Flashcards in Pain Management Deck (83):
What are the two main categories of chronic pain?
neuropathic and nociceptive
What is neuropathic pain?
pain arising from abnormal neural activity secondary to disease, injury, or dysfunction of the nervous system (described as burning or tingling)
What are the types of nociceptive pain?
musculoskeletal, inflammatory, mechanical/compressive
What is hyerpalgesia?
increased response to a stimulus that is normally painful
What is hypoalgesia?
diminished response to a normally painful stimulus
What is analgesia?
absence of pain in response to a stimulus that is normally painful
What is hyperesthesia?
increased sensitivity to stimulation, especially the skin (excluding the special senses - senses that have specialized organs devoted to them: vision [the eye] hearing and balance [the ear, which includes the auditory system and vestibular system] smell [the nose] taste [the tongue])
What is hypesthesia?
diminished sensitivity to stimulation, excluding the special senses
What is dysesthesia?
act of touching a part of the body causes some unpleasant sensation, such as pain, burning, or tingling - may be spontaneous or evoked
What is paresthesia?
an abnormal sensation, typically tingling or pricking (“pins and needles”), caused chiefly by pressure on or damage to peripheral nerves - may be spontaneous or evoked
What is allodynia?
pain resulting from a stimulus (such as a light touch) that does not normally elicit pain
What is nerve convergence?
convergence of sensory nerves from the viscera and superficial areas onto the same neurons in the spinal cord
What is the spinothalamic pathway?
major route by which pain and temperature information ascend to the cerebral cortex
What are nociceptors?
highly specialized sub-set of primary sensory neurons preferentially sensitive to a noxious stimulus or to a stimulus that would become noxious if prolonged - categorized by the kind of stimulation they respond to and the nature of their response
What are myelinated nociceptors?
relatively fast-conducting A-delta fibers that are responsible for the first (immediate) sharp pain associated with a noxious stimulus
What is the pathway of the pain response from an external stimulus?
nociceptors on the skin pass signals through the sympathetic ganglion of the ANS - the signal then passes through the dorsal root ganglion of the spinal cord and then along to the brain, which perceives the pain in the somatosensory cerebral cortex
What is transduction?
conversion of a noxious stimulus into electrical activity in the peripheral terminals of nociceptor sensory fibers
What is transmission?
passage of action potentials from the peripheral terminal along axons to the central terminal of nociceptors in the CNS
What is conduction?
the synaptic transfer of input from one neuron to another
What is modulation?
alteration (i.e., augmentation or suppression) of sensory input
What is perception?
the decoding/interpretation of afferent input in the brain that gives rise to the indiviudal's specific sensory expeirence (i.e., realization that something is painful)
What is the International Association for the Study of Pain's Pain Taxonomy?
Axis I: anatomic regions; Axis II: organ systems; Axis III: temporal characteristics/patterns of occurrence; Axis IV: intensity/time since onset of pain; Axis V: etiology
What are the six major categories of treatment options for chronic pain?
(1) pharmacologic, (2) physical medicine, (3) behavioral medicine, (4) neuromodulation, (5) interventional (neural blockade, spinal cord stimulation), (6) surgical
What is included in Step 1 for management of chronic (mild) pain?
aspirin, acetaminophen (analgesic, *not* anti-inflammatory), NSAIDs, COX-2 inhibitors, adjuvants
What is included in Step 2 for management of chronic (moderate) pain?
acetaminophen or aspirin, codeine, hydrocodone, oxycodone, dihydrocodeine, tramadol, adjuvants
What is included in Step 3 for management of chronic (severe) pain?
morphine, hydromorphone, methadone, levorphanol, fentanyl, oxycodone, nonopioid analgesics, adjuvants
What is adaptive pain?
contributes to survival by protecting the organism from injury and/or promoting healing after injury
What is maladaptive pain?
represents pathologic functioning of the nervous system
What are the two components of the nervous system?
