Materials and Methods: A prospective randomized controlled trial method was used in this study and 120 term pregnant women were recruited. The intervention group received nitrous oxide 2 minutes before starting episiotomy repair, until the end of the procedure. The control group received 5 mL of lidocaine (2%) before starting the episiotomy. The results of the 2 groups were compared with regard to pain intensity using a visual analogue scale (VAS). Mann-Whitney, student?s t test and chi-square test were used to analyze the data.

Results: Sixty women were studied in each group. Nine participants (15%) in nitrous oxide group, as opposed to 23 participants (38.4%) in lidocaine group had moderate, severe or extremely severe pain intensity (P value = 0.005). In terms of satisfaction level, there was no significant difference between 2 groups (P value = 0.713).

Conclusion: The results of this study showed that pain intensity in the nitrous oxide group was significantly lower than that in the lidocaine infiltration group. Application of nitrous oxide at least 2 minutes before repair may be an effective method for pain management in episiotomy repair.