Local Anesthetic

Lidocaine

Amide local anesthetic · Xylocaine

Mechanism: Blocks voltage-gated Na+ channels.

Calculate dose for your patient

Enter weight (kg or lb). Always verify before administration.

Patient weight

Computed weight

70.0 kg · 154.3 lb

Pre-intubation

70 mg – 105 mg

= 3.50–5.25 mL (20 mg/mL)

Exceeds typical adult max 100 mg — cap and reassess.

Blunts intubation response; also analgesic infusion 1 mg/kg/h.

Weight is saved on this device for the next calculator you open.

Full dose calculator

Onset

Rapid (1–5 min infiltration)

Duration

1–2 h (4 h with epi)

Metabolism

Hepatic (CYP3A4/1A2).

Dosing

Adult

Max: 4.5 mg/kg plain; 7 mg/kg with epi. IV: 1–1.5 mg/kg before intubation.

Pediatric

Max 4.5 mg/kg plain.

Indications

Local/regional anesthesia
IV antiarrhythmic
Attenuate intubation response

Contraindications

Amide allergy
3rd-degree heart block (IV)

Side Effects

LAST (perioral numbness → seizures → CV collapse)
Methemoglobinemia (high dose)

Clinical Pearls

1Always know your max dose and the patient's weight.

2LAST treatment: lipid emulsion 1.5 mL/kg bolus → 0.25 mL/kg/min.

References & Further Reading

1
Textbook
Flood P, Rathmell JP, Shafer S. Stoelting's Pharmacology and Physiology in Anesthetic Practice. 5th ed. Philadelphia: Wolters Kluwer; 2015.
2
GuidelineOpen source
Neal JM, Neal EJ, Weinberg GL. American Society of Regional Anesthesia and Pain Medicine Local Anesthetic Systemic Toxicity Checklist: 2020 Version. Reg Anesth Pain Med. 2021;46(1):81-82.
3
Journal
Weinberg GL. Treatment of local anesthetic systemic toxicity (LAST). Reg Anesth Pain Med. 2010;35(2):188-193.
4
Textbook
Gropper MA, Miller RD, Cohen NH, et al., eds. Miller's Anesthesia. 9th ed. Philadelphia: Elsevier; 2020.
5
Textbook
Adriano A, Morris R, eds. 2021 CA-1 Tutorial Textbook (15th Ed.). Stanford University Medical Center, Department of Anesthesiology.

Citations are provided to direct further study. Always check the most current edition of guidelines and society recommendations — the information in this chapter is a teaching summary, not primary source material.