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Magnesium Sulfate

Question 4:

In the child hospitalized with an asthma exacerbation, should intravenous magnesium sulfate be used to improve pulmonary function?
Question 5: In the child hospitalized with an asthma exacerbation, should more than one treatment with intravenous magnesium be given?


Inpatient asthma team recommendation: Based on very low quality evidence, the inpatient asthma team recommends the consideration of IV magnesium sulfate for children hospitalized for a severe asthma exacerbation if conventional therapy is failing and it has not been already given. 

Based on very low quality evidence we recommend considering the administration of intravenous magnesium for children with moderate asthma exacerbations that have failed to respond to continued therapy after one hour. Research performed in adults has shown beneficial effects of magnesium given to adult patients seen in the Emergency Department for asthma exacerbations. 

Additionally, no literature was found to answer the question about providing more than one dose of magnesium sulfate. We cannot recommend for or against multiple doses of magnesium when treating hospitalized patients with asthma exacerbations. We place a high value on using therapies with known efficacies. Further research (if performed) is likely to have an important effect on our recommendation.

Literature (Appendix C): No literature was found regarding the use of IV magnesium in children hospitalized for asthma exacerbations. However, for adult patients seen in the Emergency Department, administration of intravenous magnesium has been shown to significantly improve respiratory function as measured by PEFR (% predicted) and asthma score. SMD 1.94, 985% CI [0.8, 3.08] (Mohammed & Goodacre, 2007). This evidence is graded as very low quality based on three factors.

  1. The evidence does not directly apply to hospitalized children; all studies were completed in the ED. 

  2. The findings are imprecise. The number of subjects in the in the meta- analysis is 128 total subjects. 

  3. The outcome PEFR is difficult to measure in children < 5 years. It is unknown if the children were able to adequately perform the maneuver to obtain this outcome. 

Torres et al. (2012) reported a significant reduction in use of mechanical ventilation when IV magnesium sulfate (25 mg/kg, maximum 2 grams over 20 minutes) was administered to children aged 2-15 years within the first hour of presentation of a severe asthma attack (Wood’s score >/= 5) (See Figure 1).

We did not find any evidence to support or refute more than one treatment with IV magnesium sulfate.

Figure 1. Intravenous magnesium sulfate vs. control in Severe Asthma, Outcome: Need for mechanical ventilation

These guidelines do not establish a standard of care to be followed in every case. It is recognized that each case is different and those individuals involved in providing health care are expected to use their judgment in determining what is in the best interests of the patient based on the circumstances existing at the time. It is impossible to anticipate all possible situations that may exist and to prepare guidelines for each. Accordingly these guidelines should guide care with the understanding that departures from them may be required at times.