Prolonged antibiotics for purulent bronchiectasis in children and adults.

BACKGROUND: The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator preventing bacterial clearance and allowing the persistence of pro-inflammatory mediators. Conventional treatment with physiotherapy and intermittent antibiotics are felt to improve the condition of bronchiectasis patients although there are no conclusive data showing that these interventions influence the natural history of the condition. Various strategies have been tried to interrupt this cycle of infection and inflammation and one of these is to prolong antibiotic treatment in the hope of allowing the airway mucosa to heal. OBJECTIVES: This systematic review brings together the evidence and where possible presents a meta-analysis of the data available to answer the question 'Does treatment with prolonged courses of antibiotics influence the outcome in purulent bronchiectasis?' SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. Searches were current as of January 2007. SELECTION CRITERIA: Randomised trials looking at the use of prolonged antibiotic therapy in the treatment of bronchiectasis compared with either placebo or usual care. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by the reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Nine trials met the inclusion criteria, recruiting a total of 378 participants. Antibiotics were given for between 4 weeks and one year. Only limited meta-analysis was possible due to the diversity of outcomes in the trials. Response rates showed significant effects in favour of prolonged antibiotic treatment (Peto OR (95% CI), 3.37 (1.60 to 7.09)). Conversely for exacerbation rates there was no significant difference between prolonged antibiotics and placebo (Peto OR (95% CI), 0.96 (0.27 to 3.46)). For withdrawals there was no significant difference between treatment and placebo management (Peto OR (95% CI), 1.06 (0.42 to 2.65)). Data for lung function showed no significant benefit in favour of antibiotic treatment (% predicted FEV1 mean difference -1.05 % (95% CI -6.93 to 4.83)). AUTHORS' CONCLUSIONS: The evidence available shows a small benefit for the use of prolonged antibiotics in the treatment of bronchiectasis. This review is limited by the diversity of the trials. Further randomised controlled trials with adequate power and standardised end points are required.

Vaccines for preventing influenza in people with asthma.

BACKGROUND: Influenza vaccination is recommended for asthmatic patients in many countries as observational studies have shown that influenza infection can be associated with asthma exacerbations, but influenza vaccination itself has the potential to adversely affect pulmonary function. A recent overview concluded that there was no clear benefit of influenza vaccination in patients with asthma but this conclusion was not based on a systematic search of the literature. OBJECTIVES: Whilst influenza may cause asthma exacerbations, there is controversy about the use of influenza vaccinations, since they may precipitate an asthma attack in some people. The objective of this review was to assess the efficacy of influenza vaccination in children and adults with asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and checked reference lists of articles. The last search was carried out in February 2003. SELECTION CRITERIA: Randomised trials of influenza vaccination in children (over two years of age) and adults with asthma. Studies involving people with chronic obstructive pulmonary disease were excluded. DATA COLLECTION AND ANALYSIS: Inclusion criteria and assessment of trial quality were applied by two reviewers independently. Data extraction was done by two reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Nine trials were initially included. Four of these trials were of high quality. Five further articles have been included in two updates (Bueving 2002; Castro 2001; Redding 2002; Reid 1998). The included studies covered a wide diversity of people, settings and types of influenza vaccination, but data from the more recent studies that used similar vaccines have been pooled. The pooled results of two trials involving 2306 people with asthma did not demonstrate a significant increase in asthma exacerbations in the two weeks following influenza vaccination (Risk Difference 0.00; 95% confidence interval -0.02 to 0.02). A recent study on 696 children with asthma did not demonstrate a significant reduction in influenza related asthma exacerbations (Risk Difference 0.01; 95% confidence interval -0.02 to 0.04). REVIEWERS' CONCLUSIONS: Evidence from recently published trials indicates that there is no significant increase in asthma exacerbations immediately after vaccination (at least with inactivated influenza vaccination); however, uncertainty remains about the degree of protection vaccination affords against asthma exacerbations that are related to influenza infection.

Prolonged antibiotics for purulent bronchiectasis.

BACKGROUND: The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator preventing bacterial clearance and allowing the persistence of pro-inflammatory mediators. Conventional treatment with physiotherapy and intermittent antibiotics are felt to improve the condition of bronchiectasis patients although there are no conclusive data showing that these interventions influence the natural history of the condition. Various strategies have been tried to interrupt this cycle of infection and inflammation and one of these is to prolong antibiotic treatment in the hope of allowing the airway mucosa to heal. OBJECTIVES: This systematic review brings together the evidence and where possible presents a meta-analysis of the data available to answer the question 'Does treatment with prolonged courses of antibiotics influence the outcome in purulent bronchiectasis?' SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of identified articles were searched. SELECTION CRITERIA: Randomised trials looking at the use of prolonged antibiotic therapy in the treatment of bronchiectasis. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data extraction was carried out by the reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: 447 abstracts were found and reviewed for suitability. Six trials were included and 302 patients were randomised amongst these trials. 40% of the patients were contributed by one trial. Antibiotics were given for between 4 weeks and one year. There were 40 withdrawals due to treatment failure and intolerable side effects. Only limited meta-analysis was possible due to the diversity of the trials. Response rates showed significant effects in favour of prolonged antibiotic treatment (Peto OR (95% CI), 3.37 (1.60 to 7.09)). Conversely for exacerbation rates there was no significant difference between prolonged antibiotics and placebo (Peto OR (95% CI), 0.96 (0.27 to 3.46)). For withdrawals there was no significant difference between treatment and placebo management (Peto OR (95% CI), 1.06 (0.42 to 2.65)). Data for lung function showed no significant benefit in favour of antibiotic treatment (% predicted FEV1, WMD (95% CI) -1.05 (-6.93 to 4.83)). REVIEWER'S CONCLUSIONS: The evidence available shows a small benefit for the use of prolonged antibiotics in the treatment of bronchiectasis. This review is limited by the diversity of the trials. Further randomised controlled trials with adequate power and standardised end points are required.

