Magnesium attenuates the neutrophil respiratory burst in adult asthmatic patients

Intravenous magnesium sulfate for asthma exacerbations in children: Systematic review with meta-analysis

BACKGROUND

Asthma is the most prevalent chronic disease in children and constitutes a significant healthcare burden. First-line therapy for acute asthma exacerbations is well established. However, secondary treatments, including intravenous magnesium sulfate (IV-MgSO4), remain variable due to scarcity of data on its efficacy and safety.

OBJECTIVE

To assess the effectiveness and safety of IV-MgSO4 as a second line of treatment in managing children with asthma exacerbations.

METHODS

We searched five databases from inception until April 2023 on randomized clinical trials of IV-MgSO4 in children with acute asthma exacerbations. The primary outcomes were hospitalization rate and length, and change in the severity score. Secondary outcomes included percentage increase in peak expiratory flow rate (PEFR), hospital re-admission rate, need and length for pediatric intensive care unit (PICU) treatment, and adverse effects. Meta-analysis was performed for three outcomes with estimated odds ratios (ORs) or mean differences (MDs) and 95% confidence intervals (CIs).

RESULTS

Eleven studies met the final criteria. In comparison to control, administration of IV-MgSO4 was associated with a reduced hospitalization risk (OR 0.15; 95%CI: 0.03, 0.73) in four studies, and improvement of lung function (MD 26.77% PEFR; 95%CI: 18.41, 54.79) in two studies. There were no significant differences in the length of stay between groups. Due to heterogeneity, a narrative synthesis of other outcomes was performed.

CONCLUSION

The use of IV-MgSO4 demonstrated a reduction in the hospitalization rate and PEFR improvement in children with asthma exacerbations. Adverse effects were rare. Further well-designed studies are needed to better determine the efficacy and safety profile of IV-MgSO4.

Intravenous Magnesium Sulfate for Acute Bronchiolitis: Evaluation of the Effect on Clinical Course and Outcomes

The aim of the present study was to assess the efficacy of intravenous (IV) magnesium sulfate (MgSO4) for children with bronchiolitis. A retrospective cohort study was performed at a pediatric emergency department. Aged between 1 and 24 months, children with moderate/severe bronchiolitis according to the Modified Respiratory Distress Assessment Instrument (mRDAI) score were included. Patients who received 40 mg/kg/dose of IV MgSO4 (group 1, n: 74) or not (group 2, n: 33) were compared. Respiratory rate and mRDAI score significantly decreased at the second hour of MgSO4 treatment and the decrease was observed for 4th, 8th, and 12th hours, compared with group 2. Patients in group 2 had a higher rate of requirement and an earlier start high-flow nasal cannula oxygen therapy and a longer hospital stay than group 1. Intravenous MgSO4 provided significant improvement on clinical severity, need for respiratory support, length of hospital stay, and outcomes.

Effect of magnesium sulfate on oxygenation and lung mechanics in morbidly obese patients undergoing bariatric surgery: a prospective double-blind randomized clinical trial

BACKGROUND

Respiratory mechanics are often significantly altered in morbidly obese patients and magnesium sulfate (MgSO4) is a promising agent for managing several respiratory disorders. This study aimed to examine the effects of MgSO4 infusions on arterial oxygenation and lung mechanics in patients with morbid obesity undergoing laparoscopic bariatric surgery.

METHODS

Forty patients with morbid obesity aged 21-60 years scheduled for laparoscopic bariatric surgery under general anesthesia were randomly allocated to either the control (normal saline infusion) or MgSO4 group (30 mg/kg lean body weight [LBW] of 10% MgSO4 in 100 ml normal saline intravenously over 30 min as a loading dose, followed by 10 mg/kg LBW/h for 90 min). The primary outcome was intraoperative arterial oxygenation (ΔPaO2/FiO2). Secondary outcomes included intraoperative static and dynamic compliance, dead space, and hemodynamic parameters.

RESULTS

At 90 min intraoperatively, the Δ PaO2/FiO2 ratio and the Δ dynamic lung compliance were statistically significantly higher in the MgSO4 group (mean ± SE: 16.1 ± 1.0, 95% CI [14.1, 18.1] and 8.4 ± 0.5 ml/cmH2O, 95% CI [7.4, 9.4]), respectively), and the Δ dead space (%) was statistically significantly lower in the MgSO4 group (mean ± SE: -8.0 ± 0.3%, 95% CI [-8.6, -7.4]) (P < 0.001). No significant differences in static compliance were observed.

CONCLUSIONS

Although MgSO4 significantly preserved arterial oxygenation and maintained dynamic lung compliance and dead space in patients with morbid obesity, the clinical relevance is minimal. This study failed to adequately reflect the clinical importance of these results.

Clinical outcomes of children with acute asthma managed with intravenous magnesium sulphate outside intensive care setting

Asthma in children constitutes a well-known respiratory condition with significant mortality. In poorly controlled asthma, multiple adjunct therapies including magnesium sulphate (MgSO4), are recommended to decrease the likelihood of intubation; however, limited evidence exists to support their routine usage in day-to-day situations. Aim of this study is to determine the outcomes of pediatric patients treated with magnesium sulphate during exacerbations of asthma admitted at a tertiary care unit. A retrospective study was conducted at The Aga Khan University Hospital, Karachi, Pakistan from January 2019 to December 2021. Patients aged 6 years to 15 years presented with acute asthma through Emergency Room (ER) having clinical respiratory score (CRS) more than five, admitted in high-dependency unit (HDU) were included in the study. Patients who were started on magnesium sulfate within 24 hours of admission were categorized in magnesium sulfate (MS) group. Patients receiving all standard acute asthma treatment but were not started on magnesium therapy within 24 hours of admission were categorized in the non-magnesium sulfate (non-MS) group. Different outcome variables were compared between the groups. A total of 110 patients with asthma were enrolled. Fifty-four patients were categorized into MS group while 56 were included in non-MS group. Fewer patients were transferred from HDU to pediatric intensive care unit (PICU) (24.07%) in MS group compared to non-MS group (42.85%), (p=0.02). In MS group, the mean number of days spent on oxygen in HDU were 2.38±0.81, while non-MS group spent more days (3.10±0.84 (p<0.01). This study demonstrates that for pediatric patients with severe asthma exacerbations, administration of IV MgSO4 (within 24 hours) is beneficial and results in fewer admissions to PICU and reduces the mean number of days spent on oxygen therapy.

