A 70-kg woman is to undergo nail removal from her right ring finger in the ambulatory surgery clinic. Which of the following is the most appropriate option for local anesthesia?

The maximal safe total dose of lidocaine administered to a 70-kg person is 4.5 mg/kg, or approximately 30 to 35 mL of a 1% solution. The addition of epinephrine to lidocaine, procaine, or bupivacaine not only doubles the duration of infiltration anesthesia, but increases the maximal safe total dose by one-third (eg, 7 mg/kg for lidocaine with epinephrine) by decreasing the rate of absorption of drug into the bloodstream. However, epinephrinecontaining solutions should not be injected into tissues supplied by end aeries (eg, fingers, toes, ears, nose, penis). Hypersensitivity to local anesthetics is uncommon and occurs most prominently with anesthetics of the ester type (procaine, tetracaine). While small nerve fibers seem to be most susceptible to the action of local anesthetics, these agents act on any pa of the nervous system and on every type of nerve fiber. CNS toxicity usually appears as stimulation followed by depression, probably because of an early selective depression of inhibitory neurons; with a massive overdose, all neurons may be depressed simultaneously