Inhaled magnesium sulfate in the treatment of acute asthma

The role of magnesium in cardiac arrest

Cardiac arrest is a leading cause of death globally. Only 25.8% of in-hospital and 33.5% of out-of-hospital individuals who achieve spontaneous circulation following cardiac arrest survive to leave the hospital. Respiratory failure and acute coronary syndrome are the two most common etiologies of cardiac arrest. Effort has been made to improve the outcomes of individuals resuscitated from cardiac arrest. Magnesium is an ion that is critical to the function of all cells and organs. It is often overlooked in everyday clinical practice. At present, there have only been a small number of reviews discussing the role of magnesium in cardiac arrest. In this review, for the first time, we provide a comprehensive overview of magnesium research in cardiac arrest focusing on the effects of magnesium on the occurrence and prognosis of cardiac arrest, as well as in the two main diseases causing cardiac arrest, respiratory failure and acute coronary syndrome. The current findings support the view that magnesium disorder is associated with increased risk of cardiac arrest as well as respiratory failure and acute coronary syndrome.

Correlation Between Serum Magnesium Level and Acute Exacerbation in Patients With Chronic Obstructive Pulmonary Disease (COPD)

Introduction

Although chronic obstructive pulmonary disease (COPD) is preventable and treatable, it is a major public health problem. The mortality risks are higher in patients with exacerbations. Magnesium (Mg) is crucial in numerous physiological processes, including membrane stabilization. However, incomplete information is available regarding the effect of magnesium on the frequency of acute exacerbation of COPD.

Objectives

To determine the serum magnesium level in COPD patients and its correlation with acute exacerbation of COPD.

Materials and methods

This cross-sectional study included 100 patients diagnosed with acute exacerbation of COPD. The serum magnesium level was measured in all patients with acute exacerbation of COPD at admission. Serum Mg level <1.7 mg/dl was considered hypomagnesemia. The correlation between serum magnesium level and duration of hospital stay and patient outcome was studied. 

Results

In the present study, hypomagnesemia was reported in 57% of patients with acute exacerbation of COPD. The duration of hospital stay (more than seven days) among hypomagnesemia (80.7%) patients was significantly higher than that of the normomagnesemia patients (55.8%). Mortality in patients with hypomagnesemia was higher than in patients with normomagnesemia, although not statistically significant.

Conclusion

Hypomagnesaemia is a common finding in acute exacerbation of COPD. The level of magnesium found is related to the length of hospital stay, but it is not related to mortality among patients with acute exacerbation of COPD. Further studies with larger sample sizes and extended follow-up periods are required to validate the results.

Possibility of magnesium supplementation for supportive treatment in patients with COVID-19

Magnesium as an enzymatic activator is essential for various physiological functions such as cell cycle, metabolic regulation, muscle contraction, and vasomotor tone. A growing body of evidence supports that magnesium supplementation (mainly magnesium sulfate and magnesium oxide) prevents or treats various types of disorders or diseases related to respiratory system, reproductive system, nervous system, digestive system, and cardiovascular system as well as kidney injury, diabetes and cancer. The ongoing pandemic coronavirus disease 19 (COVID-19) characterized by respiratory tract symptoms with different degrees of important organ and tissue damages has attracted global attention. Particularly, effective drugs are still lacking in the COVID-19 therapy. In this review, we find and summarize the effectiveness of magnesium supplementation on the disorders or diseases, and provide a reference to the possibility of magnesium supplementation for supportive treatment in patients with COVID-19.

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.

Acute severe paediatric asthma: study protocol for the development of a core outcome set, a Pediatric Emergency Reserarch Networks (PERN) study

BACKGROUND

Acute severe childhood asthma is an infrequent, but potentially life-threatening emergency condition. There is a wide range of different approaches to this condition, with very little supporting evidence, leading to significant variation in practice. To improve knowledge in this area, there must first be consensus on how to conduct clinical trials, so that valid comparisons can be made between future studies. We have formed an international working group comprising paediatricians and emergency physicians from North America, Europe, Asia, the Middle East, Africa, South America, Central America, Australasia and the United Kingdom.

