Thus, pain relief is very important for the recovery speed and going back to previous activities in patients,this point deserves emphasis. The most common intervention for pain control is analgesic medications. In many people, analgesic medications can have unpleasant side effects (Perry and Potter, 2006; Smeltzeret al., 2008). There has been an explosion of pain literature and research in the last three decades, but few studies have focused on postoperative pain of cardiac
surgery patients. However, most of them focused on pain intensity. Pain intensity provides a useful measure to
recognize the amount of pain perceived by the patient and a useful comparison with other painful experiences
(Mueller, 2000).