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Magnesium Sulfate

In the pediatric patient diagnosed with a refractory migraine, what is the efficacy of intravenous magnesium sulfate to decrease migraine pain in the Emergency Department?

 

Plain language summary from the office of evidence based practice: Based on very low quality evidence, the Migraine in the ED CPG team makes a conditional recommendation against treating with IV magnesium sulfate as a first line treatment for refractory migraine in the ED. The desirable effect of reducing symptom scores were not apparent and the proportion of subjects who incurred an adverse event was greater. The evidence to support this recommendation is graded as very low quality (see Table 1). The recommendation is based on the systematic review with meta-analysis by Choi & Parmar (2014) that includes five RCTs. The evidence is graded as very low quality due to indirectness (adult populations), inconsistency (the dose of IV magnesium varied across studies), and imprecise findings (the number of subjects studied in individual studies is low).

Literature synthesis: Choi & Parmar (2014) performed a systematic review.  The meta-analysis showed for the outcome “Difference in Pain within 60 Minutes” there was no difference between the groups treated with magnesium sulfate (IV) and placebo or metoclopramide, RR = 1.05 95% CI [0.70, 1.57]. When a sensitivity analysis was done to see if there was a difference if the control group received metoclopramide or normal saline, the estimate of the effect still showed no difference between the groups (See Figure 1).

For the outcome “Need for Rescue Medication” there was no difference between the groups treated with magnesium sulfate (IV) and placebo or metoclopramide, RR= 0.98 95% CI [0.80, 1.22]. Again, when sensitivity analysis was done to see if normal saline or metoclopramide were used as control, there was no difference in the estimate of the effect (See Figure 2).

For the outcome “Adverse Events” there were significantly more adverse events, predominantly flushing, followed by dizziness and burning at the IV site for those treated with magnesium sulfate RR= 2.53 95% CI [1.53, 4.18]. When a sensitivity analysis was done to see if normal saline or metoclopramide was used as control, there were still significantly more adverse events in the groups treated with magnesium sulfate (IV) (See Figure 3).

Dose: Magnesium sulfate (IV) -50mG/kg (max 2gm) IV over one hour

See Appendix E for the full Critically Appraised Topic (CAT).

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.