Flashcards in Lectures Deck (39)
What ASA physical status score would you give to a normal healthy patient?
ASA physical status 1
What ASA physical status score would you give to a patient with mild systemic disease?
ASA physical status 2
What ASA physical status score would you give to a patient with severe systemic disease?
ASA physical status 3
What ASA physical status score would you give to a patient with severe systemic disease that
is a constant threat to life?
ASA physical status 4
What ASA physical status score would you give to a moribund patient who is not expected to
survive without the operation?
ASA physical status 5
What are the 5 phases of anaesthetising a patient?
1. Preanaesthetic assessment and preparation
Why is preanaesthetic fasting important?
Reduces the risk of vomiting/regurgitation with subsequent aspiration or reflux oesophagitis.
It also reduces the weight of the GIT, reducing respiratory stress in dorsal recumbency.
What is usually kept in an induction tray?
ET tube, Dry swab, Eye lube, Tie, Laryngoscope,Tape for Doppler, Heparinized saline, Premed and induction
Tidal volume is...
The volume of one expired breath
Minute volume is...
The volume of expired gas over one minute
Does a rebreathing or non-rebreathing system have a higher circuit resistance?
Rebreathing - due to one way valves and CO2 absorbent canister
What is the significance of 'dead space' in anaesthetics?
Will cause rebreathing of exhaled CO2 - may lead to excess CO2 (acidosis and dilution of 02 and anaesthetic)
How to prevent CO2 rebreathing?
Minimise dead space, high fresh gas flow, CO2 absorbent, one way valves.
Circuit resistance is affected by...
Diameter of tubes, one way valves, CO2 absorber unit, turbulent flow
Why is high fresh gas flow important in a non-rebreathing circuit?
To reduce CO2 rebreathing and continue to supply oxygen and anaesthetic to the patient
How much fresh gas flow is required in a non-rebreathing system to prevent rebreathing?
2-3x MV - usually about 300-500ml/kg/min
What are examples of non-rebreathing circuits?
Bain and T-piece
What is the typical fresh gas flow rate of a rebreathing system?
Why can't you use a rebreathing system in small patients?
They cannot cope with the high circuit resistance
What are the benefits of a rebreathing system?
Lower fresh gas flow rate needed, recycling of lefterover anaesthetic and O2 (less wastage), CO2 absorbent and one way valve avoid rebreathing
What are the risks of a closed system?
Hypercapnea, barotrauma, slow change in anaesthesia concentration, CO2/anaesthesia compound accumulation
In what weight range would you use a non-rebreathing system?
Name some hepatotoxic drugs
Halothane, Carprofen, oral diazapam in cats
How can you monitor arterial blood pressure?
Doppler, oscillometric, direct arterial catheterisation
What are the benefits of fluid therapy?
Volume replacement, maintenance requirements, acid base balance, electrolyte balance, colloid replacement, improved oxygen carrying capacity
What is a dog's blood volume?
8% of its body weight
What is a cat's blood volume?
6% of its body weight
What is the average fluid requirement for an anaesthetised animal?
How would you treat vagally mediated bradycardia?
Give anticholinergics (atropine/glycopyrrrolate)
What drugs can you give to improve contractility?
Positive ionotropes - Beta1 adrenergic receptor agonists (dopamine, dobutamine, ephedrine)
The class of drugs that block parasympathetic stimulation by inhibition of acetylcholine at muscarinic receptors is...
What can be used to reverse benzodiazepines?
What is naloxone used for?
In what dog breed should you avoid the use of thiopentone?
Sighthounds - lack enzyme necessary to metabolise (prolonged and rough recovery)
What is the MAC of Halothane?
What is the MAC of isoflurane?
What is the MAC of sevoflurane?
What is the MAC of Nitrous oxide?