- Life-threatening adverse reaction to local anesthetic toxicity.
- Injection of local anesthetic into systemic circulation
- Exceeding the maximum dose of local anesthetic (see table below)
- Absorption of anesthetic into systemic circulation by injection into extremely vascular area.
- Incidence = ~0.2% of nerve blocks
- Generally occurs within minutes of injection
- CNS symptoms (typically occur before CVS symptoms)
- Auditory changes
- Metallic taste
- Seizures or drowsiness
- Respiratory arrest
- Early signs
- Ventricular dysrhythmia
- Late signs
- Conduction block
- Cardiovascular collapse
- Directed by clinical picture
- Blood levels of anesthetic are available, but not clinically useful.
- Lipid emulsion, 20% solution
- 1.5 mL/kg bolus over 1 minute
- Then, 15 mL/kg per hour x 20-minute infusion (0.25 mL/kg/min for 20 min or until hemodynamic stability)
- Manage seizures with benzodiazepines; propofol is an option but may worsen CV toxicity
- ACLS modifications per ASRA (Am Soc of Regional Anesthesia):
- Small initial doses of 100 μg boluses in adults
- No vasopressin
- Avoid CCBs and BBs
- Amiodarone preferred in ventricular dysrhythmias
Medscape:Local Anesthetic Toxicity
- ↑ 1.0 1.1 1.2 Fencl JL. Local anesthetic systemic toxicity: perioperative implications. AORN J. 2015 Jun;101(6):697-700.