Bronchodilators delivered by nebuliser versus pMDI with spacer or DPI for exacerbations of COPD

BACKGROUND

Bronchodilators are a central component for treating exacerbations of chronic obstructive pulmonary disease (COPD) all over the world. Clinicians often use nebulisers as a mode of delivery, especially in the acute setting, and many patients seem to benefit from them. However, evidence supporting this choice from systematic analysis is sparse, and available data are frequently biased by the inclusion of asthma patients. Therefore, there is little or no formal guidance regarding the mode of delivery, which has led to a wide variation in practice between and within countries and even among doctors in the same hospital. We assessed the available randomised controlled trials (RCTs) to help guide practice in a more uniform way.

OBJECTIVES

To compare the effects of nebulisers versus pressurised metered dose inhalers (pMDI) plus spacer or dry powder inhalers (DPI) in bronchodilator therapy for exacerbations of COPD.

SEARCH METHODS

We searched the Cochrane Airways Group Trial Register and reference lists of articles up to 1 July 2016.

SELECTION CRITERIA

RCTs of both parallel and cross-over designs. We included RCTs during COPD exacerbations, whether measured during hospitalisation or in an outpatient setting. We excluded RCTs involving mechanically ventilated patients due to the different condition of both patients and airways in this setting.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data and assessed the risk of bias. We report results with 95% confidence intervals (CIs).

MAIN RESULTS

This review includes eight studies with a total of 250 participants comparing nebuliser versus pMDI plus spacer treatment. We identified no studies comparing DPI with nebulisers. We found two studies assessing the primary outcome of 'change in forced expiratory volume in one second (FEV1) one hour after dosing'. We could not pool these studies, but both showed a non-significant difference in favour of the nebuliser group, with similar frequencies of serious adverse events. For the secondary outcome, 'change in FEV1 closest to one hour after dosing': we found a significant difference of 83 ml (95% CI 10 to 156, P = 0.03) in favour of nebuliser treatment. For the secondary outcome of adverse events, we found a non-significant odds ratio of 1.65 (95% CI 0.42 to 6.48) in favour of the pMDI plus spacer group.

AUTHORS' CONCLUSIONS

There is a lack of evidence in favour of one mode of delivery over another for bronchodilators during exacerbations of COPD. We found no difference between nebulisers versus pMDI plus spacer regarding the primary outcomes of FEV1 at one hour and safety. For the secondary outcome 'change in FEV1 closest to one hour after dosing' during an exacerbation of COPD, we found a greater improvement in FEV1 when treating with nebulisers than with pMDI plus spacers.A limited amount of data are available (eight studies involving 250 participants). These studies were difficult to pool, of low quality and did not provide enough evidence to favour one mode of delivery over another. No data of sufficient quality have been published comparing nebulisers versus DPIs in this setting. More studies are required to assess the optimal mode of delivery during exacerbations of COPD.

Single inhaler budesonide/formoterol in exacerbations of chronic obstructive pulmonary disease

Inhaled bronchodilators, particularly short-acting inhaled beta(2)-agonists, and systemic glucocorticosteroids are effective treatments for acute exacerbations of chronic obstructive pulmonary disease (COPD). However, in the treatment of these episodes there may be some advantages to the longer-acting agents in that there will be prolonged bronchodilation. Moreover, high doses of systemic glucocorticosteroids are associated with a significant risk of side effects. In the last few years, evidence is mounting that nebulized budesonide and inhaled formoterol might be an alternative to oral prednisolone and short-acting beta(2)-agonists, respectively, in the treatment of acute exacerbations of COPD. Interestingly, some new data suggest that a combination therapy with single inhaler containing budesonide and formoterol may be an alternative to traditional therapy in the treatment of acute exacerbations of this disorder. However, since individual studies are typically statistically underpowered and are remarkably heterogeneous with regard to their conclusions, larger studies are needed to confirm these preliminary findings and determine conclusively any impact of budesonide/formoterol combination in acutely ill COPD patients.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

Effect of formoterol/budesonide combination on arterial blood gases in patients with acute exacerbation of COPD

BACKGROUND

Patients with severe chronic airway obstruction might suffer dangerous hypoxemia after administration of a beta-agonist despite bronchodilation.

METHODS

We first compared the acute effects on gas exchange of two doses of formoterol Turbuhaler (9 and 18 microg) in 10 patients with acute exacerbation of COPD. Afterwards, we compared the acute effects of formoterol Turbuhaler 9 microug with those of formoterol/budesonide combination in a single inhaler (Turbuhaler) 9/320 microg in 10 other patients with acute exacerbation of COPD. Finally, we compared the changes in PaO(2) induced by formoterol Turbuhaler 9 microg or formoterol/budesonide combination in a single inhaler (Turbuhaler) 9/320 microg with those in FEV(1) in 10 other patients with acute exacerbation of COPD. Each agent was given on separate days, and the patients' arterial blood gases were measured at baseline and at intervals of 120 min.

RESULTS

Small but statistically significant declines in PaO(2) were found after administration of both formoterol 9 and 18 microg. In the second group of patients, formoterol 9 microg alone again induced a significant decrease in PaO(2). However, the simultaneous administration of budesonide 320 microg significantly reduced the acute effect of formoterol on PaO(2). In a third group of 10 patients we confirmed a small but significant decrease in PaO(2) after formoterol alone and the reduction of this effect when budesonide was administered simultaneously. Moreover, we also documented that addition of budesonide amplified the fast onset of action of formoterol.

CONCLUSIONS

These results suggest that when treating patients suffering from acute exacerbation of COPD with formoterol, it is prudent to check their arterial blood gases. In any case, combined administration of formoterol and budesonide reduces the potential for acute effects of formoterol on blood-gas tensions.