METHODS/DESIGN

A 5-stage approach will be used: (1) a comprehensive list of outcomes relevant to stakeholders will be compiled through systematic reviews and qualitative interviews with patients, families, and clinicians; (2) Delphi methodology will be applied to reduce the comprehensive list to a core outcome set; (3) we will review current clinical practice guidelines, existing clinical trials, and literature on bedside assessment of asthma severity. We will then identify practice differences in tne clinical assessment of asthma severity, and determine whether further prospective work is needed to achieve agreement on inclusion criteria for clinical trials in acute paediatric asthma in the emergency department (ED) setting; (4) a retrospective chart review in Australia and New Zealand will identify the incidence of serious clinical complications such as intubation, ICU admission, and death in children hospitalized with acute severe asthma. Understanding the incidence of such outcomes will allow us to understand how common (and therefore how feasible) particular outcomes are in asthma in the ED setting; and finally (5) a meeting of the Pediatric Emergency Research Networks (PERN) asthma working group will be held, with invitation of other clinicians interested in acute asthma research, and patients/families. The group will be asked to achieve consensus on a core set of outcomes and to make recommendations for the conduct of clinical trials in acute severe asthma. If this is not possible, the group will agree on a series of prioritized steps to achieve this aim.

DISCUSSION

The development of an international consensus on core outcomes is an important first step towards the development of consensus guidelines and standardised protocols for randomized controlled trials (RCTs) in this population. This will enable us to better interpret and compare future studies, reduce risks of study heterogeneity and outcome reporting bias, and improve the evidence base for the management of this important condition.

Inhaled magnesium sulfate in the treatment of acute asthma

BACKGROUND

Asthma exacerbations can be frequent and range in severity from mild to life-threatening. The use of magnesium sulfate (MgSO₄) is one of numerous treatment options available during acute exacerbations. While the efficacy of intravenous MgSO₄ has been demonstrated, the role of inhaled MgSO₄ is less clear.

OBJECTIVES

To determine the efficacy and safety of inhaled MgSO₄ administered in acute asthma.

SPECIFIC AIMS

to quantify the effects of inhaled MgSO₄ I) in addition to combination treatment with inhaled β₂-agonist and ipratropium bromide; ii) in addition to inhaled β₂-agonist; and iii) in comparison to inhaled β₂-agonist.

SEARCH METHODS

We identified randomised controlled trials (RCTs) from the Cochrane Airways Group register of trials and online trials registries in September 2017. We supplemented these with searches of the reference lists of published studies and by contact with trialists.

SELECTION CRITERIA

RCTs including adults or children with acute asthma were eligible for inclusion in the review. We included studies if patients were treated with nebulised MgSO₄ alone or in combination with β₂-agonist or ipratropium bromide or both, and were compared with the same co-intervention alone or inactive control.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial selection, data extraction and risk of bias. We made efforts to collect missing data from authors. We present results, with their 95% confidence intervals (CIs), as mean differences (MDs) or standardised mean differences (SMDs) for pulmonary function, clinical severity scores and vital signs; and risk ratios (RRs) for hospital admission. We used risk differences (RDs) to analyse adverse events because events were rare.