Role of Magnesium in the Intensive Care Unit and Immunomodulation: A Literature Review

Both the role and the importance of magnesium in clinical practice have grown considerably in recent years. Emerging evidence suggests an association between loss of magnesium homeostasis and increased mortality in the critical care setting. The underlying mechanism is still unclear, but an increasing number of in vivo and in vitro studies on magnesium's immunomodulating capabilities may shed some light on the matter. This review aims to discuss the evidence behind magnesium homeostasis in critically ill patients, and its link with intensive care unit mortality via a likely magnesium-induced dysregulation of the immune response. The underlying pathogenetic mechanisms, and their implications for clinical outcomes, are discussed. The available evidence strongly supports the crucial role of magnesium in immune system regulation and inflammatory response. The loss of magnesium homeostasis has been associated with an elevated risk of bacterial infections, exacerbated sepsis progression, and detrimental effects on the cardiac, respiratory, neurological, and renal systems, ultimately leading to increased mortality. However, magnesium supplementation has been shown to be beneficial in these conditions, highlighting the importance of maintaining adequate magnesium levels in the intensive care setting.

Status Asthmaticus Gravidus: Emergency and Critical Care Management of Acute Severe Asthma During Pregnancy

One-third of women with asthma have deterioration of their asthma during pregnancy, and one-fourth of pregnant women with asthma will experience severe exacerbations necessitating emergency department (ED) visits or hospitalizations. Early recognition of acute severe asthma, including life-threatening status asthmaticus, and aggressive medical interventions with β2-agonists, anticholinergic agents, and systemic corticosteroids are necessary to treat maternal airway bronchoconstriction, support maternal and fetal oxygenation, and avoid adverse fetal outcomes. This review describes management of acute severe asthma in pregnancy, including status asthmaticus, in the ED and intensive care unit.

Magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic and progressive disease, often punctuated by recurrent flare-ups or exacerbations. Magnesium sulfate, having a bronchodilatory effect, may have a potential role as an adjunct treatment in COPD exacerbations. However, comprehensive evidence of its effects is required to facilitate clinical decision-making.

OBJECTIVES

To assess the effects of magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease in adults.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) trials portal, EU Clinical Trials Register and Iranian Registry of Clinical Trials. We also searched the proceedings of major respiratory conferences and reference lists of included studies up to 2 August 2021.

SELECTION CRITERIA

We included single- or double-blind parallel-group randomised controlled trials (RCTs) assessing magnesium sulfate in adults with COPD exacerbations. We excluded cross-over trials.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias. The primary outcomes were: hospital admissions (from the emergency room); need for non-invasive ventilation (NIV), assisted ventilation or admission to intensive-care unit (ICU); and serious adverse events. Secondary outcomes were: length of hospital stay, mortality, adverse events, dyspnoea score, lung function and blood gas measurements. We assessed confidence in the evidence using GRADE methodology. For missing data, we contacted the study investigators.

MAIN RESULTS

We identified 11 RCTs (10 double-blind and 1 single-blind) with a total 762 participants. The mean age of participants ranged from 62 to 76 years. Trials were single- or two-centre trials conducted in Iran, New Zealand, Nepal, Turkey, the UK, Tunisia and the USA between 2004 and 2018. We judged studies to be at low or unclear risk of bias for most of the domains. Three studies were at high risk for blinding and other biases.  Intravenous magnesium sulfate versus placebo Seven studies (24 to 77 participants) were included. Fewer people may require hospital admission with magnesium infusion compared to placebo (odds ratio (OR) 0.45, 95% CI 0.23 to 0.88; number needed to treat for an additional beneficial outcome (NNTB) = 7; 3 studies, 170 participants; low-certainty evidence). Intravenous magnesium may result in little to no difference in the requirement for non-invasive ventilation (OR 0.74, 95% CI 0.31 to 1.75; very low-certainty evidence). There were no reported cases of endotracheal intubation (2 studies, 107 participants) or serious adverse events (1 study, 77 participants) in either group. Included studies did not report intensive care unit (ICU) admission or deaths. Magnesium infusion may reduce the length of hospital stay by a mean difference (MD) of 2.7 days (95% CI 4.73 days to 0.66 days; 2 studies, 54 participants; low-certainty evidence) and improve dyspnoea score by a standardised mean difference of -1.40 (95% CI -1.83 to -0.96; 2 studies, 101 participants; low-certainty evidence). We were uncertain about the effect of magnesium infusion on improving lung function or oxygen saturation. For all adverse events, the Peto OR was 0.14 (95% CI 0.02 to 1.00; 102 participants); however, the event rate was too low to reach a robust conclusion.  Nebulised magnesium sulfate versus placebo Three studies (20 to 172 participants) were included. Magnesium inhalation may have little to no impact on hospital admission (OR 0.77, 95% CI 0.21 to 2.82; very low-certainty evidence) or need for ventilatory support (NIV or mechanical ventilation) (OR 0.33, 95% CI 0.01 to 8.20; very low-certainty evidence). It may result in fewer ICU admissions compared to placebo (OR 0.39, 95% CI 0.15 to 1.00; very low-certainty evidence) and improvement in dyspnoea (MD -14.37, 95% CI -26.00 to -2.74; 1 study, 20 participants; very low-certainty evidence). There were no serious adverse events reported in either group. There was one reported death in the placebo arm in one trial, but the number of participants was too small for a conclusion. There was limited evidence about the effect of magnesium inhalation on length of hospital stay, lung function outcomes or oxygen saturation. Included studies did not report adverse events.  Magnesium sulfate versus ipratropium bromide  A single study with 124 participants assessed nebulised magnesium sulfate plus intravenous magnesium infusion versus nebulised ipratropium plus intravenous normal saline. There was little to no difference between these groups in terms of hospital admission (OR 1.62, 95% CI 0.78 to 3.37), endotracheal intubation (OR 1.69, 95% CI 0.61 to 4.71) and length of hospital stay (MD 1.10 days, 95% CI -0.22 to 2.42), all with very low-certainty evidence. There were no data available for non-invasive ventilation, ICU admission and serious adverse events. Adverse events were not reported.  AUTHORS' CONCLUSIONS: Intravenous magnesium sulfate may be associated with fewer hospital admissions, reduced length of hospital stay and improved dyspnoea scores compared to placebo. There is no evidence of a difference between magnesium infusion and placebo for NIV, lung function, oxygen saturation or adverse events. We found no evidence for ICU admission, endotracheal intubation, serious adverse events or mortality. For nebulised magnesium sulfate, we are unable to draw conclusions about its effects in COPD exacerbations for most of the outcomes. Studies reported possibly lower ICU admissions and a lesser degree of dyspnoea with magnesium inhalation compared to placebo; however, larger studies are required to yield a more precise estimate for these outcomes. Similarly, we could not identify any robust evidence for magnesium sulfate compared to ipratropium bromide. Future well-designed multicentre trials with larger samples are required, including subgroups according to severity of exacerbations and COPD phenotypes.

