Preemptive vs preventive analgesia: which approach improves clinical outcomes?

Administering a drug that blocks painful (nociceptive) input from entering the central nervous system before a surgical procedure attenuates the development of changes that manifest as increased pain at later time points. Clinically, this strategy predicts not only less pain during the initial postoperative period, but also lowers the intensity of pain during the days after the procedure. By lessening pain during recovery, fewer analgesics are consumed, which results in fewer adverse drug reactions (i.e. side effects) complicating the postoperative course and delaying the patient's return to normal activities. The patient can be assured that the postoperative pain associated with the procedure will be minimized, thereby decreasing postoperative apprehension, increasing patient motivation for enduring the procedure, and enhancing the probability of a smooth postoperative course. The adaptation of this method as a standard clinical practice has been delayed by controversy over whether the pharmacological intervention should be administered before the surgical event (preemptive analgesia), before pain onset (preventive analgesia), or by repeat administration over the expected postoperative course. Evidence reviewed in this article supports all of these approaches for decreasing the development of central sensitization, attenuating postoperative pain, decreasing analgesic consumption, and enhancing recovery.