MAIN RESULTS

Twenty-five trials (43 references) of varying methodological quality were eligible; they included 2907 randomised patients (2777 patients completed). Nine of the 25 included studies involved adults; four included adult and paediatric patients; eight studies enrolled paediatric patients; and in the remaining four studies the age of participants was not stated. The design, definitions, intervention and outcomes were different in all 25 studies; this heterogeneity made direct comparisons difficult. The quality of the evidence presented ranged from high to very low, with most outcomes graded as low or very low. This was largely due to concerns about the methodological quality of the included studies and imprecision in the pooled effect estimates. Inhaled magnesium sulfate in addition to inhaled β₂-agonist and ipratropiumWe included seven studies in this comparison. Although some individual studies reported improvement in lung function indices favouring the intervention group, results were inconsistent overall and the largest study reporting this outcome found no between-group difference at 60 minutes (MD -0.3 % predicted peak expiratory flow rate (PEFR), 95% CI -2.71% to 2.11%). Admissions to hospital at initial presentation may be reduced by the addition of inhaled magnesium sulfate (RR 0.95, 95% CI 0.91 to 1.00; participants = 1308; studies = 4; I² = 52%) but no difference was detected for re-admissions or escalation of care to ITU/HDU. Serious adverse events during admission were rare. There was no difference between groups for all adverse events during admission (RD 0.01, 95% CI -0.03 to 0.05; participants = 1197; studies = 2). Inhaled magnesium sulfate in addition to inhaled β₂-agonistWe included 13 studies in this comparison. Although some individual studies reported improvement in lung function indices favouring the intervention group, none of the pooled results showed a conclusive benefit as measured by FEV1 or PEFR. Pooled results for hospital admission showed a point estimate that favoured the combination of MgSO₄ and β₂-agonist, but the confidence interval includes the possibility of admissions increasing in the intervention group (RR 0.78, 95% CI 0.52 to 1.15; participants = 375; studies = 6; I² = 0%). There were no serious adverse events reported by any of the included studies and no between-group difference for all adverse events (RD -0.01, 95% CI -0.05 to 0.03; participants = 694; studies = 5). Inhaled magnesium sulfate versus inhaled β₂-agonistWe included four studies in this comparison. The evidence for the efficacy of β₂-agonists in acute asthma is well-established and therefore this could be considered a historical comparison. Two studies reported a benefit of β₂-agonist over MgSO₄ alone for PEFR and two studies reported no difference; we did not pool these results. Admissions to hospital were only reported by one small study and events were rare, leading to an uncertain result. No serious adverse events were reported in any of the studies in this comparison; one small study reported mild to moderate adverse events but the result is imprecise.

AUTHORS' CONCLUSIONS

Treatment with nebulised MgSO₄ may result in modest additional benefits for lung function and hospital admission when added to inhaled β₂-agonists and ipratropium bromide, but our confidence in the evidence is low and there remains substantial uncertainty. The recent large, well-designed trials have generally not demonstrated clinically important benefits. Nebulised MgSO₄ does not appear to be associated with an increase in serious adverse events. Individual studies suggest that those with more severe attacks and attacks of shorter duration may experience a greater benefit but further research into subgroups is warranted.Despite including 24 trials in this review update we were unable to pool data for all outcomes of interest and this has limited the strength of the conclusions reached. A core outcomes set for studies in acute asthma is needed. This is particularly important in paediatric studies where measuring lung function at the time of an exacerbation may not be possible. Placebo-controlled trials in patients not responding to standard maximal treatment, including inhaled β₂-agonists and ipratropium bromide and systemic steroids, may help establish if nebulised MgSO₄ has a role in acute asthma. However, the accumulating evidence suggests that a substantial benefit may be unlikely.

Magnesium nebulization utilization in management of pediatric asthma (MagNUM PA) trial: study protocol for a randomized controlled trial

BACKGROUND

Up to 30 % of children with acute asthma are refractory to initial therapy, and 84 % of this subpopulation needs hospitalization. Finding safe, noninvasive, and effective strategies to treat this high-risk group would substantially decrease hospitalizations, healthcare costs, and the psycho-social burden of the disease. Whereas intravenous magnesium (Mg) is effective in severe refractory asthma, its use is sporadic due to safety concerns, with the main treatment goal being to prevent intensive care unit admission. In contrast, nebulized Mg is noninvasive, allows higher pulmonary drug concentrations, and has a much higher safety potential due to the lower rate of systemic delivery. Previous studies of inhaled Mg show disparate results due to the use of unknown/inefficient delivery methods and other methodological flaws.

