ABSTRACT
What is preemptive analgesia? The classic definition of preemptive analgesia requires two groups of patients to receive identical treatment before or after incision or surgery. The only difference between the two groups is the timing of administration of the pharmacological agent relative to incision. The constraint to include a postincision or postsurgical treatment group is methodologically appealing, because in the presence of a positive result, it provides a window of time within which the observed effect occurred, and thus points to possible mechanisms underlying the effect: the classic view assumes that the intraoperative nociceptive barrage contributes to a greater extent to postoperative pain than does the postoperative nociceptive barrage. However, this view is too restrictive and narrow in part because we know that sensitization is induced by factors other than the peripheral nociceptive barrage associated with incision and subsequent noxious intraoperative events.
