Final answer:
For a patient experiencing severe pain despite morphine administration, the nurse should administer additional breakthrough pain medication and closely monitor the patient's pain level and vital signs.
Step-by-step explanation:
When a patient reports still experiencing high levels of pain after administration of morphine, it is imperative for the nurse to take immediate steps to address this. The most appropriate intervention in this situation would be give additional breakthrough pain medication. This is important because the initial dose of morphine may not have been sufficient to manage the patient's pain. A reassessment of pain after additional medication should also be conducted to ensure effective pain management. It is also essential for the nurse to check blood pressure and monitor heart rate, considering that the patient could be experiencing side effects or complications related to pain or medication.