A laboring client is inhaling gas through a mouthpiece just before the onset of her regular contractions.

As they inhale, a valve opens and gas is released.

They continue to inhale the gas slowly and deeply until the contraction starts to subside.

When the inhalation stops, the valve closes.

What is this procedure?

Choice A rationale:

Infertility is a common issue for women with endometriosis. The endometrial tissue that grows outside the uterus can cause scarring and inflammation, which can block fallopian tubes and prevent eggs from being released or fertilized. Studies have shown that 30-50% of women with endometriosis experience infertility.

It is important to address this potential issue with the patient and discuss options for fertility preservation if desired.

Choice B rationale:

There is no evidence to suggest that women with endometriosis are more likely to have multiples. The likelihood of having multiples is primarily influenced by factors such as genetics, maternal age, and the use of fertility treatments.

Choice C rationale:

Acetaminophen may not be effective for pain relief in women with endometriosis. The pain associated with endometriosis is often severe and can be unresponsive to over-the-counter pain relievers. Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen are often more effective in managing endometriosis-related pain.

In some cases, stronger pain medications such as opioids may be necessary.

Choice D rationale:

Oral contraceptives can be helpful for women with endometriosis by:

Suppressing ovulation, which can reduce the amount of endometrial tissue that grows and bleeds each month.

Thinning the uterine lining, which can also reduce pain and bleeding.

Slowing the growth of endometrial tissue.

Oral contraceptives are not a cure for endometriosis, but they can help to manage symptoms and improve quality of life.

A rationale:

Incorrect. Nitrous oxide can be used during any stage of labor, not just the second stage. It is often used during the first stage to help manage early labor pain.

Evidence: Studies have shown that nitrous oxide is effective for pain relief during both the first and second stages of labor.

Additional information: The timing of nitrous oxide administration is typically based on the individual's preferences and needs. Some people prefer to use it as soon as labor begins, while others wait until contractions become more intense.

Choice B rationale:

Incorrect. Nitrous oxide is not a prelude to cesarean birth. It is a method of pain relief that can be used during vaginal or cesarean birth.

Evidence: Cesarean birth is a major surgical procedure that is typically performed under regional or general anesthesia. Nitrous oxide is not a type of anesthesia that would be used for this purpose.

Additional information: Cesarean birth is usually only performed when there is a medical reason why a vaginal birth is not possible or safe.

Choice C rationale:

Incorrect. Nitrous oxide is still a commonly used method of pain relief during labor. It is safe and effective, and it has a good safety profile.

Evidence: Nitrous oxide is one of the most widely used methods of pain relief during labor in many countries around the world.

Additional information: The use of nitrous oxide during labor has been increasing in recent years, as more people have become aware of its benefits.

Choice D rationale:

Correct. The procedure described in the question is an application of nitrous oxide. Nitrous oxide is a colorless, odorless gas that has analgesic and anxiolytic properties. It is often used during labor to help manage pain and anxiety.

Evidence: Nitrous oxide is a well-established method of pain relief during labor. It has been used for this purpose for over a century.

Additional information: Nitrous oxide is a safe and effective option for pain relief during labor. It is easy to administer and has few side effects.