Previous clinical studies have shown that 48% of patients receiving NSAIDs (COX2) preoperative do not require analgesics additional per 24 hours(10,11,12-15,30), however the use of the cox-2 is currently controversial despite his excellent results.
Studies that apply ketorolac indicates that up to 34% of patients do not require additional analgesia by a 24-hour period after cholecystectomy laparoscopic; while 65% of patients receiving infiltration periportal and instillation of intraperitoneal Ropivacaine did not require it(7.8) as opposed to 84%(6.8) of patients that undergoing any type of surgical procedure including laparoscopic cholecystectomy, refer pain (6,7).
It is interesting the idea of preventive analgesia for the treatment of postoperative pain, and even more the fact of combining two substances that act in different physiological processes of pain - transduction and transmission - to know their effectiveness.
NSAIDs Act by blocking signal transduction while local anesthetics Act by blocking the transmission of pain.