Magnesium Administration Rate During Code Blue
For torsades de pointes during cardiac arrest, administer magnesium sulfate 1-2g IV push over 1-2 minutes; for all other cardiac arrest rhythms, do not administer magnesium at all. 1, 2
Specific Administration Guidelines by Clinical Context
Torsades de Pointes (Polymorphic VT with Long QT)
- Push 1-2g IV rapidly over 1-2 minutes as a bolus 2, 3
- Dilute in 10mL D5W before administration 1, 4
- This is the ONLY indication for magnesium during cardiac arrest 1
- Magnesium works regardless of baseline serum magnesium levels 1, 4
All Other Cardiac Arrest Rhythms
- Do NOT administer magnesium for VF, pulseless VT, asystole, or PEA 1
- Multiple randomized trials with 444 patients showed no benefit for ROSC or survival to hospital discharge 1
- This is a Class III recommendation (No Benefit) from the American Heart Association 1
Pediatric Dosing During Code Blue
For pediatric patients with torsades de pointes:
- Administer 25-50 mg/kg IV/IO over 10-20 minutes 5
- Push faster in torsades de pointes (can be given more rapidly than the standard 10-20 minute timeframe) 5
- Maximum single dose: 2g 5
Critical Safety Considerations
Common pitfall: The FDA label states IV injection should generally not exceed 150 mg/minute (approximately 1.5 mL of 10% solution per minute), which would take 13-20 minutes for a 2g dose 2. However, this general rate does NOT apply during cardiac arrest with torsades de pointes, where rapid bolus administration over 1-2 minutes is appropriate and necessary 2, 3.
Post-Resuscitation Monitoring
- Watch for hypotension immediately after ROSC 6
- 66% of patients receiving magnesium had systolic BP <90 mmHg post-ROSC versus 42% without magnesium 6
- Have vasopressor support (levophed) immediately available 6
- Consider calcium availability to counteract potential magnesium toxicity 7
Why Speed Matters in Torsades
- Magnesium prevents reinitiation of torsades rather than pharmacologically converting it 1
- Temporal association between rapid magnesium administration and return of spontaneous circulation has been documented within 0.5-2.25 minutes after bolus delivery 6
- In pediatric studies, bolus injection over 1-2 minutes achieved complete response in 5 of 6 patients 3