Interventions for escalation of therapy for acute exacerbations of asthma in children: an overview of Cochrane Reviews

Critical reappraisal of short-acting bronchodilators for pediatric respiratory diseases

Short-acting bronchodilators are a class of medications commonly used to treat asthma, chronic obstructive pulmonary disease, and other respiratory conditions. The use of these medications has evolved over time as we have gained a better understanding of their effectiveness and safety in the pediatric population. This comprehensive review synthesizes the current understanding of short-acting β2-agonists and short-acting anticholinergics in children. It addresses indications, contraindications, safety considerations, and highlights areas where further research is needed to guide the most effective use of short-acting bronchodilators.

Analysis of guideline recommendations for treatment of asthma exacerbations in children: a Pediatric Emergency Research Networks (PERN) study

RATIONALE

There is significant practice variation in acute paediatric asthma, particularly severe exacerbations. It is unknown whether this is due to differences in clinical guidelines.

OBJECTIVES

To describe and compare the content and quality of clinical guidelines for the management of acute exacerbations of asthma in children between geographic regions.

METHODS

Observational study of guidelines for the management of acute paediatric asthma from institutions across a global collaboration of six regional paediatric emergency research networks.

MEASUREMENTS AND MAIN RESULTS

158 guidelines were identified. Half provided recommendations for at least two age groups, and most guidelines provided treatment recommendations according to asthma severity.There were consistent recommendations for the use of inhaled short-acting beta-agonists and systemic corticosteroids. Inhaled anticholinergic therapy was recommended in most guidelines for severe and critical asthma, but there were inconsistent recommendations for its use in mild and moderate exacerbations. Other inhaled therapies such as helium-oxygen mixture (Heliox) and nebulised magnesium were inconsistently recommended for severe and critical illness.Parenteral bronchodilator therapy and epinephrine were mostly reserved for severe and critical asthma, with intravenous magnesium most recommended. There were regional differences in the use of other parenteral bronchodilators, particularly aminophylline.Guideline quality assessment identified high ratings for clarity of presentation, scope and purpose, but low ratings for stakeholder involvement, rigour of development, applicability and editorial independence.

CONCLUSIONS

Current guidelines for the management of acute paediatric asthma exacerbations have substantial deficits in important quality domains and provide limited and inconsistent guidance for severe exacerbations.

Comparison of doses of Nebulized Magnesium sulphate as an adjuvant treatment with salbutamol in children with Status Asthmaticus

Objectives

To compare the response between different doses of nebulized magnesium sulphate along with Salbutamol in children between two to 12 years of age with status asthmaticus.

Methods

This single blinded, randomized clinical trial was carried out at the Department of Pediatrics, Dr. Ziauddin University Hospital, Karachi, Pakistan during October 2021 to September 2022. A total of 104 children aged between 2-12 years, with the diagnosis of asthma having "Pediatric Rapid Assessment Measure (PRAM)" score>4 and with reactive airways were included. Children either received three back-to-back nebulization with salbutamol solution only (n=50) or salbutamol and MgSO4 with three different doses (250mg, 500mg or 750mg) after every 20 minutes for 60 minutes. The PRAM score was used as an assessment tool to clinically score asthma.

Results

In a total of 104 children, 53 (51.0%) were girls. The mean age was 5.25±2.86 years. No statistically significant difference was found in PRAM scores at baseline (p=0.448) and at 20-minutes (p=0.072) but significant differences were observed at 40-minutes (p=0.009), 60-minutes (p=0.011), 120-minutes (p=0.010), 6-hours (=0.034), 12-hours (p=0.018), 18-hours (p=0.033) and at 24-hours (p=0.029). The reduction in PRAM scores from baseline to 24-hours following treatment among Salbutamol, Salbutamol+ MgSo4 250mg, Salbutamol+ MgSo4 500mg and Salbutamol+ MgSo4 750mg group were 6.53±1.09, 7.22±1.09, 6.85±1.43 and 7.57±1.06 respectively (p=0.007).

