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Microsoft PowerPoint - 2010_0124_ESRA_AcutetoChronicPain

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					        The Link Between
      Acute and Chronic Pain
                                       James P. Rathmell, M.D.
                                    Chief, Division of Pain Medicine
                                 Department of Anesthesia, Critical Care
                                           and Pain Medicine
                                    Massachusetts General Hospital
                                   Associate Professor of Anaesthesia
                                        Harvard Medical School
                                           Boston, MA USA




        Conflict of Interest


                                     None




        Massachusetts Society of Anesthesiologists Meeting  Bermuda  November 5, 2009




       Learning Objectives
• Define the term “preemptive analgesia”
• Discuss the clinical effectiveness of
  employing preemptive analgesia
• Explain why preemptive analgesia is
  marginally effective in reducing
  postoperative pain
• Describe risk factors for persistent
  postsurgical pain and the concept of
  “preventative analgesia”
        Massachusetts Society of Anesthesiologists Meeting  Bermuda  November 5, 2009




                                                                                          1
                       What is “preemptive
                          analgesia”?




        Woolf CJ. Evidence for a central component of
        post-injury pain hypersensitivity. Nature 1983;
        208:386-8.




                              Sensitization
                 10   Hyperalgesia

                                                 Injury         Normal
                 8
                                                                 pain
Pain Intensity




                                                               response
                 6
                       Allodynia
                                                          Hyperalgesia —
                 4                                        heightened sense of
                                                          pain to noxious stimuli
                                                          Allodynia — pain
                 2                                        resulting from normally
                                                          painless stimuli
                 0

                                   Stimulus Intensity




                                                                                    2
 Clinical studies of
preemptive analgesia




  Møiniche S, Kehlet H, Dahl JB. A qualitative and quantitative
 sytematic review of preemptive analgesia for postoperative pain
                         relief. Anesthesiology 2002; 96:725-41.




  Møiniche S, Kehlet H, Dahl JB. A qualitative and quantitative
 sytematic review of preemptive analgesia for postoperative pain
                         relief. Anesthesiology 2002; 96:725-41.




                                                                   3
              Møiniche S, Kehlet H, Dahl JB. A qualitative and quantitative
             sytematic review of preemptive analgesia for postoperative pain
                                     relief. Anesthesiology 2002; 96:725-41.




                     Conclusions
•Statistical improvements in postoperative pain
relief by preemptive treatment were seen at
some time points in 24/80 trials; quantitative
analysis of VAS scores within 24 hours were in
no case significant
•Lack of evidence for preemptive treatment
•Future studies should redirect focus from
timing to protective analgesia, aimed at
preventing pain hypersensitivity
              Møiniche S, Kehlet H, Dahl JB. A qualitative and quantitative
             sytematic review of preemptive analgesia for postoperative pain
                                     relief. Anesthesiology 2002; 96:725-41.




              Ong CK-S, Lirk PL, Seymour RA, Jenkins BJ. The efficacy of
            preemptive analgesia for acute postoperative pain management: a
                            meta-analysis. Anesth Analg 2005; 100:757-73.




                                                                               4
       Ong CK-S, Lirk PL, Seymour RA, Jenkins BJ. The efficacy of
     preemptive analgesia for acute postoperative pain management: a
                     meta-analysis. Anesth Analg 2005; 100:757-73.




•Pain scores
•Supplemental analgesic
•Time to first analgesic

       Ong CK-S, Lirk PL, Seymour RA, Jenkins BJ. The efficacy of
     preemptive analgesia for acute postoperative pain management: a
                     meta-analysis. Anesth Analg 2005; 100:757-73.




       Ong CK-S, Lirk PL, Seymour RA, Jenkins BJ. The efficacy of
     preemptive analgesia for acute postoperative pain management: a
                     meta-analysis. Anesth Analg 2005; 100:757-73.




                                                                       5
                      Conclusions
•Significant preemptive effect for epidural
analgesia, local anesthetic wound infiltration,
and NSAID administration
•No preemptive effect for systemic NMDA
antagonist
•Is this at odds with the earlier conclusions of
Møiniche et al.?