Magnesium Treatment in Pediatric Patients

Pediatric patients may require magnesium replacement to treat life-threatening emergencies such as torsades de pointe or asthma exacerbations, as well as for the general replacement of magnesium in patients with hypomagnesemia. Clinicians must be aware of recommendations for magnesium administration as the route, dose, timing of administration, and formulation of magnesium can differ for each indication. It is imperative for clinicians to ensure that magnesium is appropriately administered to effectively treat the presenting indication and avoid adverse effects.

Use of magnesium sulfate in continuous infusion in patients with severe acute asthma, in a pediatric emergency room

INTRODUCTION

Asthma is a chronic disease, of high prevalence, with important morbidity and that can lead to death in childhood. The use of intravenous magnesium sulfate has been indicated in cases refractory to the initial management with inhaled bronchodilators and corticosteroids.

OBJECTIVE

To evaluate the use of magnesium sulfate in continuous infusion (50 mg/kg/h in 4 h) in children with severe acute asthma in a pediatric emergency room.

LOCATION

Ten-bed general pediatric emergency room, university hospital, tertiary, in southern Brazil.

PATIENTS

All children over 2 years old with severe acute asthma refractory to the initial treatment who received a continuous infusion of magnesium sulfate at a dose of 50 mg/kg/h in 4 h, from April 2017 to October 2019.

CONCLUSION

Based on this study, the use of continuous intravenous magnesium sulfate proved to be well tolerated, leading to improved respiratory status, and can be considered as a satisfactory adjunctive therapy in the management of severe acute asthma.

Living in a Hostile World: Inflammation, New Drug Development, and Coronavirus

We present a brief history of the immune response and show that Metchnikoff's theory of inflammation and phagocytotic defense was largely ignored in the 20th century. For decades, the immune response was believed to be triggered centrally, until Lafferty and Cunningham proposed the initiating signal came from the tissues. This shift opened the way for Janeway's pattern recognition receptor theory, and Matzinger's danger model. All models failed to appreciate that without inflammation, there can be no immune response. The situation changed in the 1990s when cytokine biology was rapidly advancing, and the immune system's role expanded from host defense, to the maintenance of host health. An inflammatory environment, produced by immune cells themselves, was now recognized as mandatory for their attack, removal and repair functions after an infection or injury. We explore the cellular programs of the immune response, and the role played by cytokines and other mediators to tailor the right response, at the right time. Normally, the immune response is robust, self-limiting and restorative. However, when the antigen load or trauma exceeds the body's internal tolerances, as witnessed in some COVID-19 patients, excessive inflammation can lead to increased sympathetic outflows, cardiac dysfunction, coagulopathy, endothelial and metabolic dysfunction, multiple organ failure and death. Currently, there are few drug therapies to reduce excessive inflammation and immune dysfunction. We have been developing an intravenous (IV) fluid therapy comprising adenosine, lidocaine and Mg2+ (ALM) that confers a survival advantage by preventing excessive inflammation initiated by sepsis, endotoxemia and sterile trauma. The multi-pronged protection appears to be unique and may provide a tool to examine the intersection points in the immune response to infection or injury, and possible ways to prevent secondary tissue damage, such as that reported in patients with COVID-19.

'Magnesium'-the master cation-as a drug-possibilities and evidences

Magnesium (Mg²⁺) is the 2nd most abundant intracellular cation, which participates in various enzymatic reactions; there by regulating vital biological functions. Magnesium (Mg²⁺) can regulate several cations, including sodium, potassium, and calcium; it consequently maintains physiological functions like impulse conduction, blood pressure, heart rhythm, and muscle contraction. But, it doesn't get much attention in account with its functions, making it a "Forgotten cation". Like other cations, maintenance of the normal physiological level of Mg²⁺ is important. Its deficiency is associated with various diseases, which point out to the importance of Mg²⁺ as a drug. The roles of Mg²⁺ such as natural calcium antagonist, glutamate NMDA receptor blocker, vasodilator, antioxidant and anti-inflammatory agent are responsible for its therapeutic benefits. Various salts of Mg²⁺ are currently in clinical use, but their application is limited. This review collates all the possible mechanisms behind the behavior of magnesium as a drug at different disease conditions with clinical shreds of evidence.

Magnesium and inflammation: Advances and perspectives

Magnesium is an essential element of life, involved in the regulation of metabolism and homeostasis of all the tissues. It also regulates immunological functions, acting on the cells of innate and adaptive immune systems. Magnesium deficiency primes phagocytes, enhances granulocyte oxidative burst, activates endothelial cells and increases the levels of cytokines, thus promoting inflammation. Consequently, a low magnesium status, which is often underdiagnosed, potentiates the reactivity to various immune challenges and is implicated in the pathophysiology of many common chronic diseases. Here we summarize recent advances supporting the link between magnesium deficiency, inflammatory responses and diseases, and offer new hints towards a better understanding of the underlying mechanisms.

Question 5: Magnesium Sulphate for Acute Asthma in children

Most children who present to the emergency department with acute asthma, respond well to inhaled β₂-agonists (spacer or nebuliser), oxygen (if required) and systemic steroids. Guidelines across the world agree on this simple, straight forward evidenced based approach. In children with more severe asthma attacks and those who do not respond to initial treatment, the evidence base for the secondary level treatment is less clear. Many regimens exist for the next step. Intravenous Magnesium Sulphate (MgSO₄) is now used frequently in these situations and some centres are starting to use nebulized MgSO₄ as part of the initial maximal inhaled therapy options. This paper examines the role of MgSO₄ in acute asthma in children. It focusses on how MgSO₄ might work, what are the current recommendations for use and then what is the current evidence base to support its use. We have presented the evidence for the use of both nebulized and intravenous MgSO₄. At the end of the paper we have suggested future directions for research in this area. Our aim is to present a synthesis of the current role of MgSO₄ in the management of an acute asthma attack.

