Author: Michael Hunt, MD Educational Pearls:   Toxicity happens from local anesthetics being given too fast, too much, or in the unintended spot Systemic toxicity manifests first with neurologic symptoms like circumoral numbness, tinnitus, blurred vision, nausea, and even seizures. Severe toxicity can then progress to arrhythmias and cardiac arrest. Maximum doses of lidocaine: 4 mg/kg; and with epinephrine: 7mg/kg. Maximum dose of bupivacaine: 2mg/kg; with epinephrine 3mg/kg   Editor note: treat seizures with benzodiazepines and avoid propofol for sedation; severe toxicity can also be treated with a 20%  lipid emulsion, though there is debate on its efficacy   References Dickerson DM, Apfelbaum JL. Local anesthetic systemic toxicity. Aesthet Surg J. 2014 Sep;34(7):1111-9. doi: 10.1177/1090820X14543102. Neal JM, Mulroy MF, Weinberg GL; 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 Jan-Feb;37(1):16-8. doi: 10.1097/AAP.0b013e31822e0d8a. Vasques F, Behr AU, Weinberg G, Ori C, Di Gregorio G. A Review of Local Anesthetic Systemic Toxicity Cases Since Publication of the American Society of Regional Anesthesia Recommendations: To Whom It May Concern. Reg Anesth Pain Med. 2015 Nov-Dec;40(6):698-705. doi: 10.1097/AAP.0000000000000320.