Management of pain associated with debridement of leg ulcers: a randomized, multicentre, pilot study comparing nitrous oxide-oxygen mixture inhalation and lidocaine-prilocaine cream

Background Mechanical debridement of fibrin and/or necrosis promotes healing of arterial and venous leg ulcers but is limited by pain associated with the procedure. Objective The main objective of this study was to compare the respective analgesic effect of nitrous oxide oxygen mixture (NOOM) inhalation and lidocaine-prilocaine cream (LPC) application during the mechanical repeated debridement of chronic arterial and venous leg ulcers. Methods In this randomized, multicentre, open-label study, pain was evaluated before and after each care and debridement session using a Visual Analog Scale (VAS) and a Verbal Rating Scale (VRS), in the context of usual debridement and wound care process. The Quality of debridement and tolerability of the treatments were also assessed. Results Forty-one patients were randomized: 20 received NOOM and 21 LPC. Pain assessed by VAS and VRS was more intense in the NOOM group than in the LPC group (5.29 vs. 3.68 and 2.87 vs. 1.71, P < 0.001, for the two scales respectively). No differences were found concerning quality of debridement, safety or tolerability between the two groups. Conclusion This pilot study demonstrates the superiority of the LPC over NOOM for pain control during the mechanical debridement of chronic leg ulcers.