Clinical Studies
Magnesium sulfate as a vehicle for nebulized salbutamol in acute asthma

https://doi.org/10.1016/S0002-9343(99)00463-5Get rights and content

Abstract

Purpose: Magnesium sulfate is thought to be an effective bronchodilator when administered intravenously to patients with acute severe asthma, and it can be safely administered via inhalation to patients with stable asthma. Our goal was to determine if isotonic magnesium sulfate could be used as a vehicle for nebulized salbutamol for patients with acute asthma.

Methods: We enrolled 35 patients with acute asthma in a randomized, double-blind, controlled trial. After measurement of peak expiratory flow, patients received 2.5 mg salbutamol plus either 3 mL normal saline solution (n = 16) or isotonic magnesium sulfate (n = 19) through a jet nebulizer. Peak flow was reassessed 10 and 20 minutes after treatment.

Results: Peak flow at baseline was similar in the two groups. Ten minutes after baseline, the mean (± SD) percentage increase in peak flow was greater in the magnesium sulfate-salbutamol group (61% ± 45%) than in the normal saline-salbutamol group (31% ± 28%; difference = 30%; 95% confidence interval [CI] for the difference: 3% to 56%; P = 0.03). At 20 minutes, the percentage increase in peak flow was 57% greater in the magnesium sulfate group (95% CI: 4% to 110%, P = 0.04). There was a significant inverse correlation between baseline peak flow (percent of predicted) and the percentage increase in peak flow at 20 minutes in the magnesium sulfate group (r = −0.82, P <0.0001), but not in the saline group (r = −0.12, P = 0.67).

Conclusion: In patients with acute asthma, isotonic magnesium sulfate, as a vehicle for nebulized salbutamol, increased the peak flow response to treatment in comparison with salbutamol plus normal saline.

Section snippets

Patients

In this multicenter, randomized, double-blind, controlled study, we enrolled patients who presented to the emergency department with an acute asthma exacerbation, who were at least 18 years of age, and who gave informed consent. In addition, eligible patients had to be nonsmokers, former smokers, or current smokers of <5 pack-years; to be free of other medical illnesses; to be neither pregnant nor breast-feeding; to have not taken oral or parenteral corticosteroids in the preceding week; and to

Results

The two groups did not differ significantly in age, gender, duration of asthma, smoking status, use of inhaled β-2 agonists, previous use of corticosteroids and theophylline, duration of symptoms, duration of nebulization, baseline peak flow, or vital signs (Table 1). The duration of care in the emergency department was not significantly different between the two groups (magnesium sulfate 1.2 ± 0.5 hours versus saline 1.8 ± 2.1 hour, P = 0.3). None of the patients required further medication

Discussion

Our results show that combining nebulized salbutamol with isotonic magnesium sulfate results in a greater improvement in peak flow compared with the standard approach (salbutamol and normal saline) in acutely ill patients with asthma. This effect was evident within 10 minutes and was maintained at 20 minutes. The more severe the baseline obstruction, the greater the response to the combined magnesium sulfate and salbutamol. These results are in contrast to those from a previous study, which

References (32)

  • E.R McFadden et al.

    Comparison of two dosage regimens of albuterol in acute asthma

    Am J Med

    (1998)
  • M.S Skorodin et al.

    Magnesium sulfate potentiates several cardiovascular and metabolic actions of terbutaline

    Chest

    (1994)
  • H.J Rosello et al.

    Sulfato de magnesio en la crisis de asma

    Prensa Méd Argent

    (1936)
  • V.G Haury

    Blood serum magnesium in bronchial asthma and its treatment by the administration of magnesium sulfate

    J Lab Clin Med

    (1940)
  • H Okayama et al.

    Bronchodilating effect of intravenous magnesium sulfate in bronchial asthma

    JAMA

    (1987)
  • G Rolla et al.

    Acute effect of intravenous magnesium sulfate on airway obstruction of asthmatic patients

    Ann Allergy

    (1988)

    • Cited by (0)

    View full text
    Copyright © 2000 Excerpta Medica Inc. All rights reserved.