Final answer:
The nurse should integrate the principle of using multiple methods to ensure accurate pain data in the pain assessment and management of pediatric clients.
Step-by-step explanation:
The principle that the nurse should integrate into the pain assessment and pain management of pediatric clients is Option 1: Pain assessment may require multiple methods in order to ensure accurate pain data. Pain assessment in children can be complex due to their limited ability to describe their pain. Therefore, using multiple methods such as observation, self-report, and behavioral assessment can help obtain a more accurate understanding of the child's pain experience. By utilizing a combination of methods, the nurse can gather comprehensive data and develop an appropriate pain management plan.