Anticholinergic therapy for chronic asthma in children over two years of age.

BACKGROUND: In the intrinsic system of controlling airway calibre, the cholinergic (muscarinic) sympathetic nervous system has an important role. Anticholinergic, anti muscarinic bronchodilators such as ipratropium bromide are frequently used in the management of childhood airway disease. In asthma, ipratropium is a less potent bronchodilator than beta-2 adrenergic agents but it is known to be a useful adjunct to other therapies, particularly in status asthmaticus. What remains unclear is the role of anticholinergic drugs in the maintenance treatment of chronic asthma. OBJECTIVES: To determine the effectiveness of anticholinergic drugs in chronic asthma in children over the age of 2 years. SEARCH STRATEGY: The Cochrane Airways Group trials register and reference lists of articles were searched in January 2002. SELECTION CRITERIA: Randomised controlled trials in which anticholinergic drugs were given for chronic asthma in children over 2 years of age were included. Studies including comparison of: anticholinergics with placebo, and anticholinergics with any other drug were included. DATA COLLECTION AND ANALYSIS: Eligibility for inclusion and quality of trials were assessed independently by two reviewers. MAIN RESULTS: Eight studies met the inclusion criteria.Three papers compared the effects of anticholinergic drugs with placebo, and a meta-analysis of these results demonstrated no statistically significant benefit of the use of anticholinergic drugs over placebo in any of the outcome measures used. The results of one of these trials could not be included in the meta-analysis but the authors did report significantly lower symptom scores with inhaled anticholinergics compared with placebo. However, there was no significant difference between ipratropium bromide and placebo in the percentage of symptom-free nights or days. Two trials studied the effects of anticholinergics on bronchial hyper responsiveness to histamine, by measuring the provocation dose of histamine needed to cause a fall of 20 % in FEV1 (PD 20). One study (comparing anticholinergics with placebo) reported a statistically significant increase in PD 20 but this was not found in another study (comparing anticholinergics with a beta-2 agonist). Both trials also examined the effect of anticholinergic drugs on diurnal variation in peak expiratory flow rate (PEFR) and reported no significant effect. Two studies compared the addition of an anticholinergic drug to a beta-2 agonist with the beta-2 agonist alone. Both trials failed to show any significant benefit from the long term use of combined anticholinergics with beta-2 agonists compared with beta-2 agonists alone. One trial compared the effects of oral and inhaled anticholinergic drugs with placebo. No statistically significant differences were found in any of the outcome measures except for a higher FEV1 / VC ratio and RV / TLC ratio with oral anticholinergic therapy when compared with placebo. REVIEWER'S CONCLUSIONS: The present review summarises the best evidence available to date. Although there were some small beneficial findings in favour of anticholinergic therapy, there is insufficient data to support the use of anticholinergic drugs in the maintenance treatment of chronic asthma in children.

Caffeine for asthma.

BACKGROUND: Caffeine has a variety of pharmacological effects. It is chemically related to the drug theophylline which is used to treat asthma. Accordingly, interest has been expressed in its potential role as an asthma treatment. A number of studies have explored the effects of caffeine in asthma, this is the first review to systematically examine and summarise the evidence. OBJECTIVES: Caffeine is a weak bronchodilator and it also reduces respiratory muscle fatigue. It has been suggested that caffeine may reduce asthma symptoms. The objective of this review was to assess the effects of caffeine on lung function and identify whether there is a need to control for caffeine consumption prior to lung function testing. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and the reference lists of articles. We also contacted study authors. SELECTION CRITERIA: Randomised trials of oral caffeine compared to placebo in adults with asthma. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were done independently by two reviewers. MAIN RESULTS: Six trials involving a total of 55 people were included. The studies were all of cross-over design and of high quality. In comparison with placebo, caffeine appears to improve lung function for up to two hours after consumption. Forced expiratory volume in one minute showed a small improvement up to two hours after caffeine use (standardised mean difference -0.73, 95% confidence interval -1.20 to -0.25). Mid-expiratory flow rates also showed a small improvement with caffeine and this was sustained up to four hours. An updated search in June 2001 did not identify any further studies. REVIEWER'S CONCLUSIONS: Caffeine appears to improve airways function modestly in people with asthma for up to four hours. People may need to avoid caffeine for at least four hours prior to lung function testing.

Vaccines for preventing influenza in people with asthma (Cochrane Review).

