Magnesium administration to reduce shivering in therapeutic hypothermia post cardiac arrest

Here's a brief topic discussion at Emegency Medicine Pharm D. The evidence favoring this is quite weak but, as cited in the post, IV mag is endorsed in this review published about a year ago in Circulation. Concerning the management of shivering and general discomfort it recommends:

All patients receiving TH should receive low-dose, continuous infusions of both a sedative and an analgesic agent to prevent any potentially painful sensation or discomfort and to suppress shivering. Preference should be given to agents with short half-lives (eg, propofol or midazolam for sedatives and fentanyl or hydromorphone for analgesia)...

Magnesium sulfate may raise the shivering threshold, so we give an initial 4-g bolus to all patients receiving TH.15 If shivering persists, rapid uptitration of anesthetics with analgesic boluses is effective, although some patients require NMBAs to completely suppress shivering. We have found that selective use of NMBA boluses (3 doses of cisatracurium 0.15 mg/kg IV every 10 minutes) is often effective and allows patients to achieve target temperature without a continuous NMBA infusion. Some centers use continuous NMBAs in all patients during the entire TH process; others limit NMBA infusion to just the initiation period.