Improvement of pressurised aerosol deposition with Nebuhaler spacer device

Optimal Inhalation Profile of Pressurized Metered Dry Powder Inhaler Using a Valved Holding Chamber: A Dynamic Analysis

Background: The combined use of a pressurized metered-dose inhaler and valved holding chamber (pMDI+VHC) is recommended to improve efficiency and safety; however, aerosol release is likely to vary with the inhalation maneuver. This in vitro study investigated the aerodynamic characteristics and aerosol release features of pMDI+VHC (Aerochamber, Trudell Medical International). Methods: The static and dynamic changes in the airway resistance (Raw) during inhalation (withdrawal) through pMDI+VHC were measured. Subsequently, the aerosol released from pMDI+VHC was measured using simplified laser photometry during withdrawal with either fast ramp-up then steady or slow ramp-up followed by gradual decrement at different intensities and times to peak flow (TPWF). Results: Raw increased linearly with changes in the withdrawal flow (WF) rate between 10 and 50 L/min. The slope was steep in the low WF range (<50 L/min) and became milder in the higher range. The aerosol mass tended to increase with an increase in the peak WF (PWF) of slow ramp-up profile. When three different WF increment slopes (TPWF: 0.4, 1.4, and 2.4 seconds) were compared, the released aerosol mass tended to decrease, and the aerosol release time was prolonged at longer TPWF. When the PWF was increased, the aerosol release time became shorter, and the withdrawn volume required for 95% aerosol release became larger; however, it did not exceed 0.4 L at suitable TPWF (0.4 seconds). Conclusion: Raw analysis suggests that inhalation at 30-50 L/min is suitable for pMDI+VHC in this setting. Rapid (TPWF, 0.4 seconds) inhalation, but not necessarily long (maximum 2.0 seconds) and deep (but larger than 0.55 L), is also recommended. Practically, direct inhalation to be weaker than usual breathing, as fast as possible, and far less than 2.0 seconds.

Dynamic Analysis of Aerosol Release from a Pressurized Metered Dose Inhaler Combined with a Valved Holding Chamber Using Simplified Laser Photometry

Background: A pressurized metered dose inhaler combined with a valved holding chamber (pMDI+VHC) is used to prevent upper airway complications and improve the efficiency of inhaled drug delivery; however, the aerodynamic behavior of the released particles has not been well investigated. This study aimed at clarifying the particle release profiles of a VHC using simplified laser photometry. Methods: An inhalation simulator comprised a computer-controlled pump and a valve system that withdrew aerosol from a pMDI+VHC using a jump-up flow profile. A red laser illuminated the particles leaving VHC and evaluated the intensity of the light reflected by the released particles. Results: The data suggested that the output (OPT) from the laser reflection system represented particle concentration rather than particle mass, and the latter was calculated as OPT × instantaneous withdrawn flow (WF). Summation of OPT hyperbolically decreased with flow increment, whereas summation of OPT × instantaneous flow was not influenced by WF strength. Particle release trajectories consisted of three phases, namely increment with a parabolic curve, flat, and decrement with exponential decay phases. The flat phase appeared exclusively at low-flow withdrawal. These particle release profiles suggest the importance of early phase inhalation. The hyperbolic relationship between WF and particle release time revealed the minimal required withdrawal time at an individual withdrawal strength. Conclusions: The particle release mass was calculated as laser photometric output × instantaneous flow. Simulation of the released particles suggested the importance of early phase inhalation and predicted the minimally required withdrawal time from a pMDI+VHC.

An Investigation into the Factors Associated with Incorrect Use of a Pressurized Metered-Dose Inhaler in Japanese Patients

Rationale: Inhalation of the correct dose of a short-acting beta 2 agonist (SABA) from a pressurized metered-dose inhaler (pMDI) is essential for the relief of symptoms in patients with asthma and/or chronic obstructive pulmonary disease. The aim of this study was to evaluate the prevalence and factors associated with the incorrect use of a pMDI. Methods: This study retrospectively assessed the electronic medical records of 161 patients with various respiratory diseases. The patients had never used a pMDI and underwent training by pharmacists educated in the use of a pMDI followed by bronchodilator reversibility testing at our hospital. The patients' characteristics and various lung capacity parameters were evaluated for association with the incorrect use of a pMDI. Results: Thirty-nine of the 161 (24.2%) patients, including 46% of 28 patients older than 80 years, used the pMDI incorrectly, mainly because of incoordination between activation of the device and inhalation (n = 11), inadequate strength to manipulate the device (n = 9), too short duration of inhalation (n = 6), and difficulty in breath holding (n = 3). Advanced age; lower height; and decreased lung volumes, including vital capacity (VC), inspiratory capacity, inspiratory reserve volume (IRV), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow rate, were associated with the incorrect use of a pMDI. Neither the body weight, tidal volume, expiratory reserve volume, %FVC predicted, %FEV1 predicted, nor FEV1% was associated with the incorrect use of a pMDI. Multivariate binomial logistic regression analysis identified decreased IRV as the only independent predictor associated with the incorrect use of a pMDI. Conclusions: Physicians should be aware that elderly patients or patients with decreased IRV might be unable to obtain the correct SABA dose from a pMDI. A large-scale prospective study is required to confirm these findings from our retrospective study with a small group of patients.

[Inhalation therapy in dogs and cats with chronic lower airway disease - a literature review]

Chronic respiratory diseases are prevalent medical conditions in dogs and cats requiring lifelong treatment. Mainstay of therapy for chronic inflammatory respiratory diseases are glucocorticoids. Concurrent treatment with bronchodilators may be necessary to control clinical signs sufficiently. Due to the successful use in people as well as subsequent reduction of adverse effects of long-term glucocorticoid therapy, inhalative therapy has become increasingly important in veterinary medicine as well. Primarily spacers or valved holding chambers, in combination with metered dose inhalers, are used in dogs and cats. The technical properties of these devices, as well as their use and maintenance will be described in the following article. Furthermore, the existing literature regarding efficacy of inhalative medications for therapy of chronic inflammatory airway diseases in dogs and cats will be summarized.

Application of aerosol therapy in respiratory diseases in children: A Saudi expert consensus

The Saudi Pediatric Pulmonology Association (SPPA) is a subsidiary of the Saudi Thoracic Society (STS), which consists of a group of Saudi experts with well-respected academic and clinical backgrounds in the fields of asthma and other respiratory diseases. The SPPA Expert Panel realized the need to draw up a clear, simple to understand, and easy to use guidance regarding the application of different aerosol therapies in respiratory diseases in children, due to the high prevalence and high economic burden of these diseases in Saudi Arabia. This statement was developed based on the available literature, new evidence, and experts' practice to come up with such consensuses about the usage of different aerosol therapies for the management of respiratory diseases in children (asthma and nonasthma) in different patient settings, including outpatient, emergency room, intensive care unit, and inpatient settings. For this purpose, SPPA has initiated and formed a national committee which consists of experts from concerned specialties (pediatric pulmonology, pediatric emergency, clinical pharmacology, pediatric respiratory therapy, as well as pediatric and neonatal intensive care). These committee members are from different healthcare sectors in Saudi Arabia (Ministry of Health, Ministry of Defence, Ministry of Education, and private healthcare sector). In addition to that, this committee is representing different regions in Saudi Arabia (Eastern, Central, and Western region). The subject was divided into several topics which were then assigned to at least two experts. The authors searched the literature according to their own strategies without central literature review. To achieve consensus, draft reports and recommendations were reviewed and voted on by the whole panel.

