Forty volunteers were asked to compare pain from injection of buffered
versus unbuffered local anesthetics given for upper lid and lower lid
blepharoplasty. The concentration of the solution was 1 part 8.4% sod
ium bicarbonate to 5 parts local anesthetic. The surgeons performing t
he operations were asked to identify any difference in onset of action
, hemostasis, or duration of action. Thirty-five of the 40 patients fo
und the buffered anesthetic to be less painful and better tolerated. N
o difference in hemostasis or duration of action was noted between the
buffered or unbuffered solutions, but the buffered solution produced
faster onset of action.