Anaesthesia & Analgesia Flashcards
Anaesthesia ≠ analgesia, explain
Although consciousness is lost, pain is still processed. When you wake up from anaesthesia you still feel pain.
Analgesia is pain relief without loss of consciousness and without total loss of feeling or movement; anesthesia is defined as the loss of physical sensation with or without loss of consciousness.
What are the goals in terms of using A&A for research?
Reproducible studies:
no physiological abnormalities and pain influencing animal welfare & therefore experimental outcome. Any extra pain induced can influence and confound the experiment results. Sick and animals in pain do not behave the same as healthy animals.
Give the four general components of anaesthesia
- Unconsciousness: lack of awareness and perception of the surroundings.
- Immobility/muscle relaxation: the inability to move and relaxed muscles. Loss of movement and the righting reflex is often used as indicator of unconsciousness in
anaesthetised animals. - Analgesia: absence of pain in response to a noxious or painful stimulus.
- Amnesia: inability to recall events or an experience. Anaesthetics impact memory
Give the four types of anaesthesia
- General
- Regional
- Local
- Sedation
When is regional anaesthesia used in research?
Regional; not used much apart from maybe primates- you ‘block’ a region complete, quite difficult to use.
What function does local anaesthesia carry out?
Local anaesthetic blocks the pain stimuli locally
What is required for administering local anaesthesia? What effect may this have?
Requires restraining the animal which can stress the animal especially if a person is untrained. Having someone who is confident is important.
Can local anaesthesia be applied during general anaesthesia?
Yes, but for small procedures
What is required of A&A during a craniotomy?
If you have to do a craniotomy you want the skin to be completely anaethtetised and for that you need local analgesia
Compare sedation with tranquilisation
Sedation: a state of central depression where the animal is drowsy and relaxed to some degree. The animal is generally unaware of its surroundings but, contrary to unconsciousness, can be stimulated by noxious stimuli.
Tranquilization: animal is relaxed and non anxious but is aware of its surroundings.
What is the physiological correlate of local anaesthesia?
Blocks conduction of nerve impulses through the binding and inactivation of the sodium ion pump of sensory neuron, interrupting the signal between the nociceptor and spinal cord
Why may multiple drugs be used for small animals?
Drugs have adverse effects; higher doses mean more adverse effects and possible overdose especially with smaller animals, for this multiple drugs at low doses may be preferred to minimize desired effects.
What are the maximum doses for lidocaine & bupivicaine?
Lidocaine: up to 10/mg/kg
Bupivicaine: 4 mg/kg
Where is important to administer local anaesthesia during surgical procedure?
Infiltrate all tissue planes involved in surgical procedure
What is very sensitive to pain during craniotomies?
Periosteum (dense layer of vascular connective tissue enveloping the bones; skull; except at the surfaces of the joints) and meninges very sensitive to pain
