You arrive at your friend's apartment for a big party at the end of the college semester. When you first arrive, the music is so loud that it almost hurts your ears. After a couple of hours, even though the music is still as loud, it no longer bothers you or seems loud. This change in your sensations describes the process of .

You are assessing an 86-year-old postoperative patient who has an unexpressive, stoic demeanor. when you enter the room, the patient is curled into the fetal position and your assessment reveals that his vital signs are elevated and he is diaphoretic. you ask the patient what his pain level is on a 0-to-10 scale that you explained to the patient prior to surgery. the patient indicates a pain level of “three or so.” you review your pain-management orders and find that all medications are ordered prn. how would you treat this patient's pain?