From the Guidelines
Treatment of local anesthetic toxicity requires immediate recognition and intervention, with administration of 20% lipid emulsion therapy and benzodiazepines for seizures being the cornerstone of management, as recommended by the 2023 American Heart Association guidelines update 1. The treatment approach should prioritize securing the airway, administering oxygen, and establishing intravenous access.
- For cardiovascular symptoms, administer 20% lipid emulsion therapy (Intralipid) with an initial bolus of 1.5 mL/kg over 1 minute, followed by an infusion of 0.25 mL/kg/min for at least 10 minutes after hemodynamic stability is achieved, as supported by the guidelines 1.
- Simultaneously, treat seizures with benzodiazepines such as midazolam (0.05-0.1 mg/kg IV) or diazepam (0.1-0.2 mg/kg IV), as recommended by the guidelines 1.
- For cardiac arrest, follow standard ACLS protocols with modifications: use smaller epinephrine doses (10-100 μg boluses), avoid vasopressin, calcium channel blockers, and beta-blockers, and continue lipid emulsion therapy, as suggested by the guidelines 1. The use of lipid emulsion works by creating a "lipid sink" that extracts lipophilic local anesthetics from tissues and by providing a source of fatty acids to improve cardiac energy supply and function, as explained in the 2020 American Heart Association guidelines 1. Monitoring should continue for at least 12 hours after severe toxicity due to the risk of recurrence, as emphasized in the guidelines 1.
From the Research
Treatment for Local Anesthetic Toxicity (LAT)
The treatment for local anesthetic toxicity (LAT) involves several steps, including:
- Halting the administration of the local anesthetic immediately if systemic toxicity is suspected 2
- Requesting assistance and securing the patient's airway, breathing, and circulation (ABCs) 2
- Administering 100% oxygen and, if necessary, performing tracheal intubation and artificial respiration 2
- Using benzodiazepines to treat convulsions 2
- Administering lipid emulsion therapy to treat severe hypotension and arrhythmia 2, 3, 4, 5, 6
Lipid Emulsion Therapy
Lipid emulsion therapy is a recommended treatment for local anesthetic systemic toxicity, with a suggested initial bolus dose of 1.5 mL/kg followed by an infusion of 10 mL/min 3. The mechanisms of lipid emulsion therapy are not fully understood but may involve increasing the metabolism, distribution, or partitioning of the local anesthetic away from receptors into lipid within tissues 3. The use of lipid emulsion therapy has been shown to be effective in treating local anesthetic systemic toxicity in case reports and animal studies 3, 4, 5, 6.
Prevention and Management
Prevention of local anesthetic systemic toxicity is crucial and can be achieved by:
- Using small doses and divided administration of local anesthetics 2
- Using agents with low toxicity, such as ropivacaine and levobupivacaine 2
- Performing an aspiration test before administering the local anesthetic 2
- Monitoring the patient closely during the procedure and being prepared to treat any signs of systemic toxicity 2