Intro to Pain Management (Week 4--Pham) Flashcards
Definition of pain
Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage
Acute pain
Adaptive response necessary for the preservation of tissue integrity
Short in duration, well characterized and requires treatment of underlying disease or process
Chronic pain
Pain that has outlived its usefulness
Cause of pain is often unknown and has persisted for greater than 3 months (used to be 6 months)
Treatment involves managing underlying idsease and optimizing patient’s function
Often associated with confounding psychological factors and these should be addressed
Malignant/cancer pain
Pain due to tissue injury/invasion from cancer, HIV, etc
Non-malignant pain
Pain due to tissue damage or perceived tissue damage that is not related to malignancy
Nociceptive pain
Pain associated with tissue injury (fracture, joint inflammation, muscle trauma)
Neuropathic pain
Pain associated with peripheral nerve injury (carpal tunnel syndrome, diabetic neuropathy) or central nervous system injury (stroke, spinal cord lesion, etc)
Visceral pain
Poorly localized pain due to organ injury such as MI, pancreatitis, appendicitis
Barriers to pain management
1) Clinician’s poor ability to assess pain
2) Clinician’s poor knowledge about pain management
3) Patient’s and Clinicial’s fear of using opioids and fear of addiction
4) Various attitudes about pain
How do we assess pain?
Visual analog scale: patient mark on scale of 0-10
Verbal analog scale: patient verbally give number from 0-10
Faces: point to face scale 0-10 at increments of 2 (usually used for kids)
Pain assessment in chronic conditions should also be based on function, since traditional assessment may not be accurate
How is pain subjective?
Cultural/gender differences in expression and report of pain
Vital signs may not reflect intensity of pain experienced by patient (especially in chronic pain)
Patients react differently to pain depending on their coping skills, social/economic factors, cultural beliefs, etc
How is pain managed in acute vs. chronic pain?
Acute: NSAIDs, opioids, adjuvants (only for neuropathic pain), modalities (ice/heat/ultrasound), bracing/splinting, interventional procedures (injections/surgery)
Chronic: NSAIDs, opioids, adjuvants (only for neuropathic pain), modalities (ice/heat/ultrasound), therapeutic exercises (stretching/strengthening/aerobic), psychological management (biofeedback, coping skills, relaxation training), interventional procedures (injections/surgery)
WHO stepwise approach to pain treatment
Step 1: mild pain; non-opioid (acetaminophen/NSAIDs) +/- adjuvant
Step 2: mild to moderate pain; mild opioid + non-opioid (hydrocodone/acetaminophen (Vicodin), codeine/acetaminophen (Tylenol #3, 4), etc) +/- adjuvant
Step 3: moderate to severe pain; strong opioid (morphine, fentanyl, methadone, etc) + non-opioid +/- adjuvant
Note: can always use adjuvants if neuropathic pain
Patient controlled analgesia (PCA)
PCA is a medication-dispensing unit (pump attached to IV lines)
Patient can self-administer doses on as-needed basis
Often given to patient post-op or terminal illness
What does physician determine with PCA?
Type of medication
Max dosage given over 24 hours
Max dosage in single dose
Frequency medication can be given
If medication needs to be given as continuous drip
Indications for PCA
Moderate to severe pain
Patients needing rapid opioid titration
Patients needing pain meds >48 hours
Patients with changing pain intensity
Why PCA instead of IM/SQ injections?
Improved pain relief
Greater patient satisfaction
Lower level of drug consumption
Fewer post-op complications
Less painful than IM/SQ injections
Variable absorption with IM/SQ routes
When to convert from PCA to oral opioids?
At least 24 hours before discharge
If pain has improved or is 1-4 on Visual analog scale
Tolerating clear liquids
Adjuvants
Anti-epileptic (anti-seizure) medications for neuropathic pain, headaches, fibromyalgia (ex: gabapentin, carbamazine, topiramate, etc)
Antispasmodics/muscle relaxants (ex: Baclofen, Tizanidine)
Antidepressants for neuropathic pain, sleep disorder (ex: TCA)
How should we use NSAIDs?
Avoid chronic regular use of NSAIDs due to side effects
Use for acute exacerbations of symptoms when there is inflammatory component
Good for bone pain
Chronic daily use may lead to rebund headaches
Antispasmodics
AKA muscle relaxants
Most are centrally acting
For chronic use, select those that are not habit forming (baclofen, tizanadine)
Muscle spasm in chronic MSK pain often due to chronic deconditioning and overstrain, so rehabilitation (rather than medication) and modalities are key to management
Concerns with using opioids
Expect tolerance (loss of efficacy of medication over time) and dependence (development of adverse physical symptoms without the drug)–these happen to everybody
Watch for addiction and drug diversion (inappropriate use of prescribed medication)–don’t necessarily happen
Therapeutic exercise
Since muscles shorten to protect during acute injury, need therapeutic exercise to return muscle and connective tissue to normal length and increase endorphin release
Passive and active stretching
Relaxation
Strengthening
Aerobic
This takes time, and many people get frustrated
TENS (transcutaneous electroneurostimulation)
Stimulates large afferent fibers to inhibit pain impulses (low intensity, high frequency)
Increase endogenous opioid production (high intensity, low frequency)
Proposed similar mechanism of action as with accupuncture
Cold therapy
Causes vasoconstriction, reduces edema and inflammation
Slows nerve conduction velocity
Reduces pain
Reduces muscle spasm
Contraindicated in sensory impairment, circulatory problems
Heat therapy
Increases blood flow and metabolic rate
Increases collagen extensibility
Decreases joint stiffness and muscle spasm
Contraindicated in sensory impairment, circulatory problems
Do not use in acute injury phase due to risk of increasing inflammation
Injections/interventions
Trigger point injections for myofascial pain (lidocaine, botox, dry needling)
Intra-articular injections for joint inflammation/arthritis (corticosteroids vs. hyaluronic acid derivatives)
Epidural injections for radiculopathy (corticosteroids and lidocaine)
Spinal cord stimulator for neuropathic pain (electrodes implanted to dorsal column to suppress pain signal from periphery)
Implantable medication pump for cancer pain or severe spasticity (medication continusously released by a pump: morphine, dilaudid, baclofen)