Combating Implant Infections: Shifting Focus from Bacteria to Host

The widespread use of biomaterials to support or replace body parts is increasingly threatened by the risk of implant-associated infections. In the quest for finding novel anti-infective biomaterials, there generally has been a one-sided focus on biomaterials with direct antibacterial properties, which leads to excessive use of antibacterial agents, compromised host responses, and unpredictable effectiveness in vivo. This review sheds light on how host immunomodulation, rather than only targeting bacteria, can endow biomaterials with improved anti-infective properties. How antibacterial surface treatments are at risk to be undermined by biomaterial features that dysregulate the protection normally provided by critical immune cell subsets, namely, neutrophils and macrophages, is discussed. Accordingly, how the precise modification of biomaterial surface biophysical cues, or the incorporation of immunomodulatory drug delivery systems, can render biomaterials with the necessary immune-compatible and immune-protective properties to potentiate the host defense mechanisms is reviewed. Within this context, the protective role of host defense peptides, metallic particles, quorum sensing inhibitors, and therapeutic adjuvants is discussed. The highlighted immunomodulatory strategies may lay a foundation to develop anti-infective biomaterials, while mitigating the increasing threat of antibacterial drug resistance.

Combating COVID-19 and Building Immune Resilience: A Potential Role for Magnesium Nutrition?

Background: In December 2019, the viral pandemic of respiratory illness caused by COVID-19 began sweeping its way across the globe. Several aspects of this infectious disease mimic metabolic events shown to occur during latent subclinical magnesium deficiency. Hypomagnesemia is a relatively common clinical occurrence that often goes unrecognized since magnesium levels are rarely monitored in the clinical setting. Magnesium is the second most abundant intracellular cation after potassium. It is involved in >600 enzymatic reactions in the body, including those contributing to the exaggerated immune and inflammatory responses exhibited by COVID-19 patients.Methods: A summary of experimental findings and knowledge of the biochemical role magnesium may play in the pathogenesis of COVID-19 is presented in this perspective. The National Academy of Medicine's Standards for Systematic Reviews were independently employed to identify clinical and prospective cohort studies assessing the relationship of magnesium with interleukin-6, a prominent drug target for treating COVID-19.Results: Clinical recommendations are given for prevention and treatment of COVID-19. Constant monitoring of ionized magnesium status with subsequent repletion, when appropriate, may be an effective strategy to influence disease contraction and progression. The peer-reviewed literature supports that several aspects of magnesium nutrition warrant clinical consideration. Mechanisms include its "calcium-channel blocking" effects that lead to downstream suppression of nuclear factor-Kβ, interleukin-6, c-reactive protein, and other related endocrine disrupters; its role in regulating renal potassium loss; and its ability to activate and enhance the functionality of vitamin D, among others.Conclusion: As the world awaits an effective vaccine, nutrition plays an important and safe role in helping mitigate patient morbidity and mortality. Our group is working with the Academy of Nutrition and Dietetics to collect patient-level data from intensive care units across the United States to better understand nutrition care practices that lead to better outcomes.

Pharmacotherapeutic strategies for critical asthma syndrome: a look at the state of the art

INTRODUCTION

'Critical Asthma Syndrome' (CAS) is an umbrella term proposed to include several forms of asthma, responsible for acute and life-threatening exacerbations. CAS requires urgent and adequate supportive and pharmacological treatments to prevent serious outcomes.

AREAS COVERED

The purpose of this review is to discuss current knowledge on the pharmacotherapeutic strategies for treatment of CAS.

EXPERT OPINION

Airflow limitation, airway wall edema, and mucus plugs are the pathophysiological targets of pharmacological therapies. Strategies to achieve these goals are based on the use of various classes of drugs. Inhaled beta2-agonists are the mainstay of the initial therapy of CAS. Inhaled anticholinergic agents may be considered in the treatment of CAS in addition to beta 2 agonists. Systemic corticosteroids should be administered as soon as possible in order to counteract airway inflammation and restore normal airway sensitivity. The effectiveness of pharmacological therapies in CAS is linked not only to the timely use of drugsbut also to the dosage and route of administration. Early recognition and aggressive treatment are essential for the management of CAS; however, prevention is the best cure. Although significant progress has been made, further efforts are needed to implement an optimal exacerbation prevention strategy.

Magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects of magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease in adults.

The role of magnesium in different inflammatory diseases

Magnesium deficiency (MgD) can cause inflammation in human body. The known mechanisms of inflammation caused by MgD include activation of phagocytic cells, opening of calcium channels, activation of the N-methyl-D-aspartate (NMDA) receptor, and activation of nuclear factor (NF)-κB. In addition, MgD causes systemic stress response through neuroendocrinological pathways. The inflammation caused by MgD can result in pro-atherogenic changes in the metabolism of lipoproteins, endothelial dysfunction, and high blood pressure. Studies suggest that magnesium may play an important role in the pathophysiology of some inflammatory diseases. Several clinical trials and laboratory studies have been done on the functional role of magnesium. In this study, we review some inflammatory diseases, in which the magnesium has a role in their pathophysiology. Among these diseases, diabetes, asthma, preeclampsia, atherosclerosis, heart damage, and rheumatoid arthritis have been highlighted.

Magnesium sulfate differentially modulates fetal membrane inflammation in a time-dependent manner

PROBLEM

Chorioamnionitis and infection-associated inflammation are major causes of preterm birth. Magnesium sulfate (MgSO₄ ) is widely used in obstetrics as a tocolytic; however, its mechanism of action is unclear. This study sought to investigate how MgSO₄ modulates infection-associated inflammation in fetal membranes (FMs), and whether the response was time dependent.

METHOD OF STUDY

Human FM explants were treated with or without bacterial lipopolysaccharide (LPS); with or without MgSO₄ added either: 1 hour before LPS; at the same time as LPS; 1 hour post-LPS; or 2 hours post-LPS. Explants were also treated with or without viral dsRNA and LPS, alone or in combination; and MgSO₄ added 1 hour post-LPS After 24 hours, supernatants were measured for cytokines/chemokines; and tissue lysates measured for caspase-1 activity.

RESULTS

Lipopolysaccharide-induced FM inflammation by upregulating the secretion of a number of inflammatory cytokines/chemokines. Magnesium sulfate administered 1-hour post-LPS inhibited FM secretion of IL-1β, IL-6, G-CSF, RANTES, and TNFα. Magnesium sulfate administered 2 hours post-LPS augmented FM secretion of these factors as well as IL-8, IFNγ, VEGF, GROα and IP-10. Magnesium sulfate delivered 1- hour post-LPS inhibited LPS-induced caspase-1 activity, and inhibited the augmented IL-1β response triggered by combination viral dsRNA and LPS.

