RESUMEN
This study compared 4 local anesthetics, 1% lidocaine, 1% lidocaine with sodium bicarbonate, 2% chloroprocaine, and 0.5% bupivacaine, in a double-blinded manner for pain on intradermal injection and pain during subsequent intravenous (IV) cannulation with an 18-gauge catheter. The subjects rated their pain, using 100-mm visual analog scales, related to the local injection itself and again after the IV catheter was inserted. No statistical differences were noted in pain scores after the injection of the local anesthetic (P = . 134) or on insertion of the IV catheter itself (P = .394). However, there was a low correlation between the pain perceived during the injection of local anesthetic and insertion of the IV catheter (r = 0.483; P = .001). We found that there were no differences in pain produced by 1% lidocaine, 1% lidocaine with sodium bicarbonate, 2% chloroprocaine, and 0.5% bupivacaine during intradermal injection. There were also no differences in pain produced by an 18-gauge IV catheter being inserted after administration of any of these local anesthetics. Thus, any of these 4 local anesthetics may be used, and the choice may be based on other factors such as price and convenience.