Pre-Anaesthetic Assessment

Question 1

Why should patients be fasted prior to surgery?

Answer 1

• reduces risk of vomiting
• reduces the risk of aspiration pneumonia
• reduces pressure on diaphragm (that a full stomach would cause) and allows easier breathing and full expansion of lungs

Question 2

Should all animals be fasted for surgery?

Answer 2

No- dependant on species!
Juvenile animals should have a shorter fast
Animals that can’t vomit e.g. rabbits don’t require fasting but food should cleared from oropharynx

Question 3

What 6 things need to be done prior to inducing anaesthesia in a patient?

Answer 3

1. Fasting
2. Thorough assessment - Patient History, pre-GA bloods, physical exam, weigh
3. Select relevant diagnostic procedures
4. Select anaesthetic protocol
5. Other pre-GA procedures recommended by VS e.g. IV catheterisation
6. Preparation of anaesthetic equipment, drugs and surgical equipment

Question 4

Give examples of Class 1 ASA risk patients

Answer 4

Normal healthy animal with no underlying disease 
E.g.
- Castration
-Declaw
- Radiography
- OVH

Question 5

Give examples of Class 2 ASA risk patients

Answer 5

Animals with slight/mild systemic disturbances, able to compensate, no clinical signs of disease.
E.g.
- Neonate or Geriatric animal (because of diminished/underdeveloped kidney/liver function)
- Obese
- Fracture without shock
- Mild diabetes (stable)
- Heart murmur but no clinical signs

Question 6

Give examples of Class 3 ASA risk patients

Answer 6

Animals with severe systemic disease who is not compensating fully.
E.g. 
- anaemia
- anorexia
- moderate dehydration
- low grade heart or kidney disease

Question 7

Give examples of Class 4 ASA risk patients

Answer 7

Animals with pre-existing systemic disease of a severe nature that is a threat to life.
E.g.
- severe dehydration 
- shock
- anaemia
- toxaemia
- uncompensated heart disease

Question 8

Give examples of Class 5 ASA risk patients

Answer 8

Patients not expected to survive for more than 24 hours, moribund patients, surgery is performed in desperation to save life.
E.g.
- Advanced heart, liver, kidney or endocrine disease
- Shock
- Major trauma
- GDV potentially

Question 9

What is informed consent?

Answer 9

The owner must:

• have a clear understanding of what the procedure involves
• know the risks associated with both the anaesthesia and the surgery
• have had the opportunity to ask questions
• have had the opportunity to consider other treatment options
• have been told estimated associated fees

Question 10

When should informed consent be gained?

Answer 10

Ideally at least 1 day before the surgery is due to take place, but this may not always be possible in emergencies! Has to be obtained before the procedure though.

Question 11

What information should be included on a consent form?

Answer 11

• Name, address & telephone number of practice
• Name & address of owner
• Multiple contact telephone numbers and an emergency contact number check it works!
• Pet details - name, breed, age, sex, markings, neuter status, weight, chip number)
• Any relevant history e.g. drug reactions, anaesthetic history, pre-existing conditions
• Details of the procedure being carried out (WORDED in a way that the owner can easily understand - no shorthand)
• Estimate of cost
• Owner/authorised person’s signature (>18yrs)
• Should provide owner a copy
• Informed consent is required whenever animal is under the care of the VS

Question 12

What does a haematology test involve and what can each of these tell us?

Answer 12

1. PCV - low indicates anaemia, high indicates dehydration. Can indicate blood loss.
2. RBC count and morphology - Tells us the type of anaemia and whether animal is dehydrated.
3. WBC count - can indicate infection, inflammatory disease, leukaemia, neoplasia etc.

Question 13

What does a Biochemistry test involve what can each of these tell us?

Answer 13

1. TP - increase indicates dehydration, haemorrhage. Decrease can indicate liver failure, chronic intestinal losses and malabsorption, renal losses
2. Glucose - can indicate diabetes, insulinoma (if very low), prolonged anorexia, can indicate that patient hasn’t been fasted if high, or stress.
3. ALT/ALKP - indicates liver function , can indicate endocrine diseases
4. Urea/Creat/Phosp - kidney function, heart failure, urinary obstruction, dehydration, liver disease or shunt
5. Electrolytes - due to direct imbalances, metabolic disturbances, addisons disease, severe vomiting or diarrhoea

Question 14

What would urinalysis tell us?

Answer 14

If there’s any infection, Diabetes M, Crystalluria, urinary tract trauma or neoplasia, indicates renal function

Question 15

What does an ECG tell us?

Answer 15

If there are any arrhythmias

Question 16

What does blood gas analysis tell us?

Answer 16

If there are any diseases affecting the lungs, and how the lungs and kidneys are interacting to maintain normal pH

Question 17

Where are the respiratory control centres located?

Answer 17

Pons and Medulla Oblongata

Question 18

If RR decreases, what happens to the pH of the blood?

Answer 18

Build up of CO2 causes a decrease in blood pH

Question 19

Define Tidal Volume and what its estimated value

Answer 19

The total amount of gas passing into or out of the lungs in one breath.
Estimated at approx. 10-15mls/kg

Question 20

What is dead space? What types of dead space are there?

Answer 20

Gas passing down the respiratory tract that does not participate in actual gas exchange.
Anatomical dead space, mechanical dead space, alveolar dead space.

Question 21

If a patient is becoming hypoxic what is the first thing you should check?

Answer 21

The O2 cylinder!