Topical Anesthetics for Intravenous Insertion in Children: A Randomized Equivalency Study

Abstract

Objectives. Children view needle sticks as the worst source of pain and fear in the hospital setting. In an effort to minimize the pain of needle sticks, the use of eutectic mixture of lidocaine and prilocaine (EMLA) has become standard practice in many children’s hospitals. Unfortunately, EMLA requires at least 60 minutes to be fully effective and reportedly may cause vasoconstriction, leading to difficult vein cannulation. A newly available local anesthetic (ELA-Max) may require less time and cause less vasoconstriction. The purpose of this randomized crossover study was to investigate the anesthetic equivalence of EMLA and ELA-Max. Methods. Thirty well children (14 girls and 16 boys) who were between the ages of 7 and 13 years volunteered to have EMLA applied to the dorsal aspect of 1 hand for 60 minutes and ELA-Max applied to the other hand for 30 minutes. Right and left hands were randomized to treatment type and order of intravenous (IV) insertion. Clinical Research Center nurses, blind to the anesthetic randomization, attempted to insert a 22-gauge Teflon IV catheter into a vein in each hand. The children rated pain during IV insertion on the Oucher scale, and the nurse rated the difficulty of the insertion. Results. There was no significant difference in pain ratings for hands that were treated with EMLA (mean: 20.5) or with ELA-Max (mean: 24), and there was no difference for the difficulty of vein cannulation. Children’s preprocedure state anxiety was positively associated with pain ratings. Conclusions. ELA-Max, applied for 30 minutes before IV cannulation, has an anesthetic effectiveness similar to EMLA applied for 60 minutes. Some children rated IV insertion pain fairly high for both hands (eg, 60 on a 0- to 100-point scale) despite anesthetic treatment. Preprocedural anxiety may affect the perception and/or rating of pain. There were no differences between hands that were treated with EMLA or with ELA-Max for success of IV insertion.