Chapter 23 Flashcards
Define pain
A multidimensional, subjective experience
- an unpleasant sensory and emotional experience associated with actual or potential tissue damage
What are the 3 types of drugs used to treat pain?
- Strong narcotics
- Mild narcotics
- Mixed agonist-antagonists
What is transduction?
Term used to describe the phenomena associated with the initiation of a pain signal
Where are pain receptors found?
On the peripheral end plates of afferent neurons
What do afferent neurons do?
Carry signals into the CNS
whereas efferent neurons carry signals from the CNS to the periphery
What are pain receptors called?
Nociceptors
What are the type different types of nociceptors?
- Delta fibres
2. C fibres
Describe the pain that Delta fibres sense
Sense sharp, stinging, cutting or pinching pain
Describe the pain the C fibres sense
Dull, burning, or aching pain
What are the 4 different kinds of pain?
- Nociceptic pain
- Neuropathic pain
- Acute pain
- Chronic pain
What are the characteristics of nociceptic pain?
- indicates real or potential tissue damage
- activation of delta and C nociceptors in response to painful stimuli (injury, disease, or inflammation)
How is nociceptic pain categorized?
- Somatic (deep or superficial)
2. Visceral
What is somatic nociceptic pain?
Pain in the bone, muscle, or soft tissue (stimulated by peripheral nociceptors)
What is visceral nociceptic pain?
Pain in the deep tissues or organ (and surrounding tissues)
What is neuropathic pain?
Pain from abnormal processing of stimuli in the peripheral or CNS
What is acute pain?
The immediate phase of response to an insult or injury from tissue damage
- resolves with healing of underlying injury
Is acute pain nociceptic or neuropathic?
Usually nociceptic, but can also be neuropathic
What is chronic pain?
Not defined by how long it lasts
- may persist well beyond actual tissue injury and healing
What are the drug classifications (2) that are normally used for pain management?
Opioid analgesics
Non-steroidal anti-inflammatory (NSAIDs)
How do NSAIDs act?
Act in the peripheral nervous system, interfering with prostaglandin synthesis and preventing the transmission of pain impulses.
What are 2 examples of drugs that are used to treat mild-moderate pain?
NSAIDs
Tylenol (non-opiate analgesics)
What kind of drug is used to treat moderate-severe pain?
Opioids
What are adjunct analgesics?
Drug classes that are used as secondary pain relievers
- primary use is for other problems
What are 5 examples of classifications of adjuvant drugs?
Anti-depressants Corticosteroids Anti-epileptics Anti-emetics Anti-psychotics
What are some examples of non-pharmacologic techniques used in pain control?
- relaxation
- guided imagery
- biofeedback
- music distraction
- exercise
- transcutaneous electrical nerve stimulation
- massage
What is the most effective drug class for managing pain?
Narcotic analgesics
What are some examples of strong narcotic agonists?
- Morphine
- Hydromorphone
- Levorphanol
- Oxycodone
- Oxymorphone
- Meperidine
- Fentanyl
- Methadone
- Tramadol
- Alfentanil
- Sufentanil
What are some adverse effects of morphine?
- Excessive CNS depression
- Respiratory depression
- Hypo-ventilation
- Apnea
What are the secondary actions of morphine?
- respiration (decreased tidal volume)
- cough reflex decreased
- hypotension and orthostatic hypotension
- euphoria, dysphoria, alterations in mood
- nausea and vomiting
- itchy, flushing red eyes
- constipation
- urinary retention
Define drug tolerance
The body has become accustomed to the effects of a substance and the patient must use more of it to achieve the desired effect
Define drug dependence
Withdrawal or abstinence syndrome when the drug is discontinued
Define drug addiction
Compulsive use of a drug for a secondary gain, not for pain control
When is a better time to administer morphine, before or after the pain becomes severe?
Before the pain becomes severe
Why is it beneficial to administer continuous administration of morphine?
Promotes a steady blood level of the drug, which prevents drug troughs that allow pain to escalate
What is breakthrough pain?
Transitory flare-ups of pain over baseline in a patient receiving opioid therapy
What is a rescue dose?
An additional dose of morphine to treat break through pain
(10-30% of usual dose in a 24 hour period)
What is another name for a rescue dose?
PRN
What is the most serious adverse effect of morphine?
Respiratory depression
How is Hydromorphone (Dilaudid) different than Morphine?
Equally as effective, but more potent
If a dose of 10mg of morphine was ordered, what would be the equivalent in Hydromorphone for pain management?
Between 1 - 1.5 mg hydromorphone.
What are the effects of oxycodone?
Analgesic, antitussive, constipating, respiratory-depressive, sedating, emetic, and physical dependency effects
- similar to morphine
What are the major uses of Fentanyl?
Pre-anesthetic
Anesthetic
Analgesic
How is Fentanyl similar to Morphine, how is it different?
Analgesic properties are similar, but Fentanyl produces fewer respiratory and emetic effects
If 10 mg of morphine was administered, what would the equal analgesic amount be in Fentanyl?
0.1 mg Fentanyl
What is the action of a narcotic antagonist?
Competes for opioid receptor sites
- used to reverse the effects of opiates (respiratory depression) and treat opioid overdose
What is a name of a drug that is a narcotic antagonist?
Naloxone (Narcan)
What can happen after Narcan is administered? What WILL happen?
Will happen - reverse all analgesic effects of narcotics, precipitates withdrawal effects
Can happen - N/V, sweating, tachy, increased BP
Give some examples of mild narcotic agonists.
Codeine
Hydrocodone
Propoxyphene
What is codeine used for?
Mild to moderate pain in adults and children
- also as a cough suppressant
