Nitrous Oxide for Pain Management in Office Hysteroscopy: A Randomized Placebo-Controlled Trial

Area of Science:

• Gynecology
• Pain Management
• Minimally Invasive Surgery

Background:

• Office operative hysteroscopy is a common gynecological procedure.
• Pain and patient discomfort can limit procedure completion and satisfaction.
• Effective analgesia is crucial for improving patient experience during hysteroscopy.

Purpose of the Study:

• To evaluate the efficacy of inhaled nitrous oxide (N2O) in reducing pain during office operative hysteroscopy.
• To compare pain levels between patients receiving N2O and those receiving ambient air.
• To assess the impact of N2O on patient satisfaction and procedure completion rates.

Main Methods:

• A prospective, randomized, double-blind, placebo-controlled trial was conducted.
• 214 women undergoing office operative hysteroscopy were randomized to receive either inhaled N2O or ambient air.
• Pain was measured using a visual analog scale at uterine entry, during the procedure, and postprocedure.

Main Results:

• Inhaled N2O significantly reduced intraprocedural pain compared to ambient air (2.23 vs 3.96, P<.001).
• The analgesic effect was more pronounced in postmenopausal women, with significantly lower pain scores at uterine entry and during the procedure.
• Procedure completion rates were higher (93.6% vs 83.7%, P=.021) and patient satisfaction was significantly greater (80.9% vs 47.1%, P<.001) in the N2O group.

Conclusions:

• Inhaled nitrous oxide is an effective analgesic for office operative hysteroscopy.
• N2O improves patient satisfaction and increases procedure completion rates.
• N2O is a well-tolerated option with a low incidence of adverse events for outpatient hysteroscopy.