Reducing Pain in ED Patients During Lumbar Puncture: The Efficacy and Feasibility of Iontophoresis, Collaborative Approach

Abstract

This study examined the efficacy and feasibility of a collaborative iontophoresis procedure for dermal anesthesia prior to lumbar puncture (LP) in adult ED patients. Patients were randomized to receive lidocaine by iontophoresis or needle infiltration. Emergency nurses and physicians completed a collaborative LP procedure in those randomized to iontophoresis. Usual care was provided for needle infiltration subjects. Pain was assessed at 3 points using an 11-point numeric rating scale to measure pain, and provider satisfaction was recorded. Ninety subjects completed the protocol: infiltration group (n = 48) and iontophoresis group (n = 42). Subjects in the lidocaine infiltration group reported significantly more pain (mean, 4.1A+/-2.6) than subjects in the iontophoresis group (mean, 0.9A+/-1.6) ( t82 = 1.26, P =.000). There was no significant difference between the pain experienced during the lumbar puncture by both groups. Mean pain score during LP was 3.7 (+/-2.7) for iontophoresis compared to 3.4 (+/-2.9) for infiltration. More iontophoresis subjects (18 or 43.9%) required "rescue" lidocaine than infiltration subjects (12 or 24.5%) (chi-square 1 =3.79, P =.0515). Providers reported greater satisfaction with the collaborative procedure compared to physician administered lidocaine infiltration and anecdotally reported that iontophoretic anesthesia administration does not obscure anatomical landmarks, as needle infiltration can. Time for completion of dermal anesthesia using the iontophoretic procedure was longer than time for completion of dermal anesthesia using the lidocaine infiltration procedure (12A+/-12 min vs 2A+/-1.7 min); however, no statistically significant difference in total LP time or ED length of stay was found. Dermal anesthesia by lidocaine iontophoresis in patients undergoing an LP with emergency nurses and physicians working in collaboration during the procedure takes longer, but decreases the pain of administering anesthesia, increases provider satisfaction, and fosters collaborative practice in the emergency setting. Iontophoretic administration of anesthesia for LP is now an option for dermal anesthesia in our emergency department.