Conclusion

While children with status asthmaticus managed using salbutamol, with or without nebulized MgSO4, showed improved clinical outcomes, combining salbutamol with higher dosages of nebulized MgSO4 resulted in even greater clinical improvement.Clinical Trial Registry: https://clinicaltrials.gov/ct2/show/NCT04929626.

Noninvasive Respiratory Support for Pediatric Critical Asthma: A Multicenter Cohort Study

BACKGROUND

Noninvasive respiratory support (NRS) for pediatric critical asthma includes CPAP; bi-level positive airway pressure (BPAP); and heated, humidified, high-flow nasal cannula (HFNC). We used the Virtual Pediatric System database to estimate NRS by prescribing rates for pediatric critical asthma and characterize patient clinical features and in-patient outcomes by the initial NRS device applied.

METHODS

We performed a retrospective cohort study from 125 participating pediatric ICUs among children 2-17 years of age hospitalized for critical asthma and prescribed NRS from 2017 through 2021. The primary outcomes were NRS modality prescribing rates and trends. Secondary outcomes were descriptive and included demographics, comorbidities, severity of illness indices, and NRS failure rates (defined as escalation from the initial NRS modality to invasive ventilation, HFNC to BPAP or CPAP, or CPAP to BPAP).

RESULTS

Of the 10,083 encounters studied, the initial NRS modalities prescribed varied widely by hospital center (HFNC: 69.7 ± 29.6%; BPAP: 27.2 ± 7.1%; CPAP: 3.1 ± 5.9%). The mean rates of HFNC use increased from 59.7% in 2017 to 71.9% in 2021 (+2.5%/y). In contrast, BPAP (-1.6%/y) and CPAP (-0.8%/y) utilization declined throughout the study period. Older children who were obese and with a higher Pediatric Risk of Mortality III-Probability of Mortality score were more frequently prescribed BPAP and CPAP compared with HFNC. Those children on HFNC experienced higher noninvasive respiratory support failure rates versus BPAP (7.3% vs 2.4%; P < .001) but a lower subsequent invasive ventilation rate versus BPAP (0.8% vs 2.4%; P < .001).

CONCLUSIONS

In this multi-center cohort study, we observed that children with critical asthma are increasingly exposed to HFNC compared with BPAP and CPAP. Rates of HFNC failure were greater than those of BPAP failure, but a majority were transitioned to BPAP without subsequent invasive ventilation. The next steps include prospective trials, including practical end points such as patient comfort and optimal delivery of nebulized treatments to distinguish device superiority and suitable NRS utilization.

Core outcomes and factors influencing the experience of care for children with severe acute exacerbations of asthma: a qualitative study

OBJECTIVE

To identify the outcomes considered important, and factors influencing the patient experience, for parents and caregivers of children presenting to hospital with a severe acute exacerbation of asthma. This work contributes to the outcome-identification process in developing a core outcome set (COS) for future clinical trials in children with severe acute asthma.

DESIGN

A qualitative study involving semistructured interviews with parents and caregivers of children who presented to hospital with a severe acute exacerbation of asthma.

SETTING

Hospitals in 12 countries associated with the global Pediatric Emergency Research Networks, including high-income and middle-income countries. Interviews were conducted face-to-face, by teleconference/video-call, or by phone.

FINDINGS

Overall, there were 54 interviews with parents and caregivers; 2 interviews also involved the child. Hospital length of stay, intensive care unit or high-dependency unit (HDU) admission, and treatment costs were highlighted as important outcomes influencing the patient and family experience. Other potential clinical trial outcomes included work of breathing, speed of recovery and side effects. In addition, the patient and family experience was impacted by decision-making leading up to seeking hospital care, transit to hospital, waiting times and the use of intravenous treatment. Satisfaction of care was related to communication with clinicians and frequent reassessment.

CONCLUSIONS

This study provides insight into the outcomes that parents and caregivers believe to be the most important to be considered in the process of developing a COS for the treatment of acute severe exacerbations of asthma.

