Entonox for labor pain: a randomized placebo controlled trial

Area of Science:

• Obstetrics and Gynecology
• Anesthesiology
• Pain Management

Background:

• Effective pain relief during labor is crucial for maternal well-being.
• Nitrous oxide is a potential analgesic option for labor pain.
• Assessing its efficacy and side effects is important for clinical practice.

Purpose of the Study:

• To evaluate the effectiveness of 50% nitrous oxide and oxygen mixture in alleviating labor pain.
• To assess the impact of nitrous oxide on maternal oxygen saturation (SaO2).
• To compare pain scores and side effects between nitrous oxide and oxygen groups.

Main Methods:

• A randomized controlled trial involving 534 parturients (ASA I and II).
• Participants received either 50% nitrous oxide/oxygen or 50% oxygen via facemask, self-administered during contractions.
• Pain (Visual Analogue Scale), SaO2, blood pressure, and side effects were recorded.

Main Results:

• Nitrous oxide group showed significantly lower Visual Analogue Scale pain scores.
• Maternal SaO2 was significantly higher in the control (oxygen) group during initial measurements.
• Increased incidence of side effects was observed in the nitrous oxide group, though Apgar scores remained comparable.

Conclusions:

• 50% nitrous oxide provides significant pain relief during labor contractions.
• While associated with more side effects, nitrous oxide is rapidly implementable for advanced labor pain.
• Further research may explore strategies to mitigate side effects while maximizing pain relief.