Anticholinergic therapy for acute asthma in children

Bronchodilator Responsiveness Measured by Spirometry and Impulse Oscillometry in Patients with Asthma After Short Acting Antimuscarinic and/or Beta-2-Agonists Inhalation

Background

Bronchodilator responsiveness (BDR) in asthma involves both the central and peripheral airways but is primarily relieved with beta-2-agonists and evaluated by spirometry. To date, antimuscarinics can be added as a reliever medication in more severe asthma. We hypothesize that combining both short-acting beta-2 agonist (SABA) and short-acting muscarinic antagonist (SAMA) could also improve the responsiveness in mild-moderate asthma. Therefore, we aimed to compare the direct effects of inhaling SABA alone, SAMA alone or combining both SABA and SAMA on the central and peripheral airways in asthma.

Methods

Twenty-three patients with mild-moderate BDR in asthma performed dynamic spirometry and impulse oscillometry before (baseline) and multiple timepoints within an hour after inhalation of SABA (salbutamol), SAMA (ipratropium bromide), or both SABA and SAMA at three different visits.

Results

The use of SAMA alone did not show any improvement compared to the use of SABA alone. Inhalation of SABA+SAMA, however, averaged either similar or better BDR than SABA alone in FEV1, MMEF, FVC, R5, R20 and R5-R20. Inhaling SABA+SAMA reached a stable BDR in more patients within 0-10 minutes and also reached the FEV1 (Δ%)>12% faster (3.5 minutes) than inhaling SABA alone (5.1 minutes). Inhaling SABA+SAMA was significantly better than SAMA alone in FEV1 (p = 0.015), MMEF (p = 0.0059) and R20 (p = 0.0049). Using these three variables highlighted a subgroup (30%, including more males) of patients that were more responsive to inhaling SABA+SAMA than SABA alone.

Conclusion

Overall, combining SAMA with SABA was faster and more consistent at increasing the lung function than SABA alone or SAMA alone, and the additive effect was best captured by incorporating peripheral-related variables. Therefore, SAMA should be considered as an add-on reliever for mild-moderate patients with BDR in asthma.

Pediatric respiratory distress: California out-of-hospital protocols and evidence-based recommendations

OBJECTIVES

Prehospital protocols vary across local emergency medical service (EMS) agencies in California. We sought to develop evidence-based recommendations for the out-of-hospital evaluation and treatment of pediatric respiratory distress, and we evaluated the protocols for pediatric respiratory distress used by the 33 California local EMS agencies.

METHODS

Evidence-based recommendations were developed through an extensive literature review of the current evidence regarding out-of-hospital treatment of pediatric patients with respiratory distress. The authors compared the pediatric respiratory distress protocols of each of the 33 California local EMS agencies with the evidence-based recommendations. Our focus was on the treatment of 3 main pediatric respiratory complaints by presentation: stridor (croup), wheezing < 24 months (bronchiolitis), and wheezing > 24 months (asthma).

RESULTS

Protocols across the 33 California local EMS agencies varied widely. Stridor (croup) had the highest protocol variability of the 3 presentations we evaluated, with no treatment having uniform use among all agencies. Only 3 (9.1%) of the local EMS agencies differentiated wheezing in children < 24 months of age, referencing this as possible bronchiolitis. All local EMS agencies included albuterol and epinephrine (intravenous/intramuscular) in their pediatric wheezing (asthma) treatment protocols. The least common treatments for wheezing (asthma) included nebulized epinephrine (3/33) and magnesium (2/33). No agencies included steroids in their treatment protocols (0/33).

CONCLUSION

Protocols for pediatric respiratory distress vary widely across the state of California, especially among those for stridor (croup) and wheezing in < 24 months (bronchiolitis). The evidence-based recommendations that we present for the prehospital treatment of these conditions may be useful for EMS medical directors tasked with creating and revising these protocols.

