Clin Med - Pain Mgmt

Question 1

Define pain

Answer 1

An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

Biologists recognize that those stimuli or illnesses that cause pain are likely to damage tissue.

Question 2

How is pain subjective?

Answer 2

each individual learns the meaning of the word “pain” through experiences related to injury in early life.

Question 3

Implications of pain for clinical practice

Answer 3

• there is no physiological, imaging, or laboratory test that can identify or measure pain.
• pain is what the patient says it is.
• clinician must accept the patient’s report of pain.

Question 4

Define nociception

Answer 4

• the process by which information about a noxious stimulus is conveyed to the brain.
• the total sum of neural activity that occurs prior to the cognitive processes that enable humans to identify a sensation as pain.

Question 5

Nociception vs. pain

Answer 5

Pain is a conscious experience that results from brain activity in response to a noxious stimulus and engages the sensory, emotional and cognitive processes of the brain.

Question 6

What are the 2 dimensions/components of pain?

Answer 6

1. sensory-discriminative

2. affective-emotional

Question 7

Goal of pain therapies

Answer 7

to relieve pain whenever possible: from nociception to the conscious experience as well as to decrease the emotional response to the unpleasant experience

Reduction of symptoms = improved quality of life

Question 8

Physiology pain pathway

-4 steps

Answer 8

1. Transduction
2. Transmission via Ascending pain pathway: Spinothalamic Tract
3. Perception
4. Modulation via Descending pain pathway: Corticospinal Tract

Question 9

Define transduction

Answer 9

phys process where a noxious mechanical, chemical, or thermal stimulus is converted (transduced) via specialized receptors on primary afferents into an electrical impulse (action potential)

Question 10

Where does transduction occur?

Answer 10

nociceptors

Question 11

What are nociceptors?

Answer 11

a subpopulation of primary sensory neurons that are activated by intense stimuli such as pressure, heat, mechanical insults (a surgical incision) or irritant chemicals (including those which are released by damaged cells)

Question 12

What are some of the irritating chemicals released by cells?

Answer 12

bradykinin, cholecystokinin and prostaglandins, activate or sensitize nearby nociceptors.

Question 13

Examples of interventions that reduce transduction

Answer 13

ice or NSAIDs

*recall that NSAIDs inhibit the synthesis of prostaglandins - normally produced and released at the site of injury, and which in turn make neighboring nociceptors more responsive to noxious and innocuous stimuli.

Question 14

How are action potentials conducted to the CNS?

Answer 14

via two types of primary afferent neurons:

1. thinly myelinated, faster conducting A delta fibers and
2. unmyelinated, slowly conducting C fibers, both termed primary afferents.

Action potentials result from activation of specific sodium channels

Question 15

Nociceptive impulses travel along…

Answer 15

travel along these peripheral nerve fibers (peripheral transmission) to the dorsal horn of the spinal cord where they synapse with the second order neurons (synaptic transmission)

Question 16

Where is the impulse transmitted after it reaches the dorsal horn of the spinal cord and synapses with second order neurons?

Answer 16

the impulse is further transmitted via neurons which cross the spinal cord and ascend to the thalamus and branches to the brainstem nuclei (central transmission)

Question 17

Nociceptive impulses are then relayed…

Answer 17

to multiple areas of the brain including the:

• somatosensory cortex
• the insula
• frontal lobes
• limbic system

Question 18

Intervention action

• local anesthetics
• some epileptic drugs

Answer 18

Local anesthetics and some antiepileptic drugs block sodium channels and inhibit the production of action potentials along the nociceptive afferents

Question 19

Intervention action

-opioids

Answer 19

Opioids bind to presynaptic receptors in the dorsal horn and decrease release of neurotransmitters such as glutamate

Question 20

Intervention action

-peripheral and spinal nerve blocks

Answer 20

interfere with propagation of action potentials and pain transmission into the CNS (at the nociceptors, along the nerve, at the dorsal root ganglion and along the spinothalamic tracts)

Question 21

Intervention action

• epidural
• intrathecal

Answer 21

may provide presynaptic and postsynaptic inhibition of receptors at the level of dorsal horn neurons and affect the transmission of nociceptive impulses

Question 22

Define perception

Answer 22

the process by which a noxious event is recognized as pain by a conscious person

Question 23

What parts of the brain are involved in perception?

