local anesthetic systemic toxicity
Also written as: LAST — Local Anesthetic Systemic Toxicity
A potentially life-threatening condition caused by elevated plasma concentrations of local anesthetic agents affecting the cardiovascular and central nervous systems.
Full Definition
Local anesthetic systemic toxicity (LAST) occurs when local anesthetic agents—such as lidocaine, bupivacaine, or articaine—are inadvertently injected intravascularly or administered in doses that exceed safe plasma thresholds. In dental anesthesiology, LAST is a recognised complication of nerve blocks performed during sedation, where the patient cannot reliably report early prodromal symptoms. Clinical manifestations range from perioral numbness and tinnitus to seizures and cardiovascular collapse. Treatment includes cessation of the offending agent, airway management, and administration of intravenous lipid emulsion (Intralipid®). Editors should note: the preferred abbreviation is LAST; the condition should not be called 'local anaesthetic overdose' in formal anesthesia literature.
Usage
Usage note: Preferred abbreviation is LAST. Do not call this an 'overdose' in formal dental anesthesia writing. Note US spelling 'anesthetic' vs UK 'anaesthetic'—harmonise throughout the document.
In Context
- "The anesthesiologist aspirated before every injection to minimise the risk of local anesthetic systemic toxicity." — Clinical guideline
- "LAST must be expanded on first use; thereafter the abbreviation is acceptable throughout the manuscript." — Editing instruction