Original contribution
Pain reduction in local anesthetic administration through pH buffering

https://doi.org/10.1016/S0196-0644(88)80293-2Get rights and content

The effects of pH buffering on the pain of administration and efficacy of three local anesthetics (1% lidocaine, 1% lidocaine with 1:100,000 epinephrine, and 1% mepivacaine) were investigated in a randomized, prospective, double-blind study of 25 adult volunteers. Plain and buffered solutions of the three local anesthetics were prepared, and a 0.5 intradermal injection of each was administered. Pain of anesthetic infiltration was rated from zero to ten. The area of anesthetized skin surrounding each injection site was measured at time intervals following each injection. Buffering the local anesthetics significantly reduced the mean quantitative pain estimates compared to the nonbuffered controls: 1) 1% lidocaine compared with buffered 1% lidocaine, 4.9 ± 0.4 versus 1.1 ± 0.2 (P < 10 −6); 2) 1% lidocaine with epinephrine compared with buffered 1% lidocaine with epinephrine, 5.1 ± 0.4 versus 1.8 ± 0.4 (P < 10−6); and 3) 1% mepivacaine compared with buffered 1% mepivacaine, 5.1 ± 0.4 versus 0.9 ± 0.2 (P < 10−6). Onset, extent, and duration of skin anesthesia were not statistically altered by pH buffering. The pain of local anesthetic administration can be dramatically reduced by buffering the local anesthetic prior to its infiltration. Anesthetic efficacy is not compromised, and patient acceptance may be significantly increased.

References (12)

  • ScottJ et al.

    Graphic representation of pain

    Pain

    (1976)
  • RitchieJM et al.

    Local anesthetics

  • RundDA

    Essentials of Emergency Medicine

  • RitchieJM et al.

    The active structure of local anesthetics

    J Pharmacol Exp Ther

    (1965)
  • StrobelGE et al.

    The effects of pH gradients on the distribution of C14 — propaine and lidocaine in intact and desheathed sciatic nerve trunks

    J Pharmacol Exp Ther

    (1970)
  • HilleB

    Local anesthetic. Hydrophilic and hydrophobic pathways for the drug receptor action

    J Gen Physiol

    (1977)
There are more references available in the full text version of this article.

Cited by (260)

  • A randomized controlled trial of minor hand surgeries comparing wide awake local anesthesia no tourniquet and local anesthesia with tourniquet

    2020, Orthopaedics and Traumatology: Surgery and Research
    Citation Excerpt :

    The skin infiltration pain is largely attributed to their acidity. Solutions with lower pH cause increased pain by two different mechanisms [20,21]: first, the acidity irritates more neutral tissue and causes a burning sensation. Second, at a lower pH, the anesthetic is in an active, freely diffusible form, leading to prolonged time until the onset of anesthesia.

View all citing articles on Scopus

Presented at the University Association for Emergency Medicine Annual Meeting in Philadelphia, May 1987.

View full text