Regional Lung Deposition: In Vivo Data

The method section of this chapter on in vivo regional lung deposition highlights a nonradioactive method to measure regional deposition, which uses a photometer to quantify inhaled and exhaled particles and in that way is able to estimate the lung region from which the particles are exhaled and to what amount. The radioactive methods cover the measurement of clearance of the deposited particles as well as different imaging techniques to determine regional deposition. The result section reviews in vivo trials in human subjects. It also addresses different parameters that influence the regional deposition in the lungs: particle size, inhalation maneuver, carrier gas, disease, and inhalation device. All of these factors can affect regional deposition significantly. By choosing specific values of these parameters, it should be feasible to target different regions of the lungs for the therapy of different diseases.

[Physical and Clinical Aspects of Inhalation Therapy for Asthma and COPD]

Physical and Clinical Aspects of Inhalation Therapy for Asthma and COPD Abstract. Inhalations form the basis of the medicinal treatment of respiratory diseases. In recent years, therapy has become more complex for patients, but also for medical professionals, as new systems have come onto the market. The knowledge required for this shall be conveyed in this article.

Knowledge of spacer device, peak flow meter and inhaler technique (MDIs) among health care providers: an evaluation of doctors and nurses

Background

Metered dose inhalers are cornerstone in effective management of bronchial asthma when correctly used. Most studies hitherto have focused on assessing patient's knowledge of inhaler technique. We sought to assess the knowledge of inhaler technique, spacer device and peak flow meter among doctors and nurses in a tertiary healthcare institution in Nigeria.

Method

A cross sectional survey of nurses and doctors from emergency department, family and internal medicine; who were attending a continuous professional development lecture, was carried out. From a total of 100 questionnaires administered, we retrieved 87 of which 75 were completed, giving a response rate of 75%. It was a self-administered questionnaire. Data was analysed with SPSS version 21.0. Descriptive statistics were done. Association was examined using chi-square test.

Result

Mean age of respondent was 35.8 years ± 8.7, 47(62.7%) were < 40 years, 33(44%) were male, nurses were 30(40.0%). Only 28(37.3%) had ever used a peak flow meter. Only 4(14.3%) used peak flow meter frequently, while 12(26.7%) checked patient's inhaler technique often. Only 9 out of the 75 (12%) participants all of who are doctors knew at least 3 essential steps of the techniques in using the metered dose inhaler correctly. None of the participants got all the steps for the use of pMDI totally correct.

Conclusion

Knowledge regarding the use of the metered dose inhaler and spacer device was poor. Health practitioners should have constant reminders in the form of continuous medical education to update their knowledge regarding correct inhaler technique.

Funding

self-funded.

Optimizing the Delivery of Inhaled Medication for Respiratory Patients: The Role of Valved Holding Chambers

Valved holding chambers (VHCs) have been used with pressurized metered-dose inhalers since the early 1980s. They have been shown to increase fine particle delivery to the lungs, decrease oropharyngeal deposition, and reduce side effects such as throat irritation, dysphonia, and oral candidiasis that are common with use of pressurized metered-dose inhalers (pMDIs) alone. VHCs act as aerosol reservoirs, allowing the user to actuate the pMDI device and then inhale the medication in a two-step process that helps users overcome challenges in coordinating pMDI actuation with inhalation. The design of VHC devices can have an impact on performance. Features such as antistatic properties, effective face-to-facemask seal feedback whistles indicating correct inhalation speed, and inhalation indicators all help improve function and performance, and have been demonstrated to improve asthma control, reduce the rate of exacerbations, and improve quality of life. Not all VHCs are the same, and they are not interchangeable. Each pairing of a pMDI device plus VHC should be considered as a unique delivery system.

A review of the in vitro and in vivo valved holding chamber (VHC) literature with a focus on the AeroChamber Plus Flow-Vu Anti-static VHC

Valved holding chambers (VHCs) reduce the need for inhalation-actuation coordination with pressurized metered dose inhalers (pMDIs), reduce oropharyngeal drug deposition and may improve lung deposition and clinical outcomes compared to pMDIs used alone. While VHCs are thus widely advocated for use in vulnerable patient groups within clinical and regulatory guidelines, there is less consensus as to whether the performance differences between different VHCs have clinical implications. This review evaluates the VHC literature, in particular the data pertaining to large- versus small-volume chambers, aerosol performance with a VHC adjunct versus a pMDI alone, charge dissipative/conducting versus non-conducting VHCs, and facemasks, to ascertain whether potentially meaningful differences between VHCs exist. Inconsistencies in the literature are examined and explained, and relationships between in vitro and in vivo data are discussed. A particular focus of this review is the AeroChamber Plus® Flow-Vu® Anti-static VHC, the most recent iteration of the AeroChamber VHC family.

Nebulizer versus Inhaler with Spacer for Beta-Agonist Treatment in Acute Bronchospastic Disease

Objectives

To compare the efficacy of nebulized wet aerosol with metered-dose inhaler with a spacer (MDIS) in the management of acute bronchospasm.

Methods

It was a retrospective study by reviewing the clinical records of patients with acute exacerbation (chief complaint of shortness of breath) of asthma or chronic obstructive pulmonary disease (COPD) presenting to the Accident and Emergency Department (AED) of Tuen Mun Hospital from 1st to 30th November 2002 and 2003 respectively. All patients received beta-agonist by nebulizer, in the year 2002 (pre-SARS period) while all patients received treatment by MDIS in the year 2003 (post-SARS period). Treatment outcome measures included admission rate, length of hospitalisation for those admitted and AED re-attendance within 7 days for those discharged from the AED.

Results

Altogether 821 patients were recruited in this retrospective study, 522 belonged to the nebulizer group and 299 were of the MDIS group. The two groups had similar demographic characteristics. Concerning the admission rate (47% in the nebulizer group and 41% in the MDIS group; p=0.089) and re-attendance rate (7% in the nebulizer group and 6% in the MDIS group; p=0.607), the differences were not statistically significant. For the length of hospital stay, it was shorter in the nebulizer group than the MDIS group (3.65±SD 1.88 days vs 4.10±SD 1.94 days; p=0.035). However, the admission rate in the adult subgroup (61% in the nebulizer group and 47% in the MDIS group; p=0.002) was shown to be statistically significant. In multivariate analysis, usage of nebulizer, increase in respiratory rate and age were associated with a higher admission rate. Increase in SpO2, absence of co-morbidity and asthma patients were associated with a lower admission rate. Increase in age, respiratory rate and usage of MDIS were associated with an increase in hospital stay. Asthma was associated with a decrease in AED re-attendance rate as compared to COPD.

Conclusions

This retrospective study showed that both nebulizer and MDIS were effective for beta-agonist therapy in acute bronchospasm in AED with respect to hospital admission rate and AED re-attendance rate, but the length of hospital stay was slightly prolonged when using MDIS.

