Page 20 - BSAVA Guide to Pain Management in Small Animal Practice

3 | Acute and perioperative pain

VetBooks.ir Pre-emptive and which increase postoperative pain intensity and
analgesic re uirements. enerally, it is deemed
preventive analgesia
that preventive analgesia has been
protocols demonstrated when postoperative pain and
analgesic use are reduced beyond the duration
Pre emptive analgesia can be de ned as the of action of the target drug, which can be
administration of analgesic drugs before the de ned as . half lives of the target drug. his
onset of nociceptive stimulation issin, de nition ensures that the observed analgesic
and was the focus of gold standard analgesic e ect is not only due to a direct analgesic e ect
administration for many years. Nociception of the target drug, but also that analgesia has
refers to the sensory nervous system s response been sustained beyond the expected time
to certain harmful or potentially harmful stimuli. course of the analgesic agent. owever, there
It was hoped that the pre emptive are few studies in people that have investigated
administration of analgesic drugs would reduce the e cacy of preventive analgesia approaches
the re uirement for analgesia postoperatively compared with more traditional analgesia
and decrease pain after surgery. espite many regimens. No studies of preventive analgesia
studies being carried out in human medicine to regimens have been conducted in cats and
assess the impact of pre emptive analgesia on dogs. Nonetheless, the types of analgesic
postoperative pain scores, the evidence that approaches described in this chapter adopt the
pre emptive analgesia strategies reduce the principles of preventive analgesia, whereby
re uirement for postoperative analgesia and analgesics are administered as early as possible
reduce perioperative pain is mixed, with many before surgery and are continued during and
clinical studies showing no bene t in after surgery until the likelihood of peripheral
administering pre emptive analgesia compared and central sensiti ation as a result of tissue
with protocols in which analgesic drugs were trauma associated with surgery has waned.
administered after surgery c uay, 199 ; elly
et al., 1; oiniche et al., ; rape and
ram r, 7 . owever, some experimental Role of premedication
studies carried out in laboratory animals using in preventive analgesia
induced pain models show a good evidence of strategies
e cacy of pre emptive protocols e.g.
Nakamura and akasaki, 1 , which may he addition of analgesic agents to
re ect di erences between the complexity of premedication protocols is pivotal to the
clinical pain states compared with induced pain application of preventive analgesic strategies in
models. In veterinary medicine, a few studies cats and dogs. In animals undergoing elective
have compared pre emptive or preoperative surgery and not in pain, this ensures that
administration of analgesics with postoperative analgesics are administered before the onset of
analgesic administration and demonstrated nociceptive stimulation, which, dependent on
bene cial e ects of the pre emptive strategies the analgesic drug administered, may serve to
Lascelles et al., 1998; Slingsby and aterman reduce the likelihood of peripheral and central
Pearson, . sensiti ation. In animals that are already in pain
ore recently the concept of pre emptive at the time of surgery, the early administration
analgesia, where it is the timing of analgesic of analgesics will help limit the magnitude of
administration that is the focus, has been changes in central and peripheral sensory
replaced with an approach termed preventive processing as a result of pain. As well as
analgesia at et al., 11 . he focus of contributing to preventive analgesia strategies,
preventive analgesia is not on the relative administration of analgesics as part of
timing of analgesic treatments but on premedication protocols has a number of
attenuating peripheral and central sensiti ation, other advantages

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