Iontophoresis is a painless technique for topical
anesthesia that uses an electric field to drive charged
ions across an epithelial surface. The safety of this technique for
laceration repair has never been demonstrated. The purpose of this study was to investigate the effect of iontophoretic fields on rapidly proliferating cells involved in
laceration wound healing. The study was a prospective single-blinded animal study using a guinea pig model. Twelve guinea pigs each received four induced, uncontaminated
lacerations. Each guinea pig was randomly assigned to 1 of 3 groups (4 guinea pigs in each group). One group received
lidocaine via iontophoresis, one group received injected
lidocaine, and one group received half iontophoresis and half injected
lidocaine. After
anesthetic treatment,
wounds were then repaired in a standard fashion. The
wounds were examined grossly on a daily basis and on day 10 the incised skin containing the
laceration was examined by a pathologist blinded to the treatment group. A total of 48
wounds were assessed for wound healing, 24 of which received
lidocaine via iontophoresis and 24
lidocaine via injection. The power of the study to determine a 40% difference between the two groups was 0.8. There was significantly more
granuloma and granulation tissue formation in the iontophoresis group than in the injected
lidocaine control group (P = .0004, Fisher's exact test).(ABSTRACT TRUNCATED AT 250 WORDS)