Clinical efficacy and safety of anticholinergic therapies in pediatric patients

The burden of uncontrolled asthma in children and adolescents is high. Treatment options for pediatric patients (aged under 18 years) with asthma are largely influenced by the Global Initiative for Asthma recommendations. Algorithms for adolescents (12-18 years) and adults are identical, but recommendations for children aged under 6 years and 6-11 years differ. Although the goals of treatment for pediatric patients with asthma are similar to those for adults, relatively few new therapies have been approved for this patient population within the last decade. Designing clinical trials involving children presents several challenges, notably that children are often less able to perform lung function tests, and traditional endpoints used in clinical trials with adults, such as forced expiratory volume in 1 second, asthma exacerbations and questionnaires, have limitations associated with their use in children. There are also ethical considerations related to the performance of longer placebo-controlled exacerbation trials. This review considers additional clinical endpoints to those traditionally reported, including forced expiratory flow at 25%-75% of forced vital capacity, which may help shed light on which treatments are most effective for use in pediatric patients with asthma. The pros and cons of specific and potentially clinically relevant endpoints are considered, along with device considerations and patient preferences that may enhance adherence and quality of life. Recent advances in the management of children and adolescents, including the US Food and Drug Administration and European Medicines Agency approval of tiotropium in patients with asthma aged 6 years and over, are also discussed.

Preschool wheeze, genes and treatment

Preschool wheeze is a common but poorly understood cause of respiratory morbidity that is both distinct from and overlaps with infantile bronchiolitis and school age asthma. Attempts at classification by epidemiology, pathophysiology, therapeutic response and clinical phenotype are imperfect and yet fundamental to both treatment choice and research design. The four main therapeutic classes for preschool wheeze, namely beta₂ agonists, anticholinergics, corticosteroids and leukotriene modifiers are employed with variable and often scanty evidence base, with evidence for a genetic influence on response variations. The article will discuss the pharmacogenetics of the various options, summarise current treatment recommendations, and explore future research directions.

Guideline on management of the acute asthma attack in children by Italian Society of Pediatrics

BACKGROUND

Acute asthma attack is a frequent condition in children. It is one of the most common reasons for emergency department (ED) visit and hospitalization. Appropriate care is fundamental, considering both the high prevalence of asthma in children, and its life-threatening risks. Italian Society of Pediatrics recently issued a guideline on the management of acute asthma attack in children over age 2, in ambulatory and emergency department settings.

METHODS

The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was adopted. A literature search was performed using the Cochrane Library and Medline/PubMed databases, retrieving studies in English or Italian and including children over age 2 year.

RESULTS

Inhaled ß2 agonists are the first line drugs for acute asthma attack in children. Ipratropium bromide should be added in moderate/severe attacks. Early use of systemic steroids is associated with reduced risk of ED visits and hospitalization. High doses of inhaled steroids should not replace systemic steroids. Aminophylline use should be avoided in mild/moderate attacks. Weak evidence supports its use in life-threatening attacks. Epinephrine should not be used in the treatment of acute asthma for its lower cost / benefit ratio, compared to β2 agonists. Intravenous magnesium solphate could be used in children with severe attacks and/or forced expiratory volume1 (FEV1) lower than 60% predicted, unresponsive to initial inhaled therapy. Heliox could be administered in life-threatening attacks. Leukotriene receptor antagonists are not recommended.

CONCLUSIONS

This Guideline is expected to be a useful resource in managing acute asthma attacks in children over age 2.

