BEH Pain Flashcards
Define Pain.
an unpleasant and emotional experience associated with actual or potential tissue damage, or described in terms of such damage
What can influence pain management?
Pain management is influenced by beliefs, attitudes, education and environment
What are some cardiovascular effects of undertreated severe acute pain?
Cardiovascular:
• Tachycardia
• Hypertension
• Increased peripheral vascular resistance
• Increased myocardial oxygen consumption
• Myocardial ischaemia
• Altered regional blood flow
• Deep-vein thrombosis
• Pulmonary embolism
What are some respiratory effects of undertreated severe acute pain?
Respiratory
• Reduced lung volumes (tidal volume)
• Atelectasis
• Decreased cough
• Sputum retention
• Infection
• Hypoxaemia
What are some gastrointrstinal and genitourinary effects of undertreated severe acute pain?
Gastrointestinal
• Decreased gastric and bowel motility
• Increased risk of bacterial transgression of bowel wall
Genitourinary
• Urinary retention
What are some neuroendocrine effects of undertreated severe acute pain?
Neuroendocrine
• Increased catabolic hormones
○ Glucagon
○ Growth metabolic hormone
○ Vasopressin (ADH)
○ Aldosterone
○ Renin
○ Angiotensin
• Reduced anabolic hormones
○ Insulin
○ Testosterone
• This catabolic state leads to
○ Hyperglycaemia
○ Increased protein breakdown
○ Negative nitrogen balance
○ Leading to impaired would healing and muscle wasting
What are some psychological effects of undertreated severe acute pain?
Psychological
• Anxiety
• Fear
• Helplessness
• Sleep deprivation
• Leading to increased pain
What are some musculoskeletal and central nervous system effects of undertreated severe acute pain?
Musculoskeletal
• Muscle spasm
• Immobility (increased risk of deep-vein thrombosis)
• Muscle wasting leading to prolonged recovery of function
Central nervous system
• Chronic (persistent) pain due to central sensitisation
What is the difference between Pain Tolerance and Pain Threshold?
Pain Tolerance: the point which pain becomes unbearable and varies widely among individuals and in a single person under different circumstances
- will vary between individuals
Pain Threshold: people have a relatively constant pain threshold under normal circumstances
- same in almost everyone
- e.g. heat applied to skin at an intensity of 45-48C will initiate the sensation of pain in almost everyone
What is involved in the perception of Pain?
- sensory system
- location, duration and intenisty of the pain
- a motivational-affective component
- designeed to avoid or escape from the cause of the pain
- a cognitive-evaluative component
- information about the current pain and past experiences in order to evaluate the pain
What are Nociceptors?
respond to potentially damaging stimuli that result in pain. e.g. searing heat, extreme cold, excessive pressure and inflammatory chemicals are all interpreted as painful.
What part of the brain is responsible for the perception of pain?
Thalamus
Where are Nociceptors located?
Are widely dispersed throughout the body and can be identified in skin, periosteum, joints, muscle and viscera
What are the two main types of Nociceptors?
- A-delta fibres
- Myelinated fibres
- Stimulated by heat and noxious mechanical injury
- Action potentials 2-20 m/s
- Travel towards the dorsal horn of the spinal cord
- Synapse with second-order neurons to send message to brain
- Stimulation leaves to initial sharp pain that follows injury
- C-fibres
- Unmyelinated fibres
- Stimulated by heat and noxious chemical and mechanical injury
- Action potentials <2 m/s
- Throbbing, slow building, burning pain, following initial injury
- Subclass → C-fibre polymodal receptor
- Responds to heat, cold, pressure and chemical stimuli
What are the excitatory and inhibitory neurotransmitters released in response to pain?
Excitatory
- Glutamate
- Monoamines
- Substance P
*in the dorsal horn of spinal cord*
Inhibitory
- Gamma Amino Butyrix Acid (GABA) and GLycine
- 5-Hydroxy-Tryptamine (5-HT)
- Noradrenaline
- Endogenous Opiods
- endorphins
- dynorphins
- enkephalins
Describe the location, description and mechanism, as well as give examples of somatic, visceral and neuropathic pain.
