Decreasing the pain of local anesthesia: A prospective, double-blind comparison of buffered, premixed 1% lidocaine with epinephrine versus 1% lidocaine freshly mixed with epinephrine

• Published in: Journal of the American Academy of Dermatology Vol. 54; no. 1; pp. 128 - 131
• Main Authors: Burns, Carrine A., Ferris, Georgette, Feng, Changyong, Cooper, Jennifer Z., Brown, Marc D.
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 2006; Elsevier
• Subjects: Anesthetics, Local - administration & dosage; Anesthetics, Local - adverse effects; Biological and medical sciences; Buffers; Dermatology; Double-Blind Method; Drug Combinations; Epinephrine - administration & dosage; Epinephrine - adverse effects; Humans; Hydrogen-Ion Concentration; Injections, Intradermal; Lidocaine - administration & dosage; Lidocaine - adverse effects; Medical sciences; Pain - chemically induced; Pain - physiopathology; Pain Measurement; Sodium Bicarbonate; Solutions - chemistry; Epinephrine; Human; Drug combination; Dermatology; Anticonvulsant; Catecholamine; Antiarrhythmic agent; Local anesthetic; Prospective; Pain; Local anesthesia; Double blind study; Organic amide; Lidocaine; Comparative study
• ISSN: 0190-9622; 1097-6787; 1097-6787
• DOI: 10.1016/j.jaad.2005.06.043

Local anesthetics are acidic and cause pain on infiltration into the skin. Two methods are commonly used by dermatologists to raise the pH of lidocaine with epinephrine: buffering with sodium bicarbonate or freshly mixing lidocaine with epinephrine on the day of use. Our purpose was to compare the pain induced by infiltration of the skin with 1% lidocaine with epinephrine 1:100,000 buffered with sodium bicarbonate (buffered) versus 1% lidocaine freshly mixed with epinephrine (fresh). Sixty volunteers were recruited for this prospective, double-blind study. Each subject received an intradermal injection of the buffered solution and the fresh solution. Immediately after each injection subjects rated the pain of infiltration on a 100-mm visual analog scale. The pain scores for the anesthetic solutions were compared using the paired t test. The pain score for the buffered solution was 18.3 ± 20.3, and the pain score for the fresh solution was 23.5 ± 19.1 ( P = .0543). Sixty-five percent of subjects felt the fresh solution was more painful than the buffered solution. The results did not reach statistical significance. In this small study, buffered lidocaine with epinephine caused less pain on infiltration into the skin than lidocaine freshly mixed with epinephrine, but the results were not statistically significant.