Evaluation of a low-dose lidocaine iontophoresis system for topical anesthesia in adults and children: a randomized, controlled trial.

ABSTRACT

BACKGROUND: Commonly used classes of topical anesthetics require 30 to 60 minutes to provide effective anesthesia. A new low-dose lidocaine iontophoresis system (LDLIS) may provide topical anesthesia in 10 minutes at a lower dose than previous systems, thereby limiting adverse events. METHODS: This was a prospective, randomized, multicenter, double-blind, placebo-controlled, clinical trial. Adults and children aged 5 to 17 years (inclusive) received a 10-minute ionntophoretic treatment with either lidocaine or a saline placebo before venipuncture or venous cannulation. Intensity of pain associated with venipuncture or venous cannulation was assessed using either a 10-cm Visual Analog Scale (VAS) for adults and children aged 12 to 17 years or the Facial Affective Scale (FAS) for all children enrolled. RESULTS: Five hundred forty-eight patients (276 adults, 272 children) participated. Mean (SD) VAS pain scores were lower in adults who received iontophoresis with lidocaine rather than with placebo (0.77 [1.49] vs 2.52 [2.30], P < 0.001) and in children aged 12 to 17 years (1.50 [1.87] vs 2.58 [2.26], P = 0.001). FAS pain scores were lower among children who received iontophoresis with lidocaine rather than with placebo (0.36 [0.26] vs 0.51 [0.27], P < 0.001). Similar results were found for children stratified by age group (5-7 years 0.40 [0.30] vs 0.60 [0.31], P = 0.011; 8-11 years 0.35 [0.27] vs 0.48 [0.27], P = 0.021; 12-17 years 0.33 [0.21] vs 0.48 [0.24], P = 0.001). Mean (SD) parental ratings of pain on the FAS for children aged 5 to 11 years were also lower for the lidocaine group (0.45 [0.28] vs 0.55 [0.25], P = 0.018). Adverse events were similar between groups and included skin erythema and edema. One patient in the study experienced a partial-thickness burn. CONCLUSION: In this study of adults and children, the LDLIS provided effective topical anesthesia for venipuncture and venous cannulation within 10 minutes.