Postoperative pain is a severe problem of high incidence worldwide. According to a systematic review of the literature by Dolin et al , the incidence of moderate to severe postoperative pain in 41% of patients were found , and of these , only 23% experienced relief of the same ( 1). International Association for Study of Pain defines pain as unpleasant sensory or emotional experience associated with actual or potential damage , or described in terms of such damage ( 3). The postoperative pain is not only important for to cause suffering or unpleasant experience to the patient, but also by involving harmful effects to the body ( 4). Thus, the secondary stress to pain triggers the release of a series of hormonal mediators and activation of the sympathetic nervous system in conjunction with surgical trauma and previous comorbidities of the patient, that cause dysfunction of multiple organ systems , including the cardiovascular (5, 6) , GI (7-10) and respiratory ( 11,12 ), among others , increasing the incidence of postoperative complications such as myocardial ischemia , atelectasis ( 25-75 % after abdominal surgery) , respiratory infections (pneumonia 1-3 % after cardiac surgery ) , ileus , deep vein thrombosis and cognitive dysfunction. Thus increases the morbidity and patient recovery is delayed. (5) Similarly it has been observed that postoperative pain increases stay in the post anesthesia care unit , readmission for pain management, and delayed rehabilitation and reintegration of patients to activities of daily living , with the consequent increase in costs (5) . Considering the above arguments , it is obvious that timely intervention generates profit problem on multiple levels.