Note to me and my readers: The best review of local anesthetic systemic toxicity (LAST) is Local Anesthetic Toxicity, Mahajan A, Derian A., StatPearls Publishing; 2022 Jan-. It is the resource I find the most valuable.
In this post, I link to and post the show notes from LAST [Local Anesthetic Systemic Toxicity], prevention, recognition, and management from EM Quick Hits 26 LAST, Sodium Nitrite Poisoning, Post-intubation Care, Tetracaine for Corneal Abrasion, ST Segment in Occlusion MI, Coping with COVID*.
Topics in this EM Quick Hits podcast
Anand Swaminathan on LAST prevention, recognition and management (0:54)
Emily Austin on sodium nitrite suicide kit poisoning, methemoglobinemia and methylene blue (10:51)
Hans & Erin Rosenberg on post-intubation analgesia and sedation (17:29)
Salim Rezaie on short-term tetracaine for corneal abrasions new evidence (25:58)
Jesse MacLaren on differentiating ST deviation in occlusion MI from other causes (33:03)
Robert Maunder on a 3 step approach to coping and building resilience during the COVID pandemic (40:52 )
*Helman, A. Swaminathan, Austin, E. M. Rosenberg, H. Rezaie, S. MacLaren, J. Maunder, R. EM Quick Hits 26 – LAST, Sodium Nitrite Poisoning, Post-intubation Care, Tetracaine for Corneal Abrasion, ST depression, Coping with COVID. Emergency Medicine Cases. February, 2021. https://emergencymedicinecases.com/em-quick-hits-february-2021/. Accessed 9-30-2022.
All that follows is from Dr. Swaminathan’s LAST [Local Anesthetic Systemic Toxicity], prevention, recognition, and management.
- LAST (Local Anesthetic Systemic Toxicity) is an iatrogenic life-threatening acute neurologic/cardiac adverse reaction resulting from infiltration of local anesthetic that enters the systemic circulation
- The best treatment is prevention! Preventative measures include aspirating before injection of anesthetic to ensure that the needle is not in a blood vessel and using less than the toxic dose of the anesthetic (see table below)
- Consider LAST in any patient coming from outpatient surgical center in cardiac arrest
- Initial symptoms/signs include perioral numbness and other paresthesias, tinnitus, muscle fasciculations, hypertension, tachycardia progressing to tonic-clonic seizures, decreased LOA, apnea, hypotension, bradycardia, dysrhythmias and cardiac arrest
- Neurologic symptoms typically precede cardiovascular symptoms in lidocaine toxicity while cardiovascular symptoms typically present first in bupivacaine toxicity
- Treatment in addition to withdrawal of anesthetic and usual CABs may include epinephrine, bicarb, lipid emulsion therapy
Local anesthetic maximum doses adapted from Core EM
References
- Schwartz DR, Kaufman B. Local Anesthetics. In: Hoffman RS, Howland M, Lewin NA, Nelson LS, Goldfrank LR. eds. Goldfrank’s Toxicologic Emergencies, 10e New York, NY: McGraw-Hill; 2015.
- Neal JM et al, American Society of Regional Anesthesia and Pain Medicine. American Society of Regional Anesthesia and Pain Medicine checklist for managing local anesthetic systemic toxicity: 2012 version. Reg Anesth Pain Med 2012;37:16–8.
- Cao D et al. Intravenous lipid emulsion in the emergency department: a systematic review. J Emerg Med 2015; 48(3): 387-97.