In vitro characterization of the OptiChamber Diamond valved holding chamber

BACKGROUND

Use of a valved holding chamber (VHC) in conjunction with a pressurized metered dose inhaler (pMDI) can reduce issues relating to poor actuation-inhalation coordination and potentially improve the lung deposition of aerosol, compared with use of a pMDI alone. However, the performance of a VHC is influenced by different device-related factors, including the size and shape of the VHC and the material it is manufactured from (conventional versus antistatic). This study aimed to provide an in vitro characterization of an antistatic VHC, the OptiChamber Diamond VHC, comparing the aerodynamic particle size distribution of aerosol delivered via this VHC with results from a second antistatic VHC and a conventional VHC.

METHODS

The pMDI drug formulations (albuterol, suspension; beclomethasone dipropionate, solution) were connected to a Next Generation Impactor, either directly (pMDI alone tests) or via a VHC (VHC tests). The pMDIs were actuated (×10 per product pair) and tested at extraction flow rates of 15 L/min and 30 L/min, without any time delay between actuation and inhalation. Dose delivery using the two pMDI drug formulations was compared, and is presented with reference to key aerodynamic particle size parameters.

RESULTS

Compared with tests on pMDIs alone, use of a VHC increased the dose of aerosol within the respirable range, particularly at a 15 L/min flow rate. Between-VHC comparisons indicated that the two antistatic VHCs were equivalent. Delivery of albuterol appeared to be influenced by the VHC used, but beclomethasone dipropionate seemed unaffected.

CONCLUSIONS

The two antistatic VHCs were equivalent for both pMDI brands. Aerosol delivered from the antistatic VHCs at 15 L/min had a higher proportion of fine particles compared with the conventional VHC.

The evolution of spacers and valved holding chambers

Spacers and valved holding chambers (VHCs) are pressurized metered dose inhaler (pMDI) accessory devices, designed to overcome problems that patients commonly experience when administering aerosol via a pMDI. Spacers were developed in direct response to patient-related issues with pMDI technique, particularly, poor coordination between actuation and inhalation, and local side-effects arising from oropharyngeal deposition. Current clinical guidelines indicate the need for widespread prescription and use of spacers, but, despite their apparent ubiquity, the devices themselves are, unfortunately, all too commonly "disused" by patients. An understanding of the background from which spacers developed, and the key factors influencing the optimization of the spacer and the later VHC, is crucial to developing an appreciation of the potential of these devices, both contemporary and future, for improving the delivery of pressurized aerosols to patients. This review, informed by a full patent search and an extensive scientific literature review, takes into account the clinical and laboratory evidence, commercial developments, and the sometimes serendipitous details of scientific anecdotes to form a comprehensive perspective on the evolution of spacers, from their origins, in the early days of the pMDI, up to the present day.

In vitro comparison of the effect of inhalation delay and flow rate on the emitted dose from three valved holding chambers

BACKGROUND

Valved holding chambers (VHCs) are accessory devices for pressurized metered dose inhalers (pMDIs). Use of a VHC may help overcome coordination issues associated with drug delivery via the pMDI alone. Previous work has established that aspects of VHC use, including the time between actuation and inhalation (inhalation delay) and inhalation flow rate, can influence the amount of drug available to inhalation. This study compared the impact of inhalation delay and flow rate on the in vitro delivery of aerosol from different VHC brands.

METHODS

A custom-built inhalation delay test rig, which enabled automation of controlled inhalation delays (0, 5, or 10 sec), was developed. Extraction air flow was set to 5, 15, or 30 L/min. Delivery of albuterol (ProAir HFA 90 μg) to a filter (emitted dose) was assessed using three commercially available VHC brands (one conventional, two antistatic). Emitted dose under 27 different combinations of inhalation delay, flow rate, and VHC brand was determined in order to assess the effects of inhalation delay and flow rate. Pairwise comparisons of the different VHC brands with different inhalation delay/flow rate combinations were conducted to assess in vitro equivalence.

RESULTS

Emitted dose increased with flow rate and decreased with longer inhalation delays. Dependence on flow rate was similar for the two antistatic VHCs and more pronounced for the conventional VHC. The two antistatic VHCs showed equivalent results for the emitted dose of albuterol, across a range of flow rates and using different inhalation delays; the relation between the two antistatic VHCs fell within the ± 15% acceptance interval criteria for in vitro equivalence.

CONCLUSIONS

The different inhalation delays and flow rates had similar effects on the delivery of drug via the three VHCs. The two antistatic VHCs were shown to be equivalent in vitro in terms of emitted dose of albuterol.

Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma

BACKGROUND

In acute asthma inhaled beta(2)-agonists are often administered by nebuliser to relieve bronchospasm, but some have argued that metered-dose inhalers with a holding chamber (spacer) can be equally effective. Nebulisers require a power source and need regular maintenance, and are more expensive in the community setting.

OBJECTIVES

To assess the effects of holding chambers (spacers) compared to nebulisers for the delivery of beta(2)-agonists for acute asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Trial Register and reference lists of articles. We contacted the authors of studies to identify additional trials. Date of last search: February 2013.

SELECTION CRITERIA

Randomised trials in adults and children (from two years of age) with asthma, where spacer beta(2)-agonist delivery was compared with wet nebulisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied study inclusion criteria (one review author for the first version of the review), extracted the data and assessed risks of bias. Missing data were obtained from the authors or estimated. Results are reported with 95% confidence intervals (CIs).

MAIN RESULTS

This review includes a total of 1897 children and 729 adults in 39 trials. Thirty-three trials were conducted in the emergency room and equivalent community settings, and six trials were on inpatients with acute asthma (207 children and 28 adults). The method of delivery of beta(2)-agonist did not show a significant difference in hospital admission rates. In adults, the risk ratio (RR) of admission for spacer versus nebuliser was 0.94 (95% CI 0.61 to 1.43). The risk ratio for children was 0.71 (95% CI 0.47 to 1.08, moderate quality evidence). In children, length of stay in the emergency department was significantly shorter when the spacer was used. The mean duration in the emergency department for children given nebulised treatment was 103 minutes, and for children given treatment via spacers 33 minutes less (95% CI -43 to -24 minutes, moderate quality evidence). Length of stay in the emergency department for adults was similar for the two delivery methods. Peak flow and forced expiratory volume were also similar for the two delivery methods. Pulse rate was lower for spacer in children, mean difference -5% baseline (95% CI -8% to -2%, moderate quality evidence), as was the risk of developing tremor (RR 0.64; 95% CI 0.44 to 0.95, moderate quality evidence).

AUTHORS' CONCLUSIONS

Nebuliser delivery produced outcomes that were not significantly better than metered-dose inhalers delivered by spacer in adults or children, in trials where treatments were repeated and titrated to the response of the participant. Spacers may have some advantages compared to nebulisers for children with acute asthma.

Inappropriate home albuterol use during an acute asthma exacerbation

BACKGROUND

Increased asthma morbidity and mortality is associated with inappropriate home self-management skills.

OBJECTIVES

To examine the proportion of children presenting to the emergency department (ED) with an acute asthma exacerbation with incorrect home use of their albuterol inhaler and to identify factors associated with improper treatment.

METHODS

Caregivers of children with asthma aged 4 to 14 years, presenting to the ED with an asthma exacerbation, participated in the study. Interviewers collected caregiver's perceived severity of the asthma exacerbation and home albuterol use before the ED visit. National Asthma Education and Prevention Program guidelines were used to classify home albuterol use as appropriate or inappropriate.