CONCLUSION

Magnesium sulfate differentially modulates LPS-induced FM inflammation in a time-dependent manner, in part through its modulation of caspase-1 activity. Thus, the timing of MgSO₄ administration may be critical in optimizing its anti-inflammatory effects in the clinical setting. MgSO₄ might also be useful at preventing FM inflammation triggered by a polymicrobial viral-bacterial infection.

Magnesium and Human Health: Perspectives and Research Directions

Magnesium is the fourth most abundant cation in the body. It has several functions in the human body including its role as a cofactor for more than 300 enzymatic reactions. Several studies have shown that hypomagnesemia is a common electrolyte derangement in clinical setting especially in patients admitted to intensive care unit where it has been found to be associated with increase mortality and hospital stay. Hypomagnesemia can be caused by a wide range of inherited and acquired diseases. It can also be a side effect of several medications. Many studies have reported that reduced levels of magnesium are associated with a wide range of chronic diseases. Magnesium can play important therapeutic and preventive role in several conditions such as diabetes, osteoporosis, bronchial asthma, preeclampsia, migraine, and cardiovascular diseases. This review is aimed at comprehensively collating the current available published evidence and clinical correlates of magnesium disorders.

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 sulfate infusion for acute asthma in the emergency department

OBJECTIVES

To describe the role of intravenous magnesium sulfate (MgSO₄) as therapy for acute severe asthma in the pediatric emergency department (ED).

SOURCE

Publications were searched in the PubMed and Cochrane databases using the following keywords: magnesium AND asthma AND children AND clinical trial. A total of 53 publications were retrieved using this criteria. References of relevant articles were also screened. The authors included the summary of relevant publications where intravenous magnesium sulfate was studied in children (age <18 years) with acute asthma. The NAEPP and Global Initiative for Asthma expert panel guidelines were also reviewed.

SUMMARY OF THE DATA

There is a large variability in the ED practices on the intravenous administration of MgSO₄ for severe asthma. The pharmacokinetics of MgSO₄ is often not taken into account with a consequent impact in its pharmacodynamics properties. The cumulative evidence points to the effectiveness of intravenous MgSO₄ in preventing hospitalization, if utilized in a timely manner and at an appropriate dosage (50-75mg/kg). For every five children treated in the ED, one hospital admission could be prevented. Another administration modality is a high-dose continuous magnesium sulfate infusion (HDMI) as 50mg/kg/h/4h (200mg/kg/4h). The early utilization of HDMI for non-infectious mediated asthma may be superior to a MgSO₄ bolus in avoiding admissions and expediting discharges from the ED. HDMI appears to be cost-effective if applied early to a selected population. Intravenous MgSO₄ has a similar safety profile than other asthma therapies.

CONCLUSIONS

Treatment with intravenous MgSO₄ reduces the odds of hospital admissions. The use of intravenous MgSO₄ in the emergency room was not associated with significant side effects or harm. The authors emphasize the role of MgSO₄ as an adjunctive therapy, while corticosteroids and beta agonist remain the primary acute therapeutic agents.

Effects of nebulised magnesium sulphate on inflammation and function of the guinea-pig airway

Magnesium sulphate is a potential treatment for acute severe asthma. However, the mechanisms and dose-response relationships are poorly understood. The first objective of this study was to examine whether inhaled magnesium sulphate exerts bronchodilator activity measured as bronchoprotection against histamine-induced bronchoconstriction in conscious guinea-pigs alone and combined with salbutamol. Secondly, we examined whether inhaled magnesium sulphate inhibits airways inflammation and function in models of neutrophilic and eosinophilic lung inflammation induced, respectively, by inhaled lipopolysaccharide or the inhaled antigen, ovalbumin (OVA). Airway function was measured in conscious guinea-pigs as specific airway conductance (sG_aw) by whole-body plethysmography. Anti-inflammatory activity was measured against lung inflammatory cell influx induced by OVA inhalation in OVA-sensitised animals or by lipopolysaccharide (LPS) exposure of non-sensitised animals. Airway function (sG_aw) was measured over 24h after OVA exposure. Airway hyperresponsiveness to inhaled histamine and inflammatory cells in bronchoalveolar lavage fluid were recorded 24h after OVA or LPS challenge. Histamine-induced bronchoconstriction was inhibited by inhaled magnesium sulphate or salbutamol alone and in combination, they produced synergistic bronchoprotection. LPS-induced neutrophil influx was inhibited by 6 days pretreatment with magnesium sulphate. Early and late asthmatic responses in OVA sensitised and challenged animals were attenuated by magnesium sulphate. Lung inflammatory cells were increased by OVA, macrophages being significantly reduced by magnesium sulphate. Nebulised magnesium sulphate protects against histamine-induced bronchoconstriction in conscious guinea-pigs and exerts anti-inflammatory activity against pulmonary inflammation induced by allergen (OVA) or LPS. These properties of magnesium sulphate explain its beneficial actions in acute asthma.

Diagnostic value of a pattern of exhaled breath condensate biomarkers in asthmatic children

BACKGROUND

Diagnosing asthma in children is a challenge and using a single biomarker from exhaled breath condensate (EBC) showed the lack of improvement in it.

OBJECTIVE

The aim of this study was to assess the diagnostic potential of a pattern of simple chemical biomarkers from EBC in diagnosing asthma in children in a real-life setting, its association with lung function and gastroesophageal reflux disease (GERD).

METHODS

In 75 consecutive children aged 5-7 years with asthma-like symptoms the following tests were performed: skin prick tests, spirometry, impulse oscillometry (IOS), exhaled NO (F_ENO), 24-hour oesophageal pH monitoring and EBC collection with subsequent analysis of pH, carbon dioxide tension, oxygen tension, and concentrations of magnesium, calcium, iron and urates.

RESULTS

No significant differences were found for individual EBC biomarkers between asthmatics and non-asthmatics (p>0.05 for all). A pattern of six EBC biomarkers showed a statistically significant (p=0.046) predictive model for asthma (AUC=0.698, PPV=84.2%, NPV=38.9%). None to moderate association (R² up to 0.43) between EBC biomarkers and lung function measures and F_ENO was found, with IOS parameters showing the best association with EBC biomarkers. A significantly higher EBC Fe was found in children with asthma and GERD compared to asthmatics without GERD (p=0.049).

