Pain Flashcards
Carry Pain
Small Diameter Fibers
Inhibit Transmission of Pain Impulses
Carry non-painful stimuli
Large Fibers
NOCICEPTION
Physiological processes related to pain perception
4 parts of Nociception
- Transduction
- Transmission
- Perception
- Modulation
Transduction
1st step in experience of pain
- Nociceptors activated by exposure to noxious stimuli (mechanical, chemical, or thermal)
- Nociceptors spark electrical impulse that is conducted along nerve
3 segments of Transmission
- Pain impulse travels from peripheral nerve to spinal cord
- Transmission from spinal cord and ascension to brain stem and thalamus
- Transmission of signal between thalamus to somatic sensory cortex, where pain perception occurs
2 parts of the pain assessment
- Pain History (Subjective)
- Observation (Objective)
unpleasant sensory and emotional experience associated with actual or potential tissue damage, or it is described in terms of such damage
International Association for the Study of Pain
(def of pain)
drug injected into nerve pathway
blocks transmission of impulse
Nerve block
Cordotomy
last resort for intractable pain
usually on cervical nerve roots
Rhizotomy
used to reverse effects of narcotics
NARCAN
Rectal
- Suppository
- Good for patients with nausea/vomiting
Common Side Effects of Opioids
- Constipation
- N/V
- Sedation
- Respiratory depression
- Pruritus
- Urinary retention
Pain
- complex phenomena with NO simple definition
- Highly subjective –Individual & Personal
- difficult to assess
4 Categories of Pain
- Location
- Duration
- Intensity
- Underlying mechanism
most patients do not fit neatly in single category
Acute Pain
- Begins suddenly
- Usually sharp
- mild to severe
- moment to 6 months
- Relieved when underlying cause eliminate
If unrelieved, may become chronic
Chronic Pain
- Prolonged duration
- Interferes with functioning
- Recurrent/ longer than 6 months
- Persists when injury has healed
- May have w/o injury or evidence of damage
Intractable pain
- Resistant to relief
- Difficult to relieve
- Try multiple interventions
- Affects quality of life
can’t treat on own…. Interferes with ADL
Nociceptive Pain
Most pt’s, manageable
- Intact, functioning nervous system
- signal that tissues are damaged
- Requires attention and proper care
Subcategories of Nociceptive Pain
- Somatic Pain
- Visceral Pain
Somatic Pain
intensity and location match type and extent of injury
- Originates in skin, muscles, bone
- Highly organized
Visceral Pain
- Activation of nerve fibers from **organs or hollow viscera
- Poorly localized**
- Cramping, throbbing, aching
- Associated with diaphoresis or nausea
Neuropathic Pain
- Damaged/ malfunctioning nerves
- Difficult to treat
- Burning, electric shock, tingling, dull, aching
3 Types of Neuropathic Pain
- Peripheral
- Central
- Sympathetically Maintained
Peripheral Neuropathy
– Pain felt along peripheral nerves
– Diabetic neuropathy Peripheral Neuropathy
Central Neuropathic Pain
- Caused by lesion or dysfunction of CNS
- Post-stroke pain
- MS
Sympathetically Maintained Pain
Abnormal connections between pain fibers and sympathetic nervous system
Becomes chronic and neuropathic
Phantom limb pain
Hyperalgesia
heightened response to painful stimuli
Severe pain from paper cut
Allodynia
nonpainful stimuli produce pain
Contact with wind, linens
Dysesthesia
unpleasant abnormal sensation, there are bugs under my skin, my skin is on fire
5 dimensions of pain
- Physiologic
- Sensory
- Affective
- Behavioral
- Cognitive
Transmission
3 segments
- Pain impulse travels from peripheral nerve to spinal cord
- Transmission from spinal cord and ascension to brain stem and thalamus
- Transmission of signal between thalamus to somatic sensory cortex, where pain perception occurs
Perception
- become conscious of pain
- Opiates work well here
- shapes character, intensity, and meaning of pain to individual
Three key factors of preception
- Threshold: point which identifies pain
- Distractibility: degree can ignore pain
- Tolerance: point at which act to stop pain
Modulation
- Descending system
- Neurons in thalamus and brainstem send signals down spinal cord
- Neurons release substances (Endogenous opioids) inhibit pain impulses
Endogenous opioids
serotonin, norepinephrine
