A randomized controlled trial of entonox and oxygen in labor analgesia

Abstract

Background and objectives: Labor pain is a severe form of pain experienced by a woman, leading to tremendous stress. Several routes for labor analgesia have been tried. Entonox is a premixed homogeneous gas mixture of nitrous oxide and oxygen in the ratio of 50:50 providing conscious sedation in obstetrics during labor. It is a safe and effective analgesia for obstetrics use due to its properties of rapid onset, short half-life, and rapidly disappearing symptoms on withdrawal of the gas. Therefore, we aimed to evaluate the effect of Entonox on the severity and relief of labor pain during its various stages and its associated maternal or fetal side effects. Materials and Methods: A prospective randomized controlled trial (RCT) of 200 term pregnant mothers reporting in labor over a period of 2 months who were randomized into Entonox group and placebo oxygen control group was included in the study. Administration of both gases was done, and the pain scoring was recorded. Maternal and fetal complications were noted. Results: The intensity of labor pain was significantly lower in Entonox group as evident by lower pain scoring values. The mean duration of the active phase of labor in the Entonox group was comparable to the oxygen group. Maternal and fetal side effects were not significant in both groups. The mode of delivery is also comparable in both groups. Conclusion: Entonox usage in labor analgesia is a safe, effective, and inexpensive method of relieving labor pain, achieving immense patient satisfaction and making labor a pleasurable experience.