CONCLUSIONS

An approach that involves a pattern of EBC biomarkers had a better diagnostic accuracy for asthma in children in real-life settings compared to a single one. Poor to moderate association of EBC biomarkers with lung function suggests a complementary value of EBC analysis for asthma diagnosis in children.

Lack of efficacy of nebulized magnesium sulfate in treating adult asthma: A meta-analysis of randomized controlled trials

BACKGROUND

Nebulized magnesium sulfate (MgSO₄) has been used to treat asthma, but the efficacy remains controversial. We aimed to comprehensively review the efficacy of nebulized MgSO₄ in treating adult patients with asthma.

METHODS

PubMed, Embase, and Cochrane Library were searched for relevant studies published up to July 18, 2016. Randomized controlled trials (RCTs) were included if adult patients with acute or stable asthma had been treated with nebulized MgSO₄ compared with placebo or another bronchodilator. Standardized mean differences (SMDs), relative risks (RRs) and 95% confidence intervals (CIs) were calculated. Outcomes included pulmonary function, hospital admission and adverse events.

RESULTS

A total of 1386 patients from sixteen trials (1240 acute asthma patients and 146 stable asthma patients) were subjected to meta-analysis. Compared to placebo as normal saline, whether using in acute or stable adult asthma, nebulized MgSO₄ did not significantly improve the respiratory function: SMD 0.39 (95% CI -0.03-0.82, P = 0.07), and 1.48 (95% CI -0.14-3.11, P = 0.07), respectively. Furthermore, nebulized MgSO₄ did not reduce hospital admission in adult patients with acute asthma (RR, 0.72; 95% CI, 0.52-1.00; P = 0.05), although it was not associated with increased adverse events (RR 1.15; 95% CI, 0.88-1.52; P = 0.31).

CONCLUSIONS

Evidence to date suggests that nebulized MgSO₄ has no role in the management of adult patients with acute or stable asthma.

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.

Randomised comparison of intravenous magnesium sulphate, terbutaline and aminophylline for children with acute severe asthma

AIM

This study compared the efficacy of intravenous magnesium sulphate, terbutaline and aminophylline for children with acute, severe asthma poorly responsive to standard initial treatment.

METHODS

We enrolled 100 children, aged one to 12 years, who had failed to respond to initial standard treatment for acute, severe asthma, in this randomised controlled trial. They received either intravenous magnesium sulphate, terbutaline or aminophylline. Responses were monitored using a modified Clinical Asthma Severity (CAS) score. The primary outcome was treatment success, defined as a reduction in the CAS of four points or more 1 h after starting the intervention.

RESULTS

The magnesium sulphate group had higher treatment success (33/34, 97%) than the terbutaline and aminophylline groups (both 23/33, 70%) (p = 0.006) and faster resolution of retractions, wheeze and dyspnoea (p < 0.001). No adverse events occurred among patients receiving magnesium sulphate, but two patients receiving terbutaline had hypokalemia and nine patients receiving aminophylline had nausea and, or, vomiting.

CONCLUSION

Adding a single dose of Intravenous magnesium sulphate to inhaled beta2-agonists and corticosteroids was more effective, and safer, than using terbutaline or aminophylline when treating a child with acute severe asthma poorly responsive to initial treatment.

The role of magnesium sulfate in acute asthma: does route of administration make a difference?

PURPOSE OF REVIEW

The role of magnesium sulfate (MgSO4) in the treatment of acute asthma is not clear. Four recent systematic reviews suggest a limited role of intravenous (i.v.) and inhaled nebulized treatment. The purpose of this review is to summarize the current literature, focus on two recent large multicenter randomized controlled trials, and discuss future research directions.

RECENT FINDINGS

The Magnesium Nebulized Trial In Children (MAGNETIC) trial has shown little benefit to routine use of nebulized MgSO4 in children with acute asthma, but there may be a benefit in those with severe exacerbations and a shorter duration of symptoms. The 3Mg trial has shown no role for nebulized MgSO4 in adults and, at best a limited role for i.v. MgSO4 in only the most severe exacerbations. This is the only study with direct comparison of nebulized and i.v. MgSO4.

SUMMARY

MgSO4 has a role in severe exacerbations of acute asthma and there is no evidence of benefit outside this clinical situation. Both nebulized and i.v. treatments are well tolerated and inexpensive. In adults, the most effective route of administration is i.v. There are no direct comparison studies in children. Further research should focus on more severe exacerbations.

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.

The use of intravenous and inhaled magnesium sulphate in management of children with bronchial asthma

BACKGROUND

Asthma is the most common chronic disease of childhood and the leading cause of childhood morbidity. When uncontrolled, asthma can place significant limits on daily life, and is sometimes fatal. The use of magnesium sulphate (MgSO4) is one of numerous treatment options available during acute severe asthma in children. The efficacy of intravenous, or inhaled MgSO4 has been demonstrated, while little is known about the actual clinical use of either intravenous (IV) or inhaled MgSO4.

OBJECTIVE

To assess the effectiveness of intravenous (IV) and/or inhaled MgSO4 on hospital admissions and pulmonary function in children with asthma. This systematic review assessed the best available evidence for the use of either intravenous or inhaled MgSO4 in children with acute asthma. Magnesium deficiency is a common electrolyte disorder in children with acute severe asthma. Several authors reported that IV magnesium was effective in the treatment of moderate to acute asthma in children but evidence for nebulised magnesium was insufficient. In addition, it is used in severe, progressed cases to prevent respiratory failure and/or admission to the intensive care unit. It has bronchodilating and anti-inflammatory effects and modulates ion transport and influences intracellular calcium concentration. Intravenous MgSO4 therapy helps in achieving earlier improvement in clinical signs and symptoms of asthma, e.g. respiratory function and significantly reduced hospital admission, in children with acute severe asthma. The role of nebulised MgSO4 in asthmatic children requires further investigation.

CONCLUSION

According to the previous studies, the author recommends the use of intravenous MgSO4 as a safe and effective adjunct to conventional bronchodilator therapy in acute severe asthma in children.

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.

Inhaled magnesium sulfate in the treatment of acute asthma

BACKGROUND

Asthma exacerbations can be frequent and range in severity from relatively mild to status asthmaticus. The use of magnesium sulfate (MgSO(4)) is one of numerous treatment options available during acute exacerbations. While the efficacy of intravenous MgSO(4) has been demonstrated, little is known of the role of inhaled MgSO(4).

