Buffering lidocaine 1%/epinephrine with sodium bicarbonate in a 3:1 ratio is as effective and less painful than a 9:1 ratio

Référence

Vent A, Surber C, Graf Johansen NT, et al. Buffered lidocaine 1%/epinephrine 1:100,000 with sodium bicarbonate (sodium hydrogen carbonate) in a 3:1 ratio is less painful than a 9:1 ratio: A double-blind, randomized, placebo-controlled crossover trial. J Am Acad Dermatol 2020;83(1):159-165.

Sommaire

Lido/Epi is one of the most commonly used local anesthetics for office-based procedures. The acidic nature of lidocaine is thought to be responsible for the burning sensation during infiltration. NaHCO₃ is used as a buffering agent to minimize acidity and reduce pain during infiltration. These investigators recruited 48 healthy volunteers, aged 18 years to 75 years, who randomly received (allocation concealed) either 2 or 4 infiltrations of room temperature 2 mL Lido/Epi:NaHCO₃ in mixing ratios of 3:1, 9:1, or 10:0 (unbuffered), or a placebo (NaCl 0.9%). Mixing occurred within 1 minute prior to infiltration and the injections randomly occurred on various sites of the right and left forearm. All participants completed the trial and no serious adverse events occurred. Study participants rated the 3:1 mixture as significantly less painful than the 9:1 mixture (median pain score = 1.5 points lower on a 10-point scale, where 0 = no pain and 10 = unacceptable pain, when given first, and 0.5 points lower when given second). As expected, the unbuffered mixture was more painful than both the 3:1 and 9:1 mixtures, and the placebo mixture was significantly the most painful of all the injections. This POEM was co-authored by Christina M. Garcia, DO, MPH; Faculty Development Fellow, University of North Carolina, Chapel Hill.