Q: Which drug works best for Ventricular fibrillation resulting from hypothermia?

Answer: Bretylium

Ventricular fibrillation in a hypothermic patient is a very frustrating and desperate event. Defibrillation is usually ineffective. Recommendation is to attempt a round of chemical conversion with intravenous bretylium accompanied by CPR until active rewarming can be done to perform successful defibrillation.

References:

1. Murphy K, Nowak RM, Tomlanovich MC. Use of bretylium tosylate as prophylaxis and treatment in hypothermic ventricular fibrillation in the canine model. Ann Emerg Med. Oct 1986;15(10):1160-6.
2. Vachiery JL, Reuse C, Blecic S, Contempre B, Vincent JL. Bretylium tosylate versus lidocaine in experimental cardiac arrest. Am J Emerg Med. Nov 1990;8(6):492-5
3. Buckley JJ, Bosch OK, Bacaner MB. Prevention of ventricular fibrillation during hypothermia with bretylium tosylate. Anesth Analg. Jul-Aug 1971;50(4):587-93