OBJECTIVES

To determine the efficacy of inhaled MgSO(4) administered in acute asthma on pulmonary functions and admission rates.

SPECIFIC AIMS

To quantify the effects of inhaled MgSO(4) i) in addition to inhaled β(2)-agonist, ii) in comparison to inhaled β(2)-agonist alone or iii) in addition to combination treatment with inhaled β(2) -agonist and ipratropium bromide.

SEARCH METHODS

Randomised controlled trials were identified from the Cochrane Airways Group register of trials in September 2012. These trials were supplemented with trials found in the reference list of published studies, studies found using extensive electronic search techniques, as well as a review of the grey literature and conference proceedings.

SELECTION CRITERIA

Randomised (or pseudo-randomised) controlled trials including adults or children with acute asthma were eligible for inclusion in the review. Studies were included if patients were treated with nebulised MgSO(4) alone or in combination with β(2)-agonist and/or ipratropium bromide and were compared with β(2)-agonist alone or inactive control.

DATA COLLECTION AND ANALYSIS

Trial selection, data extraction and risk of bias were assessed independently by two review authors. Efforts were made to collect missing data from authors. Results are presented as standardised mean differences (SMD) for pulmonary function and risk ratios (RR) for hospital admission; both are displayed with their 95% confidence intervals (CI).

MAIN RESULTS

Sixteen trials (21 references) of unclear and high risk of bias were eligible and included 896 patients who were randomised (838 patients completed). Seven of the 16 included studies involved adults exclusively, three included adults and paediatric patients, four studies enrolled paediatric patients and in the remaining two studies the age of participants was not stated.The design, definitions, intervention and outcomes were different in all 16 studies; this heterogeneity made direct comparisons difficult (see additional tables 1-3).The overall risk of bias among the included studies was variable and this is reflected in the 'Summary of findings' table with most outcomes being judged as only moderate or less.Inhaled magnesium sulfate in addition to inhaled β(2)-agonistThere was no statistically significant improvement in pulmonary function when inhaled MgSO(4) and β(2)-agonist was compared with β(2)-agonist alone (SMD 0.23; 95% CI -0.27 to 0.74; three studies, n = 188); however, there was considerable between study heterogeneity. There was no clear advantage in terms of hospital admissions (RR 0.76 95% CI 0.49, 1.16; four studies, n = 249), and there were no serious adverse events reported.Inhaled magnesium sulfate versus inhaled β(2)-agonistThe results of pulmonary function in three studies that compared inhaled MgSO(4) versus β(2)-agonist were too heterogeneous to combine; however, two of the studies found poorer lung function on MgSO(4). There was no significant difference in terms of hospital admissions in a single small study when MgSO(4) was compared to β(2)-agonist (RR 0.53 95% CI 0.05, 5.31; one study, n = 33), and there were no serious adverse events reported.Inhaled magnesium sulfate in addition to inhaled β(2)-agonist and ipratropiumA further comparison has been included in the 2012 update of this review of MgSO(4) given in addition to inhaled ipratropium and β(2)-agonist therapy (as recommended by the GINA guidelines). However, there is not yet enough data for this outcome to come to any definite conclusions, but both small studies in adults with severe asthma exacerbation found improvements in pulmonary function with additional inhaled MgSO(4).

AUTHORS' CONCLUSIONS

There is currently no good evidence that inhaled MgSO(4) can be used as a substitute for inhaled β(2)-agonists. When used in addition to inhaled β(2)-agonists (with or without inhaled ipratropium), there is currently no overall clear evidence of improved pulmonary function or reduced hospital admissions. However, individual study results from three trials suggest possible improved pulmonary function in those with severe asthma exacerbations (FEV1 less than 50% predicted). Heterogeneity among trials included in this review precludes a more definitive conclusion. Further studies should focus on inhaled MgSO(4) in addition to the current guideline treatment for acute asthma (inhaled β(2) -agonist and ipratropium bromide). As the evidence suggests that the most effective role of nebulised MgSO(4) may be in those with severe acute features and this is where future research should be focused. A set of core outcomes needs to be agreed upon both in adult and paediatric studies to allow improved study comparison in future. 

Asthma diagnosis and management

Asthma is a chronic inflammatory airway disease that is commonly seen in the emergency department (ED). This article provides an evidence-based review of diagnosis and management of asthma. Early recognition of asthma exacerbations and initiation of treatment are essential. Treatment is dictated by the severity of the exacerbation. Treatment involves bronchodilators and corticosteroids. Other treatment modalities including magnesium, heliox, and noninvasive ventilator support are discussed. Safe disposition from the ED can be considered after stabilization of the exacerbation, response to treatment and attaining peak flow measures.

Characterization of cytolytic neutrophil activation in vitro by amorphous hydrated calcium phosphate as a model of biomaterial inflammation

Calcium ions are utilized in biomolecular biomaterial design for osteomimetic scaffolds and as divalent cross-linking agents, typically for gelation of alginates, stabilisation of protein structure (e.g., fibrinogen) and enzyme activation (e.g., thrombin). Biological interactions with defined calcium phosphates (e.g., hydroxyapatite) are exploited for osteogenesis, although crystalline calcium phosphates (e.g., calcium pyrophosphate) stimulate inflammation. We found that the calcium concentration used in the manufacture of prototype dermal scaffolds made from fibrin/alginate composite was related to the inflammatory infiltration during in vivo integration. In investigating a cause for this inflammatory response, we have identified and characterized a cytolytic inflammatory effect of amorphous calcium phosphate (CaP) formed in physiological solutions, relevant to biomaterial biocompatibility. Isolated human neutrophils (Nφ) were incubated in phosphate-buffered saline with CaCl(2) ranging 2.5-20 mM total calcium. Nφ activation was assessed by morphology and integrin-β2 (CD18a) expression. Mediator release (Nφ-elastase, IL-8, and TNFα) was measured from both Nφ and whole blood cultures plus CaCl(2). CaP exposure increased CD18a expression over 1 h (maximal at 10 mM calcium/ phosphate) with concurrent phagocytosis, cytolysis, and Nφ-elastase release. CaCl(2) induced expression of IL-8 and TNFα in whole blood cultures. These results suggest that CaP formed from the resorption of calcium-containing biomaterials could induce inflammation and accelerate biomaterial degradation, driving further CaP release. This demonstrates a novel mechanism for biomaterial-induced inflammation. The in vitro system described could aid preclinical evaluation of novel biomaterial inflammatory potential.

