Pain Management Flashcards
How is pain defined according to the International Association for the Study of Pain?
An unpleasant sensory and emotional experience associated with or resembling that associated with actual or potential tissue damage.
What are the types of pain?
- Nociceptive pain: Well-localized pain in soft tissue, bone, or muscle, characterized by stabbing or aching sensations.
- Neuropathic pain: Burning or tingling sensation, less localized, indicates nerve involvement.
- Psychogenic pain: Pain associated with psychological disorders, assumes an origin or relationship with psychological conditions.
What are nociceptive afferent neurons?
- A-delta (myelinated, quick, sharp, intense, localized pain)
- C-fibers (unmyelinated, dull, burning, diffuse pain).
What is Substance P?
An excitatory transmitter that produces a slow response, increases with repetitive stimulation, produces inflammation.
What are prostaglandins?
Chemical mediators released during pain responses, generated by COX enzymes, enhance pain-producing effects.
What are bradykinins?
Pain-producing substances that are worse in the presence of prostaglandins, bradykinin antagonists provide analgesic and anti-inflammatory properties.
What are the categories of pain medication?
- opioid analgesics
- non-opioid analgesics (salicylates, NSAIDs, acetaminophen)
- anesthetic agents
- skeletal muscle relaxants
- adjuvants
Describe opioid analgesics.
2
Opioid Analgesics: Used for moderate-to-severe pain, high potential for abuse and addiction, not recommended for long-term management.
What is…
- opioid tolerance = ?
- opioid-induced hyperalgesia = ?
- Opioid Tolerance: Need to progressively increase the dosage to achieve the same therapeutic effects, occurs with prolonged use.
- Opioid-Induced Hyperalgesia: Increased pain sensitivity despite opioid use, possibly due to increased neuropeptide pathways.
What is physical dependence on opioids?
Withdrawal symptoms occur when the drug is abruptly removed, causing craving and substance-seeking behaviors.
What are strong opioid agonists?
Drugs like morphine, fentanyl, and hydromorphone, used for severe pain with high affinity for opioid receptors.
What are mild-to-moderate opioid agonists?
Drugs like codeine and hydrocodone, used for moderate pain with lower affinity and efficacy.
What are mixed agonist-antagonist opioids?
Drugs like butorphanol, act differently at the same receptors, less risk of side effects and overdose.
What are opioid antagonists?
Drugs like naloxone, used for opioid overdoses and addiction, block opioid receptors without analgesic effect.
Describe the spinal effects of opioids.
Inhibit synapses from transmitting pain to higher levels, decrease release of pain-mediating transmitters like Substance P.
Describe the supraspinal effects of opioids.
Bind to receptors to activate descending pain pathways, inhibit neurons blocking this pathway.
Describe the peripheral effects of opioids.
Provide analgesic effects at peripheral sites, decrease excitability of sensory neurons, focus on stopping pain caused by inflammation.
What are the adverse effects of opioids?
- sedation
- drowsiness
- respiratory depression
- orthostatic hypotension
- GI distress
- constipation
What are the side effects of opioids related to the central and peripheral systems?
- Central: sedation, mental slowing, mood changes, respiratory depression.
- Peripheral: orthostatic hypotension, GI distress, constipation.
What are the therapy considerations for patients on opioids?
Schedule therapy during peak effective hours, educate on hydration and mobility, monitor for side effects and adverse events.
What are NSAIDs used for?
- decrease inflammation
- provide mild-to-moderate pain relief
- decrease elevated body temperature
- decrease blood clotting by inhibiting platelet aggregation
- General NSAIDs like aspirin = Manage pain, fever, inflammation, and clotting, interfere with prostaglandin synthesis, primary area addressed by aspirin.
What is the physiology of eicosanoids?
Eicosanoids include prostaglandins, thromboxanes, and leukotrienes, lipid-like compounds found in every cell, play roles in major systems.
How do NSAIDs affect inflammation?
Increase prostaglandins at the site of inflammation, mediate local redness and swelling, increase blood flow and cell permeability.
How do NSAIDs affect pain?
Mediate painful stimuli, increase sensitivity of pain receptors and pain-producing substances like bradykinin.
How do NSAIDs affect fever?
Pyretogenic - promoting fever with infection and other disorders.
How do NSAIDs affect thrombus formation?
Cause platelet aggregation, resulting in blood clot formation.
What is the mechanism of action of NSAIDs?
Inhibition of prostaglandin and thromboxane synthesis, COX inhibition.
What are the clinical applications of NSAIDs?
- mild-to-moderate pain
- inflammation
- fever
- prevention of cancer
- prevention of vascular diseases
What are the adverse effects of NSAIDs?
- GI problems
- cardiovascular issues
- renal and hepatic conditions, Reye syndrome in children, muscle issues.
What are COX-2 selective NSAIDs?
Drugs like celecoxib (Celebrex), beneficial effects with fewer side effects, increased risk of cardiovascular events.
Describe the use of acetaminophen (Tylenol).
Analgesic and antipyretic agent, used for mild-to-moderate pain, first attempt at pain management if there is no inflammation.
What are the side effects of acetaminophen?
Toxic doses can damage the liver, not associated with GI irritation.
What are the therapy considerations for acetaminophen?
- frequently used in rehabilitation
- lacks adverse effects that impact therapy
- consider stomach discomfort, toxic uses
- pain relief
What are the categories of anesthetic agents?
- general (inhaled, IV)
- local (injection, topical)
- regional (spinal anesthesia)
What are the stages of anesthesia?
- Stage I: Analgesia
- Stage II: Excitement (Delirium)
- Stage III: Surgical Anesthesia
- Stage IV: Medullary Paralysis
What are the side effects of general anesthesia?
Confusion, delirium, muscle weakness, bronchial secretions, long-term cognitive effects.
What are neuromuscular blockers used for?
Used along with general anesthesia to avoid muscle spasms during surgical procedures.
What are the side effects of neuromuscular blockers?
Cardiovascular problems, increased histamine response, hyperkalemia, residual muscle pain and weakness, immunological reactions.
What are the rehabilitation considerations for local anesthesia?
Monitor for confusion or delirium, progressive decline in cognition, persistent muscle weakness, manage bronchial secretions, avoid disturbing transdermal patches, monitor effectiveness of medication.