Answer 23

• multiple areas of the brain are involved.
• there is no one location where perception occurs, although major defining components of pain are attributed to processes that take place in specific areas of the brain

Question 24

What does the limbic system mediate?

Answer 24

the affective-emotional response to the noxious stimulus is mediated by the limbic system

Question 25

Descending input from the brainstem influences...

Answer 25

central nociceptive transmission in the spinal cord

Question 26

How does descending modulation occur?

Answer 26

specific brainstem nuclei send projections to the dorsal horn of the spinal cord and, when activated by ascending nociceptive impulses and other influences from the brain, result in descending modulation

Question 27

Modulation results in descending inhibition of nociception through which neurotransmitters?

Answer 27

release of neurotransmitters such as serotonin, norepinephrine, and endogenous opioids

Question 28

How is descending facilitation increased?

Answer 28

modulatory processes can also increase descending facilitation of nociception and consequently pain

Question 29

what role do fear and anxiety play in modulatory systems?

Answer 29

they exert facilitatory influences through these modulatory systems

Question 30

Which drugs enhance descending inhibition?

Answer 30

Certain antidepressants - tricyclics and selective norepinephrine reuptake inhibitors (SNRIs) that inhibit the reuptake of serotonin and norepinephrine enhance *opioid analgesics have direct effects on descending modulation

Question 31

Other therapies to modify descending modulation

Answer 31

cognitive behavioral therapies, spinal cord stimulation, epidural, and intrathecal delivery of drugs such as opioids

Question 32

Define hyperalgesia

Answer 32

abnormally heightened sensitivity to pain

Question 33

Define allodynia

Answer 33

previously non-painful stimuli is now noxious

Question 34

Hyperalgesia and allodynia are the result of...

Answer 34

changes in either the peripheral or central nervous systems, referred to as peripheral or central sensitization, respectively

Question 35

What kind of pain do nociceptors signal? | -significance

Answer 35

acute and chronic - when chronically sensitized, contribute to persistent pathological pain disorders from previous injury or ongoing disease

Question 36

Chronic pain is characterized by...

Answer 36

abnormal state and function of the spinal cord neurons which become hyperactive

Question 37

Spinal cord hyperactivity is a result of...

Answer 37

increased transmitter release by spontaneously active primary afferent neurons and an increased responsiveness of postsynaptic receptors (in part due to phosphorylation of glutamate-activated NMDA receptors)

Question 38

Hyperexcitable state of synaptic transmission - maintained by - aggravated by

Answer 38

- at the dorsal horn, it is maintained by release of biologically active factors from activated glia - aggravated by loss of inhibitory interneurons involved in the modulation of pain

Question 39

Treatment aims to...

Answer 39

decrease the intensity of acute pain in an effort to reduce or prevent permanent changes in the nervous system that may result in chronic pain

Question 40

What are the 3 types of pain?

Answer 40

1. nociceptive 2. neuropathic 3. inflammatory

Question 41

Nociceptive pain - definition - examples

Answer 41

-normal response to noxious insult or injury of tissues such as skin, muscles, visceral organs, joints, tendons, or bones - somatic ex: musculoskeletal (joint pain, myofascial pain), cutaneous; often well localized - visceral ex: hollow organs and smooth muscle; usually referred

Question 42

Neuropathic pain - definition - examples

Answer 42

- pain initiated or caused by a primary lesion or disease in the somatosensory nervous system - ex: diabetic neuropathy, post-herpetic neuralgia, spinal cord injury pain, phantom limb (post-amputation) pain, and post-stroke central pain

Question 43

Inflammatory pain - definition - examples

Answer 43

- result of activation and sensitization of the nociceptive pain pathway by a variety of mediators released at a site of tissue inflammation - proinflammatory cytokines are the key mediators -ex: appendicitis, rheumatoid arthritis, inflammatory bowel disease, and herpes zoster

Question 44

Pain intensity scale

Answer 44

- categorized as mild, moderate, severe | - used to identify how effective pain treatments are

Question 45

Time course | -acute pain

Answer 45

less than 3-6 months

Question 46

Time course | -chronic pain

Answer 46

greater than 6 months

Question 47

Time course | -acute-on-chronic

Answer 47

acute pain flare superimposed on underlying chronic pain

Question 48

When should you screen patients for pain?

