A patient presents with fever, chills, headache, and myalgia after returning from a trip to sub-Saharan Africa. Laboratory tests reveal intraerythrocytic ring forms and trophozoites on blood smear examination. Which of the following is the most likely causative agent?

Correct Answer: A

Rationale: The most likely causative agent in this scenario is Plasmodium falciparum, a protozoan parasite that causes malaria. The patient's symptoms of fever, chills, headache, and myalgia align with the typical presentation of malaria. Additionally, the presence of intraerythrocytic ring forms and trophozoites on blood smear examination is characteristic of Plasmodium species, particularly P. falciparum, which causes the most severe form of malaria.

Correct Answer: C

Rationale: Placenta previa is a condition in pregnancy where the placenta implants low in the uterus, partially or completely covering the cervix. This can lead to painless, bright red vaginal bleeding in the third trimester. However, in some cases, placenta previa can also present with sudden onset of severe lower abdominal pain and signs of shock, such as syncope, pallor, and abdominal distention due to concealed bleeding. In severe cases, the bleeding can be significant and life-threatening for both the mother and the baby. It is important to promptly diagnose and manage placenta previa to prevent complications.

Correct Answer: D

Rationale: Late decelerations on the fetal monitor tracing indicate a potential uteroplacental insufficiency, which could be caused by decreased oxygen supply to the fetus. One common cause of late decelerations is uterine hyperstimulation due to excessive use of oxytocin. By discontinuing the oxytocin infusion, the nurse can help alleviate the stress on the fetus and decrease the likelihood of further late decelerations. This action should be prioritized before other interventions such as changing the mother's position or administering oxygen. Immediate delivery may be necessary if the fetus continues to show signs of distress despite discontinuing the oxytocin infusion.

Correct Answer: B

Rationale: Magnesium sulfate is used to prevent eclampsia, but it can lead to toxicity if levels become too high. One common sign of magnesium toxicity is increased deep tendon reflexes, also known as hyperreflexia. This occurs because magnesium is a muscle relaxant, and elevated levels can lead to over-relaxation of muscles, causing an exaggerated reflex response. Other signs of magnesium toxicity include respiratory depression, decreased urine output, and cardiac arrest. Therefore, in a woman receiving intravenous magnesium sulfate during labor, an increase in deep tendon reflexes would indicate potential toxicity and require immediate intervention.

Correct Answer: A

Rationale: The priority nursing intervention for a woman in active labor diagnosed with postpartum hemorrhage (PPH) due to uterine atony is to massage the uterus to promote contraction. Uterine massage helps to stimulate uterine muscle tone and contraction, which can help control bleeding by reducing the size of blood vessels and promoting hemostasis. It is important to address the uterine atony promptly to prevent further blood loss and stabilize the patient's condition. Other interventions such as blood transfusion, administering antibiotics, and elevating the mother's legs can be considered based on the patient's response to the initial intervention of uterine massage.