Nitrous oxide/oxygen inhalation provides effective analgesia during the administration of tumescent local anaesthesia for endovenous laser ablation

Abstract. Background: Tumescent anaesthesia (TA) is an important but sometimes very painful step during endovenous thermal ablation of incompetent veins. The aim of this study was to examine whether the use of fixed 50% nitrous oxide/oxygen mixture (N2O/O2), also called equimolar mixture of oxygen and nitrous oxide, reduces pain during the application of TA. Patients and methods: Patients undergoing endovenous laser ablation (EVLA) of incompetent saphenous veins were included. Thirty consecutive patients inhaled N2O/O2 during the application of TA. Thirty consecutive patients received TA alone (controls). Patients were asked to complete a questionnaire immediately after the intervention to assess satisfaction with the intervention and pain-levels during the different steps of the intervention (0 = not at all, 10 = very much). Adverse events during the treatment were monitored. Results: 30 patients (14 men, mean age of 44 years) were included in the N2O/O2 group and 30 patients (9 men, mean age 48 years) w...