Thursday, May 28, 2009

Thursday May 28, 2009
Intravenous Lipid Emulsion for treatment of Overdose

Intravenous lipid emulsions, specifically Intralipid®, have been shown to be efficacious in treating overdose from local anaesthetics in animal models. The proposed mechanism of action is through a “lipid sink”. Due to the hydrophobic properties of local anaesthetics, the agents have greater affinity to the lipid properties and are drawn out of the plasma by mass action. This results in an increase in myocardial energy resulting in a greater susceptibility to resuscitation.

In addition to local anaesthetics, lipid emulsions may be used as treatment in the over dose of other agents such as propranolol, verapamil, bupropion, lamotrigine, and clomipramine.

Adverse effects include infection, thrombophebitis, dyspnea, cyanosis, injection site reaction, and hepatobiliary dysfunction.

The dosing regimens vary depending on the source.

Option 1: 20% lipid emulsion, single bolus dose 100mL or 8-16mL/kg OR Bolus 1-2 mL/kg or 100 mL + Continuous infusion 0.2-0.5 mL/kg/min

Option 2: (based on the recommendations by the Association of Anesthetists of Great Britain and Ireland): Lipid emulsion 20% 1.5 mL/kg bolus over 1 minute + Continuous infusion 0.25 mL/kg/min. Repeat bolus every 5 minutes x2 if no return of spontaneous circulation. Increase rate to 0.5 mL/kg/min if no return of spontaneous circulation after 5 or more minutes. Continue infusion until stable and adequate circulation has been restored



Reference: click to get abstract

Rosenblatt MA, Abel M, Fischer GW, Itzkovich CJ, Eisenkraft JB:
Successful use of a 20% lipid emulsion to resuscitate a patient after a presumed bupivacaine-related cardiac arrest. Anesthesiology 2006; 105:217-8