Changes in plasma epinephrine concentration after dental infiltration anesthesia with different doses of epinephrine.

To define the cardiovascular risk as a result of epinephrine in local anesthetic solutions used in dental anesthesia, we measured the plasma epinephrine levels, the mean arterial brachial pressure (MAP), and heart rate for 15 min, after infiltration anesthesia in the area buccal to the upper permanent left lateral incisor and canine. For this purpose, 12 dental student volunteers received 2.0 mL 2% lidocaine with and without 20 or 80 micrograms epinephrine, in a double-blind cross-over trial. --Plain lidocaine solution cause no significant changes in the parameters under study when compared with the baseline values. --Lidocaine with 20 micrograms epinephrine caused a sustained doubling of the plasma epinephrine concentration two min after injection, and at the same time, a slight but significant (p less than 0.05) decrease in MAP. Two min and 45 s after injection, the heart rate increased by four beats/min when compared with the baseline rate. --Lidocaine with 80 micrograms epinephrine caused a doubling of the basal plasma epinephrine value as early as one min and 25 s after injection, and a ten-fold increase above the basal value at the end of the observation period (15 min). The heart rate increased significantly (p less than 0.01) by five beats/min above the baseline value starting two min after injection, and rose to a maximum of 13 beats/min until the end of the observation period. The time-point of the decrease in MAP was earlier, but the amount of the decrease equaled that measured after submucosal injection of 20 micrograms epinephrine with 40 mg lidocaine.