Weight-Based Dosing for Lidocaine with Epinephrine
The maximum safe dose of lidocaine with epinephrine for local infiltration anesthesia in adults is 7.0 mg/kg. 1
Adult Dosing Guidelines
- For adults, the maximum recommended dose of lidocaine with epinephrine is 7.0 mg/kg 1
- For lidocaine without epinephrine, the maximum dose is lower at 4.5 mg/kg 1
- When calculating dosage, use the following conversion: 1% lidocaine = 10 mg/mL 1
- For patients with BMI >30 kg/m², ideal body weight should be used for dose calculation rather than actual body weight 1
- Ideal body weight can be calculated as: height in cm - 100 for men; height in cm - 105 for women 1
Pediatric Dosing Guidelines
- For children, the maximum dose of lidocaine with epinephrine is 3.0-4.5 mg/kg 1
- For lidocaine without epinephrine in children, the maximum dose is 1.5-2.0 mg/kg 1
- Doses of amides (including lidocaine) should be decreased by 30% in infants younger than 6 months 1
Special Considerations
- For multistage procedures like Mohs micrographic surgery, a maximum dose of 500 mg (50 mL of 1% lidocaine) delivered over several hours is considered safe 1
- Lower doses should be used in very vascular areas to reduce risk of systemic absorption 1
- When lidocaine is administered intravascularly (e.g., during intravenous regional anesthesia), the dose should be decreased to 3-5 mg/kg 1
- Duration of action for lidocaine with epinephrine is typically 90-200 minutes, depending on concentration, total dose, site of administration, and patient age 1
Safety Measures to Prevent Local Anesthetic Systemic Toxicity
- Use the lowest effective dose of local anesthetic 1
- Aspirate the needle/catheter prior to each injection to avoid introducing the drug directly into a vessel 1
- Use incremental injections of anesthetic 1
- Continually assess and communicate with the patient to monitor for signs of early toxicity 1
- Signs of toxicity follow a progression: circumoral numbness, facial tingling, slurred speech, metallic taste, auditory changes, and hallucinations, potentially followed by seizures or CNS depression 1
Clinical Pearls
- The addition of epinephrine to lidocaine significantly delays absorption, allowing for higher maximum doses 2, 3
- Epinephrine concentrations between 1:50,000 and 1:400,000 are equally effective for vasoconstriction 4
- In tumescent anesthesia techniques (highly diluted lidocaine with epinephrine), higher doses may be safely used - preliminary estimates suggest up to 45 mg/kg with liposuction and 28 mg/kg without liposuction 5
- When using lidocaine with epinephrine for intravenous analgesia, the loading dose should not exceed 1.5 mg/kg given over 10 minutes 1
Caution
- Avoid using lidocaine with epinephrine in patients with severe cardiac disease, uncontrolled hypertension, or hyperthyroidism 1
- Be aware that the maximum safe dose may need to be reduced in patients with hepatic dysfunction, severe renal impairment, or the elderly 1
- Have lipid emulsion 20% available when using high doses of local anesthetics for treatment of potential local anesthetic systemic toxicity 1