Reducing the discomfort of lidocaine administration through pH buffering.
OBJECTIVE
A prospective, double-blind study was undertaken to evaluate the effect of using a buffered lidocaine solution on the perception of pain experienced by a patient during its intradermal injection.


METHODS
One hundred fifty patients undergoing diagnostic angiographic and interventional procedures at the authors' institution were randomly assigned to receive a 1-mL aliquot of one of three lidocaine solutions: plain 1% lidocaine, 1% lidocaine diluted with normal saline in a 10:1 ratio, and 1% lidocaine diluted with 8.4% sodium bicarbonate in a 10:1 ratio. The lidocaine solutions were administered intradermally over 10-15 seconds. A numerical value was placed on the patient's perception of pain, separate from that associated with the 25-gauge needle insertion, with use of a linear visual analog scale.


RESULTS
Mean pain scores were as follows: for the 1% lidocaine solution, 2.83 +/- 2.60; for 1% lidocaine plus normal saline solution, 2.89 +/- 2.34; and for 1% lidocaine plus sodium bicarbonate solution, 1.37 +/- 1.73 (P = .0018).


CONCLUSIONS
Buffering lidocaine significantly decreased the discomfort associated with its administration as a local anesthetic.
Matsumoto
A H
AH
Department of Radiology, University of Virginia Health Sciences Center, Charlottesville 22908.
Reifsnyder
A C
AC
Hartwell
G D
GD
Angle
J F
JF
Selby
J B
JB
Tegtmeyer
C J
CJ
D000293:Adolescent; D002021:Buffers; D004311:Double-Blind Method; D006801:Humans; D007271:Injections, Intradermal / Q000009:adverse effects*; D008012:Lidocaine / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D010146:Pain / Q000517:prevention & control*; D011446:Prospective Studies; D017693:Sodium Bicarbonate
D002021:Buffers; D017693:Sodium Bicarbonate; D008012:Lidocaine