Pain Flashcards
Acute Pain
Diminishes as healing occurs; responds well to analgesics
Chronic Pain
Lasts longer than three months, nerves may have become oversensitive and react to even a slight stimulus
Neuropathic Pain
C/B damage to PNS or CNS; not well-controlled by opioids alone, needs adjuvent therapy
Characteristics of neuropathic pain
Numbing, shooting, stabbing, sharp, electric shock-like, burning. Example- diabetic nueropathy
Tolerance
Body adapts so exposure to a drug changes that result in a decrease in one or more of the drugs effects
Physical Dependance
Symptoms c/b abrupt cessation, rapid dose reduction, decreased blood level, and/or administration of an antagonist
Addiction
Primary, chronic, nuerobiologic disease w/genetic, psychosocial and environmental factors
Incident Pain
Transient increase in pain that is caused by a specific activity or event that precipitates pain. Examples- dressing changes, movement, position changes, and procedures such as catheterization
Breakthrough Pain
Transient, moderate to severe pain that occurs in patients whose baseline persistent pain is otherwise mild to moderate and fairly well controlled. 3-5 min, can last up to 30 min. Can happen several times a day
OLD CART
Onset, location, duration, characteristics, aggravating factors, relieving factors, treatment
Non-Opiods
Mild to moderate pain. NSAIDS decrease production of pain-sensitizing chemicals. Dont produce tolerance or dependence. Have an analgesic ceiling. Used with opioids to lower opioid dose.
ASA (non-opioid)
Use limited due to side effects
Tylenol (non-opioid)
Does not cause bleeding, but can be toxic to the liver
NSAIDS
Can cause bleeding, renal toxicity, CHF in elderly, some interactions with anticoagulants, oral hypoglycemics, antihypertensives, diuretics
How do opioids work?
Modify the perception of pain
Opioids: Agonists
morphine, oxycodone, hydrocodone, codeine, methadone, hydromorphone.
Often combined with non-opioid analgesics limiting the total daily dose that can be given. Potent, have no analgesic ceiling, can be given through several routes
Opioids: Agonist-antagonist
Nubain, Talwin, Stadol
Produce less resp depression but cause more dysphoria and agitation, have an analgesic ceiling, can lead to withdrawal, not used much
Avoid giving these drugs:
Darvon and Demerol- produce a toxic metabolite causing seizures
Opioids
Use for moderate to severe pain, use for breakthrough pain. Only need one b/c they are all similar pharmacologically. Can give by any route, oral route is preferred unless pain is severe or need dose titration. .
Opioids: Codeine
Weak opioid, requires an enzyme to break it down to work, not good for severe pain
Opioids: Hydrocodone
Always combined with Tylenol or Ibuprofen, so does is limited
Opioids: Oxycodone
Single or combined, long acting is OxyContin
Opioids: Morphine
Gold standard, roxanol, avinza and MS Contin are long-acting
Opioids: Hydromorphone (Dilaudid)
8* more potent than morphine, only short acting
Opioids: Fentanyl
72 hour patch (Duragesic), oral lozenge (Actiq), not for opioid-naive. Very short acting
Opioids: Methadone
Works on 2 receptors, long half-life (23-36 hrs), sedation, bad for elderly
Opioids: Tramadol (Ultram)
Atypical opioid, can cause seizures
Opioids common side effects
Constipation, n/v, sedation, respiratory depression, itching (pruritus)
Opioids less common side effects
Urinary retention (more common with epidural) dizziness, confusion, hallucinations, opioid-induced hyperalgesia (OIH)
Adjuvants
Can be used alone or in combination
Adjuvents: Corticosteroids
(prednisone, dexamethasone) Best for cancer pain, spinal cord compression, inflammatory join pain. Many side effects. Dont give with NSAIDS
Adjuvents: Antidepressants
