Local anesthetic systemic toxicity is treated by administering

• A. 10% lipid emulsion
• B. 15% hetastarch
• C. 20% lipid emulsion
• D. 25% hetastarch

Answer: (C)

When local anesthetic systemic toxicity occurs, the primary life-saving treatment is lipid emulsion therapy. The lipid emulsion acts as an intravascular lipid sink, drawing the lipophilic local anesthetic out of critical tissues like the heart and brain and reducing free drug levels, which helps reverse both cardiovascular and neurologic symptoms.

The recommended approach uses a 20% lipid emulsion given intravenously. Start with a bolus of about 1.5 mL/kg over 1 minute, then begin a continuous infusion at roughly 0.25 mL/kg/min. If there is incomplete response, repeat the bolus and/or increase the infusion rate per protocol, up to established total-dose limits (commonly up to about 10 mL/kg in the first 30–60 minutes, then reassess). Pediatric dosing is adjusted by weight but follows the same principle.

Other options don’t provide the lipid sink that neutralizes lipophilic toxins and can introduce unnecessary risks. Hetastarch fluids, for example, do not address the toxin directly and may contribute to adverse effects without reversing toxicity. A lipid emulsion at the 20% concentration is the evidence-based, effective treatment for LAST.