12. Pain mechanisms and their management Flashcards
What is acute pain?
“An unpleasant sensory or emotional experience that is associated with actual or potential tissue damaging stimuli”
Specific injury e.g. tissue damage which ceases once healed
What is the specificity theory?
That there is a direct and automatic link between the cause of pain, the signal through the spinal cord to the brain and receptors resulting in sensitisation
What is the problem with the specificity theory?
It ignores important factors which can impact on the sensation of pain e.g.
Effect of emotion, attention and distraction
Individual meaning and experience of pain
What is the gate control theory?
Proposed that there is a ‘gate’ within the spinal cord
Noxious stimuli arrives at the dorsal horn and meets the gate and can open it - information then travels towards the brain
Analgesic medication would be effective to close the gate and cease the sensation of pain
What is chronic pain?
Persistence of the memory of pain and/or the inability to extinguish the memory of pain evoked by an initial inciting injury
Long lasting
What are the three main components of the brain involved in the sensation of pain?
Sensory component - what the pain feels like and location in time and space
Affective and motivational aspect - what actions we carry out as a result of this e.g. unlikely to engage in the same actions/behaviour
Cognitive/evaluative - interpretation of the pain and its meaning
What are the other effects of chronic pain on a patient?
Closely related to high rates of depression and anxiety
What are the actions of the following neurotransmitters in pain, depression and anxiety?
Serotonin (5HT)
Noradrenaline
Dopamine
Opioid system
Serotonin - suppresses the sensation of normal bodily functions
Noradrenaline - suppresses the sensation of normal bodily functions
Dopamine - Application of important stimuli and focusses attention, dampens pain
Opioid system - Prevents the spread of pain, dampens pain and reinforces behaviour
What are the four types of pain behaviours?
Negative affect (negative emotions)
Facial/audible expression of distress
Distorted ambulation or posture
Avoidance of activity (e.g. ringing boss to say that you cannot come in)
What cognitive techniques can be used in the management of pain?
Distraction - focus on non-painful stimulus
Non-pain imagery - focus on mental scenes unrelated to pain
Pain redefinition - replace feelings of threat with realistic thoughts about the pain experience and the capacity to cope
What behavioural techniques can be used in the management of pain?
Medication scheduling - specific time to have medication and so removes medicating as a pain behaviour
Increased activity levels - reduced avoidance of behaviour
What pharmacological methods can be used in the management of pain?
Antidepressants e.g. tricyclics such as amitriptyline
5HT
Antipsychotics - work in a similar way to antidepressants but are often more sedating
Mood stabilisers may be used under special circumstances