RESULTS

Home albuterol use for the current asthma exacerbation was categorized as inappropriate (56 [68%]) and appropriate (26 [32%]) for 84 participants. Thirty-nine of the inappropriate group undertreated, with 24 not giving albuterol frequently enough and 15 without albuterol at home. Other reasons for incorrect home albuterol use included: no spacer, overtreating, overreacting, and using a controller medicine for quick relief. Those with appropriate albuterol use were more likely to have their child hospitalized for asthma in the past 48 months (P=.004). Caregivers with inappropriate use perceived their child's asthma exacerbation as more severe (P<.001) compared with physician rating. Physicians rated asthma severity higher in the appropriate group than the inappropriate group (P<.001).

CONCLUSION

A significant proportion of caregivers incorrectly treat children's asthma exacerbation with albuterol. Despite perceiving their children's asthma exacerbations as more severe, most undertreat with albuterol. Correctly assessing asthma symptom severity and appropriate home albuterol use may be linked to disease experience.

Comparison of a Multidose Powder Inhaler Containing Beclomethasone Dipropionate (BDP) with a BDP Metered Dose Inhaler with Spacer in the Treatment of Asthmatic Patients

OBJECTIVE

The clinical efficacy, tolerability and acceptability of a new multidose powder inhaler (MDPI) [Easyhaler((R)), Orion Pharma, Finland] containing a high dose (500 microg/dose) of beclomethasone dipropionate (BDP) were compared with those of BDP metered dose inhaler administered with a large volume spacer (MDI-spacer).

PATIENTS AND STUDY DESIGN

Recruited patients were adult asthmatics currently receiving 800 to 1000 microg/day of inhaled corticosteroid. The dose of BDP during the study was 1000 mg/day. The study was an open, randomised, parallel-group multicentre study and included a 2-week run-in period followed by a 12-week treatment period.

RESULTS

74 patients were randomised to both groups. During the run-in period the mean morning peak expiratory flow (PEF) was 489 and 478 L/min in the MDPI and MDI-spacer groups, respectively. During the last 2 weeks of the study the morning PEF was 485 L/min in the MDPI group and 477 L/min in the MDI-spacer group. Asthma symptom scores and use of rescue medication were low in both groups. The median dose of histamine required to decrease forced expiratory volume in 1 second (FEV(1)) by 15% was 1.05mg in the MDPI group and 0.64mg in the MDI-spacer group. The most frequent adverse events were hoarseness and sore throat. Mean serum cortisol levels were not affected in either treatment group. Patients' personal opinion regarding acceptability of the devices clearly favoured the MDPI.

CONCLUSION

In conclusion, the novel powder inhaler was well tolerated and at least equally effective compared with the conventional MDI-spacer combination in the treatment of asthma with BDP. However, in everyday use the patients clearly favoured the powder inhaler.

Spirometry with bronchodilator test: effect that the use of large-volume spacers with antistatic treatment has on test response

OBJECTIVE

To evaluate whether the use of inhaled albuterol via a metered-dose inhaler with a large-volume spacer with antistatic treatment modifies the bronchodilator test results when compared with the usual technique (no spacer).

METHODS

A prospective study involving 24 patients, 18-45 years of age, clinically suspected of having asthma, and under treatment at the Outpatient Pulmonary Clinic of the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. All of the patients underwent two bronchodilator tests: one with and one without the use of a large-volume spacer.

RESULTS

There was no significant difference in the variation of FEV1 prior to and after bronchodilator use between the two techniques (mean ΔFEV1 = 0.01 L; 95% CI: -0.05 to 0.06; p = 0.824). No statistically significant difference was found between the two techniques regarding the qualitative results on the bronchodilator test (p = 1.00). There was concordance between the techniques in terms of the bronchodilator test results (kappa coefficient = 0.909; p < 0.005).

CONCLUSIONS

According to the results of this study, the use of large-volume spacers does not significantly modify bronchodilator test results.

The Bioavailability of Salbutamol in Urine via Volumatic and Nonvolumatic Valved Holding Chambers

Purpose

Pressurized metered dose inhalers are commonly used in patients with asthma. However, the need to coordinate inhalation with inhaler actuation means that they are not suitable for use per se. Valved holding chamber devices were developed to overcome some of the problems of pressurized metered dose inhalers. Several types of holding chambers of different sizes are available in Iran. This study was designed to compare the effects of 2 commonly used valved holding chambers (Asthm Yar and Dam Yar) in Iran on bioavailability of salbutamol spray and also spirometric parameters in asthmatic patients.

Methods

This was a comparative experimental crossover study. Patients with mild to moderate asthma were entered in this study. Lung function was assessed using a portable spirometer (Spirolab, Progetti, Italy). Spirometric parameters of forced expiratory flow (FEF)_50%, FEF_25–75%, peak expiratory flow (PEF), forced expiratory volume in the first second of expiration (FEV₁), forced vital capacity (FVC), and FEV₁/FVC were measured. Urinary concentration of salbutamol as an index of pulmonary bioavailability was assayed with high-performance liquid chromatography.

Results

Forty patients (25 women and 15 men) with the mean age of 43.10 ± 12.99 years were studied. Mean ± SD changes of spirometric parameters before and after using Asthm Yar were not significantly different from those of Dam Yar. The relative bioavailability after inhalation with Asthm Yar was significantly higher than after inhalation with Dam Yar (P = 0.002).

Conclusions

Although the results indicate that relative bioavailability to the lung after inhalation with Asthm Yar was significantly higher than after inhalation with Dam Yar, its clinical importance should be tested.

Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone.

The risk for AS can be minimized through increased awareness and early recognition of at-risk patients, regular patient follow-up to ensure that the lowest effective ICS doses are being utilized to control asthma symptoms, and by choosing an ICS medication with minimal adrenal effects. Screening for AS should be considered in any child with symptoms of AS, children using high ICS doses, or those with a history of prolonged oral corticosteroid use. Cases of AS should be managed in consultation with a pediatric endocrinologist whenever possible. In patients with proven AS, stress steroid dosing during times of illness or surgery is needed to simulate the protective endogenous elevations in cortisol levels that occur with physiological stress.

This article provides an overview of current literature on AS as well as practical recommendations for the prevention, screening and management of this serious complication of ICS therapy.

Salbutamol relative lung and systemic bioavailability of large and small spacers

Differences between the size and shape of spacers may affect the emitted dose and provide different effects when interchanged during routine use. Using a urinary pharmacokinetic method we have measured the relative lung and systemic bioavailability from urinary salbutamol excretion 30 min (USAL0.5) and 24 h (USAL24), respectively, after the inhalation of two 100-μg doses from a Ventolin Evohaler when used alone (MDI) and when attached to the Volumatic (VOL) or the Aerochamber Plus (AERO) spacers. The in-vitro properties of the emitted dose were determined. The mean (s.d.) USAL0.5 values following MDI, VOL and AERO (n = 13 volunteers) were 5.7 (1.9), 16.4 (8.2) and 14.8 (7.4) μg, respectively. VOL and AERO were significantly greater (P &lt; 0.001 and &lt; 0.01, respectively) than MDI. Comparison of VOL and AERO was similar with a mean ratio (90% confidence interval) of 108.2 (84.5, 138.6)%. USAL24 values between the three inhalation methods were similar. The values for the mean (s.d.) fine particle dose of two 100-μg doses emitted from MDI, VOL and AERO were 83.0 (6.8), 83.6 (4.6) and 73.6 (2.9) μg and the mass median aerodynamic diameters were 2.7 (0.03), 2.8 (0.07) and 2.9 (0.10) μm, respectively. The results showed that during routine use the Volumatic and the Aerochamber Plus spacers should provide similar lung and systemic delivery when attached to a Ventolin Evohaler.

