Pain management Flashcards
What is the gate theory
A combo of neurons in the dorsal horn regulates the transmission of pain signals to the brain
Transmission of the pain signal is then regulated by what
Larger mechanofibers. If fibers are stimulated (non painful), the original perception of pain is diminished closing the pain gateway. Meaning a non painful input closes the gate to the painful stimuli
When the gate is closed
Pain sensation is blocked
When gate is open
Pain sensation reaches the brain
What are the 3 opiod receptors
Mu, kappa, delta
What receptor does morphine have a high affinity towards
Mu
What is the effect of Mu receptors
Analgesic effect but also induces respiratory depression, euphoria, and mydriasis (pupil dilation).
What is the effect of the Kappa receptor
Analgesic effects, but can have dysphoric and hallucinatory effects. No respiratory depression.
Where are mu receptors found
Presynaptic neurons and dorsal horn of spinal cord
Where are kappa receptors found
Widespread in the brain, pspinal cord and neurons
Where are delta receptors found
Bind to enkephalins which are peptides that regulate nociception in the body.
What is the effect of the delta receptors
So analgesic effect, but much more limited.
Anesthesia
Absence of all sensation, especially to pain.
Analgesia
Decreased or absent sensation of pain
Hyperalgesia
Extreme sensitivity to pain
Hyperesthesia
Extreme sensitivity to one of the body’s sense organs, such as pain or touch receptors in the skin
Allodynia
Pain due to a stimulus that is not usually pain provoking. Like light touch or stroking.
Dysesthesia
Abnormal reaction to touch. Occurs when a part of the body is touched and it causes some sort of unpleasant sensation like pain, burning, tingling. Caused by lesions in the nervous system
Hyperpathia
Condition of hypersensitivity to sensory stimuli (includes hyperesthesia, hyperalgesia)
Neuropathic pain
Pain caused from damage or disease to the somatic nervous system. Damage is usually to small non-myelinated fibers in the nerve which results in painful stimuli
Nociceptive pain
Usually caused by damage to body tissue and is usually described as sharp, aching, or throbbing. Can be visceral or somatic
Idiopathic pain
Unknown origin. Can by psychological in origin but may also involve both the cerebral and peripheral physiological mechanisms.
Psychogenic pain
Pain that is caused, increased or prolonged by mental or emotional factors. (i.e. back pain, stomach pain)
What is neuropathic pain characterized by
- Allodynia, hyperalgesia.
2. Stabbing, burning and tingling
Examples of neuropathic pain
- Herpes
- Neuralgia
- Post stroke pain
- Post amputation pain
- Radiculopathic pain
Types of nociceptive pain
- tissue damage
- arthropathies (arthritis)
- myalgia
- visceral pain (tumors)
Acute pain
Rapid onset of organic or traumatic cause that induces immunologic and physiologic responses (usually short duration).
Chronic pain
Pain that lasts longer than 3-6 months. after acute cause or lingers longer than expected duration
Difference in treatment of acute vs chronic pain
Acute = get rid of the pain, do not progress to chronic Chronic = manage to a level that allows the pt to live a decent life style
Physical dependence
Results from chronic use that has produced a tolerance and creates negative physical symptoms of withdrawal when the drug is stopped.
Tolerance
Body is becoming unresponsive to a given level of the drug. Increase in the dose is required to provide the same amount of analgesia. Rotate opioids if this occurs
Addiction
Drug seeking behaviors that occur when patients with sever pain cannot obtain tolerable relief (look at chart on objectives list)
What are some red flags with addicted patients
- out of control with meds
- decrease quality of life
- wants to continue meds despite side effects
- does not follow treatment plan