Acute severe asthma: new approaches to assessment and treatment

The precise definition of a severe asthmatic exacerbation is an issue that presents difficulties. The term 'status asthmaticus' relates severity to outcome and has been used to define a severe asthmatic exacerbation that does not respond to and/or perilously delays the repetitive or continuous administration of short-acting inhaled beta(2)-adrenergic receptor agonists (SABA) in the emergency setting. However, a number of limitations exist concerning the quantification of unresponsiveness. Therefore, the term 'acute severe asthma' is widely used, relating severity mostly to a combination of the presenting signs and symptoms and the severity of the cardiorespiratory abnormalities observed, although it is well known that presentation does not foretell outcome. In an acute severe asthma episode, close observation plus aggressive administration of bronchodilators (SABAs plus ipratropium bromide via a nebulizer driven by oxygen) and oral or intravenous corticosteroids are necessary to arrest the progression to severe hypercapnic respiratory failure leading to a decrease in consciousness that requires intensive care unit (ICU) admission and, eventually, ventilatory support. Adjunctive therapies (intravenous magnesium sulfate and/or others) should be considered in order to avoid intubation. Management after admission to the hospital ward because of an incomplete response is similar. The decision to intubate is essentially based on clinical judgement. Although cardiac or respiratory arrest represents an absolute indication for intubation, the usual picture is that of a conscious patient struggling to breathe. Factors associated with the increased likelihood of intubation include exhaustion and fatigue despite maximal therapy, deteriorating mental status, refractory hypoxaemia, increasing hypercapnia, haemodynamic instability and impending coma or apnoea. To intubate, sedation is indicated in order to improve comfort, safety and patient-ventilator synchrony, while at the same time decrease oxygen consumption and carbon dioxide production. Benzodiazepines can be safely used for sedation of the asthmatic patient, but time to awakening after discontinuation is prolonged and difficult to predict. The most common alternative is propofol, which is attractive in patients with sudden-onset (near-fatal) asthma who may be eligible for extubation within a few hours, because it can be titrated rapidly to a deep sedation level and has rapid reversal after discontinuation; in addition, it possesses bronchodilatory properties. The addition of an opioid (fentanyl or remifentanil) administered by continuous infusion to benzodiazepines or propofol is often desirable in order to provide amnesia, sedation, analgesia and respiratory drive suppression. Acute severe asthma is characterized by severe pulmonary hyperinflation due to marked limitation of the expiratory flow. Therefore, the main objective of the initial ventilator management is 2-fold: to ensure adequate gas exchange and to prevent further hyperinflation and ventilator-associated lung injury. This may require hypoventilation of the patient and higher arterial carbon dioxide (PaCO(2)) levels and a more acidic pH. This does not apply to asthmatic patients intubated for cardiac or respiratory arrest. In this setting the post-anoxic brain oedema might demand more careful management of PaCO(2) levels to prevent further elevation of intracranial pressure and subsequent complications. Monitoring lung mechanics is of paramount importance for the safe ventilation of patients with status asthmaticus. The first line of specific pharmacological therapy in ventilated asthmatic patients remains bronchodilation with a SABA, typically salbutamol (albuterol). Administration techniques include nebulizers or metered-dose inhalers with spacers. Systemic corticosteroids are critical components of therapy and should be administered to all ventilated patients, although the dose of systemic corticosteroids in mechanically ventilated asthmatic patients remains controversial. Anticholinergics, inhaled corticosteroids, leukotriene receptor antagonists and methylxanthines offer little benefit, and clinical data favouring their use are lacking. In conclusion, expertise, perseverance, judicious decisions and practice of evidence-based medicine are of paramount importance for successful outcomes for patients with acute severe asthma.

Usefulness of inhaled magnesium sulfate in the coadjuvant management of severe asthma crisis in an emergency department

RATIONALE

Treatment of severe asthma may be difficult despite the use of several medications including parenteral corticosteroids. Intravenous magnesium sulfate (MgSO(4)) is one ancillary drug for severe crisis; its inhaled use is controversial.

OBJECTIVES

To evaluate the usefulness of inhaled MgSO(4) compared to placebo in improving lung function, oxygen saturation, and reducing hospital admission as an adjunct to standard treatment in severe asthma crisis.

PATIENTS AND METHODS

We conducted a placebo-controlled, double-blind clinical trial with asthmatic patients >18 years of age with asthmatic crisis and FEV(1)<60% of predicted (%p). All subjects received 125 mg of IV methylprednisolone followed by nebulization with the combination of albuterol (7.5mg) and ipratropium bromide (1.5mg) diluted in 3 ml of isotonic saline solution (as placebo) or 3 ml (333 mg) of MgSO(4). After 90 min, subjects with FEV(1)<60%p or SpO(2)<88% or persistent symptoms were admitted to the emergency department (ED).

RESULTS

We included 30 patients per group who were similar at baseline. The MgSO(4) group showed higher post-bronchodilator (post-BD) FEV(1)%p (69+/-13 vs. 61+/-12, p<0.014) and SpO(2) (92+/-4 vs. 88+/-5%, p<0.006) than the placebo group. Fewer treated patients were admitted to the ED (5 vs. 13) (p<0.047), with relative risk (RR) of 0.26 (95% CI 0.079-0.870).

CONCLUSIONS

Adding inhaled MgSO(4) treatment to standard therapy in severe asthma crisis improves FEV(1)%p and SpO(2) post-BD and reduces the rate of ED admissions.

Magnesium and calcium in exhaled breath condensate of children with asthma and gastroesophageal reflux disease

BACKGROUND

Magnesium and calcium physiologic functions are closely related. Magnesium is primarily an intracellular cation, the action of which also involves maintenance of cellular ionic balance, while influencing calcium homeostasis by blocking calcium channels. The aim of this study was to compare the concentrations of magnesium and calcium in exhaled breath condensate (EBC) of children with asthma and gastroesophageal reflux disease (GERD).

SUBJECTS AND METHODS

EBC was collected from 66 children aged 7-14 years (23 children with acute asthma, 17 children with GERD, and 26 healthy children). Determination of magnesium and calcium concentrations was preceded by optimization and validation for low concentrations.

RESULTS

No difference was recorded for either magnesium or calcium concentration between study groups. However, the magnesium to calcium ratio was statistically significantly lower in both GERD and asthma children as compared with control group.

CONCLUSION

Study results showed the magnesium to calcium ratio to be a statistically significantly better indicator of certain pathologic changes than absolute concentration of either ion.