Purchase this article with an account.
M. N. Welch, L. Mihora, D. E. E. Holck; A Randomized, Prospective Double-Blind Comparison of Pain Levels During Topical Anesthesia With Lidocaine vs. Buffered Lidocaine in Bilateral Eyelid and Eyebrow Procedures. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4839.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Normal 2% lidocaine for injection has a pH of 5.5 which contributes to pain during injection. Several authors have reported on the efficacy of buffering lidocaine to a physiologic pH prior to injection. Results have been mixed, however, due to the lack of a suitable control. We proposed a bilateral symmetric surgery as a control to overcome the limitations of these previous studies. We compared injection of normal 2% lidocaine against buffered 2% lidocaine in a randomized, prospective double-blinded study using a 10 point visual analogue scale as the primary outcome measurement.
21 consecutive patients scheduled for bilateral eyelid surgery were included. Exclusion criteria included age under 18, pregnancy, nursing, and scarring, asymmetry, trauma or previous surgery to the eyelids. A marking pen was used to mark the initial site of injection at a symmetrical location on both sides. Syringe 1 contained 10 cc of 2% lidocaine without epinephrine. Syringe 2 contained 9 cc of 2% lidocaine without epinephrine and 1 cc of sodium bicarbonate 8.4% from a fresh bottle. Identical 30 gauge needles were used. The nurse randomly assigned each of the two treating physicians to a side and also randomly assigned lidocaine to one side and buffered lidocaine to the other side. The same two physicians performed all procedures and are board certified in ophthalmology. The physicians inserted the needles at the same time and applied the anesthesia at 0.05 cc/sec for a 30 second count until 1.5 cc were injected. Only one needle entry point was used on each side. The patients were then shown a visual analogue scale with a scale of 1-10 and asked to rate the pain level on each side during the injection.
14 of 21 patients reported that the buffered lidocaine was less painful than the unbuffered lidocaine. Three patients report no difference and four patients report less pain with the unbuffered lidocaine. The Wilcoxin Signed-Rank Test was used to compare the two different types of anesthesia for each patient. Overall, it was determined that patients rated their pain 1.4 less on the side with buffered lidocaine vs. unbuffered lidocaine for eyelid subcutaneous anesthesia.
2% Lidocaine without epinephrine buffered with sodium bicarbonate 8.4% offers a reduction in pain experienced by 67% of patients during subcutaneous anesthesia for surgical procedures of the eyelids. Buffering lidocaine is an inexpensive way to reduce the pain of eyelid subcutaneous anesthesia.
This PDF is available to Subscribers Only