METHODS/DESIGN

The study is a randomized double-blind controlled trial in seven Canadian pediatric Emergency Departments (two-center pilot 2011 to 2014, Canada-wide November 2014 to December 2017). The trial will include 816 otherwise healthy children who are 2 to 17 years old, having had at least one previous wheezing episode, have received systemic corticosteroids, and have a Pediatric Respiratory Assessment Measure (PRAM) ≥ 5 points after three salbutamol and ipratropium treatments for a current acute asthma exacerbation. Eligible consenting children will receive three experimental treatments of nebulized salbutamol with either 600 mg of Mg sulfate or placebo 20 min apart, using an Aeroneb Go nebulizer, which has been shown to maximize pulmonary delivery while maintaining safety. The primary outcome is hospitalization within 24 h of the start of the experimental therapy for persistent respiratory distress or supplemental oxygen. Secondary outcomes include all-cause hospitalization within 24 h, PRAM, vital signs, number of bronchodilator treatments by 240 min, and the association between the difference in the primary outcome between the groups, age, gender, baseline PRAM, atopy, and "viral induced wheeze" phenotype (Fig. 1).

DISCUSSION

If effective, inhaled Mg may represent an effective strategy to minimize morbidity in pediatric refractory acute asthma. Unlike previous works, this trial targets nonresponders to optimized initial therapy who are the most likely to benefit from inhaled Mg. Future dissemination of results will include knowledge translation, incorporation into a Cochrane Review, presentation at scientific meetings, and a peer-reviewed publication.

TRIAL REGISTRATION

NCTO1429415 , registered 2 September 2011.

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.

Nebulized magnesium for moderate and severe pediatric asthma: A randomized trial

BACKGROUND

Intravenous magnesium sulfate, a rescue therapy added to bronchodilator and systemic steroid therapy for moderate and severe asthma, is uncommonly administered. We hypothesized that nebulized magnesium would confer benefit without undue risk.

DESIGN AND METHODS

Patients aged 2 to 14 y with moderate and severe asthma (PRAM severity score ≥ 4) admitted to infirmary/observation unit care were randomized double-blind on admission to receive 800 mg nebulized magnesium or normal saline placebo after all received intensive therapy with combined nebulized albuterol-ipratropium and intravenous methylprednisolone. Time to medical readiness for discharge was the primary outcome; sample size was chosen to detect a 15% absolute improvement. Improvement over time in PRAM severity score and other secondary outcomes were compared for the overall group and severe asthma subset.

RESULTS

One hundred and ninety-one magnesium sulfates and 174 placebo patients met criteria for analysis. The groups were similar with mean baseline PRAM scores >7. Blinded active therapy significantly increased blood magnesium level 2 hr post-treatment completion compared to placebo, 0.85 vs 0.82 mmol/L, P = 0.001. There were no important adverse effects. Accelerated failure time analysis showed a non-significantly shortened time to medical readiness for discharge of 14% favoring the magnesium sulfate group, OR = 1.14, 95% CI 0.93 to 1.40, P = 0.20. Mean times until readiness for discharge were 14.7 hr [SD 9.7] versus 15.6 hr [SD 11.3] for the investigational and placebo groups, respectively, P = 0.41.

CONCLUSIONS

Adding nebulized magnesium to combined nebulized bronchodilator and systemic steroid therapy failed to significantly shorten time to discharge of pediatric patients with moderate or severe asthma.

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.

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.

[Respiratory emergencies and airway management in children]

Respiratory emergencies in children are frequent and are caused by the specific airway anatomy and the susceptibility for infections.This article reviews the specific approach to pediatric airway management. According to the ABC guidelines of the European Resuscitation Council, the described algorithm should help to identify, classify, and treat such emergencies, giving those with less pediatric experience a tool for the management of respiratory illness in children. Focus is on the emergency care of the most common diseases in this age group.

Effect of inhaled magnesium sulfate on bronchial hyperresponsiveness

OBJECTIVES

To determine the response of nebulized magnesium sulfate on the lung function of children with bronchial hyperresponsiveness.

METHODS

Eighty-four children with asthma were divided into three groups randomly: magnesium sulfate (M), albuterol (A), and a combination of magnesium sulfate and albuterol (M + A). All patients were nebulized with acetylcholine, and then treated as designed. Lung function was compared between the three groups.

