WEEK 5 Pain Concepts Flashcards
Define Pain
Sensory and emotional experience associated with actual or potential tissue damage
What is nociceptive pain?
Associated with tissues
What are the two types of nociceptive pain?
Somatic: Connective tissue
Visceral: Organ tissue
What is neuropathic pain?
Means there is something wrong with the nervous system itself. Nerves do not generally heal very well
Identify the nervous systems x3 key areas related to the sensation and perception of pain
- Afferent pathway: Consist of nociceptors (pain receptors), afferent nerve fibres and the spinal cord network
- CNS: Portions involved in the interpretation of pain signals eg. limbic system, reticular formation
- Efferent pathways: Composed of the fibres connecting the reticular formation, midbrain and substantia gelatinosa
What are nociceptors?
Sensory receptors (nerve endings) activated by noxious stimuli, transmit impulses via C fibres and A delta fibres
Where are nociceptors distributed?
Somatic structures e.g. skin, muscles, bones
Visceral structures e.g. liver, GIT
What areas are located with the superficial somatic region?
Skin, mucus membranes, subcutaneous tissue
What areas are located with the deep somatic region?
Muscles, bones, tendons
Identify the 3 types of nerve fibres
A Delta fibres
C fibres
A Beta fibres
Describe A Delta fibres
Thinly myelinated, transmit well localised, sharp pain and sensitive to mechanical and thermal stimuli. ACUTE pain
Describe C fibres
Unmyelinated, transmit poorly localised, dull, aching pain and sensitive to mechanical, thermal and chemical stimuli. PERSISTENT pain
Describe A beta fibres
Highly myelinated, rapid conducting, respond to light touch, transmit non-noxious stimuli. GATE THEORY
Identify the 4 stages of the nocicpetive pain response
- Transduction
- Transmission
- Perception
- Modulation
Describe Transduction (Nociceptive pain response)
Response to tissue injury, release of chemical mediators e.g. Histamine, Prostaglandin, Generation of action potential
Describe Transmission (Nociceptive pain response)
Made up of three phases
1. Injury to spinal cord
2. Spinal cord to brainstem and thalamus
3. Thalamus to cortex
Describe Perception (Nociceptive pain response)
Conscious experience of pain, reticular activating system, somatosensory system
Describe Modulation (Nociceptive pain response)
Signals from brain travelling downwards, release of chemical substances, signals enhanced or inhibited, variability in pain response from gate control theory
Identify the 2 pain pathways
Ascending (sensory)
Descending (motor)
Describe the ascending (sensory) pain pathway
From nociceptors to brain, neurons with long axons ascend to brain
Describe the descending (motor) pain pathway
From the brain to spinal dorsal horn, can be modulated by gate thoeory, actions e.g. rubbing the site
What is the gate control theory?
Created by Melzack and Wall 1965, theorised the existence of a “gate” that could faciliate/inhibit transmission of pain signals
What is the pain experience dependent on? (Gate control theory)
The amount of info that gets through the gate into the brain and amount of downward signalling from brain
What faciliates opening and closing of the gate (Gate control theory)
T cells within the dorsal horn, gate can be closed by activities such as touch e.g. rubbing the injured site
What is an action potential?
Generated by voltage gated ion channels embedded in a cells plasma membrane
Identify the 2 main classifications of pain
Acute Pain and Persistent Pain
Describe acute pain
Sudden onset, mild to severe, duration dependent upon “normal healing”, If pain persists acute pain cycle may occur, Pt exhibits behaviours indicative of pain e.g. crying, rubbing
Describe chronic pain
“Chronic”, extends beyond the normal healing time, mild to severe, gradual or sudden, usually resulting from pathological processes, usually no signs of sympathetic over activity e.g. increased HR, pt appears depressed and withdrawn
Identify 3 further classifications of pain
- Nociceptive pain: Response to nociceptors, normal processing
- Neuropathic/Neurogenic: Nerve damage and abnormal processing along nerve pathway
- Somatoform (Psychogenic): Physical cause cannot be found
Identify the 5 further classifications of pain
Referred pain
Phantom pain
Cancer pain
Intractable pain
Breakthrough pain
Identify the physiological structures where somatic pain may be found (nociceptive pain)
Skin, blood, muscle, connective tissue
Identify the mechanism of somatic (nociceptive pain)
Activation of nociceptors
Describe the characteristics of of somatic (nociceptive pain)
Well localised, constant, achy, may be initially acute
Idenitfy 2 examples of sources of acute somatic pain (nociceptive pain)
Incisional pain, insertion sites of tubes
Idenitfy 2 examples of sources of chronic somatic pain (nociceptive pain)
Bony metastases, OA
Idenitfy the physiological structures where visceral pain may be found (nociceptive pain)
Organs and linings of the body cavities
Identify the mechanism of visceral (nociceptive pain)
Activation of nociceptors
Describe the characteristics of visceral (nociceptive pain)
Poorly localised, diffuse, deep, cramping, splitting
Identify 2 examples of sources of acute visceral pain (nociceptive pain)
Chest tubes, abdominal tube drains, bladder distention
Idenitfy 2 examples of sources of chronic visceral pain (nociceptive pain)
Pancreatitis, liver metastses
Idenitfy the physiological structures where neuropathic pain may be found (nociceptive pain)
Nerve fibres, spinal cord and CNS
Identify the mechanism of neuropathic pain
Non nociceptive injury to nervous system structures
Describe the chacrteristics of neuropathic pain
Poorly localised, shooting, burning, shock-like
Identify a source of acute and chronic neuropathic pain
