Definition of Pain

unpleasant sensory and emotional experience arising from actual or anticipated tissue damage, or described in terms of such damage (not purely physical)

Morbidity of Pain

1. Decreased activity

increased risk of DVT, pulmonary compromise (pneumonia and atelectasis), deconditioning (loss of exercise tolerance), disruption of work and social life

2. Disordered mood

depression, anxiety, irritability, and increased risk of suicide

3. Fight or flight stress response

increased cardiovascular risk (esp. heart attack), decreased immune function-->infections

4. Sleep disturbance

5. Sexual disfunction

Ethical imperatives in pain management

"first do no harm"--minimize pain and suffering caused by medical tests/treatments

do good (beneficience)--restore function, improve quality of life, relieve suffering

Double Effect Rule

ethically permissable to give treatment that may have a harmful effect IF potential benefit outweighs potential harm, physician is not seeking out the harmful effect, patient is fully informed

used to justify use of high dose opioids in the terminally ill b/c opioids may cause respiratory depression, but if the goal all along is pain control not euthanasia it's acceptable

Do opioids hasten death in hospice patients?

No!

well, at least not according to a 2001 Japanese study

though this is still held as common knowledge and the double effect rule is used to justify prescribing opioids in hospice care

U.S. Supreme Court: right to palliative care?

U.S. Supreme Court: right to physician assisted suicide

no

each state must make its own laws

Pain undertreatment=

a. the prudent course of action

b. abuse

c.irrelevant

b. abuse

2001 California conviction of an internal medicine doctor for elder abuse and reckless negligence for inadequate pain managment

who should be treated for pain?

who should a physician not prescribe scheduled drugs for according to the AMA and the KY board of medical liscensure?

self

family

staff

Acute pain (vs. Chronic)

onset at a particular time, usually associated with an injury

resolves in days to weeks

usually nociceptive (intact nerves stimulated by tissue injury)

physical signs: grimacing, sweating, writhing

Chronic Pain (vs. Acute)

insidious onset, indeterminate or multifactorial cause

indefinate duration possible

nociceptive (intact nerves stimulated by tissue damage) or neuropathic (pain caused by disordered nerves, may exceed observable tissue damage)

may not appear obvious, may instead present with depression, tiredness, disfunction

Nociceptive pain

• intact nerves (nociceptors) stimulated by tissue injury
• may  be somatic (well localized, originates from superficial tissues, easy to describe) or visceral (difficult to describe, may be migratory or referred, originates from an organ)
• treat with opioids (if severe) and/or adjuvants/conalgesiscs like NSAIDs

Neuropathic Pain

• damaged nerves continue to transmit pain signals beyond observable injury
• burning, tingling, aching, jolting, hot/cold, shooting, stabbing, electric
• caused by compression, transection, infiltration, ischemia, or metabolic injury to the nerve (i.e. diabetic neuropathy)
• treat with opioids (if severe) and/or adjuvants/conanalgesics--multiple medications required more often than for nociceptive pain alone

Components of pain assessment

location (primary + referral pattern)

quality (sharp/dull, stabbing, throbbing, etc.)

timing

severity (1-10)

radiation

allieviating & aggravating factors

impact on function!

patient perspective (fear and apprehension can worsen pain)

effect of treatments

Functions which may be deranged by pain

motor

sensory

activities of daily life

personal relationships

social roles

components of the nervous system involved in nociceptive pain

don't freak out, he rattled these off but doesn't expect us to trace it out or anything, more of a quick review

proprioceptors, nociceptors, touch and pressure receptors, sensory nerves, dorsal root ganglia, interneurons, motor reflex arcs, decussating tracts in the spinal cord, periaqueductal grey, thalamus, cortex

Allodynia

pain in response to a normally non-painful stimulus

often follows prolonged acute pain, mechanism of a lot of chronic pain

without adequate pain control nerves in the affected region become deranged:  nociceptors (C fibers) broaden the base of stimuli which excite them and begin to fire in response to touch as well as pain

protective mechanism to prevent further tissue damage

treat all acute pain swiftly to avoid nerve damage while you do the work-up to determine underlying cause of acute pain

Sympathetically mediated pain

develops in response to severely prolonged acute pain

C fibers (nociceptors) deranged and begin to respond to sympathetic stimulation (vasodilation/constriction)

vicious cycle

often irreversible-->severe chronic pain

treat all acute pain swiftly to avoid nerve damage while you do the work-up to determine underlying cause of acute pain

General approach to pain management

• match intensity of medication to severity of pain (WHO analgesi ladder)
• educate patient and family
• re-assess therapy regularly
• holistic care (psychological, spiritual, social, practical)

WHO analgesi ladder for cancer pain

1. mild pain: aspirin (ASA), acetaminophen, NSAIDs...

2. moderate pain: acetaminophen + codeine or hydrocodone or oxycodone or dihydrocodeine, tramadol...

3. severe pain: morphine, hydromorphone, methadone, levorphanol, fentanyl, oxycodone...

