Nitrous Oxide Versus Lidocaine for Pain Relief During Episiotomy Repair: A Randomized Trial

Since pain reduction is an important concern in childbirth, this study was designed to evaluate the effects of nitrous oxide in comparison with lidocaine on pain relief, during episiotomy repair in primiparous women.
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.
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).
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.