Current Concepts and Strategies in Pain Management
1. Current Concepts and Strategies
in Pain Management
Raymond G. Tatevossian, MD
Chair, Pain &Palliative Care Committee, PSJMC
Clinical Assistant Professor of Anesthesiology,
USC Keck School Medicine
2. Lecture Objectives
• Current Understanding Of Pain
Mechanisms
• Current Treatment Strategies
• Medication Update
• Controversies Surrounding Opioids
• Prudent Opioid Prescribing
• Advanced Interventional Techniques
3. Pain: The Statistics
• 2nd leading cause of medically related lost
work days
• $100 billion/year cost to US economy
• 42% adults experience daily pain
• 50% of population see a doctor with “Pain”
as the chief complaint
• 66% of US veterans report persistent pain
attributable to military service
4. Is All Pain “Bad?”
The Gift of Pain by Dr. Paul Brand
• “The Beloved Enemy”
• Pain is evolutionarily necessary for survival
– Acute pain is protective
5. The “Gift” of Pain--an Example
• Mycobacterium leprae
– Disfigurement
• Infectious processes or
painlessness?
• The Cat Test
– Sensory Neuropathy
http://bhavanajagat.files.wordpress.com/
6. Classification of Pain
Acute Chronic
• Generally protective • Generally no useful fnctn.
• Relieved when healing • Persists after healing
complete complete
• Short duration • Long duration
• Predictable pathology • Unpredictable Pathology
• Predictable prognosis • Unpredictable prognosis
• Tx with analgesics • Tx multidisciplinary
8. Factors Contributing to
Chronic Pain
“Chronic Pain Load”
• Intensity of injury
• Duration of injury
• Repetitiveness of injury
• Chronicity of underlying disease
• Genetic predisposition
– BH4 enzyme production
• Other factors:
- Psychological
- Socioeconomic
- Cultural
9. Mechanisms of Pain: Neuroplasticity
How does a Chronic Pain State Develop?
• Peripheral Sensitization
- Injury causes release of
“sensitizing soup”
- Reduction in threshold and
increase response of nocioceptors
• Central Sensitization
- Membrane excitability, synaptic
recruitment and decreased
inhibition
- Uncoupling of pain from
peripheral stimuli
http://www.aafp.org/afp/2001
13. Goals of Treatment
• Reduce pain
• Increase activity level
• Improve quality of life
• Pre-emptive analgesia
• Stay within “Therapeutic
Window”
– Avoid undertreatment
– Avoid toxicity
• How?
– Synergism with Meds
• Morphine + Gabapentin
– Apply multimodal pain
strategies when possible
14. Analgesic Medication Update
FDA Advisory Panel Recs/Trends:
• Acetaminophen- ↓ max daily dose, ↓
max single dose
• Vicodin, Percocet - ban in current form
• Propoxyphene (Darvocet)- push for
phased withdrawal
Abuse Deterrent Opioids:
• Morphine ER+ Naltrexone (Embeda)
• Oxycodone IR+ Naltrexone (Oxytrex)
• Oxycodone IR + Niacin (Acurox)
15. Emerging Analgesic Medications
• IV Acetaminophen
(Paracetamol)
– opioid sparring, phase 3
completed
• Tapendatol (Nucynta)
µ-opioid agonist, NE reuptake
inhibitor
↓ GI effects, ER phase 3
• Hydromorphone Extended
Release (Exalgo)
– FDA approved 3/1/2010,
awaiting REMS
16. Opioids--The Evolving
Controversy
Past: Decreased Scrutiny
• 1990: Pain becomes “fifth vital sign”
• 1990: Intractable Pain Act
– “no physician or surgeon shall be subject to disciplinary action …
for prescribing controlled substances for intractable pain”
• Medical Board CA defines under treatment of pain as
“inappropriate prescribing”
• Bergman vs Chin: $ 1.5 million dollars awarded for under
treatment of pain
• 2000-2005 a 35-50% increase in opioid prescribing
17. Opioids--The Evolving
Controversy
Present: Increased Scrutiny
• Most common class of medication prescribed
– 800% increase in 10 years
