Adequate analgesia in serial chronic leg ulcer debridement can be difficult to achieve. A common analgesia method is the topical administration of local anesthetics directly onto the wound. However, complete wound debridement is often hampered by insufficient analgesia leading to interruption of the actual debridement and fragmentation of treatment into more frequent serial debridement sessions. Alternatively, the inhalation of an nitrous oxide/oxygen (N2O/O2) gas premix could be used for analgesia. In this study, the investigators have compared the analgesic method of an eutectic mixture of topically administered lidocaine/prilocaine cream (EMLA®) with the inhalation of an equimolar 50% N2O/50% O2 gas premix (Kalinox®) in serial leg ulcer debridement.