Definition: A life-threatening adverse reaction resulting from local anesthetic reaching significant systemic circulating levels. Local Anesthetic Systemic Toxicity (LAST) is rare and almost always occurs within minutes of injection of the local anesthetic.
- Injection of local anesthetic into the systemic circulation (either errantly as part of a regional block i.e. Bier block)
- Rapid absorption of local anesthetic injected into a highly vascular area
- Use of local anesthetic doses in excess of the maximum dose (typically occurs with multiple subcutaneous injections)
- Common implicated procedures: bronchoscopy, circumcision, tumescent liposuction. Consider diagnosis in any patient coming from outpatient surgical center with cardiac arrest