Final answer:
The RN should first recheck the client's blood pressure to confirm the reading before considering further actions.
Step-by-step explanation:
When an LPN reports a blood pressure that is significantly higher than the client's previous reading after a cholecystectomy, the RN's first action should be to recheck the client's blood pressure personally. This step is crucial to confirm the accuracy of the reading before taking further action. If the RN verifies that the blood pressure is indeed elevated, they can then consider additional steps like informing the surgeon or administering medications under the correct protocol and after a physician's order. Immediate documentation and continuing other tasks may not appropriately address a potentially urgent clinical change. Hence, the RN should prioritize validating the blood pressure measurement to ensure patient safety and the correct management of care.