Clinical standards for the diagnosis and management of asthma in low- and middle-income countries

BACKGROUND: The aim of these clinical standards is to aid the diagnosis and management of asthma in low-resource settings in low- and middle-income countries (LMICs).METHODS: A panel of 52 experts in the field of asthma in LMICs participated in a two-stage Delphi process to establish and reach a consensus on the clinical standards.RESULTS: Eighteen clinical standards were defined: Standard 1, Every individual with symptoms and signs compatible with asthma should undergo a clinical assessment; Standard 2, In individuals (>6 years) with a clinical assessment supportive of a diagnosis of asthma, a hand-held spirometry measurement should be used to confirm variable expiratory airflow limitation by demonstrating an acute response to a bronchodilator; Standard 3, Pre- and post-bronchodilator spirometry should be performed in individuals (>6 years) to support diagnosis before treatment is commenced if there is diagnostic uncertainty; Standard 4, Individuals with an acute exacerbation of asthma and clinical signs of hypoxaemia or increased work of breathing should be given supplementary oxygen to maintain saturation at 94-98%; Standard 5, Inhaled short-acting beta-2 agonists (SABAs) should be used as an emergency reliever in individuals with asthma via an appropriate spacer device for metered-dose inhalers; Standard 6, Short-course oral corticosteroids should be administered in appropriate doses to individuals having moderate to severe acute asthma exacerbations (minimum 3-5 days); Standard 7, Individuals having a severe asthma exacerbation should receive emergency care, including oxygen therapy, systemic corticosteroids, inhaled bronchodilators (e.g., salbutamol with or without ipratropium bromide) and a single dose of intravenous magnesium sulphate should be considered; Standard 8, All individuals with asthma should receive education about asthma and a personalised action plan; Standard 9, Inhaled medications (excluding dry-powder devices) should be administered via an appropriate spacer device in both adults and children. Children aged 0-3 years will require the spacer to be coupled to a face mask; Standard 10, Children aged <5 years with asthma should receive a SABA as-needed at step 1 and an inhaled corticosteroid (ICS) to cover periods of wheezing due to respiratory viral infections, and SABA as-needed and daily ICS from step 2 upwards; Standard 11, Children aged 6-11 years with asthma should receive an ICS taken whenever an inhaled SABA is used; Standard 12, All adolescents aged 12-18 years and adults with asthma should receive a combination inhaler (ICS and rapid onset of action long-acting beta-agonist [LABA] such as budesonide-formoterol), where available, to be used either as-needed (for mild asthma) or as both maintenance and reliever therapy, for moderate to severe asthma; Standard 13, Inhaled SABA alone for the management of patients aged >12 years is not recommended as it is associated with increased risk of morbidity and mortality. It should only be used where there is no access to ICS.The following standards (14-18) are for settings where there is no access to inhaled medicines. Standard 14, Patients without access to corticosteroids should be provided with a single short course of emergency oral prednisolone; Standard 15, Oral SABA for symptomatic relief should be used only if no inhaled SABA is available. Adjust to the individual's lowest beneficial dose to minimise adverse effects; Standard 16, Oral leukotriene receptor antagonists (LTRA) can be used as a preventive medication and is preferable to the use of long-term oral systemic corticosteroids; Standard 17, In exceptional circumstances, when there is a high risk of mortality from exacerbations, low-dose oral prednisolone daily or on alternate days may be considered on a case-by-case basis; Standard 18. Oral theophylline should be restricted for use in situations where it is the only bronchodilator treatment option available.CONCLUSION: These first consensus-based clinical standards for asthma management in LMICs are intended to help clinicians provide the most effective care for people in resource-limited settings.

Acute paediatric asthma treatment in the prehospital setting: a retrospective observational study

OBJECTIVES

To describe the incidence of and patterns of 'escalated care' (care in addition to standard treatment with systemic corticosteroids and inhaled bronchodilators) for children receiving prehospital treatment for asthma.

DESIGN

Retrospective observational study.

SETTING

State-wide ambulance service data (Ambulance Victoria in Victoria, Australia, population 6.5 million) PARTICIPANTS: Children aged 1-17 years and given a final diagnosis of asthma by the treating paramedics and/or treated with inhaled bronchodilators from 1 July 2019 to 30 June 2020.

