the presence of obstructive airways disease. A nomogram based on a combination of four bedside findings predicts airflow obstruction as well as clinicians' overall clinical impressions.

Validity of peak expiratory flow measurement in assessing reversibility of airflow obstruction

BACKGROUND

Assessing the reversibility of airflow obstruction by peak expiratory (PEF) measurements would be practicable in general practice, but its usefulness has not been investigated.

METHODS

PEF measurements were performed (miniWright peak flow meter) in 73 general practice patients (aged 40 to 84) with a history of asthma or chronic obstructive lung disease before and after 400 micrograms inhaled sulbutamol. The change in PEF was compared with the change in forced expiratory volume in one second (FEV1). Reversible airflow obstruction was analysed in two ways according to previous criteria. When defined as a 9% or greater increase in FEV1 expressed as a percentage of predicted values reversibility was observed in 42% of patients. Relative operating characteristic analysis showed that an absolute improvement in PEF of 60 l/min or more gave optimal discrimination between patients with reversible and irreversible airflow obstruction (the sensitivity and specificity of an increase of 60 l/min in detecting a 9% or more increase in FEV1 as a percentage of predicted values were 68% and 93% respectively, with a positive predictive value of 87%). When defined as an increase of 190 ml or more in FEV1, reversible airflow obstruction was observed in 53% of patients. Again an absolute improvement in PEF of 60 l/min or more gave optimal discrimination between patients with reversible and irreversible airflow obstruction (sensitivity 56%, specificity 94%, and positive predictive value 92%).

CONCLUSION

Absolute changes in PEF can be used as a simple technique to diagnose reversible airflow obstruction in patients from general practice.

Bronchodilator treatment for partially reversible chronic obstructive airways disease

The effect of six weeks' treatment with inhaled terbutaline (1 mg four times a day), optimised doses of theophylline (twice a day), the combination of theophylline and terbutaline, and placebo was studied in a randomised, double blind, crossover trial. Thirty patients with partially reversible chronic airflow obstruction and a mean forced expiratory volume in one second (FEV1) of 1.2 litres that improved by 25% were included in the study. Patients who developed non-infective exacerbations of airflow obstruction that required additional bronchodilator treatment were classed as "treatment failures." Such treatment failure occurred in 23 patients with placebo, in 22 patients with theophylline, in 12 patients with terbutaline, and in two patients taking the two drugs. Mean daily peak flow readings were highest with the combination of the two drugs, followed by terbutaline and then theophylline, and lowest with placebo. Thus a combination of terbutaline and theophylline was superior to either drug alone; inhaled terbutaline was superior to theophylline alone. Theophylline alone does not appear to have much place in the management of patients with partially reversible obstructive airways disease.

Management of asthma and chronic airflow limitation: are methylxanthines obsolete?

The widespread popularity of methylxanthine derivatives should be reassessed in light of current evidence. These drugs are relatively weak bronchodilators, respiratory muscle stimulants and inotropic agents and adverse effects, sometimes life threatening, occur fairly frequently. In contrast, beta-2 adrenergic and anticholinergic bronchodilator aerosols used in asthma or chronic obstructive lung disease, and the prophylactic anti-inflammatory aerosols of corticosteroids and cromolyn provide a spectrum of therapeutic choices which address both the inflammatory and bronchoconstrictor components of acute and chronic airflow limitation. Aerosol bronchodilators, in general, are more potent, are virtually free of important side effects, and do not require costly serum level monitoring. Adrenoceptor agonists, together with inhaled steroids, should be considered first-line drugs of choice in managing patients with reversible airflow obstruction associated with asthma or COPD, while methylxanthines should be relegated to the position of third or fourth line drugs, if they are to be used at all. If they are, they should be used with great caution and close patient supervision and, even then, only if benefit, over and above the aerosol bronchodilators and inhaled anti-inflammatory agents can be demonstrated objectively.

Theophylline in the management of airflow obstruction. 2. Difficult drugs to use, few clinical indications

The narrow therapeutic index, potential toxicity, and need to monitor plasma concentrations make theophyllines difficult to use. Other drugs provide comparable or better bronchodilator and prophylactic efficacy. In asthma theophyllines should be considered for chronic stable asthma when treatment with optimal doses of inhaled steroids and bronchodilators fails to provide adequate control; for nocturnal asthma; and for prophylaxis and relief of symptoms in children and adults when inhaled treatment cannot be given. In general, theophyllines cannot be recommended for chronic airflow obstruction. A trial of theophylline is reasonable in individual patients whose symptoms remain troublesome despite a trial of steroids and optimal doses of inhaled bronchodilators.