CNS and peripheral nervous system
What are the two components of the peripheral nervous system?
somatic (voluntary) and autonomic (involuntary)
What are the two components of the autonomic nervous system?
sympathetic (action and stress) and parasympathetic (calm and relaxed)
What is sympathetically mediated pain?
pain arising from a peripheral nerve lesion and associated with autonomic change (e.g., complex regional pain syndrome)
What is peripheral neuropathic pain?
pain due to damage to a peripheral nerve without autonomic change (e.g., post-herpetic neuralgia)
What is central pain?
pain arising from abnormal CNS activity (e.g., phantom limb pain)
What is nociceptive pain?
pain due to the perception of nociceptor input arising from tissue injury, inflammation, or mechanical deformation
What is somatic pain?
type of nociceptive pain arising from injury to body tissues, well localized, variable in description and experience (focal and described as achy, throbbing, sharp)
What is visceral pain?
type of nociceptive pain arising from the viscera mediated by stretch receptors, poorly localized, deep, dull, cramping (viscous organ and described as colicky, vague, diffuse)
When are opioids recommended for pain treatment?
persistent pain despite reasonable trial of non-opioid analgesics/adjuvants OR severe pain requiring rapid relief OR PT characteristics contraindicate use of other analgesics
What are the first line treatments for neuropathic pain?
calcium channel alpha 2 delta ligands (pregabalin, gabapentin), SNRIs (duloxetine, venlafaxine), TCAs (amitriptyline, nortriptyline)
What are the second line treatments for neuropathic pain?
antiepileptics (valproic acid), opioids, tramadol
What are third line treatments for neuropathic pain?
NMDA antagonists (dextromethorpan), tizanidine, baclofen
What are fourth line treatments for neuropathic pain?
botulinum toxin injection, intrathecal ziconotide
What are alternatives to opioids for persistent pain?
anticonvulsants, TCAs, topical medications, acetaminophen, ketamine, neural blockade, stimulatory techniques, biofeedback, relaxation therapy, CBT, acupuncture
What are the doses of muscle relaxants for chronic pain?
cyclobenzaprine (Amrix) 10 mg TID; carisoprodol (Soma) 350 mg TID; baclofen (Lioresal) 5-10 mg TID; methocarbamol (Robaxin) 1500 mg QID
What is the mechanism of action for muscle relaxants with chronic pain?
most likely sedation, not muscle relaxation
What are examples of extended release/long acting opioids?
oxycodone, oxymorphone, hydrocodone, morphine
When is it recommended to use extended release/long acting opioids?
for pain severe enough to require daily, around-the-clock long-term opioid treatment when alternative Tx options are ineffective
What should be the pattern of prescribing of opioids?
no more than 3 days in most cases (up to 7) with monitoring and reassessment every 3 months
What are the four As of pain?
analgesia, ADLs, adverse effects, aberrant drug-taking behaviors
When should urine drug testing be used with opioid prescribing?
before starting therapy and at least annually - test for prescribed medications and other controlled prescription/illicit drugs as well
What is the purpose of the Opioid Use Disorder Treatment Expansion and Modernization Act (HR4981)?
amend the Controlled Substance Act to expand access to medication-assisted treatment for patients with substance use disorder (SUD) - qualified providers can administer buprenorphine in an office-based setting for the Tx of SUD (can initially treat 30 patients)
What is recommendation #1 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
nonpharmacologic therapy and nonopioid pharmacologic therapy are preferred for chronic pain - only consider opioids if expected benefits for pain and function outweigh risks
What is recommendation #2 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
before starting opioid therapy, establish treatment goals and plans for discontinuation - continue only if there is clinical improvement in pain and function that outweighs risks
What is recommendation #3 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
before starting opioid therapy, and periodically after, discuss risks and benefits with PT
What is recommendation #4 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
prescribe immediate release opioid instead of extended release/long acting
What is recommendation #5 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
prescribe the lowest effective dose - carefully assess risks and benefits when increasing dosage to > 50 morphine milligram equivalents per day and avoid dosages > 90 MME/day or carefully justify dosage > 90 MME/day
What is recommendation #6 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
prescribe no greater quantity of opioid than needed for expected duration of pain severe enough to require opioids (generally <= 3 days)
What is recommendation #7 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
evaluate benefits and harms with PT within 1-4 weeks and again at least every 3 months
What is recommendation #8 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
evaluate risk factors for opioid-related harm and incorporate into the management plan strategies to mitigate risk
What is recommendation #9 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
review PT's Hx of controlled substance prescriptions using state prescription drug monitoring program data
What is recommendation #10 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
use urine drug testing before starting opioid therapy and consider using at least annually
What is recommendation #11 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
avoid prescribing opioid pain medication and benzodiazepines concurrently whenever possible
What is recommendation #12 from the CDC Guidelines for Prescribing Opioid Therapy for Chronic Pain?
