A PCA pump is the dosing route that fits best for a practical nurse to manage fentanyl for chronic cancer pain. It allows the patient to self-administer small, individualized doses within set limits, providing rapid relief when pain flares while helping prevent oversedation or respiratory depression through lockout intervals and dose caps. The nurse’s role is to set up the pump and monitor the patient, assessing pain scores, respiratory status, and any side effects, all under the physician’s order and the facility’s protocol. Why the other options aren’t as suitable for ongoing, titratable pain: a fentanyl transdermal patch delivers a continuous, long-acting dose that isn’t readily adjusted for breakthrough pain and typically requires patch changes by an RN or clinician, making it less responsive to fluctuating chronic pain. Transmucosal fentanyl can be useful for breakthrough episodes but involves careful, individualized dosing and monitoring that may go beyond routine LPN duties in some settings. A slow intravenous push is a direct, rapid route that demands higher-level oversight and is not ideal for steady, ongoing management of chronic cancer pain.