Amputation & Phantom Pain

Thom Bloomquist

MSN, CRNA, CH, FAAPM Advanced Anesthesia & Pain Management Bow, NH

Mass. knows about amputees

Learning Objectives

 To explore and discuss;  the incidence and causes  the pathophysiology  neuroplasticity in phantom pain and other acute-to-chronic pain states  strategies for management with a multimodal and multidisciplinary approach  the possibility of phantom pain prevention 

Amputation 

New amputee each year – 185,000



Estimated total US amputees (limb) – 2, 000,000 .

Amputation health care costs per year $8.3 billion (U.S. only) 

Lower extremity amputation, (diabetes) - 55% will require amputation of other leg within 2‐3 years

Incidence of Phantom Pain

 70% - burning, cramping other qualities of phantom pain  first few weeks post-op  50% suffer   7yrs after some life-long continuous or intermittent

 Burning  Stabbing  Crushing  Twisting  Lightning-like  Mal-positioned part

Phantom pain

 Also reported after amputation of intestines, breasts, teeth and genitals.

Wow! I didn’t know that!

 What is special about cuts nerves and amputation?



NOTHING!

Causes

 Vascular disease (54%) including diabetes and peripheral arterial disease,  amputations caused by diabetes increased 24% from 1988 to 2009.

 Trauma (45%),  Cancer (less than 2%)  Congenital malformation (small %)

Under-treated Amputation Pain

 Can lead to chronic pain  Also common after thoracotomy +  m astectomy, herniorrhaphy….



~20-40% of ALL surgeries

Elements of Chronic Phantom Pain

 Somatic pain  Psychogenic aspects  Myofacial Pain  Neuropathic pain  Sympathetically Maintained Pain (SMP)

Psychogenic Factors

 Of course! But not psychosomatic - there is true anatomic basis for this pain  The illogic of pain in a part that is no longer there “Am I nuts?”  Life long phantom limb pain?

Somatic Pain

 Remaining primary pathology (vascular disease, tissue damage from trauma)  Additional stress on affected & non affected joints/tissues due to altered biomechanics.  Overuse syndrome of remaining structures and tissues

Neuropathic pain

 Post amputation neuroma - can take weeks to form but spontaneous ectopic discharge begins at moment of nerve division and in some nerves never fades.  “…self sustaining neuronal activity at the spinal cord level….if exceeds a critical level pain may occur in the phantom limb” (Raj)

Sympathetically Maintained Pain (SMP)

 Neuroma firing is increased by sympathetic activity (Nor-Epi)  Example: urination, defecation and ejaculation can activate sympathetic efferents and trigger episodes of phantom arm pain.

“Wind-Up”

 Once the noiceptive system is stimulated, suppression of pain signaling becomes more difficult and leads to …  Hyperalgesia (severe pain from mildly noxious stimuli)  Allodynia (pain produced by innocuous stimuli)

Sherman, R.A. , Phantom Pain, 1997, New York: Plenum Publishing.

Transmission in Spinal Cord

Neuroplasticity of Entire Nocoiceptive System?

 Peripheral,.e.g., neuroma  Spinal cord level (sensitization and perhaps hardwired WDRs)  Cortical-reorganization alteration of neuromatrix

Neuroplasticity

 Critical adaptability us evolve when dinosaurs died out (a trait we may need in the future?) can work against us in this situation.  However, that very stimulus-response relationship gives us a clue.  Cause  Effect

Cause of Phantom Limb Pain

 Not clearly established  Combination of peripheral, central and sympathetic factors  Positive correlation between painful limb pre-op and developing phantom limb pain  Recruitment of normally silent high threshold nociceptors  Genetics  Chemically induced?

How to Treat Changed Anatomy?

 Best Rx may be prevention!

 Nociception drives the changes. Effective pain management may decouple the stimulus-response relationship.

 Diminish stimulus – prevent the response!

Evidence? Yes!

 “Pre-op epidural……. (Bach).

 “Perioperative epidural with diamorphine, clonidine and bupivacaine….. (Jahangiri).

 “Pre-, intra- and postoperative epidural…(Gehling)

In other words …

 Preliminary evidence - effective pre-operative analgesia IN COMBINATION WITH effective sustained post-operative pain management ……can lower the incidence +/or severity of phantom limb pain.

How?

 “Because of the low success rate of treatment in chronic phantom limb pain, … prevention cannot be overemphasized” (Raj).

Multi-Modal and Multidisciplinary Pain Management • • •

Pharmacological Non pharmacological Psychchological / social

Primum non nocere!

