We’ve all heard that lidocaine buffered with sodium bicarbonate makes the local anesthetic closer to physiologic pH. This in turn decreases time of onset and infiltration pain. However, upon further investigation, this may not be so true.
Hobeich et al. concluded that 2% lidocaine with epinephrine buffered with 5% or 10% sodium bicarbonate did not significantly decrease time to anesthetic onset and infiltration pain when compared to nonbuffered solution.
– Prospective, randomized double blind study
– 30 healthy subjects received single maxillary canine infiltration injections of 1.8mL 2% lidocaine with 1:100,000 epinephrine, 2% lidocaine with epi buffered with 5% sodium bicarbonate, and 2% lidocaine with epi buffered with 10% sodium bicarbonate over 3 separate visits at least 1 week apart
– Mean anesthetic onset was 119 sec for nonbuffered solution, 116 sec for 5% buffered solution, and 121 sec for 10% buffered solution
- No significant difference
– Mean pain score (Heft-Parker visual analogue score) was 34 for nonbuffered solution, 40 for 5% buffered solution, and 40 for 10% buffered solution
- No significant difference
Similarly, Balasco et al. concluded that addition of sodium bicarbonate to 2% lidocaine with 1:100,000 epinephrine did not significantly decrease pain on local infiltration and subsequent I&D procedure when compared to nonbuffered solution.
Hobeich P, Simon S, Schneiderman E, He J. A prospective, randomized, double-blind comparison of the injection pain and anesthetic onset of 2% lidocaine with 1:100,000 epinephrine buffered with 5% and 10% sodium bicarbonate in maxillary infiltrations. J Endod. 2013 May;39(5):597-9. doi: 10.1016/j.joen.2013.01.008. Epub 2013 Mar 20.
Balasco M, Drum M, Reader A, Nusstein J, Beck M. Buffered lidocaine for incision and drainage: a prospective, randomized double-blind study. J Endod. 2013 Nov;39(11):1329-34. doi: 10.1016/j.joen.2013.07.008. Epub 2013 Sep 5.
