Anaes · Critical incidents
Local anaesthetic systemic toxicity (LAST)
Also known as LAST · Local anaesthetic toxicity · Lipid rescue · Intralipid · Bupivacaine cardiotoxicity
Exam-exhaustive LAST: mechanism, dose limits, early CNS prodrome, cardiovascular collapse, ASRA prevention checklist, and lipid emulsion resuscitation that differs from standard ALS.
Checked against its sources on 11 Sept 2026
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Target exams
Red flags
- LAST progresses from mild CNS signs to seizure and cardiac arrest within minutes — stop injection and call for lipid early.
- Lipid emulsion 20% is first-line rescue: 1.5 mL/kg lean-body-weight bolus then 0.25 mL/kg/min infusion; max ~12 mL/kg.
- LAST arrest is not standard ALS — avoid vasopressin, calcium-channel blockers, and beta-blockers; prolonged CPR may be needed.
- Ultrasound, aspiration, fractionation, and dose ceilings prevent most events — prevention is the exam half-mark.
- Have lipid in the block room before high-dose plexus or fascial-plane boluses.
Meet the patient
A 68 kg woman is booked for an ultrasound-guided transversus abdominis plane block with 40 mL of 0.25% levobupivacaine. Two minutes after the second side she says her mouth tastes of metal, her tongue tingles, and then she seizes. The lipid bag is two theatres away, and the next sixty seconds decide whether this is a story she remembers.[1]
Hold two questions before you ever draw up a block: can I stop the toxic plasma level happening? (count every milligram, aspirate, fractionate, and have lipid in the room) and if I cannot, do I have the rescue script cold? Everything below hangs off those two.[1]
References4ShowHide
- [1]Neal JM et al. The Third American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity: Executive Summary 2017 Reg Anesth Pain Med, 2018.PMID 29356773
- [2]Horlocker TT et al. Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Fourth Edition) Reg Anesth Pain Med, 2018.PMID 29561531
- [3]Donaldson AJ, Thomson HE, Harper NJ, et al. Bone cement implantation syndrome Br J Anaesth, 2009.PMID 19059919
- [4]Panchal AR, Bartos JA, Cabañas JG, et al. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Circulation, 2020.PMID 33081529