Final answer:
For a lumbar puncture on a school-age child, EMLA should be applied an hour before the procedure to ensure effective analgesia. This cream numbs the skin to reduce pain from needle injections.
Step-by-step explanation:
When a lumbar puncture is needed on a school-age child, the most appropriate action to provide analgesia during this procedure is to apply EMLA (eutectic mixture of local anesthetics) 1 hour before the procedure. This allows proper numbing of the area, ensuring the child experiences less pain. EMLA is a combination of lidocaine and prilocaine that numbs the skin and is often used to decrease the pain of needle injections like those in a lumbar puncture. It's essential to allow adequate time for local anesthetics to take effect. Transdermal fentanyl (Duragesic) patch is not appropriate to use immediately before a procedure due to its slow onset of action. TAC also needs appropriate time to take effect, though its application is less common for a procedure like lumbar puncture.