Mechanisms Mediating Pediatric Severe Asthma and Potential Novel Therapies

Although a rare disease, severe therapy-resistant asthma in children is a cause of significant morbidity and results in utilization of approximately 50% of health-care resources for asthma. Improving control for children with severe asthma is, therefore, an urgent unmet clinical need. As a group, children with severe asthma have severe and multiple allergies, steroid resistant airway eosinophilia, and significant structural changes of the airway wall (airway remodeling). Omalizumab is currently the only add-on therapy that is licensed for use in children with severe asthma. However, limitations of its use include ineligibility for approximately one-third of patients because of serum IgE levels outside the recommended range and lack of clinical efficacy in a further one-third. Pediatric severe asthma is thus markedly heterogeneous, but our current understanding of the different mechanisms underpinning various phenotypes is very limited. We know that there are distinctions between the factors that drive pediatric and adult disease since pediatric disease develops in the context of a maturing immune system and during lung growth and development. This review summarizes the current data that give insight into the pathophysiology of pediatric severe asthma and will highlight potential targets for novel therapies. It is apparent that in order to identify novel treatments for pediatric severe asthma, the challenge of undertaking mechanistic studies using age appropriate experimental models and airway samples from children needs to be accepted to allow a targeted approach of personalized medicine to be achieved.

Intravenous magnesium sulfate for treating children with acute asthma in the emergency department

BACKGROUND

Acute asthma in children can be life-threatening and must be treated promptly in the emergency setting. Intravenous magnesium sulfate is recommended by various guidelines for cases of acute asthma that have not responded to first-line treatment with bronchodilators and steroids. The treatment has recently been shown to reduce the need for hospital admission for adults compared with placebo, but it is unclear whether it is equally effective for children.

OBJECTIVES

To assess the safety and efficacy of intravenous magnesium sulfate (IV MgSO4) in children treated for acute asthma in the emergency department (ED).

SEARCH METHODS

We identified studies by searching the Cochrane Airways Review Group Specialised Register up to 23 February 2016. We also searched ClinicalTrials.gov and reference lists of other reviews, and we contacted study authors to ask for additional information.

SELECTION CRITERIA

We included randomised controlled trials of children treated in the ED for exacerbations of asthma if they compared any dose of IV MgSO4 with placebo.

DATA COLLECTION AND ANALYSIS

Two review authors screened the results of the search and independently extracted data from studies meeting the inclusion criteria. We resolved disagreements through discussion and contacted study authors in cases of missing data and other uncertainties relating to the studies.We analysed dichotomous data as odds ratios and continuous data as mean differences, both using fixed-effect models. We assessed each study for risk of bias and rated the quality of evidence for each outcome with GRADE and presented the results in a 'Summary of findings' table. There was insufficient evidence to conduct the planned subgroup analyses.

MAIN RESULTS

Five studies (182 children) met the inclusion criteria, and four contributed data to at least one meta-analysis. The included studies were overall at low risk of bias, but our confidence in the evidence was generally low, mainly due to the small sample sizes. Treatment with IV MgSO4 reduced the odds of admission to hospital by 68% (odds ratio (OR) 0.32, 95% confidence interval (CI) 0.14 to 0.74; children = 115; studies = 3; I(2) = 63%). This result was based on data from just three studies including 115 children. Meta-analysis for the secondary outcomes was extremely limited by paucity of data. We performed meta-analysis for the outcome 'return to the emergency department within 48 hours', which showed a very imprecise effect estimate that was not statistically significant (OR 0.40, 95% CI 0.02 to 10.30; children = 85; studies = 2; I(2) = 0%). Side effects and adverse events were not consistently reported and meta-analysis was not possible, however few side effects or adverse events were reported.

AUTHORS' CONCLUSIONS

IV MgSO4 may reduce the need for hospital admission in children presenting to the ED with moderate to severe exacerbations of asthma, but the evidence is extremely limited by the number and size of studies. Few side effects of the treatment were reported, but the data were extremely limited.

