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Three Part Question

In [patients with an exacerbation of COPD] does [the addition of intravenous magnesium to conventional treatments] improve [PEFR or discharge rate or morbidity or mortality]?

Clinical Scenario

A 65 year old man presents to the emergency department with an exacerbation of COPD. You are aware that intravenous magnesium is used as a bronchodilator in acute severe asthma and wonder if it would benefit this patient.

Search Strategy

Medline 1966-11/03 using the Ovid interface.
[exp Magnesium OR magnesium.mp] AND [exp Pulmonary Disease, Chronic Obstructive OR COPD.mp OR COAD.mp OR exp Lung Diseases] LIMIT to human and English language.

Search Outcome

Altogether 465 papers were found of which 1 was relevant.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Skorodin MS et al, 1995, USA	72 adults (70 male) presenting to ED with exacerbation COPD randomized to 1.2g magensium sulfate or placebo after receiving 2.5 mg nebulized salbutamol	Double blinded PRCT	Change in PEFR at 30 mins & 45 mins	25.1 L/Min better for MgSO4 at 30 mins 7.4 L/min better for MgSO4 at 45 mins (p=0.03)	Male bias Patients with high temperature or radiological signs of infection excluded 3 patients received 3g magnesium sulfate instead of 1.2g
			Change in % PEFR at 30 & 45 min	22.4% for MgSO4at 30 mins, 6.1% at 45 mins (p=0.01)
			Need for hospitalisation	28.1% for MgSO4 group vs 41.9% for placebo (p=0.25)

Comment(s)

There is only one small study addressing this question and it excludes patients with acute infection which is one of the commonest causes of exacerabtion of COPD. However it does show a small improvement in PEFR with iv magnesium. The clinical significance of this change may be small but appears to show a non-significant trend towards a reduced rate of admission. A larger trial including patients with signs of acute infection would be helpful.

Editor Comment

Search updated in Nov 2003, no new papers found from original submission.

Clinical Bottom Line

Intravenous magnesium is worth considering in patients with an exacerbation of COPD

Level of Evidence

Level 3 - Small numbers of small studies or great heterogeneity or very different population.

References

1. Skorodin MS, Tenholder MF, Yetter B et al. Magnesium sulfate in exacerbations of chronic obstructive pulmonary disease. Arch Intern Med 1995;155(5):496-501.