Postoperative opioid analgesia: time for a reconsideration?

Postoperative pain relief has improved in recent years with the development of new analgesics, additional routes of administration and the appearance of the hypothesis of preemptive as well as balanced analgesia (Kehlet H; Postoperative pain relief-what is the issue? Br J Anaesth 1994;72:375-8). Many initial improvements simply involved the administration of opioid analgesics in new ways, such as continuous or on demand intravenous (i.v.) or epidural infusion. These methods allow lower total opioid dosages, provide a more stable concentration of opioid at the receptor and correspondingly better analgesic effects, and also fewer unwanted side effects. Although opioids have played a prominent role in postoperative analgesia for centuries and are still often administered as a matter of routine, their frequent minor side effects and the increasing availability of suitable alternatives may limit their future use in some situations. Thus, the recent emphasis on ambulatory surgery and accelerated surgical stay programs, both with a focus on early recovery of organ function and provision of functional analgesia [i.e., pain relief that allows normal function (Kehlet H: Postoperative pain relief-what is the issue? Br J Anaesth 1994;72:375-8)] provide an opportunity for a reappraisal of opioid use in these settings. For this debate, controlled clinical studies on the opioid-sparing effect of different analgesic techniques are mentioned, and preferably studies with multiple dosing of analgesics and/or a reasonably large patient sample size. These data do not allow a proper meta-analysis to be performed because of the large variability in surgical procedures, dosing regimens, assessment criteria, among others.