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


CONCLUSIONS
In this study of adults and children, the LDLIS provided effective topical anesthesia for venipuncture and venous cannulation within 10 minutes.
Zempsky
William T
WT
University of Connecticut School of Medicine, Connecticut Children's Medical Center, Hartford, CT 06106, USA. wzempsk@ccmckids.org
Sullivan
Janice
J
Paulson
Daniel M
DM
Hoath
Steven B
SB
D000293:Adolescent; D000328:Adult; D000698:Analgesia; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007478:Iontophoresis / Q000295:instrumentation / Q000379:methods*; D008012:Lidocaine / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D010147:Pain Measurement
D000779:Anesthetics, Local; D008012:Lidocaine