offer or arrange evidence-based treatment for PTs with opioid use disorder
What is pain?
a somatic perception containing (1) bodily sensation with qualities like those reported during tissue-damaging stimulation, (2) an experienced threat associated with this sensation, and (3) a feeling of unpleasantness or other negative emotion based on this experienced threat
How is chronic pain defined?
pain which lasts beyond the ordinary duration of time that an insult or injury to the body needs to heal (usually 3 months)
What are unmylenated nociceptors?
majority of nociceptors - slow conducting primary afferents that respond to thermal, mechanical, and chemical stimuli - mediate delayed and longer-lasting pain, typically characterized as dull
What are the major causes of pain hypersensitivity that lead to persistent pain?
(1) peripheral sensitization - tissue inflammation results in changes in the chemical environment of peripheral nociceptors and (2) central sensitization - amplifies the synaptic transfer from the nociceptor terminal to dorsal horn neurons
What are associated symptoms that should be assessed when taking a PT's history of pain?
restriction of ROM, stiffness, swelling, muscle aches/cramps/spasms, color/temp change, sweating, skin/hair/nail growth, muscle strength, sensation
What are some of the specific instruments used to assess neuropathic pain?
neuropathic pain scale, S-LANSS (Leeds Assessment of Neuropathic Symptoms and Signs), DN4
When are blood tests appropriate in pain assessment?
when specific causes of pain (e.g., rheumatologic, infectious, oncologic) are suggested by the patient's history or physical exam
When should you refer to a pain specialist?
pain is debilitating, pain is located at multiple sites, symptoms do not respond to initial therapies, there is an escalating need for pain medication
What is first line treatment for trigeminal neuralgia?
carbamazepine or oxcarbazepine
What is the mechanism of action of antiepileptic drugs that makes them effective for neuropathic pain?
gabapentin and pregabalin bind to the voltage-gated calcium channels at the alpha 2-delta subunit and inhibit neurotransmitter release - both can cause dizziness and sedation
What are some common adjuvants used in the treatment of pain?
topical lidocaine (well-localized neuropathic pain), capsaicin cream (post perpetic neuralgia, diabetic neuropathy), topical NSAIDs, anstispasmodics, botulinum toxin, benzodiazepines, cannabis
What are some nonpharmacologic therapies for pain?
CBT, biofeedback, relaxation therapy, psychotherapy, aerobic exercise, acupuncture, PT, chiropractics, ultrasonic stimulation, electrical modulation, heat/cold, ablation, nerve block, surgery
What are the different modalities of transcutaneous electrical stimulation (TENS)?
(1) conventional - high frequency, short pulse duration, low intensity - produces paraesthesia; (2) acupuncture-like - low frequency, long pulse duration, high intensity; (3) burst - high frequency and low intensity; (4) intense - high frequency, long pulse duration, high intensity
What are possible treatment of diabetic neuropathy and post-herpetic neuralgia?
pregabalin (Lyrica) and gabapentin (Neurontin)
What is the PEG scale?
tracks patient outcomes (pain and function) for pain management: Pain assessment, Enjoyment of life, and General activity
What is the definition of clinically meaningful improvement in pain management?
30% improvement in pain and function (according to PEG scale)
How long should you wait before increasing the dosage of an opioid medication?
at least 5 half-lives (around 1 week)
What is the recommendation for tapering opioids?
10-50% of the original dosage over 2-3 weeks - if PT has been on meds for years, need to go slow (10% per month)
What are common signs of opioid withdrawal?
drug craving, anxiety, insomnia, abdominal pain, vomiting, diarrhea, diaphoresis, mydriasis, tremor, tachycardia, piloerection