(TCA’s- Elavil, SNRI’s-Cymbalta) Increases serotonin & norepinephrine, promotes sleep, dont give if hx of seizures or cardiac disease, bad for older adults (long half life), many side effects, SNRI’s have less side effecs, but cost more
Adjuvents: Antiseizure drugs
(Lamictal, Neurontin, Lyrica) Affect peripheral nerves and CNS
Adjuvents: GABA receptor agonists
(Baclofen) inhibits pain trandmission, used for muscle spasms, best used intrathecally
Adjuvents: Alpha Adrenergic Agonists
(clonidine, zanaflex) used for chronic headaches, nueropathic pain
Adjuvents: Local analgesics
Interrupts transmission of pain signals to the brain, works for types of nueropathic pain
Med Administration: Breakthrough or Incident Pain
Use fast acting meds
Med Administration: Titration
Adjusting does based on adequacy of analgesic effect verse side effects
Med Administration: Equinanalgesic dosing
Carefully monitor and adjust for each individual patient
Administration Routs: Oral
Route of choice if GI system is good. Opioids require a larger dose than IV or Im due to first pass effect. Slower onset, peak in 1-2 hours, dont crush, break, chew sustained-release drugs
Administration Routes: Sublingual/buccal
Bypasses the first pass effect, doesnt always work well,Fentanyl can be given as a “lollipop”
Administrarion Routes: Intranasal
Stadol, Sumatriptan; used for headache and migraines
Administration Routes: Rectal
Often overlooked, Good if pt has n/v, NPO, at home. Lasts 4-6 hours, can’t use if bleeding risk
Administration Routes: Transdermal
Fentanyl Patch. Slow to reach full effect when first applied. Can cause death from overdose (s/s- slow RR, confusion, dizziness) Can absorb med too quickly if febrile
Administration Routes: Creams/Lotions
Trolamine salicylate for joint/muscle pain; capsaicin; EMLA. Little systemic absorption, can cause skin reactions
Administration Routes: Parenteral (SC, IM, IV)
IM is not recomended due to pain, unreliable absorption, abscesses with frequent use
SC is rarely used due to slow response, but can be used if no IV access
IV is best for immediate analgesia and rapid titratin (fastest onset but shorter duration, peaks in 5-15 min, not good for constant pain)
Administration Routes: Intraspinal
Epidural or Intrathecal. Intermittent bolus or intrathecal. Tip of catheter placed as close to nerve as possible. Highly potent and requires much smaller doses.
Administration Routes: Intraspinal Cx and s/e
S/E- itching, nausea, urinary retention.
Cx- Catheter displacement, accidental infusion of nuerotoxic agents, infection
Adminstration Routes: Patient Controlled Analgesia
IV delivery system or epidural catheter. PT decides when dose is needed, can have continuous basal rate, be careful w/opioid naive patients, monitor sedation level and resp rate, important to do good pt teaching.
*Give before pain is severe, assure them they can’t “overdose,” start oral drugs as PCA is being tapered, only the pt can push the button
Nerve Block
regional analgesia, used during and after surgery, sometimes used for chronic pain syndromes
Nueroblative Techniques
Used for severe pain unresponsive to other tx, destroys the nerves by surgical resection or thermocoagulation
Nueroaugmentation
Electrical stimulation of the brain and spinal cord, used for chronic back pain from nerve damage, also CRPS, spinal cord injury
Non-Drug Therapies
Massage, exercise, TENS (primarily for acute pain), acupuncture, heat, cold, distraction, hypnosis, relaxation strategies
Gerontologic Considerations W/drug therapy
High prevalence of cognitive, sensory-perceptual, and motor problems making it harder to assess. Metabolize drugs more slowly. NSAIDS cause serious GI bleeding in elderly. Cognitive impairment/ataxia can be worsened w/analgesics
Substance Abusers
Still use opioids but not opioid agonist-anatagonists. Avoid psychoactive drugs. Many need higher doses or increased frequency of administration. Need a multidisciplinary approach.