• Fatal opioid poisonings have tripled 1999-2006
• Food & Drug Administration Act (2007)
– Creation of REMS for new and existing drugs
• McLellan and Turner, Annals On Internal,
Editorial, Jan 2010
- “prescribing opioids at high doses is both dangerous amd
questionable”
- White House Office of National Drug Control Policy
19. Strategic Opioid Prescribing
Prescription Monitoring Opioid Contract
• CURES (CA) • Call it “Opioid Consent”
• Pharmacists, physicians, • Discuss risks and
and law enforcement benefits of opioids
officials • Educational
• Real time, S II – IV • Establish rules of
• https://pmp.doj.ca.gov/pm prescribing
preg
20. Intrathecal Drug Delivery
Systems
AKA: Pain pump
Mechanism of Action:
• Drug delivered directly to the
intrathecal space
Drugs:
• Morphine
• Baclofen
• Ziconotide (Prialt®)
http://www.medtronic.com/IN/images/intro_intrathecal1.gif
• Bupivicaine
• Clonidine
• Ketamine
21. Intrathecal Drug Delivery
Systems
PROS CONS
• Short reversible trial • Short reversible trial
• Delivery of drug ∀ ↓opioid benefit with
directly to the site of time (40% failure with
action time)
• 1mg IT Morphine = • Contraindications to
300 gm oral Morphine placement
• Cancer Pain: ↓pain, • Complications
↓toxicity, ↑survival (granuloma)
6mo
22. Spinal Cord Stimulation
• Production of electrical
field over dorsal columns
by epidurally placed
electrodes
• Gate Control Theory
– Gate exists in dorsal horn that governs pain
signal transmission
– Closing gate decreases pain
• Parasthesia produced
over painful body area
23. Spinal Cord Stimulation
Grade A Evidence
• Failed Back Surgery
• Arachnoiditis
Grade B Evidence
• CRPS I
• CRPS II
Other Indications
• Phantom limb, post herpetic
neuralgia, spinal cord injury
www.medscape.com
24. References
1. Arthritis Foundation. (2000) Pain in America. http://www.arthritisfoundation.org
2. American Pain Foundation. http://www.painfoundation.org.
3. National Institutes of Health. NIH Guide: New Directions in Pain Research: Bethsea.1998.
4. Brand P and Yancey P. The Gift of Pain. Michigan: Zondervan Publishing House, 1997.
5. Turk D. Pain Hurts-Individuals, Significant Others, and Society. APS Bulletin. 2006;16:1.
6. Payne J. Pain medications: What you need to know about acetaminophen, darvon, and darvocet. US News
and World Report 2009.
7. Jamison R and Clark D. Opioid Medication Management:Clinician beware. Anesthesiology 2010; 112:777-8.
8. Tucker K. Promoting good pain management in california. California Health Law News 2004;22:1-4.
9. McLellan T. Chronic noncancer pain management and opioid overdose: Time to change prescribing
practices. Annals of Internal Medicine 2010;152:123-4.
10. http://cdc.gov/nchs/data/databriefs/db22.htm
11. http://www.painmed.org/pdf/rems_comments.pdf
12. Cousins M, Carr D, et al. Neural blockade in clinical anesthesia and pain medicine. New York: LWW,
2009.
13. American Society of Anesthesiologists Task Force on Chronic Pain Management. Practice guidelines for
chronic pain management: an updated report by the ASA. Anesthesiology 2010;112:810-33.
14. Gilron I, Bailey J, et al. Morphine, gabapentin, or their combination for neuropathic pain. NEJM
2005;352:1324-34.
15. Smith T, Staats P, et al. Randomized clinical trial of an implantable drug delivery system compared with
comprehensive medical management for refractory cancer pain:impact on pain, drug-related toxicity, and
survival. J of Clinical Oncology. 2002;20:4040-9.
16. Barolat G, Massaro F, et al. Mapping of sensory responses to epidural stimulation of the intraspinal neural
structures in man. J. Neurosurg 1993;78:233-239.