PRIMARY AND SECONDARY OUTCOME MEASURES

We classified 'escalation of care' as parenteral administration of epinephrine, or provision of respiratory support. We compared clinical, demographic and treatments administered between those receiving and not receiving escalation of care.

RESULTS

Paramedics attended 1572 children with acute exacerbations of asthma during the 1 year study period. Of these, 22 (1.4%) had escalated care, all receiving parenteral epinephrine. Patients with escalated care were more likely to be older, had previously required hospital admission for asthma and had severe respiratory distress at initial assessment.Of 1307 children with respiratory status data available, at arrival to hospital, the respiratory status of children had improved overall (normal/mild respiratory distress at initial assessment 847 (64.8%), normal/mild respiratory distress at hospital arrival 1142 (87.4%), p<0.0001).

CONCLUSIONS

Most children with acute exacerbations of asthma did not receive escalated therapy during their pre-hospital treatment from ambulance paramedics. Most patients were treated with inhaled bronchodilators only and clinically improved by the time they arrived in hospital.

International perspective on research priorities and outcome measures of importance in the care of children with acute exacerbations of asthma: a qualitative interview study

BACKGROUND

Acute exacerbations of asthma are common in children, however, treatment decisions for severe exacerbations are challenging due to a lack of robust evidence. In order to create more robust research, a core set of outcome measures needs to be developed. In developing these outcomes, it is important to understand the views of clinicians who care for these children in particular, views that relate to outcome measures and research priorities.

METHODS

To determine the views of clinicians, a total of 26 semistructured interviews based on the theoretical domains framework were conducted. These included experienced clinicians from emergency, intensive care and inpatient paediatrics across 17 countries. The interviews were recorded, and later transcribed. All data analyses were conducted in Nvivo by using thematic analysis.

RESULTS

The length of stay in hospital and patient-focused parameters, such as timing to return to school and normal activity, were the most frequently highlighted outcome measures, with clinicians identifying the need to achieve a consensus on key core outcome measure sets. Most research questions focused on understanding the best treatment options, including the role of novel therapies and respiratory support.

CONCLUSION

Our study provides an insight into what research questions and outcome measures clinicians view as important. In addition, information on how clinicians define asthma severity and measure treatment success will assist with methodological design in future trials. The current findings will be used in parallel with a further Paediatric Emergency Research Network study focusing on the child and family perspectives and will contribute to develop a core outcome set for future research.

Asthma Attacks in Children-Challenges and Opportunities

Asthma is the most common chronic disease of childhood worldwide, and is responsible for significant morbidity and mortality in children and young people (CYP). Given the inherent dangers of a child experiencing even a single asthma attack, it is essential to identify and manage modifiable risk factors at every clinical opportunity. Following an attack, there is an opportunity to prevent future attacks by assessing compliance and optimizing asthma control. Careful questioning will allow physicians to identify asthma triggers, barriers to good asthma control, and health beliefs or socioeconomic obstacles that may have contributed to this attack. The vast majority of children with asthma can achieve good symptom control with appropriate use of low-dose inhaled corticosteroids.

Stating the obvious: intravenous magnesium sulphate should be the first parenteral bronchodilator in paediatric asthma exacerbations unresponsive to first-line therapy

What is the most appropriate second-line intravenous bronchodilator treatment when a child with a severe asthma attack is not responsive to initial inhaled therapy? The second-line treatment options for acute asthma include parenteral β₂-agonists, methylxanthine and magnesium sulphate (MgSO₄). There is a poor evidence-base to inform this decision. This review argues that intravenous MgSO₄ is the obvious treatment of choice for this situation as the initial treatment based on current knowledge.  We describe the mode of action, scope and limitations of MgSO₄, safety profile, economic impact, comparisons of the alternatives, and finally, what the guidelines say.  This review explores the suitability of intravenous MgSO₄ as a pragmatic and safe initial second-line therapy for children unresponsive to initial asthma management.