Safety of daily albuterol in infants with a history of bronchospasm: a multi-center placebo controlled trial

Introduction:

Inhaled short-acting bronchodilators are recommended for the quick relief of bronchospasm symptoms in children including those less than five years of age. However, limited safety data is available in this young population.

Methods:

Safety data were analyzed from a randomized, double-blind, parallel group, placebo-controlled multicenter, study evaluating albuterol HFA 90µg or 180µg versus placebo three times a day for 4 weeks using a valved holding chamber, Aerochamber Plus and facemask in children birth ≤24 months old with a history of bronchospasm.

Results:

The overall incidence of adverse events (AE) during treatment was: albuterol 90µg (59%), albuterol 180µg (76%) and placebo (71%). The most frequently reported AEs were pyrexia in 7 (24%), 2 (7%), and 3 (11%) subjects in the albuterol 180µg, albuterol 90µg, and placebo groups, respectively. Upper respiratory tract infection (URTI) occurred in 5 (17%) and 3 (11%) subjects in the albuterol 180µg and placebo groups, respectively. Sinus tachycardia occurred in 5 (17%), 2 (7%) and 2 (7%) subjects receiving albuterol 180µg, albuterol 90µg and placebo, respectively. One subject in each of the albuterol treatment groups experienced drug related agitation and/or restlessness or mild sinus arrhythmia. No drug-related QT prolongation or abnormal serum potassium and glucose levels were reported in the albuterol treatment groups.

Conclusion:

This study provides additional albuterol HFA safety information for the treatment of children aged birth ≤24 months with a history of bronchospasm.

Oropharyngeal candidiasis with dry-powdered fluticasone propionate: 500 microg/day versus 200 microg/day

We aimed to determine the frequency of oropharyngeal candidiasis and its clinical correlates in the asthmatic patients who use fluticasone propionate (FP) as a dry powdered inhaler. We selected four groups of patients: 62 asthmatic patients who were taking 200 microg/d FP, 122 asthmatics who were taking 500 microg/d FP, 50 asthmatic patients who had not been on inhaled corticosteroid (ICS) treatment and 40 normal non-asthmatic subjects. The frequency of positive swabs for Candida colonization was higher in 500 microg/d FP group than asthmatics without ICS use (chi2 = 6.8, p < 0.05) and normal controls (chi2 = 4.9, p < 0.05), whereas it wasn't different in the 200 microg/day FP group when compared to controls. When we considered patients who used ICS, the most effective variables affecting the occurrence of Candida colonization were washing of the throat by the patients (OR = 9.4, 95 % Confidence Interval [CI] = 3.9-22.7, p < 0.0001) and duration of ICS use more than 12 months (OR = 2.5, 95 % CI = 1.1-2.6, p < 0.05). The present study showed that in the patients who use ICS, the most important determinants on colonization were not washing the throat regularly and duration of ICS use for more than 12 months.

Hypothalamic-pituitary-adrenal axis suppression in asthmatic children on inhaled corticosteroids (Part 2)--the risk as determined by gold standard adrenal function tests: a systematic review

The evidence for hypothalamic-pituitary-adrenal axis (HPA) suppression by inhaled corticosteroids (ICS) was found to be conflicting. Reviewers have not distinguished between gold standard and basal adrenal function tests. The utility of the latter is limited by physiological and pathological variability as well as by methodological concerns. The risk of HPA suppression in asthmatic children and adolescents treated with ICS, as determined by gold standard adrenal function tests, needs to be established. A systematic review of the literature from January 1973 to July 2005 was performed. The Medline and Cochrane databases were searched, the reference lists of retrieved articles were inspected and pharmaceutical companies were approached. Randomized-controlled trials, cohort and case-control studies designed to detect HPA suppression caused by ICS, diagnosed by the insulin tolerance test (ITT) or the metyrapone test, performed on asthmatics of all ages not on oral steroids, were included and assessed for methodological quality. Of the 22 identified studies only four met the criteria for inclusion. All of these were published before 1988 and only one was methodologically sound. The cohort study showed that the baseline risk for HPA suppression is 0% while the absolute risk is 100% in asthmatic children treated with a beclomethasone dipropionate metered dose inhaler at a dose of 250-600 mug/m(2)/day for 6-42 months. As suggested by other observations these results could be generalized to other ICS. They may be of clinical significance especially if children are subjected to stress. Further research is needed to establish the cumulative dose for all ICS at which HPA suppression will be precipitated. Guidelines for future trials are suggested.

Aerosol therapy: the special needs of young children

Efficient aerosol therapy in young children is a challenge. The aerosol administration method requires special features, because young children can not perform an inhalation manoeuvre, breath usually through the nose and may be distressed during the administration. The prescribing clinician should be aware of the advantages and disadvantages of the different inhalation devices available, in order to select the proper device for each individual patient. For maintenance asthma therapy in young children the pressurized metered dose inhaler (pMDI) combined with spacer is the first choice for delivering aerosols. A facemask can be attached if a child is unable to breath through the mouth. A small leak of the facemask can reduce the dose delivered dramatically, therefore a good seal is crucial. Lung deposition can be improved by using a pMDI with extra-fine particles. However, even if the most optimal device is chosen, cooperation during administration remains the most important determinant for efficient drug delivery. During crying the dose to the lungs is minimal. Optimal aerosol delivery to the lungs of young children can be achieved with a good facemask seal, good cooperation of the child, with quiet breathing and an aerosol with small particles.

High-dose inhaled fluticasone does not replace oral prednisolone in children with mild to moderate acute asthma

BACKGROUND

Inhaled corticosteroids are not as effective as oral corticosteroids in school-aged children with severe acute asthma. It is uncertain how inhaled corticosteroids compare with oral corticosteroids in mild to moderate exacerbations.

PRIMARY OBJECTIVE

The purpose of this work was to determine whether there is a significant difference in the percentage of predicted forced expiratory volume in 1 second in children with mild to moderate acute asthma treated with either inhaled fluticasone or oral prednisolone.

METHODS

This was a randomized, double-blind controlled trial conducted between 2001 and 2004 in a tertiary care pediatric emergency department. We studied a convenience sample of 69 previously healthy children 5 to 17 years of age with acute asthma and forced expiratory volume in 1 second at 50% to 79% predicted value; 41 families refused participation. Albuterol was given in the emergency department and salmeterol was given after discharge to all patients, as well as either 2 mg of fluticasone via metered dose inhaler and valved holding chamber in the emergency department plus 500 microg twice daily via Diskus for 10 doses after discharge (fluticasone group, N = 35) or 2 mg/kg of oral prednisolone in the emergency department plus 5 daily doses of 1 mg/kg of prednisolone after discharge (prednisolone group, N = 34). We measured a priori defined absolute change in percent predicted forced expiratory volume in 1 second from baseline to 4 and 48 hours in the 2 groups. RESULTS. At 240 minutes, the forced expiratory volume in 1 second increased by 19.1% +/- 12.7% in the fluticasone group and 29.8% +/- 15.5% in the prednisolone group. At 48 hours, this difference was no longer significant (estimated difference: 4.0 +/- 3.4; P = .14). The relapse rates by 48 hours were 12.5% and 0% in the fluticasone group and prednisolone group, respectively.