 Acute pain strategies can be counterproductive in chronic pain  Higher amputation attempted – ------ restarted same process!

Neuropathic Pain - Rx

 NSAIDs are ineffective and opiates are not first line for neuropathic pain  Local anesthetics (Na+ Channel blockers) can provide pain relief in doses that will not cause sensory or motor block

MMPM - Medications for Chronic Pain

 Antidepressants (Tricyclics, SNERIs, SSRIs, Dopamenerics)  Alpha 2 agonists (clondine)  Antiarrhythmics (mexiletine, lido)  NSAIDs (Cox 1 or Cox 2)  Opiates - when appropriate

Anticonvulsants

   Carbamazepine Gabapentin Lamotrigine  Pregabalin  P.O. Pre-op -D.O.S.

  Topiramate Valproic Acid and Derivatives ***

Narcotics for Chronic Pain (selected cases)  Oxycontin and MSContin - work well (expensive)  Methadone (just as effective and less expensive)  Provide immediate release preparation for breakthrough pain  Use MMPM to lower narcotic requirement and increase effectiveness

PERCOCET VICONDIN

EUPHORIA

METHADONE OXYCONTIN MS CONTIN WITHDRAWAL PAIN LEVEL

Topical - Pharmacolgic (peripheral factors)  Mutli-cmpd topical preparations  E.g. gabapentin, NSAID, local anesthetic combination from compounding pharmacist.  5% lidocaine patches (Lidoderm)  OTCs (capsaicin, ASA)

NMDA Blockers

 Receptor site modulates nociceptive afferent signals.  resting state, blocked by Mg+.  Ketamine  Also  amantadine (antiviral),  dextromethorphan (cough medicine).

Perioperative Epidurals

 Effective but may not feasible in your setting  Expensive  Invasive  Complication rate

Option? – O. P. MMPM

 Consider mutli-modal program including:  NSAID (Cox1 or Cox2)  Opiates (SR & IR)  Antidepressants (multi-pathway)  Anticonvulsant  NMDA blocker (dextromethorphan)  Clonidine ?

Outpatient Program cont’d

 Important - include counseling with prepared amputee & psych.

 Meet with Prosthetist  Include family/spouse  Amputee support group (no “Whine fests)  ACA Peer Visitor

Non-Pharmacologic Modalities

 Acupuncture  Biofeedback  Chiropractic  Cold  Electrical Stimulation  Exercise  Heat  Massage  Meditation  Psychotherapy  Shrinker Socks  Wearing Your Artificial Limb

Hypnosis (huge!)

 When desired, the mind can literally affect what the body does/perceives.  Proof?

 Visualize a lemon  Smell the lemon – cut the lemon- feel the juice – bite the lemon – taste the lemon

Did you salivate?

(I did)

 It’s that simple and this was the merest example

Mirror Therapy The subconscious mind can re-map perception

Multi-disciplinary PM Team

 Anesthesia/Pain Mgt.  Primary  PT/OT/Massage  Prosthetist  Psych (ARNP, PhD, MD/DO)  Support group  Survivors or “whine festival”

Progress - but more to do

What’s in he pipeline?

Osseointegrated pins

 Neuroplasticity as a treatment?

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You can play an important role in preventing unwanted neuroplastic changes!

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You can be somebody’s hero!

Thank You!

My family sleeps well & safe – because of them

History

The Rig-Veda, an ancient sacred poem of India, is said to be the first written record of a prosthesis. Written in Sanskrit between 3500 and 1800 B.C., it recounts the story of a warrior Queen Vishpla, who lost her leg in battle, was fitted with an iron prosthesis, and returned to battle.

History

 Herodotus wrote of a prisoner who escapes his chains by cutting off his own foot. He later fashioned a substitute from wood.  The oldest known artificial limb, dating from 300 BC was made from copper and wood - unearthed near Capri, Italy.

In France

 Parre, a French surgeon describes Phantom limb pain in 1551.

 Larry, Napoleon's surgeon, recorded in his memoirs that extremely cold weather (-19

o

F) allowed him to perform painless amputations.

Revolutionary War “If amputation was chosen, the patient was laid out at table height, covered with double blankets, and given pillows for his head. Alcohol, if available, was used to help sedate the patient. The following procedure was then performed by a surgeon.

A good surgeon cut fast, performing the procedure in about a minute. If the patient was lucky, he'd pass out before feeling the searing pain.”

Civil War  Chloroform came into use for anesthesia, for PM. Opium and derivatives were widely used.  Civil War veterans commonly suffered in agony from war wounds for the rest of their lives