Effects of Added Epinephrine on Plasma Concentration of Lidocaine Following Epidural Anesthesia / 대한마취과학회지

ABSTRACT

Sixteen healthy adult female patients scheduled for elective abdominal hysterectomy were divided into two groups, and the venous plasma concenrations of lidocaine for both groups were measured at 5, 10, 15, 30, 45 and 60 minutes after an epidural injection of 2% lidocaine 500 mg. Group 1 received plain lidocaine, and group 2 received lidocaine with 5 ug/ml epinephrine. We observed that the mean measured plasma concentration of lidocaine in group 2 was significantly lower than in group 1 over the entire studied time course(P<0.05). The addition of epinephrine to the lidocaine solution reduced the peak plasma concentrations by 49% (from 7.76 to 3.97); however, this did not prolong the times at which the peak concentrations were reached. We hypothesized that these results may have been caused by some reduced epidural blood flow which have decreased the amount of lidocaine absorption.