CONCLUSION

Airway obstruction in children with mild to moderate acute asthma in the emergency department improves faster on oral than inhaled corticosteroids.

Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma

BACKGROUND

In acute asthma inhaled beta2-agonists are often administered to relieve bronchospasm by wet nebulisation, but some have argued that metered-dose inhalers with a holding chamber (spacer) can be equally effective. Nebulisers require a power source and need regular maintenance, and are more expensive in the community setting.

OBJECTIVES

To assess the effects of holding chambers (spacers) compared to nebulisers for the delivery of beta2-agonists for acute asthma.

SEARCH STRATEGY

We last searched the Cochrane Airways Group trials register in January 2006 and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 4, 2005).

SELECTION CRITERIA

Randomised trials in adults and children (from two years of age) with asthma, where spacer beta2-agonist delivery was compared with wet nebulisation.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied study inclusion criteria (one reviewer for the first version of the review), extracted the data and assessed trial quality. Missing data were obtained from the authors or estimated. Results are reported with 95% confidence intervals (CI).

MAIN RESULTS

This review has been updated in January 2006 and four new trials have been added. 2066 children and 614 adults are now included in 25 trials from emergency room and community settings. In addition, six trials on in-patients with acute asthma (213 children and 28 adults) have been reviewed. Method of delivery of beta2-agonist did not appear to affect hospital admission rates. In adults, the relative risk of admission for spacer versus nebuliser was 0.97 (95% CI 0.63 to 1.49). The relative risk for children was 0.65 (95% CI: 0.4 to 1.06). In children, length of stay in the emergency department was significantly shorter when the spacer was used, with a mean difference of -0.47 hours (95% CI: -0.58 to -0.37). Length of stay in the emergency department for adults was similar for the two delivery methods. Peak flow and forced expiratory volume were also similar for the two delivery methods. Pulse rate was lower for spacer in children, mean difference -7.6% baseline (95% CI: -9.9 to -5.3% baseline).

AUTHORS' CONCLUSIONS

Metered-dose inhalers with spacer produced outcomes that were at least equivalent to nebuliser delivery. Spacers may have some advantages compared to nebulisers for children with acute asthma.

Assessment of different methods of inhalation from salbutamol metered dose inhalers by urinary drug excretion and methacholine challenge

AIMS

Methods to determine the lung delivery of inhaled bronchodilators from metered dose inhalers include urinary drug excretion 30 min post inhalation and methacholine challenge (PD20). We have compared these two methods to differentiate lung delivery of salbutamol from metered dose inhalers using different inhalation methods.

METHODS

In phase 1 of the study, on randomized study days, 12 mild asthmatics inhaled placebo, one and two 100 microg salbutamol doses from a breath actuated metered dose inhaler, in randomized fashion on different days. In phase 2, they inhaled one 100 microg salbutamol dose from a metered dose inhaler using a SLOW (20 l min(-1)) and a FAST (60 l min(-1)) inhalation technique and a slow inhalation delayed until after they had inhaled for 5 s (LATE). Urinary excretion of salbutamol (0-30 min) and PD20 were measured after each dose.

RESULTS

Following placebo, one and two 100 microg salbutamol doses, the geometric mean for PD20 was 0.10, 0.41 and 0.86 mg respectively and the mean (SD) urinary drug excretion after one and two doses was 2.25 (0.65) and 5.37 (1.36) microg, respectively. After SLOW, FAST and LATE inhalations the geometric mean for PD20 was 0.50, 0.40 and 0.42 mg, respectively, and mean (SD) salbutamol excretion was 2.67 (0.84), 1.90 (0.70) and 2.72 (0.67) microg, respectively. Only the amount of drug excreted during the FAST compared with the SLOW and LATE inhalations showed a statistical difference (95% confidence interval on the difference 0.12, 1.54 and 0.06, 1.59 microg, respectively).

CONCLUSIONS

Urinary salbutamol excretion but not PD20 showed differences between the inhalation methods used. When using a metered dose inhaler slow inhalation is better and co-ordination is not essential if the patient is inhaling when they actuate a dose of the drug.

Inhaled Beclomethasone Dipropionate Acutely Stimulates Dose-Dependent Growth Hormone Secretion in Healthy Subjects

STUDY OBJECTIVES

It is well known that systemic administration of corticosteroids has a dual effect on growth hormone (GH) secretion in man: acute systemic administration stimulates GH release, whereas chronic administration consistently blocks it. In this study, we evaluate whether administration of inhaled corticosteroids could acutely stimulate GH secretion, and whether this effect could be dose related.

DESIGN

Double-blind, placebo-controlled, crossover study.

PARTICIPANTS

Eight normal male volunteers all recruited at our institution.

INTERVENTIONS

Administration of increasing doses of inhaled beclomethasone dipropionate (BDP; range, 50 to 1,500 mug) or placebo.

MEASUREMENTS AND RESULTS

Blood samples for GH determinations were collected at - 15, 0, 60, 120, 180, 240, 300, and 360 min in relation to BDP or placebo administration. The results of this study show a peak GH secretion at 240 min after the administration of BDP at doses > 100 microg. The comparisons among the peaks obtained with increasing doses showed a dose-response effect on GH secretion, starting from 100 to 1,000 microg. BDP 1,500 microg did not induce a peak significantly different from that obtained with 1,000 microg. When we calculated the GH response to BDP as an area under the curve (micrograms per liter x 6 h), the data confirmed that GH secretion was elicited in a dose-related manner.

CONCLUSIONS

Our data show that inhaled BDP at dose > 100 microg acutely stimulates GH secretion in a strictly dose-dependent manner. We propose this test as a surrogate for systemic absorption and as a valuable test to compare systemic effects among different inhaled steroids.

Effect of high-dose fluticasone propionate on bone density and metabolism in children with asthma

Significant concern remains over the long-term side effects of inhaled steroids. This cross-sectional study evaluates the effect of high-dose inhaled fluticasone propionate (FP) on biochemical markers of bone metabolism and bone density in children with asthma. Children with chronic asthma using FP >/= 1,000 mcg daily for at least 6 months, and healthy controls, were entered in the study. No children had taken oral prednisolone within the previous month. Fasting morning serum was analyzed for bone formation markers, and spot urine for bone resorption markers. Dual-energy X-ray absorptiometry (DEXA) results were reviewed in a subgroup of patients. Forty-nine children with asthma and 32 controls were recruited. The mean FP dose was 771.2 +/- 253.35 mcg/m2/day. Unpaired t-test analysis revealed no significant difference in biochemical markers studied. In subjects with asthma; 13 of 37 (35.1%) had lumbar spine density more than one standard deviation below the mean (P = 0.001). This fell to 6/37 (16.2%) with bone age correction (NS). In conclusion, no significant reduction in bone metabolism or bone age-corrected bone mineral density was observed in children with asthma on prolonged high doses of inhaled FP.

