intro to pain and assessment Flashcards
Pain serves an important _______
3 main functions
protective function
● Alerts about a problem (i.e., actual or potential
tissue damage) in the body
● Protects the body from further injury
○ Activation of flexor motor neurons generates the
withdrawal reflex
● Facilitates healing
○ Negative feedback of movement keeping the
body at rest
Discouraging movement of injured body part
define transduction, transmission, modulation and perception
Transduction: activation of nerve ending
Transmission: trasmit pain signal all the way up to sensory cortex
Modulation: downward regulation of pain usually to reduce pain response but sometimes to enhance pain
Perception: complex process involving intention, expectation, and interpretation of pain
Changes to any 4 can lead to change in sensitization of pair
Pain Definition (IASP)
● Pain is ________
● Each individual ____ the application of the word through experiences related to injury in early life
● It is recognized that those stimuli or illnesses that cause pain are
likely to cause ____
● Accordingly, pain is an experience we associate with ______
● It is always ____and therefore an _______
● Pain is subjective
● Each individual learns the application of the word through
experiences related to injury in early life
● It is recognized that those stimuli or illnesses that cause pain are
likely to cause tissue damage
● Accordingly, pain is an experience we associate with actual or
potential tissue damage
● It is always unpleasant and therefore an emotional experience
An unpleasant sensory and
emotional experience associated
with actual or potential tissue
damage, or described in terms of
such damage
if pt describes it, it is considered pain
Congenital Insensitivity to Pain
Some individuals are born
without a sense of pain
Some may sense “pain”, but lack
the affective response accompanying pain
May lead to multiple traumas and injuries or early death
Lack emotional response and awareness that there is tissue damage
Tend to have chronic owunds or lesions
Poor wound healing
Lip deformity after biting on it
Dislocated elbow permanent after repeated dislocaton
define alloydyina, analgesia, hyperalgesia, dysesthesia,Noxious stimulus
Allodynia - pain due to a stimulus that does not normally provoke pain
Analgesia - absence of pain in response to stimulation which normally would be painful
Hyperalgesia - increased pain from a stimulus that normally provokes pain
Dysesthesia - an unpleasant abnormal sensation, whether spontaneous or evoked
Noxious stimulus - a stimulus that is damaging or threatens damage to normal tissues
define pain threshold, paresthsia, sensitizatoin
Pain threshold - minimum intensity of a stimulus that is perceived as painful
Paresthesia - an abnormal sensation (that is not unpleasant), whether spontaneous or
evoked
Sensitization - increased responsiveness of nociceptive neurons to their normal input,
and/or recruitment of a response to normally subthreshold inputs
Pain Factors
Compared to iceberg
Much below surface, antecedant factors that shape it
Adverse childhood or traumatic experiences
Cultural expectations, ethnicity, genetics, religion and other values
vicious cycle which leads to suffering which leads back to chronic pain
Importance of Effective Pain Control
In acute pain, minimize suffering
Prevent transition to chronic pain
In chronic pain, heavy emotional, physical, social and
economic burdens are imposed on the patient and their
family and this also represents a costly problem for society
describe progression from acute to chornic pain
Chronic pain is not just sustained activation of nociceptive fibres
Transient activation of periph noceptive fibres after surgery or injury of acute pain
Sustained activation –> sensitization of nociceptive fibres
structural remodeling causes CNS neuroplasticity and hyperactivity
Central sensitization leading to chroonic pain
Acute vs Chronic Pain
see slide 17 for charactersitics of acute and chronic pain
Dependency, dpression more common for chronic pain
Chronic pain pt may not be fully pain free
Goal is make them more functional
Acute Pain
● Pain of recent onset and probable limited duration
● Usually has an identifiable temporal and causal relationship to injury or disease
● Has a physiologic protective function
Chronic Pain
● Pain lasting for long periods of time and persisting beyond the time of healing of an injury
● Often no clearly identifiable cause
● No longer serves a physiologic function (pathological
Physiologic pain vs pathologic pain
causal vs associative hypothesis
causal hypothesis: if you adequately manage pre and post operative pain, better chance of preventing it changing to chronic pain
associative hypothesis: if there are mutliple factors involved with post op pain and transition to chronic pain, just adequately managing pain perioperative or post op may less likely prevent it changing to chronic pain post surgery
Multimodal analgesia better at managing certain pain
describe nociceptive pain
Mixed - mix of nociceptive, neuropathic, nociplastic pains
- common
no NS lesion or inflamm, no pain from no stimulus or from normally nonpainful stimulus
- stimulus dependent pain: evoked by high intensity stimuli
- adaptive: protects by signaling potential tissue damage
- Peripheral amplification or sensitization happening
- Seeing a bit of central sensitization sometimes
- Beginning of maladaptive changes
Important to adequaely treat pain
stimuli: mechanical, theraml, chemical injury, abnormal mechanical forces, organ injury
describe inflammatory pain
pain from active inflammation,
Sometimes classified as Subset of nociceptive pain
- spontaneous and stimulus-depending pain:
evoked by low and high intensity stimuli
- Pain from no stimulus or normally nonpainful stimulus
Peripheral amplification or sensitization happening
Seeing a bit of central sensitization sometimes
Beginning of maladaptive changes
Important to adequaely treat pain
describe dysfunctional pain
No known nervous system lesion or active inflammation
Spontantous, can be intense pain
and stimulus dependent pain
Evoked by low and igh intensity pain
present wtith lack of stimulus
Peripheral and central sensitixation
Maladaptive and potentially persistent
Considered pathologic pain
describe neuropathic pain
Known ns lesion or disease or marked neuroimmune response
(Nerve trauma, herpes zoster, Stroke, spinal cord injury)
Spontantous pain in presence of norm nonpainful stimulus
High intentsity pain regarless of high or low stimulus
Central + peripheral ampliciation
Maladaptive and commonyl persistent
Considered pathologic pain
- Somtimes patients can have it resolved, usually pt can't be fully free from it
