An unpleasant sensory and/or emotional experience.
What are the two components of pain?
Physical:sensation of pain - nociceptors are pain receptors involving PNS and CNS.
Psychological:emotional response to pain sensation.
What is pain influenced by?
Age
Gender
Culture
Previous experience of pain and pain management
Personality
Peer influence
Stress
Anxiety
Classifications of pain?
Acute
Chronic
Nociceptive pain
Neurogenic pain
Neuropathic neurogenic pain
Psychogenic pain
Breakthrough pain
Referred pain
What are the four basic processes involved in nocicpetion
Transmission
Transduction
Perception
Modulation
What is transduction?
Begins when nerve endings (nocicpeotors) of C fibres and A-delta fibres of primary afferent neurons respond to noxious stimuli.
Nociceptors are exposed to noxious stimuli when tissue damage and inflammation occurs.
What is transmission?
Pain impulse is generated by depolarisation and repolarisation at the cell membranes
Resulting in an action potential and generation of a pain impulse.
This stimulation causes a release of neurotransmitters/chemical mediators from the damaged cell.
The pain impulse is transmitted from the site of transduction along the nocicpetors fibres to the dorsal horn in the spinal cord.
This is then transmitted to the the brain stem and thalamus via two main pathways: spinothalamic pathway and spinoparabrachial pathway. Then they are processed.
What is perception?
Is the result of pain transmission where pain becomes a conscious experience.
Multiple cortical areas are activated: The reticular system-autonomic and and motor response, Somatosensory cortex-perception and interpretation of sensations, identifies the intensity, relates to past experiences; Limbic system-emotional and behavioural response to pain.
What is modulation?
Involves changing or inhibiting transmission of pain impulses.
Multiple pathways erferred to as: descending modulatory pain pathway and these can either increase or decrease the transmission of pain impulses.
What are the three types opioid receptors?
Mu, kappa and delta
What is the aim of pain assessment?
To help determine the course of the pain, the impact on quality of life, the best treatments and the effectiveness of current treatment.