Monitoring Flashcards
How to establish depth of anaesthesia
- jaw tone
– want it loose - palpebral reflex
- eye position
What does a central eye with a dilated pupil for an anaesthetised (otherwise normal) animal indicate?
- too much CNS depression
- the pt is too deep
What does a central eye with a normal or constricted pupil for an anaesthetised (otherwise normal) animal indicate?
- potentially too light for surgery
Why is checkin eyes an unreliable indicator of depth of anaesthesia with ketamine?
- ket increases muscle tone
- eyes tend to rotate the way they do during anaesthesia bc of muscle relaxation
- therefore, with ket the eyes don’t move as they would with other drugs
Which breeds often maintain jaw tone during anaesthesia?
- brachycephalics
What problems can peri-operative hypothermia cause?
- slow recoveries
- post-op wound infections
Monitoring the CV system - what can you monitor?
- HR and rhythm
- mm colour and CRT
- bleeding from surgical site
- bp
- haemoglobin oxygen saturation
- arrhythmias
Normal heart rate range for dog or cat under GA
- 60-120bpm
What must you do to assess the CV system in conjunction to listening to the heart with a stethoscope?
- palpate the pulses at the same time
What colour mm and CRT indicate vasodilation? Examples of causes of this
- usually v pink or red with rapid CRT
- sepsis
- anaesthetic drugs e.g. anaphylaxis
- low MAP
What colour mm and CRT indicate vasoconstriction? Examples of causes of this
- usually v pale with slow CRT
- anaemia
- inadequate blood flow
- alpha-2 agonists
What should healthy gums be?
- pink & moist
What do dry or tacky mm indicate?
- dehydration
- hypovolaemia
What do wet mm indicate?
- over infusion
- nausea
What is cyanosis?
- bluish/purplish discolouration of the skin or mm due to tissues near the skin surface having low oxygen saturation
What does cyanosis indicate?
- severe hypoxaemia
Normal bp ranges for healthy non-anaesthetised animals
- systolic: 100-160mmHg
- diastolic: 80-120mmHg
- mean: 60-100mmHg
What MAP (& systolic) is needed to properly perfuse the heart, brain and kidneys?
- MAP of 60mmHg
- systolic >90mmHg
What can MAP <60mmHg for over 30 mins lead to?
- renal failure
- delayed recovery
- neuromuscular complications
- decreased hepatic metabolism of drugs
- CNS abnormalities such as blindness
What is SpO2?
- % of haemoglobin that is saturated with oxygen
What should the SpO2 of a healthy pt be?
- > 95%
ECG pad/lead placement
- red: cranial right region / axilla
- yellow: left axilla
- green: back left
Monitoring the respiratory system - what can you monitor?
- rr, rhythm & effort
- adequacy of respiration (EtCO2 [end tidal carbon dioxide])
- blood gases (O2 & CO2)
What does capnography tell us?
- tissue metabolism (CO2 metabolism)
- perfusion (blood flow carrying CO2 from tissue via the heart to the pulmonary capillaries)
- ventilation (carrying CO2 from alveoli in exhaled breath)
Normal EtCO2 ranges for dogs and cats
- 35-45mmHg
- cats often a bit lower: ~28-45mmHg
Will hypothermia lead to an increase or decrease in CO2 production?
- increase
Will hyperthermia lead to an increase or decrease in CO2 production?
- decrease
