Lidocaine Buffering for Aesthetic Numbing

Recommended Mixing Ratio

The American Academy of Dermatology recommends mixing 1% lidocaine with 1:100,000 epinephrine with 8.4% sodium bicarbonate in a 10:1 ratio for optimal pain reduction during injection 1
Alternative acceptable ratio of 9:1 (9 mL lidocaine/epinephrine to 1 mL bicarbonate) is also effective in clinical practice and reduces injection pain by 20-40% compared to unbuffered lidocaine with epinephrine 1

The American Academy of Dermatology advises against buffering bupivacaine with sodium bicarbonate, as this causes precipitation and decreased efficacy 1
Epinephrine concentration decreases by approximately 25% per week after buffering, so freshly prepared solutions provide optimal vasoconstriction 1

Buffering with sodium bicarbonate reduces injection pain in approximately 2 out of 3 patients, according to the American Academy of Dermatology 1
Adding epinephrine prolongs anesthetic duration by approximately 200% and provides hemostasis by slowing anesthetic mobilization and reducing peak blood levels, as recommended by the American Academy of Dermatology 2

The American Academy of Dermatology considers this mixture safe for use on all body sites, including digits, ears, nose, hands, and feet 2
The historical dogma about avoiding epinephrine in end-arterial territories has been definitively refuted by multiple systematic reviews showing no cases of necrosis, according to the American Academy of Dermatology 2
The American Academy of Dermatology recommends using the lowest effective epinephrine concentration (typically 1:100,000 or 1:200,000) and consulting cardiology if uncertain about stable cardiac disease 2
This mixture may be used in small amounts during pregnancy, preferably in the second trimester for urgent procedures, as advised by the American Academy of Dermatology [2] [3]

Mixing local anesthetics such as bupivacaine and lidocaine is a common practice that has been studied in multiple randomized controlled trials in both ophthalmologic and dermatologic settings, and is considered safe and effective 4, 5
Evidence suggests that mixing these agents for local infiltration and nerve blocks is safe and effective, according to the American Academy of Dermatology 5, 6

The American Academy of Dermatology suggests that adding epinephrine to either agent or their mixture is safe and can prolong anesthetic duration by approximately 200% 7, 8
The use of the lowest effective concentration of epinephrine (typically 1:100,000 or 1:200,000) is recommended by the American Academy of Dermatology 7, 8

The American Academy of Dermatology notes that injecting bupivacaine into an area previously injected with lidocaine reduces the extended duration of bupivacaine 7
Sodium bicarbonate can be added to lidocaine to reduce injection pain, but should not be added to bupivacaine as it may cause precipitation of the anesthetic and decrease efficacy, according to the American Academy of Dermatology and Praxis Medical Insights 6, 9

The American Academy of Dermatology advises against buffering bupivacaine with sodium bicarbonate as it may precipitate and reduce efficacy 6, 9

The American Academy of Dermatology recommends the use of lidocaine with epinephrine on the penis, with a Level A (strong) recommendation for the addition of epinephrine to local anesthesia on all body sites, including the penis, although the provided reference is not explicitly stated here, a similar recommendation is found 10

Local injected lidocaine is safe for use on the penis, and the addition of epinephrine is also safe and provides significant clinical benefits including prolonged anesthesia and improved hemostasis, as supported by the Journal of the American Academy of Dermatology 10

The maximum safe dose for adults is 7 mg/kg of lidocaine with epinephrine, which allows up to 490 mg or 49 mL of 1% solution for a 70 kg adult, according to the Journal of the American Academy of Dermatology 10

Avoid using lidocaine with epinephrine within 4 hours of other local anesthetic interventions to prevent cumulative toxicity, as recommended by Anaesthesia 11
True allergy to lidocaine is rare, representing only 1% of all adverse reactions, as noted in the Journal of the American Academy of Dermatology 10