In the event of shoulder dystocia, the nurse can assist by performing maneuvers to release the shoulder.

Choice A rationale

The cost of a medication is a logistical consideration, not a scientific or pharmacological basis for its clinical preference during labor. The selection of an analgesic is primarily determined by its therapeutic profile, including efficacy, safety for both mother and fetus, and its mechanism of action, rather than economic factors.

Choice B rationale

The administration route is a clinical characteristic, but it does not explain why these specific drugs are preferred. Butorphanol and nalbuphine are typically administered intravenously or intramuscularly, not orally, to achieve rapid onset and predictable plasma concentrations, which is crucial for managing acute labor pain.

Choice C rationale

These medications, like most opioids, are lipophilic and have low molecular weights, allowing them to readily cross the placental barrier via passive diffusion. This is a significant aspect of their pharmacology. The preference for these specific drugs lies in their partial agonist/antagonist activity, which mitigates some of the risks of fetal respiratory depression.

Choice D rationale

Butorphanol and nalbuphine are synthetic opioid agonist-antagonists. This unique pharmacological profile means they bind to and activate kappa opioid receptors while acting as antagonists or partial agonists at mu opioid receptors. This dual action provides effective pain relief while concurrently limiting the degree of respiratory depression compared to full mu-opioid agonists, making them a safer choice for both mother and fetus during labor. *.

Choice A rationale

Guided imagery is a cognitive-behavioral technique that uses mental focus on a peaceful scene or image to distract from pain. While it can be an effective pain management strategy for some women in labor, it is not specific to the physiological cause of back labor. Back labor pain is caused by the occiput of the fetus pressing against the maternal sacrum, which requires a physical, rather than a psychological, intervention to be most effective.

Choice B rationale

Progressive relaxation is a technique that involves tensing and relaxing different muscle groups throughout the body to relieve tension and promote comfort. Like guided imagery, it is a general pain management technique that can be useful for reducing overall labor discomfort. However, it does not directly address the specific cause of back labor, which is the physical pressure from the fetal head on the sacrum.

Choice C rationale

Slow, deep breathing is a common and effective technique for managing labor pain by promoting relaxation, increasing oxygenation, and distracting the patient. It helps the woman focus and cope with contractions. While beneficial for managing labor pain, it is not a targeted intervention for the intense, localized pressure and pain associated with back labor, which responds better to direct physical pressure.

Choice D rationale

Back labor pain is caused by the occiput of the fetus pressing against the maternal sacrum. Counterpressure is a physical intervention that involves applying firm, steady pressure with the heel of the hand or a fist against the sacral area during contractions. This direct pressure helps to displace the fetal head and counteract the pain, making it a highly effective and specific relief measure for back labor.