Does Topical Anesthetic Reduce Pain During Intraosseous Pin Removal in Children? A Randomized Controlled Trial

Background: The purpose of this study was to determine the effectiveness of topical liposomal lidocaine in reducing the pain perceived by children undergoing percutaneous intraosseous pin (PP) removal in the outpatient orthopaedic clinic. Methods: A triple-blinded, randomized, placebo-controlled clinical trial comparing topical liposomal lidocaine to a placebo was conducted at the Stollery Children's Hospital between September 2008 and February 2011. Subjects undergoing the removal of PP in the orthopaedic outpatient clinic between ages 3 and 16 years were recruited. A computer-generated variable-block randomization scheme was used to determine each subject's group assignment. Pain was recorded just before randomization and immediately after the procedure using the Oucher Scale (for subjects) and a 10-cm Visual Analog Scale (for parents and an observing orthopaedic technician). In a subset of individuals, follow-up telephone calls were made 24 hours postprocedure to inquire about any adverse event from the use of the topical liposomal lidocaine. Data were analyzed using the Student t test. Results: Of a total of 296 recruited subjects, complete data were available on 281 subjects (140 intervention and 141 control). There were no significant differences between the 2 groups with regards to baseline characteristics, including preprocedure pain scores. Although postprocedure pain scores demonstrated an increase in pain in both groups (2.3 points in the treatment group and 2.0 points in the placebo group), no statistically significant difference was seen in postprocedure pain scores between groups (P=0.81). No adverse events were observed or reported. Conclusions: Topically applied liposomal lidocaine was not effective in reducing pain during this procedure, compared with a placebo. However, this study demonstrates that PP removal is a painful procedure in children. Given the large volume of patients who undergo this procedure and the long-term consequences of experiencing painful procedures in childhood, it is important to find safe and fast-acting methods to decrease procedural pain associated with PP removal. Level of Evidence: Level I-therapeutic trial.