[Dry powder inhalers in extreme clinical situations]

INTRODUCTION

Dry powder inhalers (DPIs) require a certain threshold of inspiratory effort to generate respirable particles. We undertook a literature review to determine whether this may, in particular clinical settings (young children, elderly subjects, acute or chronic respiratory obstructive syndromes - asthma and COPD), constitute a limitation on their use.

STATE OF THE ART

Currently marketed DPIs exhibit different technical characteristics. Many factors may influence their efficacy, so that the predictive utility of in vitro tests is limited. Published clinical studies indicate that aerosol therapies inhaled with DPIs show clinical efficacy even at low inspiratory air flows in adults and children with acute asthma, in acute bronchoconstriction experimentally provoked by methacholine or histamine, in acute asthma attacks in adults and children, and in COPD-related airway obstruction. The efficacy of DPIs appears comparable to that of p-MDIs or nebulisation. However, the studies often have some limitations (including limited statistical power and patient selection) that may affect their value.

PERSPECTIVES

The published studies analysed suggest that DPIs may be used in the great majority of clinical situations, subject to careful patient education. Nevertheless, p-MDIs with spacers remain recommended by international guidelines for children under the age of 6.

CONCLUSIONS

Additional well-designed clinical studies remain desirable to establish firmly the efficacy of DPIs in these situations.

A single high dose of formoterol is as effective as the same dose administered in a cumulative manner in patients with acute exacerbation of COPD

Several clinical trials have shown that the inhaled beta2-agonists with long-acting properties, formoterol and salmeterol, may be effective in acute exacerbations of chronic obstructive pulmonary disease (COPD). However, there is a great deal of controversy regarding the timing and optimal dose of inhaled beta2-agonists in this pathologic condition. In this double-blind, randomised, crossover study, we have compared the bronchodilating effect and the safety of inhaled formoterol administered via Turbuhaler using either a cumulative dose regimen or the equivalent single dose in 16 patients with acute exacerbations of COPD. On the two consecutive days, the patients received, in a randomised order, each of the following active dose regimens: (A): 9 + 9 + 18 microg of formoterol via Turbuhaler (36 microg cumulative delivered dose) or (B): 36 + 0 + 0 microg of formoterol via Turbuhaler. The three doses on each treatment day were administered at 30-mm intervals, with measurements being made 5 and 30 min after each dose. Contemporaneously, we also measured oxygen saturation by pulse oximetry (SpO2) and pulse rate. Both the high dose and the cumulative one induced a significant bronchodilation expressed as change in FEV1. The difference between the two regimens was significant (P=0.0332) only 60 min after the first inhalation. The trend of FVC and IC was similar to that of FEV1. All treatment regimens were well tolerated and no adverse events were reported. Neither the administration ofthe high dose nor that of the cumulative one modified heart rate in a significant manner. Also they did not influence SpO2. This study indicates that a single high dose offormoterol is as effective as the same dose administered in a cumulative manner in patients with acute exacerbation of COPD.

Acute effects of higher than customary doses of salmeterol and salbutamol in patients with acute exacerbation of COPD

Worsening of underlying bronchospasm may be associated with acute exacerbations of chronic obstructive pulmonary disease (COPD). As airway obstruction becomes more severe, the therapeutic option is to add salbutamol, but not salmeterol, as needed to cause rapid relief of bronchospasm. Unfortunately the most effective dosage of beta2-agonists may increase above that recommended during acute exacerbations. In this study, we compared the acute effects of higher than customary doses of salmeterol and salbutamol in 20 patients with acute exacerbation of COPD. A dose-response curve to salmeterol pMDI, 25 microg/puff or salbutamol pMDI, 100 microg/puff, was constructed using 1, 1, and 2 puff' i.e., a total cumulative dose of 100 microg salmeterol or 400 microg salbutamol on 2 consecutive days. After baseline measurements, dose increments were given at 30-min intervals with measurements being made 25 min after each dose. Hear rate (HR) and pulse-oximetry (SpO2) measurements were then taken. Both salmeterol and salbutamol induced a larg and significant (P < 0.05) dose-dependent increase in FEV1 [mean differences from baseline (L) = after 100 microg salmeterol 0.174 (95% CI: 0.112 to 0.237); after 400 microg salbutamol: 0.165 (95% CI: 0.080 to 0.249)], in IC [mean differences from baseline (L) = after 100 microg salmeterol: 0.332 (95% CI: 0.165 to 0.499); after 400 microg salbutamol: 0.281 (95% CI: 0.107 to 0.456)] (Fig. 2), and in FVC mean differences from baseline (L) = after 100 microg salmeterol: 0.224 (95% CI: 0.117 to 0.331); after 400 microg salbutamol: 0.242 (95% CI: 0.090 to 0.395)]. There was no significant difference between the FEV1 values (P=0.418), the ICvalues (P=0.585), and the FVCvalue (P=0.610) after 100 microg salmeterol and 400 microg salbutamol. HR [mean differences from baseline (beats/min) = after 100 microg salmeterol: 3.15 (95% CI: -0.65 to 6.96); after 400 microg salbutamol: 2.30 (95% CI: -0.91 to 5.51)] and SpO2 [mean differences from baseline (%) = after 100 microg salmeterol: -0.20 (95% CI: -1.00 to 0.60); after 400 microg salbutamol: -0.11 (95% CI: -1.00 to 0.79)] did not change significantly from baseline (P > 0.05). These data indicate that salmeterol is effective and safe in the treatment of acute exacerbation of COPD and support its use in this clinical condition.