Pain Management Flashcards
What is a nociceptor?
A nociceptor is a sensory neuron (nerve cell) that responds to potentially damaging stimuli by sending signals to the spinal cord and brain. The process is called nociception and causes the perception of pain.
What are the three components of pain?
Sensory - pain sensation, 120 different adjectives can be used to be describe it.
Motivational - affective e.g. ‘It grinds me down’
Cognitive - evaluative component ‘It’s impossible’
What are the two ways to classify pain?
Nociceptive and non-nociceptive pain
What is nociceptive pain? What are the two types of nociceptive pain?
Nociceptive pain is maintained by continual tissue damage; nociceptors are pain receptors that respond to tissue damage.
a) Somatic pain comes from the joints, bones, muscles and other soft tissues.
b) Visceral pain comes from the internal organs.
What is non-nociceptive pain? What are the two types of non-nociceptive pain?
Pain that comes from the nervous system is called non-nociceptive because there are no specific pain receptors.
a) Neuropathic - from injury to nerve/neural structures. Pinched/trapped nerve, neural degeneration (e.g. stroke, MS). Sharp, burning.
b) Idiopathic pain - no apparent underlying cause. If organic cause, pain is out of proportion to cause. Psychogenic/somatoform pain is is physical pain that is caused, increased, or prolonged by mental, emotional, or behavioral factors.
Define acute pain
Lasts less than six months
Associated with:
a) tissue damage
b) arousal of the autonomic nervous system (ANS), which results in physiological symptoms like anxiety and fear (e.g., sweating, palpitations, dry mouth, lightheadedness, upset stomach).
Define chronic pain
Longer than six months
a) Chronic recurrent - recurring basis with discrete episodes e.g. migraines
b) Chronic intractable - never goes away but intensity changes e.g. LBP
c) Chronic progressive - gets worse over time e.g. cancer related
What is the gate control theory of pain?
Melzack and Wall (1965)
There is a gating system in the substantial gelatinosa of the dorsal horns of the grey matter of the spinal cord. This gating system modulates the transmission of information from the nociceptors (A delta and C fibres) to the dorsal horn’s transmission cells through inhibitory processes at the neuronal level. This controls the quantity and intensity of the signals to the central nervous system. Higher cortical functions also contribute which is how psychological phenomena affect the brain.
What controls the gate?
- Amount of activity in the A delta and C fibres
- Amount of activity in the A beta fibre (touch)
- Amount of activity in descending pathways
What opens the gate?
Physical: Deconditioning, muscle tension, drug abuse
Cognitive: attention to pain, negative beliefs and thoughts about self and pain e.g. uncontrollable
Negative affect: e.g. hopelessness, helplessness, inhibited anger, anxiety, depression
Unhealthy behaviours e.g. poor eating, inactivity, smoking, poor sleep
Social: Too much or too little support, others focusing on pain, reduced intimacy
What closes the gate?
Physical: Drugs, surgery, reduced muscular tension Cognitive: Distraction or external focus of attention, thoughts of control over pain, beliefs about pain as predictable and manageable
Affect: Emotional stability, relaxation, and calm, positive mood
Behaviours/activity: Appropriate pacing of activity, positive health habits, balance between work, recreation, rest, and social activity
Social: Support from others, reasonable involvement from family and friends, encouragement from others to maintain moderate activity
Describe the neurochemistry of pain and endogenous pain management
- The neurotransmitter, substance P, is released by afferent pain fibres and stimulates transmission cells which send pain messages to the brain.
- Analgesia is produced when serotonin activates the inhibitory interneurons prompting endorphin release.
How do behavioural principles contribute to pain?
Classical conditioning - association of pain with antecedents
Operant conditioning - positive reinforcement for pain behaviours; negative reinforcement (avoidance), modelling
How would you assess pain?
Clinical interview 0-10 self report scales Pain diary Pain scales e.g. McGill Pain Questionnaire; Coping Strategies Questionnaire (cognitive), BDI, MMPI, West Haven-Yale Multidimensional Pain Inventory Observation, family and carer reports
What should be explored in a pain interview?
- Description of the pain
- History of pain problem
- Emotional adjustment to pain
- Impact of pain on lifestyle e.g. daily activities ‘If I was a fly on the wall, what would I see?’
- Impact of pain on the things that matter to them
- Triggers/antecedents and consequences of pain and pain behaviour e.g. sexual dysfunction
- Current coping with pain e.g. medication use, is daily life shaped around medication regime and medication half-life?
- Social context of pain e.g. early abuse, family models of pain or disability