Management of Acute Exacerbation of Asthma and Chronic Obstructive Pulmonary Disease in the Emergency Department

Acute asthma and chronic obstructive pulmonary disease (COPD) exacerbations are the most common respiratory diseases requiring emergent medical evaluation and treatment. Asthma and COPD are chronic, debilitating disease processes that have been differentiated traditionally by the presence or absence of reversible airflow obstruction. Asthma and COPD exacerbations impose an enormous economic burden on the US health care budget. In daily clinical practice, it is difficult to differentiate these 2 obstructive processes based on their symptoms, and on their nearly identical acute treatment strategies; major differences are important when discussing anatomic sites involved, long-term prognosis, and the nature of inflammatory markers.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

Evaluation and treatment of critical asthma syndrome in children

The heterogeneity of asthma is illustrated by the significantly different features of pediatric asthma compared to adult asthma. One phenotype of severe asthma in pediatrics includes atopy, lack of reduction in lung function, and absence of gender bias as the main characteristics. Included in the NIH NAEPP EPR-3 are recommendations for the treatment and management of severe pediatric asthma and critical asthma syndrome, such as continuous nebulization treatments, intubation and mechanical ventilation, heliox, and magnesium sulfate. In addition, epinephrine, intravenous immunoglobulin, intravenous montelukast, extracorporeal membrane oxygenation, and many biological modulators currently under investigation are additional current and/or future treatment modalities for the severe pediatric asthmatic. But, perhaps the most important strategy for managing the severe asthmatic is preventative treatment, which can significantly decrease impairment and risk, particularly for severe acute exacerbations requiring emergency care and/or hospitalization. In order for preventative therapy to be successful, several challenges must be met, including selecting the correct therapy for each patient and then ensuring compliance or adherence to a treatment plan. The heterogeneity of asthma renders the former difficult in that not all patients will respond equally to the same treatment; the latter is only helpful if the correct treatment is employed. Strategies to ensure compliance include education of caregivers and patients and their families. As newer medications are introduced, options for individualized or customized medicine increase, and this may pave the way for significant decreases in morbidity and mortality in severe pediatric asthma.

The acute management of asthma

Patients presenting to the emergency department (ED) or clinic with acute exacerbation of asthma (AEA) can be very challenging varying in both severity and response to therapy. High-dose, frequent or continuous nebulized short-acting beta2 agonist (SABA) therapy that can be combined with a short-acting muscarinic antagonist (SAMA) is the backbone of treatment. When patients do not rapidly clinically respond to SABA/SAMA inhalation, the early use of oral or parenteral corticosteroids should be considered and has been shown to impact the immediate need for ICU admission or even the need for hospital admission. Adjunctive therapies such as the use of intravenous magnesium and helium/oxygen combination gas for inhalation and for driving a nebulizer to deliver a SABA and or SAMA should be considered and are best used early in the treatment plan if they are likely to impact the patients' clinical course. The use of other agents such as theophylline, leukotriene modifiers, inhaled corticosteroids, long-acting beta2 agonist, and long-acting muscarinic antagonist currently does not play a major role in the immediate treatment of AEA in the clinic or the ED but is an important therapeutic option for physicians to be aware of and to consider initiating at the time of discharge from clinic, hospital, or ED to reduce later clinical worsening and readmission to the ED and hospital. A comprehensive summary is provided of the currently available respiratory pharmaceuticals approved for asthma and other airway syndromes. Clinicians must be prepared to use the entire spectrum of medications available for the treatment of acute asthma exacerbations and the agents that should be initiated to prevent worsening or additional exacerbations. They need to be familiar with the major potential drug toxicities associated with their use.

Continuous Inhalation of Ipratropium Bromide for Acute Asthma Refractory to β2-agonist Treatment

To present the case of a patient with persistent bronchospasm, refractory to treatment with β2-agonists, that resolved promptly with continuous inhalation of large dose (1000 mcg/hr) ipratropium bromide, and to discuss the possibility of tolerance to β2-agonists as the cause for his failure to respond to adrenergic medications. The patient had received multiple doses of albuterol, as well as subcutaneous terbutaline (0.3 mg), intravenous magnesium sulfate (1 g) and intravenous dexamethasone (10 mg) prior to his admission to the intensive care unit. He remained symptomatic despite systemic intravenous steroids, continuous intravenous terbutaline (up to 0.6 mcg/kg/min), and continuous nebulized albuterol (up to 20 mg/hr for 57 hr) followed by 49 hours of continuous levalbuterol (7 mg/hr). Due to the lack of response, all β2-agonists were discontinued at 106 hours post-admission, and he was started on large dose ipratropium bromide (1000 mcg/hr) by continuous nebulization. Clinical improvement was evident within 1 hour and complete resolution of his symptoms within 4 hours. Continuous inhalation of large dose ipratropium bromide may be an effective regimen for the treatment of patients hospitalized with acute asthma who are deemed to be nonresponsive and/or tolerant to β2-agonist therapy.

