By Jer5150 – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19669589

Pearl: In cardiac arrest, consider esmolol (500mcg/kg loading dose, then 0-100mcg/kg/min drip) for refractory ventricular fibrillation.

Background: Ventricular fibrillation is one of our two “shockable” rhythms and is supposed to portend a better cardiac arrest outcome. But what if your patient is refractory to standard treatment (defibrillation, amiodarone, lidocaine) either by never exiting v-fib or by returning to v-fib immediately? Aside from dual-synchronous defibrillation, which is not yet a data-driven technique, to we have any other tools in our back pocket?

Explanation: There is some data, retrospective and non-randomized, to support improved outcomes with the infusion of esmolol to patients in refractory v-fib cardiac arrest. Two studies, one at Hennepin County (1) and one in Korea (2) both retrospectively analyzed patients in refractory v-fib arrest (defined as at least 3 shocks in both, amiodarone was also required by Hennepin). At Hennepin, sustained ROSC was 100% better and survival to discharge was 300% better, but no p-values were provided. In the Korean study, 56% in the esmolol group achieved sustained ROSC vs 16% in the non-esmolol group (p 0.007). There are also some pig model studies that support esmolol reducing the rate of v-fib recurrence after treatment (3,4)

Bottom Line: There are no randomized or large studies, but if your patient will not come out of ventricular fibrillation, consider giving esmolol as a bolus (500mcg/mg/kg) followed by an infusion.

(1) Driver BE1Debaty G2Plummer DW3Smith SW3. Use of esmolol after failure of standard cardiopulmonary resuscitation to treat patients with refractory ventricular fibrillationResuscitation. 2014 Oct;85(10):1337-41. doi: 10.1016/j.resuscitation.2014.06.032. Epub 2014 Jul 14.

(2) Lee YH1Lee KJ2Min YH3Ahn HC4Sohn YD5Lee WW6Oh YT7Cho GC8Seo JY9Shin DH10Park SO11Park SM12. Refractory ventricular fibrillation treated with esmololResuscitation. 2016 Oct;107:150-5

(3) Jingjun L1Yan ZWeijieDongdong ZGuosheng LMingwei B.Effect and mechanism of esmolol given during cardiopulmonary resuscitation in a porcine ventricular fibrillation model.Resuscitation. 2009 Sep;80(9):1052-9.

(4) Wallis DE1Wedel VAScanlon PJEuler DE.Effect of esmolol on the ventricular fibrillation threshold.Pharmacology. 1988;36(1):9-15.