Trials of preemptive analgesia compare the effect of drugs administered before injury with
the same treatment administered after injury, whereas studies of perioperative analgesia
include comparisons of preinjury administration with no particular analgesic treatment at all.
In contrast to earlier reports, recent animal behavioral studies of persistent nociception and
clinical trials of preemptive analgesia using randomized, controlled protocols strongly
indicate that conventional treatments such as local anesthetics and opioids do not exhibit …