Management of asthma in childhood: study protocol of a systematic evidence update by the Paediatric Asthma in Real Life (PeARL) Think Tank

INTRODUCTION

Clinical recommendations for childhood asthma are often based on data extrapolated from studies conducted in adults, despite significant differences in mechanisms and response to treatments. The Paediatric Asthma in Real Life (PeARL) Think Tank aspires to develop recommendations based on the best available evidence from studies in children. An overview of systematic reviews (SRs) on paediatric asthma maintenance management and an SR of treatments for acute asthma attacks in children, requiring an emergency presentation with/without hospital admission will be conducted.

METHODS AND ANALYSIS

Standard methodology recommended by Cochrane will be followed. Maintenance pharmacotherapy of childhood asthma will be evaluated in an overview of SRs published after 2005 and including clinical trials or real-life studies. For evaluating pharmacotherapy of acute asthma attacks leading to an emergency presentation with/without hospital admission, we opted to conduct de novo synthesis in the absence of adequate up-to-date published SRs. For the SR of acute asthma pharmacotherapy, we will consider eligible SRs, clinical trials or real-life studies without time restrictions. Our evidence updates will be based on broad searches of Pubmed/Medline and the Cochrane Library. We will use A MeaSurement Tool to Assess systematic Reviews, V.2, Cochrane risk of bias 2 and REal Life EVidence AssessmeNt Tool to evaluate the methodological quality of SRs, controlled clinical trials and real-life studies, respectively.Next, we will further assess interventions for acute severe asthma attacks with positive clinical results in meta-analyses. We will include both controlled clinical trials and observational studies and will assess their quality using the previously mentioned tools. We will employ random effect models for conducting meta-analyses, and Grading of Recommendations Assessment, Development and Evaluation methodology to assess certainty in the body of evidence.

ETHICS AND DISSEMINATION

Ethics approval is not required for SRs. Our findings will be published in peer reviewed journals and will inform clinical recommendations being developed by the PeARL Think Tank.

PROSPERO REGISTRATION NUMBERS

CRD42020132990, CRD42020171624.

Paediatrics: how to manage acute asthma exacerbations

Background

Asthma is the most common chronic disease of childhood and a major source of childhood health burden worldwide. These burdens are particularly marked when children experience characteristic ‘symptom flare-ups’ or acute asthma exacerbations (AAEs). AAE are associated with significant health and economic impacts, including acute Emergency Department visits, occasional hospitalizations, and rarely, death. To treat children with AAE, several medications have been studied and used.

Methods

We conducted a narrative review of the literature with the primary objective of understanding the evidence of their efficacy. We present this efficacy evidence in the context of a general stepwise management pathway for paediatric AAEs. This framework is developed from the combined recommendations of eight established (inter)national paediatric guidelines.

Discussion

Management of paediatric AAE centres around four major care goals: (1) immediate and objective assessment of AAE severity; (2) prompt and effective medical interventions to decrease respiratory distress and improve oxygenation; (3) appropriate disposition of patient; and (4) safe discharge plans. Several medications are currently recommended with varying efficacies, including heliox, systemic corticosteroids, first-line bronchodilators (salbutamol/albuterol), adjunctive bronchodilators (ipratropium bromide, magnesium sulfate) and second-line bronchodilators (aminophylline, i.v. salbutamol, i.v. terbutaline, epinephrine, ketamine). Care of children with AAE is further enhanced using clinical severity scoring, pathway-driven care and after-event discharge planning.

Conclusions

AAEs in children are primarily managed by medications supported by a growing body of literature. Continued efforts to study the efficacy of second-line bronchodilators, integrate AAE management with long-term asthma control and provide fair/equitable care are required.

Analysis of the Efficacy and Mechanism of Action of Xuebijing Injection on ARDS Using Meta-Analysis and Network Pharmacology

Objective

Acute respiratory distress syndrome (ARDS) is defined as the acute onset of noncardiogenic edema and subsequent gas-exchange impairment due to a severe inflammatory process known as cytokine storm. Xuebijing injection (hereinafter referred to as Xuebijing) is a patent drug that was used to treat ARDS or severe pneumonia (SP) in China. However, its efficacy and mechanism of actions remain unclear. In this study, we used meta-analysis and network pharmacology to assess these traits of Xuebijing.