Anticholinergics/antimuscarinic drugs in asthma

Anticholinergic alkaloids have been used for thousands of years for the relief of bronchoconstriction and other respiratory symptoms, and their use in the treatment of chronic obstructive pulmonary disease is well established. Acetylcholine, acting through muscarinic receptor (M) receptor, modulates multiple physiologic functions pertinent to asthma including airway muscle tone, mucus gland secretion, and various parameters of inflammation and remodeling. In addition, activation of M receptors may inhibit beta2 adrenoreceptor. These observations offer the rationale for the use of M receptors antagonists in the treatment of asthma. Short-acting antimuscarinic agents may be effective alone or in combination with short-acting beta agonists for the relief of acute symptoms. Long-acting antimuscarinic agents have emerged as potentially useful in the long-term treatment of difficult-to-control asthma. This review will analyze the mechanisms of action and therapeutic role of antimuscarinic agents on asthma including current guidelines regarding antimuscarinic drugs, recent studies in asthma, special populations to consider, and possible predictors of response.

Utilisation and off-label prescriptions of respiratory drugs in children

Respiratory drugs are widely used in children to treat labeled and non-labeled indications but only some data are available quantifying comprehensively off-label usage. Thus, we aim to analyse drug utilisation and off-label prescribing of respiratory drugs focusing on age- and indication-related off-label use. Patients aged ≤18 years documented in the Bavarian Association of Statutory Health Insurance Physicians database (approx. 2 million children) between 2004 and 2008 were included in our study. Annual period prevalence rates (PPRs) per 10,000 children and the proportion of age- and indication-related off-label prescriptions were calculated and stratified by age and gender. Within the study period, highest PPRs were found for the fixed combination of clenbuterol/ambroxol (between 374–575 per 10,000 children) and the inhaled short acting beta-2-agonist salbutamol (between 378–527 per 10,000 children). Highest relative PPR increase was found for oral salbutamol (approx. 39-fold) whereas the most distinct decrease was found for oral long-acting beta-2-agonist clenbuterol (−97%). Compound classes most frequently involved in off-label prescribing were inhaled bronchodilative compounds (91,402; 37.3%) and oral beta-2-agonists (26,850; 22.5%). The highest absolute number of off-label prescriptions were found for inhaled salbutamol (n = 67,084; 42.0%) and oral clenbuterol/ambroxol (fixed combination, n = 18,897; 20.7%). Off-label prescribing due to indication was of much greater relevance than age-related off-label use. Most frequently, bronchodilative compounds were used off-label to treat respiratory tract infections. Highest off-label prescription rates were found in the youngest patients without relevant gender-related differences. Off-label prescribing of respiratory drugs is common especially in young children. Bronchodilative drugs were most frequently used off-label for treating acute bronchitis or upper respiratory tract infections underlining the essential need for a more rational prescribing in this area.

Intravenous magnesium sulfate for treating adults with acute asthma in the emergency department

BACKGROUND

Asthma is a chronic respiratory condition characterised by airways inflammation, constriction of airway smooth muscle and structural alteration of the airways that is at least partially reversible. Exacerbations of asthma can be life threatening and place a significant burden on healthcare services. Various guidelines have been published to inform management personnel in the acute setting; several include the use of a single bolus of intravenous magnesium sulfate (IV MgSO4) in cases that do not respond to first-line treatment. However, the effectiveness of this approach remains unclear, particularly in less severe cases.