RESULTS

Forced expiratory volume in first second (FEV1) significantly improved in all the three groups but it was better in (A) and (M + A) compared to (M) at 10 min and 20 min [10 min: 1.26 L ± 0.53 (A) vs. 1.10 L ± 0.27 (M), 1.35 L ± 0.59 (M + A) vs. 1.10 L ± 0.27 (M), p < 0.05; 20 min: 1.32 L ± 0.61 (A) vs. 1.17 L ± 0.30 (M), 1.42 L ± 0.59 (M + A) vs. 1.17 L ± 0.30 (M), p < 0.05]. Variation of FEV1, as absolute value at 10 min or 20 min over post-Ach FEV1 was significantly different in (A) or (M + A) compared to (M).

CONCLUSIONS

Nebulized albuterol and magnesium sulfate + albuterol can more effectively improve FEV1 in children with bronchial hyperresponsiveness than nebulized magnesium sulfate at 10 min and 20 min after inhalation. It is further suggested that addition of magnesium sulfate to albuterol does not result in additional benefit.

Interventions for managing asthma in pregnancy

BACKGROUND

Asthma is the most common respiratory disorder complicating pregnancy, and is associated with a range of adverse maternal and perinatal outcomes. There is strong evidence however, that the adequate control of asthma can improve health outcomes for mothers and their babies. Despite known risks of poorly controlled asthma during pregnancy, a large proportion of women have sub-optimal asthma control, due to concerns surrounding risks of pharmacological agents, and uncertainties regarding the effectiveness and safety of different management strategies.

OBJECTIVES

To assess the effects of interventions (pharmacologic and non-pharmacologic) for managing women's asthma in pregnancy on maternal and fetal/infant outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 June 2014) and the Cochrane Airways Group's Trials Register (4 June 2014).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing any intervention used to manage asthma in pregnancy, with placebo, no intervention, or an alternative intervention. We included pharmacological and non-pharmacological interventions (including combined interventions). Cluster-randomised trials were eligible for inclusion (but none were identified). Cross-over trials were not eligible for inclusion.We included multi-armed trials along with two-armed trials. We also included studies published as abstracts only.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial eligibility and quality and extracted data. Data were checked for accuracy.

MAIN RESULTS

We included eight trials in this review, involving 1181 women and their babies. Overall we judged two trials to be at low risk of bias, two to be of unclear risk of bias, and four to be at moderate risk of bias.Five trials assessed pharmacological agents, including inhaled corticosteroids (beclomethasone or budesonide), inhaled magnesium sulphate, intravenous theophylline, and inhaled beclomethasone verus oral theophylline. Three trials assessed non-pharmacological interventions, including a fractional exhaled nitric oxide (FENO)-based algorithm versus a clinical guideline-based algorithm to adjust inhaled corticosteroid therapy, a pharmacist-led multi-disciplinary approach to management versus standard care, and progressive muscle relaxation (PMR) versus sham training.The eight included trials were assessed under seven separate comparisons. Pharmacological interventionsPrimary outcomes: one trial suggested that inhaled magnesium sulphate in addition to usual treatment could reduce exacerbation frequency in acute asthma (mean difference (MD) -2.80; 95% confidence interval (CI) -3.21 to -2.39; 60 women). One trial assessing the addition of intravenous theophylline to standard care in acute asthma did not report on exacerbations (65 women). No clear difference was shown in the risk of exacerbations with the use of inhaled beclomethasone in addition to usual treatment for maintenance therapy in one trial (risk ratio (RR) 0.36; 95% CI 0.13 to 1.05; 60 women); a second trial also showed no difference, however data were not clearly reported to allow inclusion in a meta-analysis. No difference was shown when inhaled beclomethasone was compared with oral theophylline for maintenance therapy (RR 0.88; 95% CI 0.59 to 1.33; one trial, 385 women). None of these trials reported on neonatal intensive care admissions.

