Excessive and improper administration of local anesthetic (a.k.a. local anesthetic systemic toxicity or L.A.S.T.) can lead to cardiac toxicity with symptoms ranging from benign arrhythmias to overt cardiac arrest.
Administration of a 20% intra-lipid emulsion has been experimentally known to reverse L.A.S.T in animal models, but in 2006 the first documented human case of ILE was successfully used during cardiac arrest secondary to L.A.S.T. with hemodynamic recovery and good neurologic outcome. Many case reports have emerged since then, including the use of ILE in toxicity with other lipophilic drugs (e.g., calcium channel blockers, tricyclic antidepressants, etc.)
Several mechanisms have been proposed explaining how ILE works. They include:
binding circulating toxins in the blood stream, minimizing its exposure to tissues
improving mitochondrial metabolism (which is inhibited in L.A.S.T.)
reducing re-perfusion injury and cellular apoptosis post cardiac-arrest
Dosing of ILE:
1.5 mL/kg intravenous bolus of 20% ILE over 2-3 minutes (may be repeated, if necessary) then,
starting a continuous infusion of 0.25-0.5 mL/kg/min and continuing infusion for 10 minutes after vital signs return.
Check out this video by our own Dr. Bryan Hayes(@PharmERToxGuy) and Lipidrescue.orgfor more information.
References
Weinberg, G. Lipid emulsion infusion: resuscitation for local anesthetic and other drug overdose. Anesthesiology 2012 Jul;117(1):180-7.
Follow me on Twitter (@criticalcarenow) or Google+ (+criticalcarenow)