Answer 48

regularly screen all patients for pain and perform a comprehensive pain assessment when pain is present

Question 49

Diagnosis of pain | -keys

Answer 49

- history and physical - understanding that it is multidimensional (affecting function, quality of life, emotional state, and general well-being

Question 50

Pain history | -"QISS TAPED"

Answer 50

- Quality - Impact - Site - Severity - Temporal characteristics - Aggravating – Alleviating Factors - Past response - Expectations - Diagnostics – Physical Exam

Question 51

What is meaningful pain relief?

Answer 51

33-50% decrease in intensity of both acute and chronic pain is clinically meaningful

Question 52

Acute pain treatment - goals - mainstays

Answer 52

- pain control and relief | - analgesics, but nondrug methods (pt education, heat/cold, massage, distraction/relaxation, others) are essential too

Question 53

Chronic pain treatment | -goals

Answer 53

- pain control, but more focused on quality of life and function - also, prevention of secondary pain problems such as myofascial pain is essential

Question 54

Multi-modal treatment can include

Answer 54

- Physical Therapy - Acupuncture - Chiropractic Therapy - Interventional Pain Management - DCS / Intrathecal Implanted Device

Question 55

What are the 2 types of acute exacerbation of chronic pain?

Answer 55

1. pain flare | 2. disease progression

Question 56

1. Pain flare | - definition

Answer 56

- transient increases in pain that can last for hours to days - flares are extremely common and generally benign although they may be perceived as harmful by the patient

Question 57

Caution in pain flare

Answer 57

care should be used with additional short-acting analgesics since they are not appropriate from a mechanistic standpoint and may only lead to escalated use of analgesics

Question 58

2. Disease progression | - definition

Answer 58

if pain is exacerbated and does not remit with flare management techniques, look for and treat any change in the causative disease process

Question 59

Define breakthrough pain (BTP)

Answer 59

a transitory exacerbation of pain (predictable or spontaneous) that occurs on a background of otherwise stable pain in a cancer patient receiving chronic opioid therapy

Question 60

Categories for increases in pain

Answer 60

- incident related - end of dose failure - idiopathic

Question 61

What are the 5 R's of analgesics?

Answer 61

- Right Analgesic - Right Dose - Right Route of Administration - Right Dosing interval - Right Expectations

Question 62

Interventional pain management | - examples

Answer 62

- epidural steroid injections - vertebroplasty - intrathecal drug delivery - spinal cord stimulation * neurolysis by radiofrequency of surgery reserved for patients with limited life expectancy

Question 63

Treatment time course | -reassessment

Answer 63

- define an appropriate time frame for accomplishment of goals - reassessment is crucial to ascertain whether treatment is working or needs further modification

Question 64

Treatment end

Answer 64

treatment may end if: - goals are not met - treatment has not worked - pt unable/unwilling to continue - maximum possible progress has been achieved

Question 65

When should you refer to specialist?

Answer 65

any provider should refer a patient to a specialist or other provider when he/she has reached the limits of comfort or competence, or when patients desire referral.

Question 66

Responsible opioid prescribing | -FSMB 8 basic elements

Answer 66

1. Evaluation of the patient 2. Medication agreement / contract 3. Development of a treatment plan 4. Informed consent and agreement for treatment 5. Periodic review 6. Consultation 7. Maintenance of comprehensive medical records 8. Compliance with controlled substances laws and regulations

Question 67

What 4 outcomes must be regularly assessed and documented?

Answer 67

1. analgesia: pain relief 2. activities of daily living (ADL): physical and psychosocial functioning 3. ADRs: side effects (these are common and can affect function and adherence) 4. aberrant behaviors: may indicate addiction or inadequate treatment

Question 68

Define addiction

Answer 68

a primary, chronic, neurobiologic disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations

Question 69

What is addiction characterized by?

Answer 69

behaviors that include one or more of the following: - impaired control over drug use - compulsive use - continued use despite harm - craving

Question 70

Define tolerance

Answer 70

a state of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug's effects over time

Question 71

What do you call an alligator in a vest?

Answer 71

An investigator :)