Final answer:
The nurse should first change the client's position if the external fetal monitor shows a pattern of variable decelerations in fetal heart rate. This can help alleviate potential cord compression and should be the initial response before considering more invasive interventions.
Step-by-step explanation:
When a nurse is caring for a client in labor and the external fetal monitor shows a pattern of variable decelerations in fetal heart rate, the first action should generally be to change the client's position. This is a non-invasive and immediate step that can help alleviate potential cord compression, which might be contributing to the variable decelerations. Only if repositioning the client does not resolve the decelerations, or if there are signs of fetal distress or other complications, would the nurse consider escalating interventions, which may include administrating oxygen, checking for conditions like placenta previa, or preparing for an emergency cesarean section.
It is important to respond to any signs of fetal distress promptly, as sustained decelerations in heart rate can indicate that the fetus is not receiving enough oxygen. Quick and appropriate management is vital to ensuring the well-being of both the mother and the fetus during labor.