SECONDARY OUTCOMES

inhaled magnesium sulphate in acute asthma was shown to improve lung function measures (one trial, 60 women); intravenous theophylline in acute asthma was not associated with benefits (one trial, 65 women). No clear differences were seen with the addition of inhaled corticosteroids to routine treatment in three trials (374 women). While inhaled beclomethasone, compared with oral theophylline, significantly reduced treatment discontinuation due to adverse effects in one trial (384 women), no other differences were observed, except for higher treatment adherence with theophylline. Four of the five trials did not report on adverse effects. Non-pharmacological interventionsPrimary outcomes: in one trial, the use of a FENO-based algorithm was shown to significantly reduce asthma exacerbations (RR 0.61; 95% CI 0.41 to 0.90; 220 women); and a trend towards fewer neonatal hospitalisations was observed (RR 0.46; 95% CI 0.21 to 1.02; 214 infants). No exacerbations occurred in one trial assessing pharmacist-led management; this approach did not reduce neonatal intensive care admissions (RR 1.50; 95% CI 0.27 to 8.32; 58 infants). One trial (64 women) assessing PMR did not report on exacerbations or neonatal intensive care admissions.

SECONDARY OUTCOMES

the use of a FENO-based algorithm to adjust therapy led to some improvements in quality of life scores, as well as more frequent use of inhaled corticosteroids and long-acting β-agonists, and less frequent use of short-acting β-agonists (one trial, 220 women). The FENO-based algorithm was associated with fewer infants with recurrent episodes of bronchiolitis in their first year of life, and a trend towards fewer episodes of croup for infants. Pharmacist-led management improved asthma control scores at six months (one trial, 60 women); PMR improved lung function and quality of life measures (one trial, 64 women). No other differences between comparisons were observed.

AUTHORS' CONCLUSIONS

Based on eight included trials, of moderate quality overall, no firm conclusions about optimal interventions for managing asthma in pregnancy can be made. Five trials assessing pharmacological interventions did not provide clear evidence of benefits or harms to support or refute current practice. While inhaled magnesium sulphate for acute asthma was shown to reduce exacerbations, this was in one small trial of unclear quality, and thus this finding should be interpreted with caution. Three trials assessing non-pharmacological interventions provided some support for the use of such strategies, however were not powered to detect differences in important maternal and infant outcomes. While a FENO-based algorithm reduced exacerbations, the effects on perinatal outcomes were less certain, and thus widespread implementation is not yet appropriate. Similarly, though positive effects on asthma control were shown with PMR and pharmacist-led management, the evidence to date is insufficient to draw definitive conclusions.In view of the limited evidence base, further randomised trials are required to determine the most effective and safe interventions for asthma in pregnancy. Future trials must be sufficiently powered, and well-designed, to allow differences in important outcomes for mothers and babies to be detected. The impact on health services requires evaluation. Any further trials assessing pharmacological interventions should assess novel agents or those used in current practice. Encouragingly, at least five trials have been identified as planned or underway.

The efficacy of nebulized salbutamol, magnesium sulfate, and salbutamol/magnesium sulfate combination in moderate bronchiolitis

The aim of this paper is to compare the effect of nebulized magnesium sulfate to nebulized salbutamol and salbutamol/magnesium sulfate on successful discharge from the emergency department. A total of 56 infants were included in this double-blinded, prospective study. Infants were grouped according to the nebulized treatment they received: group 1-salbutamol/normal saline, group 2-magnesium sulfate and normal saline, and group 3-salbutamol plus magnesium sulfate. Heart beat, bronchiolitis, clinical severity scores (CSS), and oxygen saturation of the patients were determined before and after nebulization (0, 1, 4 h). The patients were monitored for adverse reactions. Post-treatment mean CSS results were significantly lower than pre-treatment scores in all groups at 4 h with no significant difference within groups. CSS scores were lower in the salbutamol/magnesium sulfate group when compared with the magnesium sulfate and salbutamol groups (3.4 (2.4-4.3), 4.7 (3.8-5.7), 4.0 (3.2-4.3)). CSS were significantly lower than those from the magnesium sulfate group.

