Pre-emptive and multi-modal analgesia

Question 1

What is allodynia?

Answer 1

Pain from stimuli which are not normally painful. The pain may occur other than in the area stimulated.

Question 2

What is Multi-modal analgesia?

Answer 2

*Multi-modal analgesia = using drugs from
different drugs groups to provide analgesia,
targeting different parts of the pain pathway.

*Provides more effective analgesia than just
giving one large dose of one drug

*In using smaller doses of drugs, have less side
effects

Question 3

Which part of the pain pathway do NSAIDs modulate?

Answer 3

Transduction

Question 4

Which part of the pain pathway do local anaesthetics modulate?

Answer 4

*Transmission
*Block sodium channels, and
thus nerve conductions
*Only true analgesics

Question 5

Which part of the pain pathway do opiods, ketamine, alpha 2s, nitrous oxide modulate?

Answer 5

Modulation

Question 6

Which part of the pain pathway do opiods, ketamine, alpha 2s, modulate?

Answer 6

Perception.

Question 7

What are the side effects of opioids?

Answer 7

*Dysphoria
*Respiratory depression
*Bradycardia
*Nausea
*Sedation

Question 8

What are the side effects of NSAIDs?

Answer 8

*Renal dysfunction
*Gastro-intestinal disturbances
*Clotting dysfunctions

Question 9

What are the side effects of alpha 2s?

Answer 9

*Bradydysrrythmias
*Respiratory depression
*Vasoconstriction
*Sedation
*Nausea

Question 10

What are the side effects of ketamine?

Answer 10

*Hallucinatory effects
*Increased heart rate and blood pressure
*Respiratory depression

Question 11

What are the side effects of local anaesthetics?

Answer 11

*Cardiotoxicity
*Neurotoxicity

Question 12

What are the side effects of nitrous oxide?

Answer 12

*>66% inspired fraction will decrease amount
of available oxygen to the patient
*Problems associated with use of nitrous oxide and air filled spaces will occur more quickly if higher percentages are used

Question 13

What should you try and use during an anaesthetic?

Answer 13

Try and incorporate at least three drug
groups
*Opioid in premed
*NSAID/paracetamol if appropriate
*Local anaesthetic techniques
*+/- Nitrous oxide
*+/- ketamine
*+/- alpha 2 adrenergic agonists

Question 14

What are the benefits of pre-emptive analgesia?

Answer 14

*Analgesic agents are acting before nociceptive input starts.
*Helps to prevent peripheral and central
sensitisation.
*Should prevent phenomena such as
‘hyperalgesia’ and ‘allodynia’.
*Should make the analgesia more effective and
so should reduce analgesia requirements in post operative period.

Question 15

What analgesia should animals go home with post dental?

Answer 15

*NSAIDs
*Paracetamol (in dogs)
*Buprenorphine SL (in cats)1
*Tramadol?
*Gabapentin or amantadine if chronic pain suspected

Question 16

What are the disadvantages of anaesthesia-free dentistry?

Answer 16

*Patient stress and pain
*Injury to patient, staff and equipment
*Risk of aspiration
*Lack of diagnostic capabilities
*Only cleans the visible surfaces of the teeth and therefore lulls the owners into a false sense of security

Question 17

What are the percentage risks of anaesthesia?

Answer 17

– Dogs [overall] 0.17% [ASA I-II] 0.05% [ASA III-VI] 1.33%

– Cats [overall] 0.24% [ASA I-II] 0.11% [ASA III-VI] 1.4%

Question 18

What should be involved in a pre-anaesthetic examination?

Answer 18

*Mucous membrane
colour, moistness and
CRT
*Hydration status
*Pulse quality and rate
*Auscultation of all four
heart valves, noting
grade and PMI of any
murmurs.
*Auscultation of the lung fields
*If any irregular rhythm
is auscultated,
concurrent pulse
palpation should be
performed to identify
any pulse deficits.
*Observation of
respiratory rate and
pattern
*Rectal temperature
taking?

Question 19

What clinical history do you need before an anaesthetic?

Answer 19

*Co-morbidities
*Current medication
*Previous anaesthetics
*Exercise tolerance
*Eating/drinking ok
*Coughing/sneezing
*Vomiting/diarrhoea
*Signs of pre-existing pain

Question 20

What is the triad of analgesia?

Answer 20

Unconsciousness
Relaxing
Analgesia

Question 21

What are the best type of endotracheal cuffs?

Answer 21

Square profile, high volume low
pressure cuffs

Question 22

How much should you inflate a cuff for a cat?

Answer 22

In cats, 1.6 +/- 0.7ml is needed to inflate cuff appropriately.
In cadaver cats, 6ml cuff inflation caused tracheal ruptures in 7/10 cats.

Question 23

How can you recognise tracheal ruptures?

Answer 23

Immediate signs
– Pneumomediastinum
– Subcutaneous
emphysema
– Pneumothorax
– Pneumopericardium
– Decompensation during GA

Later signs
*Dyspnoea
*Coughing
*Gagging
*Anorexia
*Stridor
*Lethargy

Question 24

What can be used to for suction during anaesthesia?

Answer 24

*May be used at induction, during anaesthesia
and just before extubation
*Yankauer suction tip
*Urinary catheter

Question 25

How can volatile agent pollution be countered/reduced?

Answer 25

*Use cuffed endotracheal tubes
*Do not switch on vaporiser until cuff inflated
*Consider TIVA or PIVA
*Ensure high rates of ventilation in work space
*Use low fresh gas flow rates
*At end of procedure, keep patient attached to breathing system until most volatile agent has been exhaled