Safety of the newer inhaled corticosteroids in childhood asthma

Inhaled corticosteroids (ICS) remain a vital part of the management of persistent asthma, but concerns have been raised about their potential adverse effects in children. This review examines the safety data on three new ICS - fluticasone propionate, mometasone, and extrafine beclomethasone in hydrofluoroalkane (HFA-134a) propellant (QVAR The use of tradenames is for product identification purposes only and does not imply endorsement. formulation) in relation to the older corticosteroids. Topical adverse effects such as thrush and dysphonia are rare, but dental erosion is a possibility with powder forms of ICS because of their low pH. Thus, it is important to stress mouth rinsing after administration and maintaining good dental hygiene to minimize this risk. Biochemical adrenal suppression can be readily demonstrated, particularly with high doses of all ICS. The clinical relevance of this was uncertain in the past, but there have now been >50 reported cases of acute adrenal crises in children receiving ICS, most of whom were on fluticasone propionate. In order to minimize the risk of symptomatic adrenal suppression, it is important to back-titrate the ICS dose and alert families of children receiving high-dose ICS of this potential adverse effect. A pediatric endocrine opinion should be sought if adrenal suppression is suspected. The older ICS cause temporary slowing of growth velocity, but the limited data available do not show any significant compromise of final adult height. The effect on growth of fluticasone propionate may not be as great as with the older ICS, but the studies have been short term and only used low doses of fluticasone propionate. There have been case reports of growth suppression in children receiving high doses of fluticasone propionate. The limited studies performed on the effect of ICS on bone mineral density in children did not show any adverse effects, but there may be an increased risk of fractures. Hydrofluoroalkane beclomethasone (QVAR) is essentially the same drug as chlorofluorocarbon beclomethasone, but with double the lung deposition owing to the smaller particle size. Thus, it could be expected that any adverse effects seen with chlorofluorocarbon beclomethasone would be the same with hydrofluoroalkane beclomethasone. However, some of the published data, particularly in adults, suggest that hydrofluoroalkane beclomethasone may be less systemically active than chlorofluorocarbon beclomethasone, even at equipotent doses. As yet, there are no long-term data on mometasone, but initial studies in adults suggest there may be less suppression of the hypothalamic-pituitary-adrenal axis, although further studies are required, particularly in children.ICS will remain a cornerstone in the management of persistent pediatric asthma, provided that the diagnosis of asthma is secure. It is very important to use ICS appropriately and to ensure the lowest possible doses are used to achieve symptom control, thus minimizing the risk of serious adverse effects.

A randomized controlled trial of inhaled flunisolide in the management of acute asthma in children

BACKGROUND

Inhaled corticosteroids (ICS) may provide benefit in the therapy of acute asthma. The purpose of this study was to test the hypothesis that ICS are as effective as oral corticosteroids (OCS) in the management of acute childhood asthma.

METHODS

A randomized, masked, placebo-controlled study was conducted in children aged 6 to 16 years seeking emergent care for an acute exacerbation of asthma. Patients were randomized into one of two groups: group 1 (OCS), oral prednisone, 2 mg/kg (maximum of 60 mg/d) for 7 days, and placebo pressurized metered-dose inhaler with valved holding chamber, four inhalations bid; and group 2 (ICS), flunisolide, four inhalations (1 mg) bid for 7 days, and daily placebo tablets. Spirometry (FEV(1)) was performed at baseline, day 3, and day 7 of the study. A symptom diary and twice-daily peak expiratory flow were recorded.

RESULTS

A total of 58 subjects receiving ICS (n = 27) or OCS (n = 28) were enrolled. Baseline asthma severity, race, gender, and age were balanced between the two groups. chi(2) showed no significant difference in symptom severity between the two groups at any time during the study. FEV(1) percentage of predicted was lower in the ICS group on day 3 (65% vs 78%, p = 0.03) and on day 7 (77% vs 95%, p = 0.002).

CONCLUSION

ICS were found to be useful in the management of acute asthma in children; however, spirometry data suggested a more rapid resolution of asthma with OCS.

The influence of inhaler selection on efficacy of asthma therapies

Many different devices are available to aid inhalational drug delivery. Although each device is claimed to have advantages over its rivals, the evidence to support greater efficacy of a particular device is scanty. Most comparative studies are underpowered or flawed in their design. They may use inappropriate end-points, or involve healthy subjects, whose response may be very different from the patient with acute severe asthma. The dosage of drug used in a trial may be at the shallow part of the dose-response curve, masking differences in devices. Only in a few cases have clinical trials detected a significant difference between devices, and trials have rarely taken patient preference into account. The most efficacious device in practice is likely to be the one that the patient will use regularly and in accordance with a health care workers' recommendations.

Effect of detergent-coated versus non-coated spacers on bronchodilator response in children with asthma

OBJECTIVE

Previous studies have demonstrated that coating spacers with ionic detergents minimizes the static charge and thereby improves in vivo drug deposition. The present study aims to examine the effect of coated spacers versus non-coated spacers in the clinical situation.

METHODS

A randomized, double-blind study in children with asthma and a ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) of < or =72% predicted was carried out. Spirometry was performed at baseline and at 10 min and 20 min after inhalation of two puffs of salbutamol (100 microg/puff) through either a detergent-coated or a non-coated spacer.

RESULTS

Fifty children were studied (mean age 11.6 years, range 7-18 years): 26 in the group using coated spacers (CG); and 24 in the group using non-coated spacers (NCG). The mean percentage change in FEV1 from baseline 10 min after inhalation was 18.8% (range 5-50%) in the CG versus 18.5% (range 3-35%) in the NCG. At 20 min after inhalation, the per cent increase in FEV1 was 19.8% (range 0-50%) in the CG versus 19.5% (range 9-35%) in the NCG. There was no significant difference between groups in the percentage change in FEV1 after 10 min (P = 0.91), or after 20 min (P = 0.93).

CONCLUSIONS

There was no improvement in bronchodilatation from detergent-coated spacers in the present study, possibly because a maximal bronchodilator response was achieved with the lower output.

Holding chambers versus nebulisers for beta-agonist treatment of acute asthma

BACKGROUND

In acute asthma inhaled beta-2-agonists are often administered to relieve bronchospasm by wet nebulisation, but some have argued that metered-dose inhalers with a holding chamber (spacer) can be equally effective. In the community setting nebulisers are more expensive, require a power source and need regular maintenance.

OBJECTIVES

To assess the effects of holding chambers compared to nebulisers for the delivery of beta-2-agonists for acute asthma.

SEARCH STRATEGY

We last searched the Cochrane Airways Group trials register in November 2002 and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2002).

SELECTION CRITERIA

Randomised trials in adults and children (from two years of age) with asthma, where holding chamber beta-2-agonist delivery was compared with wet nebulisation.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied study inclusion criteria (one reviewer for the first version of the review), extracted the data and assessed trial quality. Missing data were obtained from the authors or estimated. Results are reported with 95% confidence intervals (CI).