CONCLUSION

Nebulized magnesium sulfate plus salbutamol may have additive effects for improving the short-term CSS.

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.

Magnesium for acute exacerbation of chronic obstructive pulmonary disease: A systematic review of randomised trials

The efficacy of magnesium sulphate in chronic obstructive pulmonary disease (COPD) was assessed by conducting a systematic review of published randomized clinical trials through extensive searches in MEDLINE and SCOPUS with no date limits, as well as manual review of journals. Outcome measures varied depending on route(s) of administration of magnesium sulphate and medications co-administered. Risk of bias was evaluated and quality of evidence was graded. Four (4) randomized trials were included. All trials had a moderate risk of bias and were of average methodological quality. Magnesium sulphate given intravenously did not seem to have an immediate bronchodilatory effect; however it appears to potentiate the bronchodilatory effect of inhaled beta-2 agonists. Increase in peak expiratory flow rate (PEFR) at 30 and 45 min was greater in those who received magnesium sulphate compared to placebo (P = 0.03), although the mean percentage change in PEFR was just 24%, without significant differences in dyspnoea scores, hospital admission rates, or emergency department readmission rates compared to placebo. Nebulized magnesium sulphate with salbutamol versus nebulized salbutamol with saline placebo showed no significant differences is forced expiratory volume in 1 s (FEV₁) measured at 90 min after adjustment for baseline FEV₁ (P = 0.34) or differences in the need for hospital admission. Combined inhalational and intravenous magnesium sulphate versus intravenous saline placebo and nebulized ipratropium bromide were comparable in terms of hospital admission, intubation and death, but the ipratropium bromide group showed better bronchodilator effect and improvement in arterial blood gas parameters. Overall, trial evidence for trial evidence for magnesium sulphate in acute exacerbation of COPD is poor, and further well-designed trials are needed.

Magnesium sulphate in acute severe asthma in children (MAGNETIC): a randomised, placebo-controlled trial

BACKGROUND

Little evidence is available for the effect of nebulised magnesium sulphate (MgSO(4)) in acute asthma in children. We assessed the effect of MgSO(4) treatment in children with severe acute asthma.

METHODS

In this randomised placebo-controlled, multi-centre, parallel trial, we enrolled children (aged 2-16 years) with severe acute asthma who did not respond to standard inhaled treatment from 30 hospitals in the UK. Children were randomly allocated (1:1) to receive nebulised salbutamol and ipratropium bromide with either 2·5 mL of isotonic MgSO(4) (250 mmol/L; 151 mg per dose; MgSO(4) group) or 2·5 mL of isotonic saline (placebo group) on three occasions at 20-min intervals. Randomisation was done with a computer-generated randomisation sequence, with random block sizes of two to four. Both patients and researchers were masked to treatment allocation. The primary outcome measure was the Yung Asthma Severity Score (ASS) at 60 min post-randomisation. We used a statistical significance level of p<0·05 for a between-group difference, but regarded a between-group difference in ASS of 0·5 as the minimal clinically significant treatment effect. Analysis was done by intention to treat. This trial is registered with controlled-trials.com, number ISRCTN81456894.

FINDINGS

Between Jan 3, 2009, and March 20, 2011, we recruited and randomly assigned 508 children to treatment: 252 to MgSO(4) and 256 to placebo. Mean ASS at 60 min was lower in the MgSO(4) group (4·72 [SD 1·37]) than it was in the placebo group (4·95 [SD 1·40]; adjusted difference -0·25, 95% CI -0·48 to -0·02; p=0·03). This difference, however, was not clinically significant. The clinical effect was larger in children with more severe asthma exacerbation (p=0·03) and those with symptoms present for less than 6 h (p=0·049). We detected no difference in the occurrence of adverse events between groups.

INTERPRETATION

Overall, nebulised isotonic MgSO(4), given as an adjuvant to standard treatment, did not show a clinically significant improvement in mean ASS in children with acute severe asthma. However, the greatest clinical response was seen in children with more severe attacks (SaO(2)<92%) at presentation and those with preceding symptoms lasting less than 6 h.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.