Methods

We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang databases for randomized controlled trials (RCTs) that evaluated Xuebijing therapy for ARDS or SP. The outcomes were total mortality, intensive care unit (ICU) stay time, and TNF-α and IL-6 levels. We performed a meta-analysis using RevMan 5.3 software. The putative targets, top 10 proteins, and possible pathway of Xuebinjing on ARDS were analyzed by network pharmacology. TNF-α and IL-6 were further docked with the six main active components of Xuebinjing using AutoDock 4.2.6 and PyMol 1.5.0.3 software.

Results

Fifteen RCTs involving 2778 patients (13 ARDS and 2 SP) were included. Compared with the control, Xuebijing treatment significantly reduced the mortality rate (risk ratio, 0.64 (95% credible interval (CrI), 0.54-0.77)), reduced the ICU stay time (mean difference (MD), -4.51 (95% CrI, -4.97--4.06)), reduced the TNF-α ((MD), -1.23 (95% CrI, -1.38--1.08)) and IL-6 ((MD), -1.15 (95% CrI, -1.52--0.78)) levels. The 56 putative targets, top 10 proteins (MAPK1 (mitogen-activated protein kinase 1), MAPK8 (mitogen-activated protein kinase 8), RELA (transcription factor p65), NFKB1 (nuclear factor NF-kappa-B p105 subunit), JUN (transcription factor AP-1), SRC (proto-oncogene tyrosine-protein kinase), TNF (tumor necrosis factor), HRAS (GTPase HRas), IL6 (interleukin-6), and APP (amyloid-beta A4 protein)), and possible pathways (Ret tyrosine kinase, IL2-mediated signaling events, CD4+/CD8+ T cell-related TCR signaling, p75(NTR)-mediated signaling, CXCR4-mediated signaling events, LPA receptor-mediated events, IL12-mediated signaling events, FAS (CD95) signaling pathway, and immune system) of Xuebinjing's action on ARDS were obtained. The molecular docking results showed that all the six components of Xuebinjing docked with TNF-α, and two components docked with IL-6 got the binding energies lower than -5.

Conclusion

Our results recommended Xuebijing treatment for patients with ARDS. Xuebijing has therapeutic effects on ARDS patients partly by regulating the immune cell/cytokine pathways and thus inhibiting the cytokine storm. TNF-α is the cytokine both directly and indirectly inhibited by Xuebijing, and IL-6 is the cytokine mainly indirectly inhibited by Xuebijing.

Emergency department treatment of asthma in children: A review

Asthma is the most common chronic illness in children, with >700,000 emergency department (ED) visits each year. Asthma is a respiratory disease characterized by a combination of airway inflammation, bronchoconstriction, bronchial hyperresponsiveness, and variable outflow obstruction, with clinical presentations ranging from mild to life-threatening. Standardized ED treatment can improve patient outcomes, including fewer hospital admissions. Informed by the most recent guidelines, this review focuses on the optimal approach to diagnosis and treatment of children with acute asthma exacerbations who present to the ED.

Treating acute severe asthma attacks in children: using aminophylline

Aminophylline does have a role in treating severe asthma attacks in children with asthma. Clinicians just need to be aware of the toxic side-effects of the drug and manage the drug carefully. https://bit.ly/3o7IJV1.

Interventions for escalation of therapy for acute exacerbations of asthma in children: an overview of Cochrane Reviews

BACKGROUND

Asthma is an illness that commonly affects adults and children, and it serves as a common reason for children to attend emergency departments. An asthma exacerbation is characterised by acute or subacute worsening of shortness of breath, cough, wheezing, and chest tightness and may be triggered by viral respiratory infection, poor compliance with usual medication, a change in the weather, or exposure to allergens or irritants. Most children with asthma have mild or moderate exacerbations and respond well to first-line therapy (inhaled short-acting beta-agonists and systemic corticosteroids). However, the best treatment for the small proportion of seriously ill children who do not respond to first-line therapy is not well understood. Currently, a large number of treatment options are available and there is wide variation in management.