MAIN RESULTS

This review has been updated in 2003 and has now analysed 1076 children and 444 adults included in 22 trials from emergency room and community settings. In addition, five trials on in-patients with acute asthma (184 children and 28 adults) have been added to the review. Method of delivery of beta-2-agonist did not appear to affect hospital admission rates. In adults, the relative risk of admission for holding chamber versus nebuliser was 0.88 (95% CI 0.56 to 1.38). The relative risk for children was 0.65 (95% CI 0.4 to 1.06). In children, length of stay in the emergency department was significantly shorter when the holding chamber was used, with a weighted mean difference of -0.47 hours, (95% CI -0.58 to -0.37 hours). Length of stay in the emergency department for adults was similar for the two delivery methods. Peak flow and forced expiratory volume were also similar for the two delivery methods. Pulse rate was lower for holding chamber in children, weighted mean difference -7.6% baseline (95% CI -9.9 to -5.3% baseline).

REVIEWER'S CONCLUSIONS

Metered-dose inhalers with holding chamber produced outcomes that were at least equivalent to nebuliser delivery. Holding chambers may have some advantages compared to nebulisers for children with acute asthma.

Comparison of two budesonide powder inhalers, Easyhaler and Turbuhaler, in steroid-naïve asthmatic patients

The objective of this multicenter study was to compare the clinical efficacy, safety, and acceptability of Easyhaler and Turbuhaler for the delivery of budesonide 200 micrograms/dose twice daily in steroid-naïve asthmatic patients. Three hundred and twenty-six newly diagnosed, steroid-naïve adult patients with mild-to-moderate asthma were recruited into this randomized, double-blind, double-dummy, parallel-group study, comprising a 2-week run-in period and 8 weeks of treatment. Patients received budesonide inhalation powder 400 micrograms/day either via Easyhaler (n = 159) or via Turbuhaler (n = 167), plus salbutamol inhalation powder (100 micrograms/dose) via Easyhaler as rescue therapy. The study was completed by 292 patients: 143 in the Easyhaler group and 149 in the Turbuhaler group. The primary outcome variable, mean morning peak expiratory flow (PEF), improved significantly and almost similarly by 36.3 and 30.6 l/min, respectively, from run-in to weeks 7-8. At weeks 7-8, the mean (SE) difference in morning PEF between the two treatments was 7.1 (9.4) l/min (90% CI from -8.4 to 22.6) on per protocol analysis, which was within the defined limits for therapeutic equivalence. There were no significant differences between treatments in terms of secondary efficacy variables or adverse events. However, patients found Easyhaler more acceptable than Turbuhaler. The results show that budesonide via Easyhaler is clinically as effective as Pulmicort Turbuhaler when equal daily doses of budesonide are delivered to steroid-naïve asthmatic patients. Moreover, patients found Easyhaler more acceptable than Turbuhaler, and a majority would prefer Easyhaler if given a choice.

Relative lung and systemic bioavailability of sodium cromoglycate inhaled products using urinary drug excretion post inhalation

The relative lung and systemic bioavailability of sodium cromoglycate following inhalation by different methods have been determined using a urinary excretion pharmacokinetic method. On three separate randomised study days, 7 days apart, subjects inhaled (i) 4x5 mg from an Intal metered dose inhaler (MDI), (ii) 4x5 mg from an MDI attached to a large volume spacer (MDI+SP) and (iii) 20 mg from an Intal Spinhaler (DPI). Urine samples were provided at 0, 0.5, 1, 2, 5 and 24 h post dose. The mean (S.D.) amount of sodium cromoglycate excreted in the urine during the first 30 min post inhalation was 38.1 (27.5), 222.3 (120.3) and 133.1 (92.2) microg following MDI, MDI+SP and DPI, respectively. The mean ratio (90% confidence interval) of these amounts excreted in the urine over the first 30 min for MDI+SP vs. MDI, DPI vs. MDI and MDI+SP vs. DPI was 801.0 (358.0, 1244; p<0.002)%, 457.0 (244.0, 670.0; p<0.02)% and 262.4 (110.2, 414.5)%, respectively. Similarly for the 24 h cumulative amount of sodium cromoglycate excreted over the 24 h post inhalation the ratios were 375.4 (232.9, 517.9; p<0.005)%, 287.5 (183.4, 391.6; p<0.02)% and 211.4 (88.3, 334.5)%, respectively. The results highlight better lung deposition of sodium cromoglycate from a metered dose inhaler attached to a large volume spacer.

Safety of inhaled corticosteroids in children

Inhaled corticosteroids (ICS) are now first-line therapy for persistent asthma in children. The major safety concerns of long-term ICS therapy for childhood asthma are potential effects on adrenal function, growth, and bone mass. Dosage, type of inhaler device, and individual drug characteristics influence systemic effects of ICS. Sensitive measures of basal adrenal function can show statistically significant changes during ICS therapy, but these do not accurately predict clinically meaningful adrenal axis suppression. Adrenal insufficiency is rare and confined to children receiving high doses of ICS. Dose-related inhibition of growth has been seen in some short- and intermediate-term studies, but long-term studies have found no detrimental effect on final height. ICS therapy has not been associated with significant changes in measurements of bone and bone biomarkers, but more studies of high doses and of therapy in adolescents are needed. Overall, although ICS are the most effective anti-inflammatory treatment available for asthma, high doses of ICS in children are still of concern. The risk of high doses is compounded in children with concomitant allergic conditions that require multiple forms of topical corticosteroids. Benefits of ICS clearly outweigh potential adverse effects and risks associated with poorly controlled asthma. Risk can be minimized by using the lowest effective ICS dose, limiting systemic availability of the drug through proper technique to minimize swallowed drug, and selection of agents with efficient first-path hepatic inactivation of swallowed drug. Adjuvant treatments can reduce the dose of ICS required for asthma control, allowing a reduction in overall systemic exposure for most children with mild-to-moderate persistent asthma. Therefore, these agents should be added to, but should not replace, ICS therapy.

Influence of respiratory spacer devices on aerodynamic particle size distribution and fine particle mass of beclomethasone from metered-dose inhalers

Respiratory spacer devices are used mainly with pressurized metered dose inhalers, especially those containing corticosteroids, to assist with patient coordination and reduce oropharyngeal side effects. This investigation examines the influence of different spacer devices on the delivered fine particle mass (aerodynamic diameter of <3.3 microm and <4.7 microm) of the corticosteroid beclomethasone dipropionate, which approximates the respirable dose. The Anderson Mark II Cascade Impactor was used to characterise the deposition of single doses of beclomethasone dipropionate from several metered-dose inhalers. Following actuation of one single dose the amount of beclomethasone dipropionate deposited on each stage of the impactor was quantified using reverse phase high-performance liquid chromatography and ultraviolet detection. The fine particle mass smaller than 4.7 microm for Respocort delivered by the Sanner and Fisonair spacer devices was 77.7% and 41.3% higher (p < 0.04), respectively, than the metered-dose inhaler alone, while the Breathatech spacer delivered 21.4% lower (p < 0.01). The fine particle mass of Becotide delivered by the Sanner, Fisonair, Nebuhaler, and Volumatic spacer devices were 81%, 42.4%, 46.9%, and 32.8% higher (p < 0.008), respectively, than be metered dose inhaler alone. The fine particle mass for Becloforte delivered by the Sanner, Fisonair, and Volumatic spacer devices was 82.8%, 36.9%, and 48.0% higher (p < 0.009) than that delivered by metered dose inhaler alone. This study suggests that there are significant differences in the fine particle mass of beclomethasone dipropionate delivered by respiratory spacer devices when used in conjunction with commercially available metered dose inhalers of this drug.