Intravenous Lipid Emulsion Therapy and the American Society of Regional Anesthesia Checklist for Local Anesthetic Toxicity

Abstract

With the increased utilization of regional anesthesia as part of a multimodal analgesic regimen in enhanced recovery after surgery protocols, the pain practitioner must be aware of the diagnosis and management of local anesthetic systemic toxicity (LAST). The mainstay of treatment for LAST is the administration of intravenous lipid emulsion (ILE) therapy, which is provided as an initial bolus followed by an infusion. ILE works by several mechanisms, which include both a redistribution of local anesthetic from areas of toxicity to areas of metabolism and direct cardiotonic and vasoactive effects. LAST differs from other advanced cardiac life support (ACLS) scenarios as resuscitation is often prolonged, and several common code medications such as epinephrine and vasopressin should have dose reductions or be omitted entirely. The American Society of Regional Anesthesia and Pain Medicine (ASRA) maintains a checklist for the treatment of LAST, last updated in 2017. The checklist describes the diagnosis and management of suspected LAST, several risk-reducing measures to prevent LAST, and a proposed LAST rescue kit that should be readily available whenever local anesthetic is used.