LAST (Local Anesthetic Systemic Toxicity)

Cardiovascular and CNS toxicity from inadvertent IV injection or systemic absorption of local anesthetic. Bupivacaine highest cardiotoxicity. Ropivacaine + lidocaine slightly safer.

Recognition

•Early CNS: tinnitus, perioral numbness, metallic taste, agitation
•Progressive: seizures, LOC
•Cardiovascular: arrhythmias (especially ventricular), hypotension, asystole
•Bupivacaine: may go directly to CV collapse without CNS prodrome

Steps

1
Stop injection. Call for help + lipid emulsion.
2
Airway management + 100% O₂
Hypoxia + acidosis worsen toxicity dramatically.
3
Lipid Emulsion 20% — bolus 1.5 mL/kg over 1 min
Repeat 1–2× if no response. Then infusion 0.25 mL/kg/min.
4
Modified ACLS
Avoid vasopressin. Reduce epi to ≤1 mcg/kg (≤100 mcg). No CCBs, β-blockers, or LA antiarrhythmics.
5
Treat seizures
Benzodiazepine (midazolam 2–5 mg). Avoid propofol (cardiac depression in unstable patient).
6
Continue lipid 10 min after stability
Max ~12 mL/kg lipid (relative limit).
7
Consider ECMO for refractory cardiac arrest
Bupivacaine washout takes hours.
8
Report to LipidRescue.org registry

Drugs + doses

Drug	Dose	Note
Lipid Emulsion 20%	1.5 mL/kg bolus, repeat ×1–2; infusion 0.25 mL/kg/min
Epinephrine	≤1 mcg/kg (≤100 mcg) IV — much smaller than usual ACLS dose
Midazolam	2–5 mg IV for seizures

Pitfalls

!Standard-ACLS-dose epi worsens bupivacaine arrest — go small.
!Avoid vasopressin, calcium channel blockers, β-blockers, lidocaine, procainamide.
!Propofol is NOT a substitute for lipid emulsion (10× too dilute).

Sources

ASRA 2020 Practice Advisory
Neal Reg Anesth Pain Med 2018
AAGBI

Anatomy reference

Sourced reference images. 4 matches for "cardiac sodium channel local anesthetic".

Heart_and_cardiac_blood_vessels,_1717._Wellcome_L0000338

Wikimedia · CC BY 4.0

Pattern_of_cardiac_muscle_from_R._Lower's_Tractatus_de_Corde_Wellcome_L0002029

Wikimedia · CC BY 4.0

Wikimedia · CC BY 4.0

OpenStax · CC BY 4.0

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Education only — not a substitute for facility protocols, MOC certification, or clinical judgment. Always follow your institutional crisis algorithm and confirm doses against current package inserts.