Lidocaine Patches Prior to Percutaneous Nerve Evaluation

Objectives: To determine whether the use of a lidocaine patch prior to percutaneous nerve evaluation (PNE) improves pain associated with the procedure

Methods: This double-blinded, randomized clinical trial compared 4% lidocaine patch to a placebo at the time of PNE. Female patients older than 18 years and without allergy to lidocaine or adhesives were included if they were undergoing office sacral neuromodulation trial with PNE for any indication. PNEs were performed bilaterally and without fluoroscopy. Either lidocaine or placebo patch was placed over the sacrum 30 minutes prior to a PNE Additional local anesthesia with 1% lidocaine was administered at surgeon discretion. The study was powered to detect a 1.5-point difference on a 10-point visual analog score (VAS) pain scale with a sample size of 34, 17 in each group. Secondary outcomes included the volume of injectable lidocaine used, progression to permanent implant, amplitude of perineal sensation, and satisfaction.

Results: A total of 39 women were enrolled in the study. 19 patients received placebo adhesive without lidocaine and 20 received lidocaine patch at the time of PNE. Patient characteristics are described in Table 1. The mean age (62.4 ± 16.4 lidocaine vs 56.8 ± 10.3 placebo) and body mass index (31.7 ±7.3 vs 33.6 ± 8.5 placebo) were similar between the groups. The most common indication for PNE was urge incontinence with 90% with lidocaine versus 79% with placebo. There was a statistically and clinically significant improvement in pain based on the 10-point VAS score (4.5 ± 1.7 lidocaine vs 6.05 ± 2.12 placebo, p=0.02). When analyzing secondary outcomes, the total injectable lidocaine was similar (13.2 ± 4.9ml lidocaine vs 13.3 ± 6 ml patch, p=0.94) between the groups. Patient satisfaction was measured using a 0-3 Likert scale where a score of 2 indicating “moderate” satisfaction and 3 indicating “quite a bit”. Patient satisfaction was similar between the groups (2.6 ± 0.68 lidocaine vs 2.3 ± 0.75 placebo, p=0.11) Both lidocaine and placebo patch groups had high rates of progression to permanent implant (80% lidocaine vs 68% placebo p=0.2). There was a significant difference in reprogramming during the PNE trial with more patients in the placebo arm requiring reprogramming due to a delayed uncomfortable stimulation (0/20, 0% lidocaine vs 4/19, 21% placebo, p=0.015).

Conclusions: In this appropriately powered, randomized trial, patients experienced significantly less pain at the time of PNE with a pre-procedural lidocaine patch when compared to a placebo, despite similar use of local anesthetic. Satisfaction rates were high among all patients.