Clinical Tools

Local Anesthetic Systemic Toxicity

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Recognition

[1/9]

Recognition: CNS symptoms include tinnitus, perioral numbness, metallic taste, agitation, confusion, and seizures. Cardiovascular symptoms include hypotension, bradycardia, ventricular arrhythmias, and asystole. Symptoms may be delayed up to 30 minutes after injection.

Call for Help

[2/9]

Call for help. Get the 20% Intralipid (lipid emulsion) kit immediately.

Manage Airway and Seizures

[3/9]

Manage airway: oxygenate and ventilate. For seizures, administer midazolam 0.05-0.1 mg/kg IV. Avoid propofol if hemodynamically unstable.

Midazolam

Enter weight above for calculated dose

0.05-0.1 mg/kg IV for seizure control. Avoid propofol if hemodynamically unstable.

Cardiac Arrest Management

[4/9]

If cardiac arrest occurs: begin CPR per ACLS guidelines. Reduce epinephrine dose to less than 1 mcg/kg per bolus. Avoid vasopressin, calcium channel blockers, beta-blockers, and additional local anesthetics.

Epinephrine (reduced dose)

Enter weight above for calculated dose

Use less than 1 mcg/kg per dose. Standard ACLS doses may worsen toxicity.

20% Lipid Emulsion Therapy

[5/9]

20% Lipid emulsion: bolus 1.5 mL/kg IV over 1 minute, then start infusion at 0.25 mL/kg/min. If hemodynamically unstable at 5 minutes: repeat bolus (up to 2 additional boluses), double infusion rate to 0.5 mL/kg/min. Maximum total dose approximately 12 mL/kg.

20% Lipid Emulsion (bolus)

Enter weight above for calculated dose

May repeat bolus up to 2 additional times if unstable at 5 min.

20% Lipid Emulsion (infusion)

Enter weight above for calculated dose

Double to 0.5 mL/kg/min if unstable at 5 min. Max total ~12 mL/kg.

Prolonged CPR

[6/9]

Continue CPR for at least 60 minutes if cardiac arrest occurs. Local anesthetic toxicity may respond to prolonged resuscitation.

Consider Bypass or ECMO

[7/9]

Consider cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) if available and arrest is refractory to lipid emulsion and standard resuscitation.

Post-Stabilization Monitoring

[8/9]

Post-stabilization: ICU monitoring for 4-6 hours minimum. Obtain serial troponins. Monitor for recurrence of symptoms as lipid emulsion wears off.

Report Event

[9/9]

Report the event to lipidrescue.org and your institutional adverse event reporting system.

Source: ASRA Third Practice Advisory (2018), Checklist 2020

Limitations

  • This protocol is a reference aid and does not replace clinical judgment.
  • Presentation may be atypical -- cardiovascular collapse may occur without preceding CNS symptoms.
  • Lipid emulsion mechanism is not fully understood and efficacy data is largely from case reports and animal studies.
  • Propofol is NOT a substitute for lipid emulsion despite containing lipid.

References

  1. Neal JM, et al. The Third American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity. Reg Anesth Pain Med. 2018;43(2):113-123.
  2. ASRA LAST Checklist. 2020 revision. https://www.asra.com/guidelines-articles/guidelines/guideline-item/guidelines/2020/11/01/last-checklist
  3. Weinberg GL. Lipid emulsion infusion: resuscitation for local anesthetic and other drug overdose. Anesthesiology. 2012;117(1):180-187.