Organs damaged by long-term acetaminophen use

Liver

Kidneys (renal papillary necrosis)

maximum recommended dose recently lowered to 3000mg/day

Organs damaged by long-term NSAID use

Stomach (bleeding ulcers)

Renal failure

Heart attacks

Increased propensity to bleed

Adverse effects of corticosteriods

 proximal myopathy, steroid psychosis, aseptic necrosis of hips may occur in short-term

long-term use can cause Cushing's syndrome which can lead to diabetes, cardiovascular disease, osteoporosis, mood disorders, sexual disfunction, infertility, and skin infections

Adverse effects of Opioids

high risk for addiction and diversion (to black market)

common: constipation (prescribe prophylactic laxatives as a precaution) and when starting therapy: dry mouth, nausea, vomiting, sedation, sweats

uncommon: bad dreams,  hallucinations, dysphoria, delirium, myoclonus, seizures, pruritis, respiratory depression (especially in patients niaive to opioids!!!), urinary retention

no end-organ damage, unlike acetaminophen, steriods, and NSAIDs

Which adjuvant analgesics are useful to supplement opioids for inflammatory pain?

corticosteriods i.e. dexamethasone

reduce inflammation in CNS edema, visceral invasion by cancers, bone pain

beware long-term use in non-terminal patients (Cushing's syndrome)

Which adjuvant analgesics are useful to supplement opioids for neuropathic pain?

constant burning/tingling: tricyclic antidepressants (desipramine, nortriptyline)

spasmodic shooting/Stabbing: anticonvulsants (valproate, phenytoin, carbamazepine) but narrow therapeutic index

any kind of neuropathic pain: gabapentin (neurontin) and pregabalin (lyrica)

classes of adjuvant analgesics to supplement opioid use

• local anaesthetics (lidocaine)
• antispasmodics (hyoscyamine for smooth muscle, baclofen for skeletal)
• sympatholytics (clonidine)
• atypical opioids (methadone, tramadol)
• NMDA receptor antagonists (ketamine)
• corticosteroids (dexamethasone)
• tricyclic antidepressants (nortriptyline)
• anticonvulsants (phenytoin)
• NSAIDs
• Acetaminophen
• Aspirin

Non-pharamacologic pain managment techniques

• neurostimulation (TENS, acupuncture)
• anesthesiologic (nerve blocks)
• surgical
• physical therapy
• cognitive therapy (relaxation, hypnosis)
• biofeedback
• behavior therapy
• massage
• art/music/aroma therapy

Trifold goals of medical treatment

Survival

Function

Comfort

Reasons doctors refuse to prescribe opioids

• fear of causing/abetting addiction
• fear of legal repercussions
• distrust of patients
• under-valuation of comfort goal
• uncertainty
• lack of time and energy

Reasons doctors over-prescribe opioids

• fear of confrontation
• desire to be the good guy for their patients
• unquestioning trust in patients
• over-valuaion of comfort goal of medical treatment
• uncertainty
• lack of time and energy

Is prescription drug abuse increasing, decreasing, or holding steady currently?

Increasing!

Now the biggest drug addiction problem in the U.S.-->lost productivity, health problems, increased costs of police  and judicial systems, more people in jail, more people using social welfare programs

FDA and palliative care community often at odds in terms of desired legislation

Substance Abuse

• maladaptive pattern of use not related to therapy
• recurrent adverse consequences
• compulsive use despite harm
• use outside of socially acceptable norms

Addiction

Neurobiological disease not equivalent to physical dependence (withdrawl) or tolerance (requiring a higher dosage to achieve desired effect) both of which are to be expected even in appropriate long-term opioid use

addiction includes impaired control, compulsive and continued use despite harm, craving, expense of tremendous energy in obtaining substance, psychological dependance in addition to physical dependance

addiction is influenced by genetic, psychosocial, and environmental factors and is not the inevitable consequence of exposure to an addictive substance

Drug diversion

Theft, trade, and fraud centered around illigetimate sale of prescription drugs, often opioids

Prescription Drug Addiction risk factors

family history

alcoholism

other illicit drug use

mental illness

Clinical tools to decrease the risk of opioid abuse and drug diversion

• informed consent
• controlled medication agreement (one doctor/one pharmacy, random urine/serum drug screening, no early refills, must notify police if meds stolen, have patient sign agreement)
• EKASPER (Ky all schedule prescription electronic reporting--allows doctor to see how many controlled substance prescriptions the patient has gotten--do not show patient or put in chart!)
• consultation (pain & addiction specialists etc.)

Red Flags for Drug Abuse or Diversion

• lost or stolen medications
• multiple doctors and pharmacies
• calling off-hours for early refills
• odd allergies to all but favorite medication
• unwilling to accept adjuvant therapies or consultations

EKASPER

Substance users/abusers at end of life

Often have pain with terminal illness like any other patient

deserve compassion and pain management too

...and probably a consultation with pain and addiction specialists to help determine how best to treat their pain

DESK

a non-judgemental approach to difficult discussions of undesired behavior

D.escribe the behavior

E.xplain why it is a problem

S.how what behavior is desired

K.now the consequences if undesired behavior continues