OBJECTIVES

Main objective - To summarise Cochrane Reviews with or without meta-analyses of randomised controlled trials on the efficacy and safety of second-line treatment for children with acute exacerbations of asthma (i.e. after first-line treatments, titrated oxygen delivery, and administration of intermittent inhaled short-acting beta₂-agonists and oral corticosteroids have been tried and have failed) Secondary objectives - To identify gaps in the current evidence base that will inform recommendations for future research and subsequent Cochrane Reviews - To categorise information on reported outcome measures used in trials of escalation of treatment for acute exacerbations of asthma in children, and to make recommendations for development and reporting of standard outcomes in future trials and reviews - To identify relevant randomised controlled trials that have been published since the date of publication of each included review METHODS: We included Cochrane Reviews assessing interventions for children with acute exacerbations of asthma. We searched the Cochrane Database of Systematic Reviews. The search is current to 28 December 2019. We also identified trials that were potentially eligible for, but were not currently included in, published reviews. We assessed the quality of included reviews using the ROBIS criteria (tool used to assess risk of bias in systematic reviews). We presented an evidence synthesis of data from reviews alongside an evidence map of clinical trials. Primary outcomes were length of stay, hospital admission, intensive care unit admission, and adverse effects. We summarised all findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We identified 17 potentially eligible Cochrane Reviews but extracted data from, and rated the quality of, 13 reviews that reported results for children alone. We excluded four reviews as one did not include any randomised controlled trials (RCTs), one did not provide subgroup data for children, and the last two had been updated and replaced by subsequent reviews. The 13 reviews included 67 trials; the number of trials in each review ranged from a single trial up to 27 trials. The vast majority of comparisons included between one and three trials, involving fewer than 100 participants. The total number of participants included in reviews ranged from 40 to 2630. All studies included children; 16 (24%) included children younger than two years of age. Most of the reviews reported search dates older than four years. We have summarised the published evidence as outlined in Cochrane Reviews. Key findings, in terms of our primary outcomes, are that (1) intravenous magnesium sulfate was the only intervention shown to reduce hospital length of stay (high-certainty evidence); (2) no evidence suggested that any intervention reduced the risk of intensive care admission (low- to very low-certainty evidence); (3) the risk of hospital admission was reduced by the addition of inhaled anticholinergic agents to inhaled beta₂-agonists (moderate-certainty evidence), the use of intravenous magnesium sulfate (high-certainty evidence), and the use of inhaled heliox (low-certainty evidence); (4) the addition of inhaled magnesium sulfate to usual bronchodilator therapy appears to reduce serious adverse events during hospital admission (moderate-certainty evidence); (5) aminophylline increased vomiting compared to placebo (moderate-certainty evidence) and increased nausea and nausea/vomiting compared to intravenous beta₂-agonists (low-certainty evidence); and (6) the addition of anticholinergic therapy to short-acting beta₂-agonists appeared to reduce the risk of nausea (high-certainty evidence) and tremor (moderate-certainty evidence) but not vomiting (low-certainty evidence). We considered 4 of the 13 reviews to be at high risk of bias based on the ROBIS framework. In all cases, this was due to concerns regarding identification and selection of studies. The certainty of evidence varied widely (by review and also by outcome) and ranged from very low to high.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on interventions for escalation of therapy for acute exacerbations of asthma in children from Cochrane Reviews of randomised controlled trials. A vast majority of comparisons involved between one and three trials and fewer than 100 participants, making it difficult to assess the balance between benefits and potential harms. Due to the lack of comparative studies between various treatment options, we are unable to make firm practice recommendations. Intravenous magnesium sulfate appears to reduce both hospital length of stay and the risk of hospital admission. Hospital admission is also reduced with the addition of inhaled anticholinergic agents to inhaled beta₂-agonists. However, further research is required to determine which patients are most likely to benefit from these therapies. Due to the relatively rare incidence of acute severe paediatric asthma, multi-centre research will be required to generate high-quality evidence. A number of existing Cochrane Reviews should be updated, and we recommend that a new review be conducted on the use of high-flow nasal oxygen therapy. Important priorities include development of an internationally agreed core outcome set for future trials in acute severe asthma exacerbations and determination of clinically important differences in these outcomes, which can then inform adequately powered future trials.