A nurse is caring for a client who is at 41 weeks of gestation and has a positive contraction stress test. For which of the following diagnostic tests should the nurse prepare the client?

A. Instructing the client to increase her respiratory rate to more than 42 breaths per minute may exacerbate hyperventilation and cause respiratory alkalosis. This is not the appropriate action in this situation.

B. Breathing into a paper bag is an outdated and potentially dangerous practice. It can lead to a buildup of carbon dioxide in the body and may have adverse effects on both the mother and the baby. It is not recommended.

C. Having the client tuck her chin to her chest is the correct action.

This maneuver helps decrease the respiratory rate and prevent hyperventilation. It promotes a controlled and appropriate breathing pattern during labor.

D. Administering oxygen via nasal cannula is not the first-line intervention for lightheadedness and tingling during labor. The client's symptoms are likely due to hyperventilation, and addressing the breathing pattern is more appropriate.

The correct answer is C.

A. Acrocyanosis of the extremities: Acrocyanosis, or blueness of the extremities, is a common finding in newborns and is usually considered normal. It often resolves on its own and doesn't typically require intervention.

B. Murmur at the left sternal border: It's not uncommon for newborns to have innocent murmurs, and many resolve on their own as the infant grows. A murmur at the left sternal border alone may not necessarily indicate a problem, but it should be assessed by a healthcare provider.

C. Substernal chest retractions while sleeping: Chest retractions can be a sign of respiratory distress, and intervention is needed to assess and address the cause. Substernal retractions suggest increased work of breathing and may indicate a respiratory issue that requires attention.

D. Positive Babinski reflex: The Babinski reflex is a normal neurological response in infants. It involves the toes fanning out when the sole of the foot is stroked. A positive Babinski reflex is expected in a 12-hour-old newborn and does not require intervention.