19 - Intro to Pain Flashcards
1
Q
Describe the 3 types of pain
A
- Neuropathic: pain initiated or caused by a primary lesion or dysfunction in the NS (either peripheral or central NS); common descriptors = burning, shooting
- Nociceptive: pain caused by injury to body tissues (MSK, cutaneous, visceral); common descriptors = aching, sharp, throbbing
- Mixed: pain w/ neuropathic and nociceptive components (ex: lumbar radiculopathy, cervical radiculopathy, cancer pain, fibromyalgia)
2
Q
Describe dependence and tolerance to medication in acute vs. chronic pain
A
- Acute = unusual
- Chronic = common
3
Q
Describe psychological component in acute vs. chronic pain
A
- Acute = usually not present
- Chronic = often a problem
4
Q
Describe organic cause in acute vs. chronic pain
A
- Acute = common
- Chronic = may not be present
5
Q
Describe environmental/ family issues in acute vs. chronic pain
A
- Acute = small
- Chronic = significant (px often have poor relationships)
6
Q
Describe insomnia in acute vs. chronic pain
A
- Acute = unusual
- Chronic = common
7
Q
Describe general tx goal in acute vs. chronic pain
A
- Acute = pain reduction
- Chronic = functionality
8
Q
Describe presence of depression in acute vs. chronic pain
A
- Acute = uncommon
- Chronic = common
9
Q
Describe relief of pain in acute vs. chronic pain
A
Highly desirable in both
10
Q
What is an acronym that can be used for a brief pain assessment?
A
PQRST
- P = provokes, precipitates (what brings it on and what takes it away?)
- Q = quality (in the px own words; prompt only if necessary)
- R = radiation, referral (does the pain move to another spot? Are there other sx associated w/ the pain, ex: nausea, SOB)
- Radiation generally means nerves are involved
- S = severity (how does the pt rate the pain?)
- Not often used for chronic pain
- T = timing (when did the pain start? Has it occurred before? Is it constant or does it come and go?)
11
Q
What are some important questions to assess function w/ pain?
A
- How does the pt look and mobilize?
- Are they able to perform valued activities?
- Are they dysphoric, irritable, depressed?
- How are they sleeping?
- Do they feel well enough to socialize?
- Are they enjoying life?
12
Q
Goals of therapy for acute pain
A
- Pain reduction**
- Increased mobility
- Sleep
- QOL, exercise, decreased side effects
- Improved mood
- Decreased pill burden and cost (minor goals since don’t want pt on meds long term)
13
Q
Goals of therapy for chronic pain
A
- Sleep, exercise, increased mobility**
- QOL, decreased side effects, improved mood
- Pain reduction
- Decreased cost
- Decreased pill burden
14
Q
Acetaminophen for pain – dose, onset, pros, cons, efficacy
A
- Dose -> 325-1000 mg q4-6h
- Onset ~ 15-30 minutes
- Pros -> well tolerated; generally, high doses required to result in toxicities; few drug interactions; cheap and accessible
- Cons -> mild benefit for many chronic conditions, found in many products
- Max dose = 4 g/day (some proposing to lower to 3 g/day)
- Minimal effectiveness in acute pain (headache and post-dental surgery) but no significant effect vs. placebo for chronic pain (osteoarthritis & back pain)
15
Q
Acetaminophen harm
A
- Major concern = hepatotoxicity (> 50% of serious liver injury associated w/ unintentional overdoses)
- Decrease dose to max. 3g/day in elderly, poor nutrition status, fasting/anorexia, alcoholism, viral liver disease
- Contraindication = severe hepatic impairment
16
Q
NSAIDs for pain – efficacy, cons
A
- More effective than acetaminophen for certain conditions (such as dental surgery & OA pain; no effect on chronic low back pain)
- Can be given topically
- Use w/ opioids can result in decreased opioid dose requirement
- Cons -> GI bleeds, acute kidney injury, increased BP, increased risk of MI (depends on pt)
17
Q
Risk factors for GI problems w/ NSAIDs
A
- Age > 65 y/o
- Use of anticoagulants, steroids
- Hx of PUD
- High dose of NSAID
- Presence of H. pylori
18
Q
How to decrease risk of GI problems
A
- PPI cotherapy
- Use of coxib products
- Tx of H pylori
19
Q
Risk factors for AKI w/ NSAID use
A
- Volume depletion
- CHF
- ACE/ARB use
- Renal disease
- Cirrhosis
- 70 years and older
20
Q
Risk factors for cardiac problems w/ NSAID use
A
- Use of diclofenac and high-dose celecoxib
- Absolute risk depends on other risks for CHF, CAD
21
Q
Topical NSAIDs for pain – advantage, disadvantage, when to recommend or not recommend
A
- Advantage -> less major SE b/c only 2-15% is systemically available
- Disadvantage -> local skin reaction, “stickiness”
- Reasonable to recommend for osteoarthritis and for acute pain (ex: sprains, strains, overuse injuries)
- No evidence to support use for back pain, neuropathic or widespread pain
22
Q
Pros and cons to opioids
A
- Pros -> highly effective for some pain types (ex: nociceptive), high dose ceiling effect (no general ceiling dose, depends on pt), IV/SC doses for improved access and quicker onset