BACKGROUND: Influenza vaccination is recommended for asthmatic patients in many countries as observational studies have shown that influenza infection can be associated with asthma exacerbations, but influenza vaccination itself has the potential to adversely affect pulmonary function. A recent overview concluded that there was no clear benefit of influenza vaccination in patients with asthma but this conclusions was not based on a systematic search of the literature. OBJECTIVES: Whilst influenza may cause asthma exacerbations, there is controversy about the use of influenza vaccinations, since they may precipitate an asthma attack in some people. The objective of this review was to assess the effects of influenza vaccination in children and adults with asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and checked reference lists of articles. SELECTION CRITERIA: Randomised trials of influenza vaccination in children (over two years of age) and adults with asthma. Studies involving people with chronic obstructive pulmonary disease were excluded. DATA COLLECTION AND ANALYSIS: Inclusion criteria and assessment of trial quality were applied by two reviewers independently. Data extraction was done by two reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Nine trials were included. Four of these trials were of high quality. One further article has been included since the previous version of this review. Inclusion of the new trial has not altered the conclusions of this review. The included studies covered a wide diversity of people, settings and types of influenza vaccination, so data from the different trials were not pooled. In one trial, no protective effect of influenza vaccination against asthma exacerbation was demonstrated, but the incidence of influenza was low during the study period. A higher number of asthma exacerbations following killed influenza vaccination was found in one trial (risk difference 3 1%, 95% confidence interval 0.3% to 5.8%). When people with upper respiratory tract infections were excluded, this difference was no longer significant. A small trial using recombinant vaccine found no significant difference in asthma exacerbations between the vaccinated and placebo groups. Updated search conducted July, 2000. No new trials were identified. REVIEWER'S CONCLUSIONS: There is not enough evidence to assess the benefits and risks of influenza vaccination for people with asthma.

Vaccines for preventing influenza in people with asthma.

BACKGROUND: Influenza vaccination is recommended for asthmatic patients in many countries as observational studies have shown that influenza infection can be associated with asthma exacerbations, but influenza vaccination itself has the potential to adversely affect pulmonary function. A recent overview concluded that there was no clear benefit of influenza vaccination in patients with asthma but this conclusions was not based on a systematic search of the literature. OBJECTIVES: Whilst influenza may cause asthma exacerbations, there is controversy about the use of influenza vaccinations, since they may precipitate an asthma attack in some people. The objective of this review was to assess the effects of influenza vaccination in children and adults with asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and checked reference lists of articles. SELECTION CRITERIA: Randomised trials of influenza vaccination in children (over two years of age) and adults with asthma. Studies involving people with chronic obstructive pulmonary disease were excluded. DATA COLLECTION AND ANALYSIS: Inclusion criteria and assessment of trial quality were applied by two reviewers independently. Data extraction was done by two reviewers independently. Study authors were contacted for missing information. MAIN RESULTS: Nine trials were included. Four of these trials were of high quality. One further article has been included since the previous version of this review. Inclusion of the new trial has not altered the conclusions of this review. The included studies covered a wide diversity of people, settings and types of influenza vaccination, so data from the different trials were not pooled. In one trial, no protective effect of influenza vaccination against asthma exacerbation was demonstrated, but the incidence of influenza was low during the study period. A higher number of asthma exacerbations following killed influenza vaccination was found in one trial (risk difference 3 1%, 95% confidence interval 0.3% to 5.8%). When people with upper respiratory tract infections were excluded, this difference was no longer significant. A small trial using recombinant vaccine found no significant difference in asthma exacerbations between the vaccinated and placebo groups. REVIEWER'S CONCLUSIONS: There is not enough evidence to assess the benefits and risks of influenza vaccination for people with asthma.

Caffeine for asthma.

BACKGROUND: Caffeine has a variety of pharmacological effects. It is chemically related to the drug theophylline which is used to treat asthma. Accordingly, interest has been expressed in its potential role as an asthma treatment. A number of studies have explored the effects of caffeine in asthma, this is the first review to systematically examine and summarise the evidence. OBJECTIVES: Caffeine is a weak bronchodilator and it also reduces respiratory muscle fatigue. It has been suggested that caffeine may reduce asthma symptoms. The objective of this review was to assess the effects of caffeine on lung function and identify whether there is a need to control for caffeine consumption prior to lung function testing. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and the reference lists of articles. We also contacted study authors. SELECTION CRITERIA: Randomised trials of oral caffeine compared to placebo in adults with asthma. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were done independently by two reviewers. MAIN RESULTS: Six trials involving a total of 55 people were included. The studies were all of cross-over design and of high quality. In comparison with placebo, caffeine appears to improve lung function for up to two hours after consumption. Forced expiratory volume in one minute showed a small improvement up to two hours after caffeine use (standardised mean difference -0.73, 95% confidence interval -1.20 to -0.25). Mid-expiratory flow rates also showed a small improvement with caffeine and this was sustained up to four hours. REVIEWER'S CONCLUSIONS: Caffeine appears to improve airways function modestly in people with asthma for up to four hours. People may need to avoid caffeine for at least four hours prior to lung function testing.