Intravenous magnesium sulfate as an adjunct in the treatment of acute asthma.
OBJECTIVE
This study was conducted to determine whether intravenous magnesium sulfate (MgSO4), when used as part of a standardized treatment protocol, can improve pulmonary function and decrease admission rate in patients presenting to the emergency department with exacerbations of asthma.


METHODS
In this randomized double-blind placebo-controlled study, patients with acute asthma were treated with inhaled beta-agonists at regular intervals and intravenous (IV) steroids. At 30 min after entry, patients received either 2 g IV MgSO4 or IV placebo. Patients were monitored for up to 4 h with regular measurements of pulmonary function. Patients who were discharged from the emergency department were contacted at 1 day and 7 days for follow-up.


METHODS
Emergency departments of a university-affiliated, voluntary hospital and municipal hospital.


METHODS
Asthmatics aged 18 to 65 years during acute exacerbation with FEV1 less than 75% predicted both before and after a single albuterol treatment.


METHODS
Patients were given 2 g of MgSO4 or placebo as an adjunct to standardized emergency department procedure for acute asthma.


RESULTS
One hundred thirty-five patients were studied. Hospital admission rates were 35.3% for placebo-treated group and 25.4% for the magnesium-treated group (p = 0.21). FEV1 measured at 120 min was 56% predicted for the placebo-treated group and 55% predicted for the magnesium-treated group. (p = 0.92) For subgroup analysis, patients were divided into "severe" (baseline FEV1 < 25% predicted on presentation) or "moderate" (baseline FEV1, 25 to 75% predicted on presentation). For the severe group, admission rates were 78.6% (11/14) for the placebo-treated group and 33.3% (7/21) for the magnesium-treated group (p = 0.009). For the moderate patients, admission rates were 22.4% (11/49) for the placebo-treated group and 22.2% (10/25) for the magnesium-treated group (p = 0.98). There was no significant improvement in FEV1 in the moderate group for magnesium-treated patients. However, in the severe group, there was a significant improvement in FEV1 at 120 min and 240 min (p = 0.014 and 0.026, respectively).


CONCLUSIONS
Intravenous MgSO4 decreased admission rate and improved FEV1 in patients with acute severe asthma but did not cause significant improvement in patients with moderate asthma.
Bloch
H
H
Department of Emergency Medicine, Long Island Jewish Medical Center, Albert Einstein College of Medicine, New Hyde Park, NY 12042, USA.
Silverman
R
R
Mancherje
N
N
Grant
S
S
Jagminas
L
L
Scharf
S M
SM
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000420:Albuterol / Q000008:administration & dosage; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D003131:Combined Modality Therapy; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007262:Infusions, Intravenous; D008278:Magnesium Sulfate / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged
D008278:Magnesium Sulfate; D000420:Albuterol