Monitoring the anaesthetised patient

Question 1

What should be recorded during anaesthesia?

Answer 1

patient’s signalemnt
drugs administered
fluid therapy
parameters every 5-10 minutes (LEGAL MAX)
important events
complications
vital parameteres of the animal in recovery)

Question 2

Why do we monitor our patients?

Answer 2

to maintain body as cloas as possible to physiological normality
to maintain adequate depth of anaesthesia
to promote patient and personnel safety
legal requirement

Question 3

How do we monitor?

Answer 3

listen for: ventilation sounds, alarms, gas leaks
look at: eye position, chest movements, mucous membrane colour
feel: pulse quality, rate and rhythm, jaw tone, reflexes
smell: volatile agent (leak or disconnection)

Question 4

How can we monitor the CNS/depth of anaesthesia?

Answer 4

assessment of reflexes
eye position, movement of globe, lacrimation, pupil size
Electroencephalography EEG
Bispectral index BIS

Question 5

What are the factors determining tissue perfusion and oxygen delivery?

Answer 5

cardiac output
stroke volume (blood volume, vasc. resistance)
heart rate (nerves, hormones)

Question 6

What do we monitor for arterial blood pressure?

Answer 6

MAP
CO
Systemic vascular resistance

Question 7

When is systolic arterial pressure considered hypertensive?

Answer 7

over 160 mmHg

Question 8

When is the arterial blood pressure considered hypotensive?

Answer 8

systolic arterial pressure under 90
mean art pressure under 60 (70 for horses)
diastolic art press under 40

Question 9

What do we use to quickly check arteriall blood pressure?

Answer 9

feel HR and pulse quality

Question 10

What are non invasive and invasive ways to monitor arterial bp?

Answer 10

noninvasive: oscillometry, doppler
invasive: direct arterial bp

Question 11

What do we know about oscillometry?

Answer 11

accuracy depends on cuff
cuff leveled with heart
gives sap, map, dap
tendency of under estimation

Question 12

What do we know about doppler?

Answer 12

accuracy depends on cuff, leveled with heart
only gives SAP
in cats value is between SAP and MAP

Question 13

What do we know about IBP?

Answer 13

gold standard
arterial catheter
transducer at lvel of heart

Question 14

How do we troubleshoot low BP during anaesthesia?

Answer 14

asses depth of anaesthesia and REDUCE if possible
IV fluid therapy
vasopressors (positive inotropes, vasoconstrictors)

Question 15

What should we avoid during hypotension in anaesthesia?

Answer 15

NSAIDs

Question 16

What do we observe to monitor the resp system?

Answer 16

breathing rate
breathing rhythm
tidal volume/ depth of each breath
mucous membrane

Question 17

What is the equation for minute volume?

Answer 17

MV= TV x RR

Question 18

What does white mm indicate?

Answer 18

anaemia, intense vasoconstriction

Question 19

What does yellow mm indicate?

Answer 19

jaundice, carotens

Question 20

What does grey/purple/cyanotic mm indicate?

Answer 20

poor tissue oxygen delivery

Question 21

What does navy blue mm indicate?

Answer 21

excess of nitrous oxide (severe cyanosis)

Question 22

What does cherry red mm indicate?

Answer 22

carbon monoxide poisoning

Question 23

What does mudy brown mm indicate?

Answer 23

metaHb (nitrite, paracetamol poisoning)

Question 24

What does brick red/brown mm indicate?

Answer 24

systemic inflammation response, sepsis

Question 25

What does capnography tell us?

Answer 25

measures how well animal is ventilating
normal is 35-45mmhg, 4.5-6kPA

Question 26

What are the 4 phases of a normal capnogram?

Answer 26

1: insp. baseline, later part of inspiration
2. exp. upstroke, emptying of connecting airways and beginning of emptying alveoli
3. alveolar plateau
4. insp downstroke

Question 27

What does an increase in EtCO2 mean?

Answer 27

increase CO2 = hypercapnia

Question 28

What can cause hypercapnia?

Answer 28

alveolar hypoventilation
increased CO
hyperthermia
bicarb administration

Question 29

What does a decrease in EtCO2 mean?

Answer 29

decreased CO2 = hypocapnia

Question 30

What causes hypocapnia?

Answer 30

decreased CO (shock, cardiac arrest)
hypothermia
hyperventilation/panting
pulmonary thromboembolism

Question 31

What is spirometry?

Answer 31

assesses ventilation
connects to ET tuve, non invasive

Question 32

What can we observe to monitor the oxygenation of a ptx?

Answer 32

mucous membrane

Question 33

What devices can give us oxygenation status?

Answer 33

pulse oximetry: measure at level of arterioles
arterial blood gas analysis: invasive, intermittent results

Question 34

What does pulse oximetry measure?

Answer 34

oxyhaemoglobin as a percentage of the total haemoglobin in the arterial blood

measurement of saturation enables estimation of oxygen content and oxygen delivery to tissues

Question 35

What is a normal SpO2?

Answer 35

95-100%

Question 36

What to do if SpO2 is less than 95%?

Answer 36

1. check probe position
2. check oxygen supply and FiO2
3. check perfusion
4. hypoxemia

Question 37

If perfusion is cause of low SpO2 what do we do?

Answer 37

check BP
administer alpha 2 agonist

Question 38

If hypoxemia is cause of low SpO2 what are the potential causes?

Answer 38

R-to-L shunting
ventilation/perfusion mismatch
impaired diffusion
hypoventilation

Question 39

How do we monitor temperature during anaesthesia?

Answer 39

skin temp is unreliable
core temp through oesophagus or rectum

Question 40

What patients are at risk of hypothermia?

Answer 40

smaller ptx
due to increased surface area to body mass ratio