Intravenous magnesium for acute asthma: failure to decrease emergency treatment duration or need for hospitalization.

STUDY OBJECTIVE

To evaluate the efficacy of routine early administration of i.v. magnesium to patients with acute asthma.

DESIGN

Prospective, randomized clinical trial.

SETTING

Urban teaching hospital emergency department.

TYPE OF PARTICIPANTS

One hundred twenty consecutive patients aged 18 to 65 years with acute asthma unresponsive to a single albuterol treatment.

INTERVENTIONS

All patients received oxygen, 125 mg i.v. methylprednisolone, and hourly albuterol inhalation therapy. The study group also received 2 g i.v. magnesium sulfate infused over 20 minutes.

MEASUREMENTS AND MAIN RESULTS

Demographic and clinical characteristics were similar in both groups. Hospitalization was necessary in 13 of 58 patients who received magnesium (22%; 95% confidence intervals [CI], 13% to 32%) and 11 of 62 control patients (17%; 95% CI 10% to 26%; P = .523). Duration of ED treatment in discharged patients was 224 +/- 75 minutes in the magnesium group (95% CI, 208 to 240 minutes) and 228 +/- 90 minutes in the control group (95% CI, 209 to 247 minutes, P = .832). In addition, changes in peak expiratory flow were not statistically different.

CONCLUSION

Routine early administration of IV magnesium in acute asthma does not alter treatment outcome.