Final answer:
The medication a nurse would likely administer to a patient experiencing respiratory depression due to morphine sulfate is Naloxone (Narcan), as it is an opiate antagonist effective in reversing opioid-induced respiratory depression.
Step-by-step explanation:
If a postoperative patient with an epidural infusion of morphine sulfate experiences a decline in respiratory rate to 8 breaths per minute, the nurse would anticipate administering Naloxone (Narcan). This is because Naloxone is an opiate antagonist that rapidly reverses the effects of opioids, including respiratory depression caused by narcotics such as morphine. The use of Naloxone is essential in cases of opioid overdose as it helps to restore normal respiration and can prevent death. It acts by antagonizing the actions of morphine at all its receptors and is given parenterally due to its limited duration of action.