20 - Chronic Non-Cancer Pain Flashcards
1
Q
Definition of acute, subacute, and chronic pain
A
- Acute pain: a sx that plays a functional role in body defenses and resolves w/ tissue recovery (< 2 weeks)
- Subacute pain = 2-12 weeks
- Chronic pain: no such functional role, doesn’t resolve w/ tissue recovery, and can be a primary diagnosis
- Involves complex CNS signaling that can be amplified by stressors
2
Q
Define sensitization, allodynia and hyperalgesia
A
- Sensitization: activity is generated by nociceptors during inflammation => increased excitability of nerve cells (ie: a fire alarm sounds continuously or frequent false alarms)
- Allodynia: normally non-painful stimulus is perceived as pain
- Hyperalgesia: increased pain intensity in response to the same noxious stimulus (ex: moderate pressure causes severe pain)
3
Q
Goals of therapy for chronic non-cancer pain
A
- Pain reduction (ideal = 30-50%; realistic = 20%)
- Increased mobility
- Exercise, sleep, QOL
- Improved mood
- Minimal SE, cost, and pill burden
4
Q
Analgesic comparisons for chronic non-cancer pain
A
Pain improvement for OA from lowest to highest:
- Acetaminophen
- Tramadol
- Topical NSAIDs
- Opioids
- Glucosamine
Function improvement from lowest to highest:
- Topical NSAIDs, acetaminophen, and glucosamine
- Opioids and tramadol
5
Q
What to do w/ subacute pain
A
- Reinforce self-care and return to usual activities/ exercise
- Reassess response to pharm and non-pharm therapies
- If opioid continuation considered, assess abuse risk potential
- Assess for comorbidities that cause or increase pain
6
Q
6 A’s of opioid therapy
A
- Analgesia
- Activity
- Adverse effects
- Affect (mood)
- Accurate records
- Aberrant behaviour/ abuse risk
7
Q
Abuse and diversion risk
A
- Utilize an opioid risk assessment tool +/- an opioid contract/ agreement
- Be pt-centered and firm from the start (you and the physician)
- Visit doesn’t equal refill
- Inform pt of exit strategy if goals aren’t achieved (reach agreement that once you reach a certain dose you won’t increase it and will actually taper off)
- Breach of contract is serious
- Small fills at shorter durations
- Enquire about recovery and disposal if opioid no longer used
8
Q
Describe the “affect” of opioid therapy
A
Consider pain w/ -> depression, anxiety, or sleep disturbance; substance abuse or personality disorder; comorbid general medical condition
9
Q
Pharm options for chronic low back pain
A
- Muscle relaxants (cyclobenzaprine) -> only if spasms involved; 7-14 days max
- Acetaminophen -> no better than placebo (good chance for deprescribing)
- Oral NSAIDs -> few studies show equivalent to opioids
- TCAs -> same as placebo
- Gabapentin -> only use if sciatica along w/ low back pain; caution w/ substance abuse hx & high-risk opioid score b/c high street value
- Epidural corticosteroids -> if sciatica
- Goal = use relatively passive modalities (drugs) to support active rehabilitation
10
Q
Non-pharm therapies for chronic low back pain **important
A
- Heat, massage, yoga, exercise
- Physiotherapy
- Multidisciplinary programs
11
Q
Opioid-induced hyperalgesia (OIH)
A
- Can reach a point where the dose of the drug is too high and is causing sensitization
- Unknown cause
- Ends up making the px pain worse
- Typically occurs when px are on opioids for a long time and dose has been escalating
- Only cure is to completely taper the opioid dose
- Red flag = multiple dose increases in a short period of time that isn’t helping pain or making it worse
12
Q
Opioid adverse effects
A
- Short term -> sedation, nausea, dizziness, itchiness, dry mouth
- Long term -> constipation, dependence, tolerance
- Opioid induced hyperalgesia
- Unintentional overdose
- Most are dose-related
- 80% of px will have at least 1 SE, so counselling is very important
13
Q
When should we be concerned w/ opioid use?
A
- Daily doses >/ 100 mg morphine equivalents associated w/ up to a 9-fold increase in overdose and 2-fold increase in opioid-related death compared to low doses
- When treating chronic pain, dose escalation hasn’t been proven to reduce pain or increase function, but can increase risks
14
Q
Opioid trials
A
- Start off w/ codeine or tramadol for 2 weeks then re-assess pain and function; prn or regular use?
- If no/minimal improvement, can:
- Stop opioids all together
- May consider a short trial of a strong opioid (increase dose q1-2weeks as tolerated)
- *Make sure an exit plan is in place from the start
15
Q
Guiding principles (NOUGG) Canadian
A
- “Opioids produce a graded analgesic response -> pt experiences the greatest benefits at lower doses and a plateauing of analgesic response at higher doses”
- Response less likely if minimal improvement after 2-3 dose increases
- “Px who receive high opioid doses and remain incapacitated by pain should be considered tx failures, even if the opioid “takes the edge off” the pain”
