Monitoring

Question 1

Why do we monitor anaesthesia?

Answer 1

Prevent patient nociception to surgical stimulation
To detect abnormalities before they become complications
Maintain tissue perfusion and oxygenation to improve patient outcome and prevent worsening of disease

Question 2

What do these symbols represent on an anaesthesia chart?

Answer 2

Question 3

What are the causes of decreased tissue perfusion during anaesthesia?

Answer 3

Decreased blood flow:
- Decreased BP
- Decreased HR
- Haemorrhaging
-Anaemia
Decreased oxygen and nutrients:
- Decreased RR
- Equipment failure
- Decreased HR
- Lung pathologies
- Obesity

Question 4

What 3 problems always occur (to a certain extent) in anaesthesia?

Answer 4

Hypotension
hypothermia
Hypoventilatino

Question 5

How can depth of anaesthesia be determined?

Answer 5

Checking jaw tone (solid - light anaesthesia) (brachy breeds often maintain jaw tone)
Positive palpebral reflex = too light
Eye position (rostrally rotated eye = ideal)
capnography
HR
RR
BP

Question 6

When can eye position not be used to assess depth of anaesthesia?

Answer 6

Ketamine use increases muscle tone so eyes may not rotate

Question 7

Assess the depth of anaesthesia in this eye

Answer 7

Central eye:
- dilated pupils = too much CNS depression
OR
normal or constricted pupils = potentially too light for surgery

Question 8

What methods are there to check temp in surgery?

Answer 8

Rectal thermometer
Oesophageal temperature probe

Question 9

How can cardiovascular system be assessed during surgery?

Answer 9

Heart rate and rhythm
mm colour
CRT
bleeding
BP
haemoglobin oxygen saturation
arrythmias.

Question 10

What equipment can be used to monitor the cardiovascular system during surgery?

Answer 10

Bp monitors
pulse oximeters
ECG
Stethoscopes
Oesophageal stethoscope
Feeling a pulse to detect deficits

Question 11

What are the different sites of pulse palpations?

Answer 11

Sublingual (ventral aspect of the tongue)
Mandibular
Digital metacarpal
Digital metatarsal
Dorsal pedal (usually palpable over the dorsum of the metatarsal area)
Femoral (medial aspect of the femur)
Coccygeal artery on the ventral surface of the tail

Question 12

What does bluish/purple MM mean?

Answer 12

cyanosis - low O2 saturation, severe hypoxaemia

Question 13

What methods of measuring blood pressure can be used during surgery?

Answer 13

Doppler
Oscillometric

Question 14

What MAP (mean arterial pressure) is needed to properly perfuse the heart, brain and kidneys?

Answer 14

60mmHg (systolic >90mmHg)

Question 15

An MAP of <60mmHg for over 30 mins can lead to:

Answer 15

Renal failure.
Delayed recovery
Neuromuscular complications
Decreased hepatic metabolism of drugs
CNS abnormalities such as blindness.

Question 16

What does pulse oximetry tell us?

Answer 16

Sp02 =% of haemoglobin that is saturated with oxygen (healthy patient should be >95%)
Detects hypoxaemia
Measures pulse rate
Displays a photoplethysmographic (PPG) waveform (“pleth” for short)

Question 17

What the possible places a pulse oximetry probe can be placed?

Answer 17

Tongue
Nose
Lip
Pinna
Toe web
Flank
Tail
Achilles tendon
Rectum
Vulva
Penis

Question 18

What are the benefits of pulse oximetry?

Answer 18

Inexpensive.
Non invasive
Well tolerated
Continuous
Automatic
Portable
Audible
User friendly

Question 19

What are the limitations of pulse oximetry?

Answer 19

Can give inaccurate readings with:
-Vasoconstriction (alpha 2 agonists, hypothermia, shock)
- Hypoperfusion
- Movement
- Hypothermia
- Bright overhead lights
- Smoke inhalation (abnormal haemoglobin)
- Pigmented skin
- Anaemia
- Shock.

Question 20

Why is it important to use a pulse oximeter with blood pressure monitoring?

Answer 20

A patient may not be hypoxaemic (pulse ox reading less < 95%) but may be hypoxic

Question 21

How can the respiratory system be monitored?

Answer 21

Respiratory rate, rhythm and effort:
- lungs sounds
- visibly breathing
- capnographs

Question 22

What equipment can be used to monitor the respiratory system?

Answer 22

Assess adequacy of respiration (EtC02 (end tidal carbon dioxide))
Check or estimate blood gases (O2
and CO2)

Question 23

What can capnographs be used for in assessing respiratory function?

Answer 23

Monitoring of ventilation in spontaneously breathing anaesthetised patients
Monitoring of patients undergoing mechanical or manual ventilation
Monitoring of patients undergoing CPR
Monitoring of ventilation in intubated coma patients
Confirmation of endotracheal tube placement
Confirmation of naso-oesophageal feeding tube placement

Question 24

What are the 3 levels of info do we get from capnographs?

Answer 24

Metabolism
Perfusion
Ventilation
Level 1:
- Breathing or not
- Respiratory rate.
Level 2:
- Expired and inspired CO2 levels.
- understand the state of the patient’s respiration i.e. normocapnic, hypocapnic or hypercapnic.
Level 3:
- Waveform profile

Question 25

What are the normal EtCO2 ranges for cats and dogs?

Answer 25

Dogs - 35-45 mmHg
Cats - 28-45mmHg

Question 26

What is the main cause of hypocapnia?

Answer 26

Hyperventilation => CO2 is exhaled faster than it is produced

Question 27

What is the main cause of hypercapnia?

Answer 27

Hypoventilaion => CO2 being exhaled slower than it is being produced

Question 28

What is EtCO2?

Answer 28

end tidal CO2

Question 29

Label the diagram

Answer 29

Question 30

What can blood gas analysis measure?

Answer 30

PaCO2 (partial pressure of carbon dioxide in the blood)
PaO2 (partial pressure of oxygen in the blood)
Blood pH
Electrolytes
Lactate
Others

Question 31

Label this diagram

Answer 31

Question 32

Label this diagram

Answer 32

BP readings - oscillometric

Question 33

Label this diagram

Answer 33

Temp