Final answer:
The priority nursing action is to assess the accuracy of the PAOP measurement and closely monitor the patient's vital signs and respiratory status.
Step-by-step explanation:
The priority nursing action in this situation would be to assess the patient's PAOP measurement using an alternate method or equipment to verify the accuracy of the reading. The nurse should consider using a different catheter or consulting with a more experienced nurse to ensure accurate measurement.
In addition, the nurse should closely monitor the patient's vital signs and respiratory status, as well as assess for any signs of distress or changes in condition. If there is a significant discrepancy between the PAOP measurement and the patient's clinical presentation, further investigation and consultation with the healthcare team may be necessary.