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Intravenous magnesium is ineffective in adult asthma, a randomized trial
R S Porter1, Nester, L E Braitman
1Department of Emergency Medicine, Albert Einstein Medical Center, Philadelphia, PA 19141, USA.
Abstract:
Intravenous magnesium sulphate (MgSO4) has been tried in the emergency department treatment of asthma since the mid-1980s, but published reports vary as to its efficacy. The literature suggests that it may be effective in the more severely ill asthmatic. We evaluated i.v. MgSO4 in adult asthmatics having a moderate to severe exacerbation. The study was performed in a convenience sample of adult asthmatics between the ages of 18 and 55 presenting to the emergency department with a peak expiratory flow (PEF) of < 100 l/min or < 25% of predicted flow. Patients received either 2.0 grams of MgSO4 or placebo in a randomized, double-blind fashion. All patients received inhaled bronchodilators and i.v. steroids. Outcome variables were: improvement in PEF, subjective respiratory distress as measured by the Borg dyspnoea scale (BDS) and hospital admission. The first visits of 42 patients presenting with acute asthma exacerbations were evaluated, 18 receiving MgSO4 and 24 receiving placebo. The t = 60 peak flow in the MgSO4 group was 174 l/min versus 212 l/min in placebo, p = 0.04. Controlling for age, heart rate, initial PEF and initial BDS in ordinal logistic regression, the t = 60 Borg scale of subjective dyspnoea had an odds ratio of 1.54 in favour of more dyspnoea in MgSO4 (95% C.I., 0.36-6.67; p = 0.56). Five of 18 patients (28%) receiving MgSO4 were admitted compared with 5 of 24 (21%) receiving placebo (p = 0.72). In moderately severe adult asthmatics, 2.0 grams of MgSO4 i.v. resulted in less improvement in peak expiratory flow compared with placebo. MgSO4 did not appear to decrease subjective dyspnoea or the hospital admission rate. This evidence does not support the use of MgSO4 in the treatment of acute asthma.
Insights
Intravenous magnesium sulfate (MgSO4) did not improve peak expiratory flow in adults with moderate to severe asthma exacerbations. This study suggests MgSO4 is not effective for treating acute asthma attacks.
Area of Science:
- Emergency Medicine
- Pulmonology
- Pharmacology
Background:
- Intravenous magnesium sulfate (MgSO4) has been explored for emergency department asthma treatment since the 1980s.
- Published data on its efficacy in acute asthma exacerbations are inconsistent.
- Some literature suggests potential benefits in severely ill asthmatics.
Purpose of the Study:
- To evaluate the efficacy of intravenous magnesium sulfate (MgSO4) in adult patients experiencing moderate to severe asthma exacerbations.
- To assess the impact of MgSO4 on peak expiratory flow (PEF), subjective respiratory distress, and hospital admission rates.
Main Methods:
- A randomized, double-blind study involving 42 adult asthmatics (18-55 years) with moderate to severe exacerbations (PEF < 100 L/min or < 25% predicted).
- Patients received either 2.0 grams of intravenous MgSO4 or a placebo, in addition to standard inhaled bronchodilators and intravenous steroids.
- Outcomes measured included improvement in PEF, Borg Dyspnea Scale (BDS) scores, and hospital admission rates.
Main Results:
- The MgSO4 group showed less improvement in PEF at 60 minutes (174 L/min) compared to the placebo group (212 L/min; p=0.04).
- No significant difference in subjective dyspnea (Borg scale) or hospital admission rates was observed between the MgSO4 and placebo groups.
- Five out of 18 patients (28%) receiving MgSO4 were admitted, versus 5 out of 24 (21%) receiving placebo (p=0.72).
Conclusions:
- In moderately severe adult asthma exacerbations, 2.0 grams of intravenous MgSO4 did not lead to greater improvement in peak expiratory flow compared to placebo.
- Intravenous magnesium sulfate did not demonstrate a significant benefit in reducing subjective dyspnea or hospital admission rates.
- Current evidence does not support the routine use of intravenous magnesium sulfate for treating acute asthma in this patient population.
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