               Ong CK-S, Lirk PL, Seymour RA, Jenkins BJ. The efficacy of
             preemptive analgesia for acute postoperative pain management: a
                             meta-analysis. Anesth Analg 2005; 100:757-73.




         Why doesn’t preemptive
            analgesia work?




                  Nociception




                                                                               6
Persistent post-surgical pain:
 risk factors and prevention




Persistent postsurgical pain




     Kehlet H, Woolf CJ. Persistent postsurgical pain: risk factors and
                             prevention. Lancet 2006; 367:1618-25.




     Kehlet H, Woolf CJ. Persistent postsurgical pain: risk factors and
                             prevention. Lancet 2006; 367:1618-25.




                                                                          7
          Risk factors for persistent
              postsurgical pain
    •Genetic susceptibility
    •Preceding pain
    •Psychosocial factors
    •Age and sex


           Kehlet H, Woolf CJ. Persistent postsurgical pain: risk factors and
                                   prevention. Lancet 2006; 367:1618-25.




        From “preemptive” to
       “preventative” analgesia




 Potential for prevention of post-surgical pain
•Surgical technique
•Pre-emptive and aggressive multimodal
analgesia
•New targets for prevention and treatment
  •Symptom control
  •Disease modification
           Kehlet H, Woolf CJ. Persistent postsurgical pain: risk factors and
                                   prevention. Lancet 2006; 367:1618-25.




                                                                                8
                Preventive Analgesia
•85 patients undergoing colon resection
•Randomized to receive IV or epidural local
anesthetic / clonidine / sufentanil
•All patients received antihyperalgesic dose of
ketamine intraoperatively
•VAS, analgesic consumption, hyperalgesia, and
residual pain measured from 2 wks - 12 mos
           Lvand’homme P, De Lock M, Waterloos H. Intraoperative epidural
            analgesia combined with ketamine provides effective preventative
                     analgesia in patients undergoing major digestive surgery.
                                             Anesthesiology 2005; 103:813-20.




          Lavand’homme P, De Lock M, Waterloos H. Intraoperative epidural
            analgesia combined with ketamine provides effective preventative
                     analgesia in patients undergoing major digestive surgery.
                                             Anesthesiology 2005; 103:813-20.




          Lavand’homme P, De Lock M, Waterloos H. Intraoperative epidural
            analgesia combined with ketamine provides effective preventative
                     analgesia in patients undergoing major digestive surgery.
                                             Anesthesiology 2005; 103:813-20.




                                                                                 9
Lavand’homme P, De Lock M, Waterloos H. Intraoperative epidural
  analgesia combined with ketamine provides effective preventative
           analgesia in patients undergoing major digestive surgery.
                                   Anesthesiology 2005; 103:813-20.




Lavand’homme P, De Lock M, Waterloos H. Intraoperative epidural
  analgesia combined with ketamine provides effective preventative
           analgesia in patients undergoing major digestive surgery.
                                   Anesthesiology 2005; 103:813-20.




Lavand’homme P, De Lock M, Waterloos H. Intraoperative epidural
  analgesia combined with ketamine provides effective preventative
           analgesia in patients undergoing major digestive surgery.
                                   Anesthesiology 2005; 103:813-20.




                                                                       10
                Preventive Analgesia
•Analgesic requirements, VAS, and hyperalgesia
were higher in the intravenous group, and more
patients (28%) reported residual pain from 2 wks
– 1 yr
•The incidence of residual pain at 1 yr was 11%
in those receiving postoperative epidural
analgesia compared to 0% in the group receiving
intraoperative epidural analgesia

          Lavand’homme P, De Lock M, Waterloos H. Intraoperative epidural
            analgesia combined with ketamine provides effective preventative
                     analgesia in patients undergoing major digestive surgery.
                                             Anesthesiology 2005; 103:813-20.




                           Conclusions
•Preemptive analgesia is no more effective than
traditional approaches to perioperative pain
management
•Persistent post-surgical pain in common
•Aggressive suppression of the symptom of pain
at the time of surgery is probably inadequate
•Treatment should be targeted at the progression
of mechanisms that lead to the neuro-
degenerative disease known as neuropathic pain




              Under the Falls  Niagara Falls, Ontario, Canada  2009




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