Comparison of Iontophoretic Lidocaine to EMLA Cream for Pain Reduction Prior to Intravenous Cannulation in Adults

The insertion of intravenous IV catheters, required for most operative anesthesia, can be a source of pain and anxiety. Lidocaine, a local anesthetic, is frequently injected intradermally to decrease pain associated with IV cannulation in adults. Topically administered EMLA Eutectic Mixture of Local Anesthetics cream is frequently used, but it takes one hour for it to effectively anesthetize venipuncture sites, which limits its usefulness. A method gaining acceptance in healthcare is the iontophoresis transdermal administration of ionizable drugs utilizing an electric current of a polarized local anesthetic. Using iontophoresis, a local anesthetic such as lidocaine, a positively charged molecule, can be used to effectively anesthetize the skin to depths of up to 8mm without the use of needles, in as few as ten minutes. The purpose of this study was to compare the iontophoresis of lidocaine with epinephrine to EMLA cream for producing local anesthesia prior to intravenous cannulation. A descriptive study utilizing the experimental method with a cross over design was used. The procedures for the study consisted of the random application of EMLA cream for 60 minutes or the iontophoresis of 4 lidocaine HCl 40 mgml with 150,000 epinephrine 20 mcgml 40 milliamp minutes to either the dorsal surface of the right or left hand. Results were that the iontophoresis of 4 Lidocaine HCl with Epinephrine 150,000 20 microgramsmillimeter mcgml reduced pain more effectively than EMLA cream associated with intravenous cannulation in adults 14 mm vs. 3 mm for the EMLA cream and Iontophoresis respectively. The majority of subjects preferred iontophoresis.