Nerve tissue injury due to diabetes, HIV, chemotherapy
Describe somatoform pain disorder
Pain caused, increased, or prolonged by mental, emotional or behavioural factors, diagnosis of exclusion e.g. headache or abdo pain
Describe cancer pain
Has its own category, usually persistent (long term)
Describe breakthrough pain
Sudden onset, short duration, unresponsive to pain management
Describe intractable pain
Pain not relieved by ordinary medical, surgical or nursing measures, excruciating pain e.g. firbomyalgia
Describe phantom pain
Pain felt in a body part that is missing, sensation or pain
Describe referred pain
Pain felt at another site other than the injured body part
Identify one harmful effect of unrelieved pain for endocrine system
When a person is under stress the endocrine system releases excessive amounts of hormones e.g. increased cortisol
Identify one harmful effect of unrelieved pain for metabolic system
Sympathetic stimulation results in release of glucose into bloodstream for energy in other areas e.g. hyperglycaemia
Identify one harmful effect of unrelieved pain for CVS system
CVS responds by activating the sympathetic nervous system resulting in fight or flight response e.g. incrased HR
Identify one harmful effect of unrelieved pain for respiratory system
Increased RR, decreased coughing
Identify one harmful effect of unrelieved pain for genitourinary system
Excessive release of hormones resulting in decreased urinary output and urinary retention
Identify one harmful effect of unrelieved pain for GIT system
Reduction in gastric emptying = decreased bowel motility
Identify one harmful effect of unrelieved pain for cognitive system
Pain may produce crisis reactions = reduction in cognitive function and mental confusion
Identify one harmful effect of unrelieved pain for immune system
Immune cell supression = immunocompromised
Describe the 5 aspects of the pain assessment plan
- Initial assessment
- Assessment tools
- Goals of pain management
- Ongoing assessment
- Documentation
Idenitfy 3 factors relevant to effective treatment
- Ability to use appropriate pain measurement tools
- Coping mechanisms
- Family expectations and beliefs about pain and patinets illness
Identify the two types of pain assessment tools
- Uni dimensional tools
- Multi dimensional tools
Describe uni dimensional pain tools and provide an example
Accurate, simple, easy to use e.g. Numerical or visual analogue scale
Describe multi dimensional pain tools and provide an example
Provide information about qualitative and quantitiative aspects of pain, requires pt to have good verbal skills e.g. PQRSTU
Describe an acute pain assessment
Definable injury, definite onset, duration limited and predictable and asscociated with clincial signs of sympathetic overactivity
Describe the initial pain assessment tool
Location, quality, manner expressing pain, what relieves it/makes it worse and effects of pain e.g. decreased sleep
Describe the behavioural pain assessment scale
Face expressions, restlessness, muscle tone, vocalisation and consolability (out of 10)
Describe the functional activity score pain assessment
Asks the patient to perform an activity related to their painful area
A: No limitation by pain
B: Mild limitation by pain
C: Severe limitation by pain
Describe a persistent pain assessment
Individual may not have a definable injury or illness, may not have a definite onset, no clinical signs of sympathetic overactivity
Identify 3 additonal questions for a peristsent pain assessment
- Does pain increase as the day goes on?
- Is there numbess or loss of muscle strength associated?
- Is there any weather that makes it worse?
Describe the brief pain inventory (BPI) for persistent pain assessment
Assesses pain severity and degree of interference with function using 0-10 scale
Describe the McGill pain questionarre for persistent pain assessment
Evaluates sensory, affective emotional, evaluative and temporal aspects of the pain. Three pain scores are collected (Sensory, affective and total pain index)
Describe the leeds neuropathic assessment (LANSS) for persistent pain assessment
Varying questions e.g. sensitivity of skin, skin temp
Idenitfy 4 other pain assessment tools
Pain catastrophising scale
PASS: Pain anxiety symptom scale
DN4: Neuropathic/nociceptive discrimination
Chronic pain grade (pain activity questionarre)
Describe QUESTT as a paediatric pain assessment
Q: Question the child
U: Use pain rating scale
E: Evaluate behaviour/phsyiological changes
S: Secure parents involvement (Experts)
T: Take cause of pain into account
T: Take action and evaluate results
Identify 4 ways of assessing pain in paediatrics
- Faces (Wong Baker)
- Numerical scale
- Behvaioural: FLACC, consolability
- Physiological e.g. increased HR, RR
Idenitfy 3 acute pain effects in children
Altered temperament
Infant stress behaviours
Increased behaviour/physiological change
Identify 3 variables which may effect pain
Genetic
Developmental
Psychological
Identify a psychological factor which may influence ones perception of pain
Poor insight, cognitive defecit
Identify a enviornmental factor which may influence ones perception of pain
Lack of secure housing, unhealthy environment
Identify a social factor which may influence ones perception of pain
Lack of family support, unemployed
Identify 5 psychosocial effects of persistent pain
Loss of employement/income
Isolation
Lowered self esteem/confience
Marital and family dysfunction
Sleep disorders
Identify 3 things which pain can be impacted by
Attention the person pays to it
Emotions and mood
Coping strategies
Identify 3 aspects of the persistent pain cycle
Persistent pain leads to:
- Being less active
- Sleep probs, tiredness, fatigue
- Negative thinking, fear of the future
