title: Effect of intravenous magnesium sulfate on mortality in patients with severe acute asthma.
abstract: OBJECTIVE
  Intravenous magnesium sulfate is used as adjunctive therapy for severe asthma exacerbations. However, previous randomized controlled trials of the administration of intravenous magnesium sulfate for asthma exacerbations have shown mixed results, and no study has evaluated its effect on mortality in patients with life-threatening asthma. The objective of this study was to investigate the association between intravenous magnesium sulfate administration and mortality in patients with severe asthma.
  
  
  METHODS
  Patients with severe asthma requiring intravenous corticosteroids and oxygenation were selected using the Japanese Diagnosis Procedure Combination inpatient database. One-to-one propensity score matching was performed between patients having received or not intravenous magnesium sulfate. Primary outcomes were 7-, 14- and 28-day mortalities. Secondary outcomes were total dose of intravenous corticosteroids during hospitalization, duration of mechanical ventilation and length of stay.
  
  
  RESULTS
  Among 14,122 eligible patients, 619 received intravenous magnesium sulfate. Propensity score matching created a matched cohort of 599 pairs with and without intravenous magnesium sulfate. There were no significant differences between patients with and without intravenous magnesium sulfate in terms of 28-day mortality (1.3% vs 1.8%, P = 0.488), median total dose of intravenous corticosteroids (2400 mg vs 2400 mg, P = 0.580), median duration of mechanical ventilation (1 day vs 1 day, P = 0.118) and median length of stay (16 days vs 13 days, P = 0.640).
  
  
  CONCLUSIONS
  This study found no significant benefit of intravenous magnesium sulfate use in terms of mortality in patients with severe acute asthma.
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Hirashima
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Yamana
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
mesh_terms: D000208:Acute Disease; D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D003131:Combined Modality Therapy / Q000401:mortality*; D018450:Disease Progression; D004359:Drug Therapy, Combination; D005260:Female; D006760:Hospitalization; D006801:Humans; D007262:Infusions, Intravenous; D008278:Magnesium Sulfate / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012121:Respiration, Artificial
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D008278:Magnesium Sulfate
keywords: asthma exacerbation; intravenous magnesium sulfate; mortality; propensity score matching