Pain 1 Students Ppt

8/4/2019 Pain 1 Students Ppt

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Pain

8/9/2011


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Learning Outcomes Define pain

Describe the meaning of pain

Discuss the physiology of pain transduction,transmission, perception and modulation.

Describe theories of pain

Describe various types of pain

Identify clinical manifestations of pain.

Describe cultural beliefs and responses to pain.


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QuestionWhy is it important for nurses to have an

understanding of pain?

(Think, pair, share)


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Pain definition An unpleasant sensory and emotional experience

associated with actual or potential tissue damage ordescribed in terms of such damage

(The international Association for the study of pain).


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What is pain Subjective sensation

Pain perceptions based on

Expectations Past experience

anxiety


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Pain perceptionsAffective-ones emotional factors can affect pain

experience.

Behavioral how one expresses or controls pain Cognitive ones beliefs or attitudes about pain


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Pain receptors and mediatorsNociceptors : are pain receptors which are sensitive

to noxious stimuli.

The term nociception refers to the process by whichpain information is carried from the peripherysense receptors in the skin and in the viscera tothe cerebral cortex through network of neuronal

networks


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Physiology of painAcute pain is a physiological response.

It warns us of danger.

The process of nociception describes the normalprocessing of pain and the response to noxiousstimuli that are damaging or potentiallydamaging to normal tissue.


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Nociceptors Nociceptors are distributed in the:

Somatic structures

Visceral structures The C fibers and A delta fibers are associated with

different qualities of pain.


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Nociceptive action potentials are transmitted throughtwo types of afferent nerve fibers:

Myelinated A Delta fibers Unmyelinated C fibers


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Characteristics and functions of C

fibersCharacteristics Pain quality

Primary afferent fibers

Small diameter Unmyelinated

Slow conducting

Receptor Type

Polymodal respond to morethan I type of noxiousstimuli.

. Diffuse

Dull Burning

Aching

Referred to as slow or secondpain


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A Delta FibersCharacteristics Pain quality

Primary afferent fibers

Large diameter Myelinated

Fast conducting

Receptor Type

High thresholdmechanoreceptors respond tomechanical stimuli overcertain intensity.

Well localized

SharpStingingPrickingReferred to as

fast or first pain


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Noxious stimuli and responsesCategories of noxiousstimuli

Causes of stimulation may be:

Mechanical

Thermal Chemical

Internal

External


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Chemical mediators Prostaglandin

Bradyk inn

Serotonin

Potassium and histamine


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4 basic processes involved in

nociception Transduction

Transmission

modulation perception


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Transduction of pain Transduction begins when the free nerve endings

(nociceptors) of C fibers and A-Delta fibers of primaryafferent neurons respond to noxious stimuli whentissue damage and inflammation occurs.


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Transmission Pain that may be described as sharp or pricking

and can easily be localized is transmitted by the Adelta fibers.

Pain that may be described as burning dull oraching and that is more diffuse results from impulsestransmitted by the C fibers.


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Transmission From the site of conduction pain impulses move along

nociceptor fibers to the dorsal horn of the spinalcord.

From the spinal cord then to the brain stem

Then through connections between the thalamus,cortex and higher levels of the brain.


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Modulation of pain The modulation of pain involves changing or

inhibiting transmission of pain impulses in the spinalcord.


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Modulation of pain Descending inhibition involves the release of

inhibitory neurotransmitters that block or partiallyblock the transmission of pain impulses, and thereforeproduce analgesia.


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Inhibitory neurotransmitters involved with themodulation of pain include;

Endogenous opoids (encephalins,endorphins anddynorphins))

Serotonin

Nor epinephrine

Gamma-aminobutyric acid (GABA) Neurotensin, acetylcholine and oxytocin.


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Perception Perception of pain is the end result of the neuronal

activity of pain transmission and where pain becomesa conscious multidimensional experience.

The multidimensional experience of pain has;

Affective-motivational, sensory-discriminative,emotional and behavioral components.


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PerceptionWhen painful stimuli are transmitted to the brain

stem and thalamus, multiple cortical areas areactivated and responses are elicited.

These areas are;

The reticular system

Somatosensory cortex

Limbic system


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Reticular system This is responsible for the autonomic and motor

response to pain and for warning the individual to dosomething.

It also has a role in the affective motivationalresponse to pain.


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Somatosensory cortex This is involved with the perception and interpretation

of sensations.

It identifies the intensity, type and location of the painsensation and relates the sensation to pastexperiences, memory and cognitive ability.

It identifies the nature of the stimulus before it

triggers a response.


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Limbic system This is responsible for the emotional and behavioral

responses to pain.


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Pain messages are two-way traffic. Inhibitory effectsare achieved through the descending pathways, whichreach from the conscious brain down to the gates in

the subconscious brain and the spinal cord. The reasonfor this is that the gates are places where the flow ofpain messages can be controlled or influenced (Wells &Nown 1998). By sending responses back to the

periphery, the brain can order the release of chemicalsthat have analgesic effects, which can reduce or inhibit

pain sensation.


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Break Go over your notes

Any questions ??????????????

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Pain 1 Students Ppt