OBJECTIVES

To assess the safety and efficacy of IV MgSO4 in adults treated for acute asthma in the emergency department.

SEARCH METHODS

We identified trials from the Cochrane Airways Review Group Specialised Register (CAGR) up to 2 May 2014. We also searched www.ClinicalTrials.gov and reference lists of other reviews, and we contacted trial authors to ask for additional information.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adults treated in the emergency department (ED) for exacerbations of asthma if they compared any dose of IV MgSO4 with placebo.

DATA COLLECTION AND ANALYSIS

All review authors screened titles and abstracts for inclusion, and at least two review authors independently extracted study characteristics, risk of bias and numerical data. Disagreements were resolved by consensus, and we contacted trial investigators to obtain missing information.We analysed dichotomous data as odds ratios using study participants as the unit of analysis, and we analysed continuous data as mean differences or standardised mean differences using fixed-effect models. We rated all outcomes using GRADE and presented results in Summary of findings table 1.We carried out subgroup analyses on the primary outcome for baseline severity of exacerbations and whether or not ipratropium bromide was given as a co-medication. Unpublished data and studies at high risk of bias for blinding were removed from the main analysis in sensitivity analyses.

MAIN RESULTS

Fourteen studies met the inclusion criteria, randomly assigning 2313 people with acute asthma to the comparisons of interest in this review.Most studies were double-blinded trials comparing a single infusion of 1.2 g or 2 g IV MgSO4 over 15 to 30 minutes versus a matching placebo. Eleven were conducted at a single centre, and three were multi-centre trials. Participants in almost all of the studies had already been given at least oxygen, nebulised short-acting beta2-agonists and IV corticosteroids in the ED; in some studies, investigators also administered ipratropium bromide. Ten studies included only adults, and four included both adults and children; these were included because the mean age of participants was over 18 years.Intravenous MgSO4 reduced hospital admissions compared with placebo (odds ratio (OR) 0.75, 95% confidence interval (CI) 0.60 to 0.92; I(2) = 28%, P value 0.18; n = 972; high-quality evidence). In absolute terms, this odds ratio translates into a reduction of seven hospital admissions for every 100 adults treated with IV MgSO4 (95% CI two to 13 fewer). The test for subgroup differences revealed no statistical heterogeneity between the three severity subgroups (I(2) = 0%, P value 0.73) or between the four studies that administered nebulised ipratropium bromide as a co-medication and those that did not (I(2) = 0%, P value 0.82). Sensitivity analyses in which unpublished data and studies at high risk for blinding were removed from the primary analysis did not change conclusions.Within the secondary outcomes, high- and moderate-quality evidence across three spirometric indices suggests some improvement in lung function with IV MgSO4. No difference was found between IV MgSO4and placebo for most of the non-spirometric secondary outcomes, all of which were rated as low or moderate quality (intensive care admissions, ED treatment duration, length of hospital stay, readmission, respiration rate, systolic blood pressure).Adverse events were inconsistently reported and were not meta-analysed. The most commonly cited adverse events in the IV MgSO4 groups were flushing, fatigue, nausea and headache and hypotension (low blood pressure).

AUTHORS' CONCLUSIONS

This review provides evidence that a single infusion of 1.2 g or 2 g IV MgSO4 over 15 to 30 minutes reduces hospital admissions and improves lung function in adults with acute asthma who have not responded sufficiently to oxygen, nebulised short-acting beta2-agonists and IV corticosteroids. Differences in the ways the trials were conducted made it difficult for the review authors to assess whether severity of the exacerbation or additional co-medications altered the treatment effect of IV MgSO4. Limited evidence was found for other measures of benefit and safety.Studies conducted in these populations should clearly define baseline severity parameters and systematically record adverse events. Studies recruiting participants with exacerbations of varying severity should consider subgrouping results on the basis of accepted severity classifications.

