A patient sustains a third-degree laceration and repair with the birth of her son.
Which of the following statements by the nurse would best explain this condition?

Choice A rationale

Checking urinary output is an important part of overall patient care to assess hydration status and kidney function. However, it is not a direct or immediate intrauterine resuscitation measure for addressing late decelerations, which are a sign of uteroplacental insufficiency and require interventions to improve oxygenation and blood flow to the fetus.

Choice B rationale

Cardiopulmonary resuscitation (CPR) is a life-saving procedure performed when a person's heart stops beating or they stop breathing. It is not an appropriate intervention for a laboring mother with late decelerations unless she experiences a cardiopulmonary arrest herself, which is not indicated by this fetal heart rate pattern.

Choice C rationale

Repositioning the mother onto her side, especially the left side, shifts the weight of the gravid uterus off the inferior vena cava and aorta. This action scientifically improves venous return to the heart and increases cardiac output, thereby enhancing blood flow and oxygen delivery to the placenta and fetus, which can resolve late decelerations.

Choice D rationale

Increasing IV fluids expands the maternal circulating blood volume, which can improve placental perfusion. This increase in intravascular fluid volume leads to a rise in maternal cardiac output and blood pressure, thereby increasing the flow of oxygenated blood to the intervillous spaces of the placenta, addressing the root cause of late decelerations.

Choice E rationale

Applying a non-rebreather oxygen mask to the mother at a flow rate of 8 to 10 liters per minute increases the oxygen saturation of the maternal blood. This higher concentration of oxygen is then delivered to the placenta, increasing the oxygen available for transfer to the fetus and thereby addressing the fetal hypoxemia that is causing the late decelerations. .

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. *.