Desperado said:
The only trial I saw on the subject showed Bicarb didn't make a significant difference. I'm a big believer in slow injection though.
Anesth Analg. 1998 Feb;86(2):379-81. Related Articles, Links
The effect of needle gauge and lidocaine pH on pain during intradermal injection.
Palmon SC, Lloyd AT, Kirsch JR.
Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
Local anesthetics can produce pain during skin infiltration. We designed a randomized, prospective trial to determine whether needle gauge and/or solution pH affect pain during the intradermal infiltration of lidocaine. After approval by our institution's human studies review board, 40 healthy adult volunteers gave their consent to participate in this study. All of the volunteers randomly received four intradermal injections. Each volunteer was blinded as to the content of the intradermal injections and to which needle size was used for each injection. Each volunteer randomly received a 0.25-mL intradermal injection of the following four solutions: 1) lidocaine 2% administered through a 25-gauge needle (lido-25); 2) lidocaine 2% mixed with sodium bicarbonate (4 mL of 2% lidocaine plus 1 mL of sodium bicarbonate, pH 7.26) administered through a 25-gauge needle (lido-bicarb-25); 3) lidocaine 2% administered through a 30-gauge needle (lido-30); and 4) lidocaine 2% mixed with sodium bicarbonate (4 mL of 2% lidocaine plus 1 mL of sodium bicarbonate) administered through a 30-gauge needle (lido-bicarb-30). In each patient, the injection site was in the same region for each of the four injections. The skin wheal was tested for appropriate anesthesia using a 19-gauge needle on the skin wheal. A visual analog pain score was recorded after each intradermal injection. The pain scores were significantly higher in the lido-25 (3.2 +/- 0.2) group than in the lido-30 (2.5 +/- 0.3), lido-bicarb-25 (1.9 +/- 0.2), and lido-bicarb-30 (1.3 +/- 0.2) groups. The lido-bicarb-30 injection was also rated as less painful than the lido-30 injection. We found no differences between the lidobicarb-25 and the lido-bicarb-30 injections. Complete analgesia for the 19-gauge needle pain stimulus was achieved in all patients for each injection. We conclude that, overall, the pain intensity of an intradermal injection of 2% lidocaine is low. The addition of sodium bicarbonate to 2% lidocaine decreases the pain associated with an intradermal skin wheal, and although the use of a 30-gauge needle decreases the pain of injection, the addition of sodium bicarbonate seems to have a greater overall effect than needle size. Implications: Forty volunteers randomly received four intradermal injections consisting of 2% lidocaine with or without sodium bicarbonate via a 25- or 30-gauge needle. The addition of bicarbonate had a greater overall effect than needle size in decreasing the pain associated with the intradermal injection of lidocaine.
Publication Types:
Clinical Trial
Randomized Controlled Trial
Efficacy of alkalinized lidocaine for reducing pain on intravenous and epidural catheterization.
Nakayama M, Munemura Y, Kanaya N, Tsuchida H, Namiki A.
Department of Anesthesiology, Sapporo Medical University School of Medicine, South-1, West-16, Chuo-ku, Sapporo 060-8543, Japan.
PURPOSE: To investigate whether increasing the pH of lidocaine could reduce the pain caused by its skin infiltration as well as that caused by intravenous and epidural needle insertion. METHODS: A randomized, double-blind trial was undertaken in patients who were allocated to receive topical anesthesia with either plain (plain group; n = 25) or alkalinized lidocaine (alkalinized group; n = 25). An alkalinized lidocaine solution was prepared by adding 8.4% sodium bicarbonate to a plain 1% lidocaine solution at a ratio of 1 : 10. Pain was assessed using the verbal analog scale (VAS). RESULTS: In the alkalinized group, the VAS scores on skin infiltration in the hand (2.5 +/- 1.4) and the back (2.7 +/- 1.4) were significantly lower than the respective scores in the plain group (3.5 +/- 1.4, and 4.9 +/- 1.9). Although the VAS score on intravenous needle insertion did not differ between the two groups, the VAS score on epidural needle insertion was significantly lower in the alkalinized group (1.3 +/- 1.0) than in the plain group (3.6 +/- 1.3). CONCLUSIONS: Alkalinization of lidocaine was effective in attenuating pain on skin infiltration and on epidural needle insertion.
PMID: 14569436 [PubMed]
Neutralization of lidocaine-adrenaline. A simple method for less painful application of local anesthesia]
[Article in Danish]
Momsen OH, Roman CM, Mohammed BA, Andersen G.
Odense Universitetshospital, Plastikkirurgisk afdeling.
The amount of sodium bicarbonate necessary to neutralise commercially available lignocaine-epinephrine (pH 4.7) to physiologically neutral pH (7.4) was established. The analysis showed that neutral pH could be accomplished by adding 1.0 ml sodium bicarbonate (8.4 g/l) to 10 ml lignocaine-epinephrine (1%, 5 microgram/ml). Chemical analysis also established that the neutralised lignocaine-epinephrine was stable for 24 hours after adding sodium bicarbonate. A double-blinded randomised clinical trial with crossover design done on volunteers from hospital staff proved that injection of neutralised lignocaine-epinephrine is less painful than commercially available lignocaine-epinephrine (p < 0.001).
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 10962963 [PubMed - indexed for MEDLINE]
Br J Plast Surg. 1998 Jul;51(5):385-7. Related Articles, Links
Randomised control trial of pH buffered lignocaine with adrenaline in outpatient operations.
Masters JE.
Department of Plastic Surgery Christchurch Public Hospital, New Zealand.
Bicarbonate buffering of local anaesthetics is known to significantly decrease the pain of their administration and yet few practising surgeons do so. A double-blind randomised cross-over clinical trial was conducted to confirm the practicality and efficacy of bicarbonate buffering of lignocaine with adrenaline in the setting of a busy local anaesthetic operating theatre. 40 patients received either buffered or control local anaesthetic solutions in equivalent sites on opposite sides of the body. The pain of each injection was rated from 0 (no pain) to 10 (extreme pain). The mean pain score for the buffered solution was significantly lower than the control solution (3.06 vs 4.34, P = 0.002). Bicarbonate buffering of lignocaine with adrenaline is effective, inexpensive and simple; its widespread use should be encouraged.