- Cons -> abuse potential, side effects (whether day-to-day or long-term), threshold for serious toxicity can be low in some, tolerance/ dependence, most require a duplicate Rx
23
Q
Morphine, hydromorphone, or oxycodone
A
- All strong opioids w/ similar analgesic abilities, onsets, and durations (when equipotent doses used)
- Morphine -> active metabolites renally eliminated, so caution w/ accumulation in renal dysfunction; caution w/ cirrhosis-
- Hydromorphone -> caution in renal dysfunction, but less so than morphine; caution w/ cirrhosis; less histamine release (so less itchiness as a SE)
- Oxycodone -> similar to morphine in renal/ hepatic considerations; big street value
- Not first line for opioid naïve
24
Q
Clinical pearls of opioids
A
- Codeine -> caution w/ breastfeeding women; lower risk of overdose and addiction than stronger opioids
- Tramadol -> associated w/ seizures in px w/ high seizure risk or when combined w/ medications that increase serotonin levels
- Morphine -> avoid in renal dysfunction (active metabolite can accumulate to toxic levels)
- Oxycodone, hydromorphone, hydrocodone -> use w/ caution for px at higher risk for opioid misuse and addiction; may have higher abuse liability than morphine
25
Q
Clinical pearls – fentanyl
A
- Before starting, obtain complete hx of opioid use w/in last 2 weeks to ensure pt is fully opioid tolerant
- Tolerance can be assumed if pt is on a moderate, stable dose of a strong opioid (TDD of at least 60-90 mg/day morphine equivalent for at least 2 weeks)
- Don’t switch from codeine to fentanyl regardless of codeine dose, as some codeine users may have little or no opioid tolerance
- Maintain initial dose for at least 6 days; use extra caution w/ px at higher risk for overdose (ex: elderly, px on BZDs)
- Be alert for signs of overdose (ex: slurred speech, emotionally liable, ataxia, nodding off during conversation or activity) and if detected, remove patch and seek medical attention
- Also, a good idea to have a naloxone kit
- Apply as prescribed; don’t apply more than 1 patch at a time or change more often than directed
- Avoid heat sources
- Dispose of patches securely; a used patch contains large amounts of fentanyl and could be dangerous to others
26
Q
Switching opioids
A
- Converting -> safer to under-dose at first, so give 50% (for elderly) to 75% of calculated amount
- Monitoring** -> what will they do for the next few days and who else can monitor them (ex: in hospital, at home, etc.)
- Signs and sx of overdose
- Also, counsel someone who can stay w/ them
- Recommend naloxone kit
27
Q
Adjuvants for pain relief
A
- Muscle relaxants -> only used for muscle spasms associated w/ acute injury
- Limited benefit at OTC doses; only use if pt has hx of good overall effect
- Cyclobenzaprine meta-analysis showed most of benefit in first 4-7 days; may use up to 2 weeks
- Common limitation = drowsiness
- Local corticosteroid injections (ex: knee for OA)
28
Q
Non-pharms for different types of pain
A
- For acute or chronic -> heat and/or cold; physiotherapy; massage
- Primarily chronic -> exercise, music, yoga, CBT
- Likelihood of benefit dependent on type of pain being treated
29
Q
Monitoring pain
A
- PQRST
- Analgesic use (dose and frequency)
- Non-drug approaches being used
- Pain diary -> helpful for px to look at overall med use and triggers of pain as well as document function (to determine if it’s improving)
30
Q
When might a pain diary be helpful?
A
- When looking at how to dose long-acting meds
- Determining what causes pain (and being proactive about tx)
- Helping pt understand their pain better
- Document what they were able to do
31
Q
Monitoring function
A
- Ability to perform valued activities
- Ability to exercise
- Relief from dysphoria/irritability or improved depression/anxiety
- Sleep
- Minimized medication SE
- Feeling well enough to socialize
- Financial
32
Q
Pain in the elderly
A
- Under-reported, under-recognized, and under-treated
- Poorly controlled pain can result in -> malnutrition, weight loss, falls, fractures, depression, less socialization
- Physiologic changes result in increased sensitivity to therapeutic and adverse effects
33
Q
Approach to pain in the elderly
A
- Vigilant dose titration; start low (1/2 of usual starting dose), go slow, and review often
- Caution w/ oral NSAID use -> increased risk of GI bleed, CV and renal events
- Add PPI if ongoing use
- Monitor renal function
- Use topical instead if indicated
- Caution w/ opioid use (elderly, increased fracture risk, renal or hepatic impairment, COPD and sleep apnea, cognitive impairment)
- Do a “3-day tolerance check” after starting (may want to call after 24 h b/c likely to have effects immediately)
- Assess for sedation, imbalance, confusion, constipation
- Avoid skeletal muscle relaxants