Combined inhaled anticholinergics and short-acting beta2-agonists for initial treatment of acute asthma in children

BACKGROUND

There are several treatment options for managing acute asthma exacerbations (sustained worsening of symptoms that do not subside with regular treatment and require a change in management). Guidelines advocate the use of inhaled short acting beta2-agonists (SABAs) in children experiencing an asthma exacerbation. Anticholinergic agents, such as ipratropium bromide and atropine sulfate, have a slower onset of action and weaker bronchodilating effect, but may specifically relieve cholinergic bronchomotor tone and decrease mucosal edema and secretions. Therefore, the combination of inhaled anticholinergics with SABAs may yield enhanced and prolonged bronchodilation.

OBJECTIVES

To determine whether the addition of inhaled anticholinergics to SABAs provides clinical improvement and affects the incidence of adverse effects in children with acute asthma exacerbations.

SEARCH METHODS

We searched MEDLINE (1966 to April 2000), EMBASE (1980 to April 2000), CINAHL (1982 to April 2000) and reference lists of studies of previous versions of this review. We also contacted drug manufacturers and trialists. For the 2012 review update, we undertook an 'all years' search of the Cochrane Airways Group's register on the 18 April 2012.

SELECTION CRITERIA

Randomized parallel trials comparing the combination of inhaled anticholinergics and SABAs with SABAs alone in children (aged 18 months to 18 years) with an acute asthma exacerbation.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We used the GRADE rating system to assess the quality of evidence for our primary outcome (hospital admission).

MAIN RESULTS

Twenty trials met the review eligibility criteria, generated 24 study comparisons and comprised 2697 randomised children aged one to 18 years, presenting predominantly with moderate or severe exacerbations. Most studies involved both preschool-aged children and school-aged children; three studies also included a small proportion of infants less than 18 months of age. Nine trials (45%) were at a low risk of bias. Most trials used a fixed-dose protocol of three doses of 250 mcg or two doses of 500 mcg of nebulized ipratropium bromide in combination with a SABA over 30 to 90 minutes while three trials used a single dose and two used a flexible-dose protocol according to the need for SABA.The addition of an anticholinergic to a SABA significantly reduced the risk of hospital admission (risk ratio (RR) 0.73; 95% confidence interval (CI) 0.63 to 0.85; 15 studies, 2497 children, high-quality evidence). In the group receiving only SABAs, 23 out of 100 children with acute asthma were admitted to hospital compared with 17 (95% CI 15 to 20) out of 100 children treated with SABAs plus anticholinergics. This represents an overall number needed to treat for an additional beneficial outcome (NNTB) of 16 (95% CI 12 to 29).Trends towards a greater effect with increased treatment intensity and with increased asthma severity were observed, but did not reach statistical significance. There was no effect modification due to concomitant use of oral corticosteroids and the effect of age could not be explored. However, exclusion of the one trial that included infants (< 18 months) and contributed data to the main outcome, did not affect the results. Statistically significant group differences favoring anticholinergic use were observed for lung function, clinical score at 120 minutes, oxygen saturation at 60 minutes, and the need for repeat use of bronchodilators prior to discharge from the emergency department. No significant group difference was seen in relapse rates.Fewer children treated with anticholinergics plus SABA reported nausea and tremor compared with SABA alone; no significant group difference was observed for vomiting.

AUTHORS' CONCLUSIONS

Children with an asthma exacerbation experience a lower risk of admission to hospital if they are treated with the combination of inhaled SABAs plus anticholinergic versus SABA alone. They also experience a greater improvement in lung function and less risk of nausea and tremor. Within this group, the findings suggested, but did not prove, the possibility of an effect modification, where intensity of anticholinergic treatment and asthma severity, could be associated with greater benefit.Further research is required to identify the characteristics of children that may benefit from anticholinergic use (e.g. age and asthma severity including mild exacerbation and impending respiratory failure) and the treatment modalities (dose, intensity, and duration) associated with most benefit from anticholinergic use better.