The damage to nerve cells, peripheral or CNS pain. Can be phantom limb pain
What is cutaneous pain?
Superficial pain, easily localized, just below the skin between high concentration of nerve endings that produce a well-defined pain.
Abrupt onset and a burning quality depending on type of nerve fiber involved
What is somatic pain and where does it originate?
Deep pain that originates from ligaments, tendons, bones, blood vessels, and nerves. Poorly localized, accompanied by inflammation, such as a sprained ankle
What is visceral pain?
Originates from viscera or organs, such as appendicitis, kidney, liver pain. Difficult to localize more aching and longer duration than somatic pain. May cause referred pain
Describe psychogenic pain
mental or emotional problems that can cause, increase or prolong pain. Diagnosed when other causes of pain are ruled out
What is the difference between pain threshold and pain tolerance
Threshold is where they can start to feel the pain and tolerance is how much pain they can take
What are some sociocultural factors affecting pain?
Age, gender, meaning of pain, anxiety, past experiences with pain, expectation and placebo effect
What do local anesthetics do and what are some examples
Temporarily block nerve impulses between peripheral structures and higher centers. Causes loss of feeling and sensation, no LOC, used in minor surgery, reversible, works in minutes to hours
Lidocaine-topical and intravascular block works within 5-10 minutes.
Bupivacaine-slow onset, lasts 4-8 hours 4X more potent than lidocaine, blocks sensory nerves as opposed to motor nerves
What do nerve blocks do?
Reversible or irreversible interruption of nerve pathways, blocks conductivity, given for pain relief
Describe topical local anesthetics
Sprays, pastes that may reduce pain, EMLA is a commonly used cream with lidocaine and prilocaine applied before venipuncture
Describe the first tier/step of WHO pain ladder
Non-opioid analgesics (pain medications) that have a ceiling effect but do not cause physical dependence or tolerance, can have anti-inflammatory effects
List the medications onthe first tier of the WHO pain ladder
Aspirin-most effective non-opioid analgesic, can cause GI upset and anti-clotting effect
Salicylate salts-similar to aspirin but without the GI upset. Examples include: Trilisate (trisalicylate) & Dolobid (diflunisal)
Acetaminophen-no GI effects, no anti-inflammatory effects, drug of choice for viral infections, metabolized in liver, do not exceed daily dose of 4000 mg
NSAIDS-non-steroidal anti-inflammatory drugs that decrease inflammation and block prostaglandin synthesis, helpful for cancer or post-op patients, Ibuprofen (motrin) and ketorolac (Toradol), can cause GI upset and bleeding
COX-2 inhibitors such as celecoxib (Celebrex)
What is the Second & Third step/tier on the WHO ladder and describe
2nd Opioids to treat mild to moderate pain
3rd Opioids t treat moderate to sever pain
Opiod agonists bring about pain relief by producing the maximum degree of receptor binding with no ceiling effect
Opioid Antagonist-reverse the side effects and analgesia of opioids, produces no pain relief such as naloxone (Narcan)
Opioid Agonist-Antagonist-engage one receptor type while inhibiting receptor bidning of another
What are the adverse effects of analgesics?
Cutaneous effects-itching, sweating, flushing
What are adjuvant medications?
Meds developed for other problems that may have pain-reducing properties
Corticosteroids-reduces edema and the inflammation in the periphery, reducing compression caused by swelling and the availability of chemical medicators of nociception, predinsone, dexamethasone (Decadron), methylprednisolone (Solu-Medrol)
What influences the effectiveness of analgesics?
Relative potency-ratio of doses of 2 analgesics required to produce the same effect, which one is stronger
Duration of action-how long it lasts
Oral potency v. SQ, IV routes-opioids are absorbed from the intestine and pass through the liver and into the systemic circulation then differ in the degree to which they are active
Ceiling effect-occurs when a medication has a max effective dose, increasing the dose cannot increase pain relief but may increase side effects
What is the difference between tolerance and physical dependence?
Tolerance is a physiologic phenomenon and ocurs when larger doses of medications are needed to provide the same amount of pain relief as the previous smaller dose, opiate receptors become less sensitive
Dependence occurs when meds are taken over a long period of time, physical manifestations asociated with sudden termination of the med and symptoms may include anxiety, irritabililty, chills/hot flashes, N/V, etc.