Microsoft PowerPoint - 2010_0124_ESRA_AcutetoChronicPain

Shared by: accinent

Tags

Stats

views:: 118
posted:: 4/21/2010
language:: English
pages:: 11

Public Domain

Document Sample

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.

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.

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.

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.

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.

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

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