Pain Management Flashcards
What is pain?
- Sensory experience associated with tissue damage
- Emotional component in humans and animals
Forms of pain management? (3)
- Analgesia
- Multi-modal analgesia
- Pain scoring methods (pain behaviour)
Why should pain be avoided? (Mention 4 things)
- Stress to patient
- Prolonged recovery
- Poor or delayed wound healing
- Self-trauma
- Impairs respiratory and cardiovascular function
- Reduced food intake
- Reduced mobility
- Our ethical responsibility!
Name 3 responses to pain
- Intra-operative pain
- Increased HR
- Increased RR
- Dilation of bronchi
- Adrenaline release
- Cardiac arrhythmias due to adrenaline release
- Dilation of blood vessels in skeletal muscle
- Constriction of blood vessels in gastrointestinal tract
What is acute pain associated with?
Injury / trauma
- may be post surgical
When does acute pain usually abate
- as healing occurs
What is acute pain?
Pain that does not usually outlast the initial painful stimulus
What is chronic pain?
Pain that does outlast the initial painful stimulus
OR
British pain society: ‘pain lasting longer than 12 weeks’
OR
pain lasting longer than anticipated
What can chronic pain cause changes in
- Can cause changes in pain pathways of the central and peripheral nervous system
- Continued pain can lead to changes in the way the animal responds to painful stimulus
What is pre-emptive analgesia
Administration of analgesics prior to pain stimulation preventing neuron sensitisation
What are the three kinds of pain?
- Physiological
- Inflammatory
- Neuropathic
What is physiological pain?
Response that is proportionate to stimulus and pain goes when stimulus is removed
- ‘Protective pain’
What is inflammatory pain?
Clinical pain
- caused by surgery?
inflammation
What is neuropathic pain?
Caused by direct damage to the nervous system
What is the physiology of pain
- Noxious (painful) stimulus associated with tissue damage and release of inflammatory mediators leading to the activation of pain receptors in nociceptors
- Nociceptors transmit pain signals to CNS
What can repeated stimulus of pain pathways cause?
Heightened sensitivity
What are nerve endings that detect painful stimuli called?
Nociceptors
What are the main inflammatory mediators?
Prostaglandins
What is transduction
Pain being detected by nociceptors that then convert the painful stimulus into a nervous signal
What are the pain fibres?
Að and C
What is the aim of analgesia?
To interrupt or modify some or all parts of the CNS pathway
What can ongoing pain cause?
Chronic hypersensitivity to pain that can outlast the actual pain event
What is Allodynia?
Sensitivity to stimuli that would not normally cause pain e.g. touch
What is hyperalgesia
Greater intensity and duration of pain that would be expected
What 5 kinds of drugs are most commonly used
Opioids NSAIDs Alpha-2-adrenoreceptor agonists Local anaesthetics Ketamine Gabapentin
Name 2 opioids used for analgesia and pain management
Methadone
Buprenorphine
Fentanyl
Where do opioids act?
Centrally and peripherally
How do NSAIDs work?
Inhibit the production of inflammatory mediators via the inhibition of COX enzymes
What kind of NSAIDS are safer for the gut?
Cox-2 selective
Name 3 NSAIDs commonly used
meloxicam Carprofen Robencoxib Asprin Phenybutazone Ketoprofen Paracetamol
What are NSAIDs used for
Management of chronic pain
Peri-operative pain relief
When should you avoid NSAID usage? (name 2)
In patients that are:
- Dehydrated
- Hypotension (Shocked)
- Have pre-existing renal disease
- Liver disease
- Animals already on corticosteroids or other NSAIDs
Name 2 Alpha-2-adrenoreceptor agonists
medetomidine
dexmedetomidine
Xylazine
What is used to reverse Alpha 2’s
Atipamezole
Name a local anaesthetic used for pain management
Lignocaine
Bupivicaine
Mepivicaine
What kind of analgesia do local anaesthetics provide?
Total analgesia
What type of analgesia does ketamine provide
somatic analgesia
Why is ketamine used for pain management
- thought to prevent ‘wind up’
- acts centrally and can block central sensitisation
When is Gabapentin used for pain management?
To block neuropathic pain in adult animals
What is neuropathic pain
Pain caused by disease of sensory nerves
What is a disadvantage of gabapentin
Cost
Exact mechanism of action is unknown
Why is acupuncture used?
- For chronic pain
- To compliment pharmaceutical measures in pain patients
What are NSAID’s often combined with to create multi-modal analgesia? (name 1)
- Opioids
- Alpha-2-agonists
- Local anaesthetics
What kind of ‘infusion’ is often avoided in cats and why
‘Milk’ infusions due to sensitivity to lidocaine
What is a ‘milk’ infusion’
combo of:
- NaCl 0.9 or Hartmanns
- Morphine
- Lidocaine
- Ketamine
What variables can cause a variation in pain behaviour?
Species Breed Age Sex Temperament
Name 2 scales used to determine pain?
- Simple descriptive scale
- Numerical rating scale
- Visual analogue scale
- Glasgow composite pain scale
- Colorado pain scale for cats
Why are pain scales made?
To standardise and improve pain management
How do you determine if it pain or a stormy recovery?
Palpation of would: Should elicit painful or heightened response
- Painful animals may be temporarily distracted unlike those who are dysphoric
Name 4 additional roles of the VN to enhance a smooth recovery, and pain management
- Monitor
- Record and report signs of pain
- Give good nursing care
- Give clean warm bedding
- Tend to wounds e.g. bandaging
- Comfortable environment
- Allow toileting and eating as close to normal
- Provide psychological support
