Painful procedures, such as skin surgery, wound repair, lumbar puncture, or the insertion of vascular catheters, are common practices that cause distress. The pain of these procedures is attenuated by infiltration of local anesthesia and, in certain patient populations (eg, young children, adults with a complicated laceration repair), procedural sedation. (See "Procedural sedation in children outside of the operating room" and "Procedural sedation in adults".)
Topical anesthesia may be appropriate in some patients, such as prior to insertion of intravascular catheters (see "Topical anesthetics in children"). However, with surgery on intact skin, large wounds, or the need for an immediate anesthetic effect, local infiltration is necessary to safely achieve adequate analgesia.
Most local anesthetics are classified as amides or esters (table 1) [1,2]. Local anesthetics in the amide class include lidocaine (the most commonly used agent), mepivacaine, bupivacaine, etidocaine, prilocaine, ropivacaine, and levobupivacaine [2,3]. Common ester agents include procaine (Novocaine®), 2-chloroprocaine, tetracaine, cocaine, and benzocaine . Because of toxicity and allergic reactions, the ester agents have limited indications for local infiltration, except in patients with allergy to amide agents [3,4].
Lidocaine, bupivacaine, mepivacaine, and procaine are the most commonly used agents for infiltration of local anesthesia . Issues related to the choice of anesthetic and the techniques for local infiltration are reviewed here. The following related topics are discussed separately:
●A comprehensive discussion of local anesthetics, including their pharmacodynamics and pharmacokinetics