Monitoring In Veterinary Anaesthesia

Question 1

What is the main aim of monitoring in veterinary anaesthesia?

Answer 1

• Maintain an adequate anaesthesia depth
• Assess the adequacy of analgesia
• Maintain the function of different body systems
• Identify changes/ issues
• Evaluate treatment response

Question 2

How often should you record vital signs on the anaesthetic record?

Answer 2

at least once every 5 minutes

It is used as a source of info for future anaesthetics

Question 3

How would you monitor the central nervous system during anaesthetic?

Answer 3

• Eye position and Movement
• Jaw tone
• Vagal tone
• Anal tone
• Pedal reflex
• Righting reflex

Question 4

What is the purpose of monitoring the central nervous system?

Answer 4

To ensure an adequate anaesthetic level

Question 5

What plane are you aiming for during anaesthesia?

Answer 5

Stage III, plane 2

Question 6

What does the light anaesthetic plane look like?

Answer 6

• Eyes in central position
• Palpebral reflex
• Mild/ Strong Jaw Tone
• Possible Movements

Question 7

What does the surgical plane look like?

Answer 7

• Eyes are rotated in the ventromedial position
• Palpebral reflex to no palpebral reflex
• Relaxed jaw tone

Question 8

What does the deep plane look like?

Answer 8

• Eyes in the Central position
• No palpebral reflex
• No jaw tone
• No Movement
• RR and HR usually decrease

Question 9

What three things do you observe when monitoring the respiratory system?

Answer 9

• Chest Movements
• Reservoir Bag Movements
• RR on monitor

Question 10

What does a change in respiratory rate and pattern usually indicate?

Answer 10

Change in the depth of anaesthesia

Question 11

What is Capnometry?

Answer 11

• Breath by Breath analysis of expired Co2
• Respiratory Rate
• FiCo2

Question 12

What is FiCo2?

Answer 12

The Inspired Co2 Levels

should be zero

Question 13

What is capnography?

Answer 13

Graphical representation of Capnometry through the respiratory cycle

Question 14

What are the normal mercury levels in capnography?

Answer 14

35-45mmHg

Question 15

What is Hypocapnia?

Answer 15

Mercury levels below 35mmHg

Question 16

What is hypercapnia?

Answer 16

Mercury levels above 45mmHg

Question 17

What are the benefits of Capnography?

Answer 17

• Non-Invasive, Continuous
• Early issue detection

Question 18

What does capnography estimate?

Answer 18

• Arterial Co2
• Ventilation/ Perfusion missmatch

Question 19

What does the alveolar dead space in capnography show?

Answer 19

Alveoli that are poorly perfused, this is larger in large animals

shows that there is more Co2 in the airways

Question 20

What three things does capnometry give us information on?

Answer 20

• Metabolism
• Cardiac Output
• Alveolar Ventilation
• Anaesthetic Equipment
• Respiratory Rhythm

Question 21

What is sidestream Capnography?

Answer 21

• Continuous gas aspiration
• Sample is carried away and analysed

Question 22

What is mainstream capnography?

Answer 22

Directly connected, has no delay
Heavy
Can burning

Not usually used

Question 23

What is the function of pulse-oximetry?

Answer 23

• Measures the degree of saturation of haemoglobin
• Calculates the amount of Oxy-Hb as a % of a total Hb

Question 24

What is the normal range of haemoglobin in Pulse-Oximetry?

Answer 24

Normal range is 98%- 100%

Question 25

What are the benefits of Pulse-Oximetry?

Answer 25

• Easy to use
• Non-Invasive
• Continuous measurements
• Detects hypoxaemia earlier than the human eye

Question 26

Where can Pulse-Oximetry be positioned?

Answer 26

tongue, ears, prepuce, vulva, lips, toe web, skin flap…

Question 27

How does Pulse-Oximetry Work?

Answer 27

• PULSE PLETHYSMOGRAPHY to detect pulse waveform
• INFRARED SPECTROSCOPY to detect absorption of light (red & infrared) by tissue under probe

Question 28

What does a plethysmograph give additional information on?

Answer 28

Additional info on: * Vascular tone
* Perfusion
* Fluid responsiveness * Pulse deficits/variation during arrhythmias

Question 29

What three leads do you use in an ECG?

Answer 29

Both arms and left leg
* Paws, axilla, inguinal region, ears

Question 30

What is the most common ECG lead for monitoring?

Answer 30

Lead II (Right Shoulder to left leg)

Question 31

What is the equation for blood pressure?

Answer 31

Force of blood flow/ Area (of the arterial wall)

Question 32

Name three reasons why we care about Mean Arterial Pressure?

Answer 32

• Indirect indicator of Tissue perfusion
• Anaesthetic drugs depress autoregulatory mechanisms
• Start treatment if MAP< 70 mmHg & SAP <90 mmHg

Question 33

How do you measure arterial blood pressure (non-invasive)

Answer 33

• Oscillometric devices
• HDO device
• Doppler

Question 34

How do you measure arterial blood pressure (invasive)

gold standard

Answer 34

• Arterial Cannula placement
• Different locations in different species
• Accurate, reliable, beat to beat monitoring
• Can be challenging
• Signs of asepsis

Question 35

Where should a BP cuff be placed?

Answer 35

distal limb or tail, cuff as close as possible to the level of the right atrium

Question 36

What should the width of the BP cuff be?

Answer 36

30-40% of the circumference of anatomical location where the cuff is applied

Question 37

What is the effect of making the BP cuff too big?

Answer 37

underestimation

Question 38

What is the effect of making the BP cuff too small?

Answer 38

Over estimation