Support and Monitoring the Anaesthetised Patient Flashcards
Not 6 things which should be recorded in the monitoring record (legal document)?
- Fill in details before you start
- Record exact mg of drugs given
- Assess risk for patient
- Record as many parameters as possible
- Note events occurring
- Assess recovery and analgesia
What are the two reasons we support our patients?
- influence of outcome
2. ethical considerations - they are relying on us
Name 10 things we should be monitoring as part of basic anaesthesia monitoring?
- muscle relaxation
- neck muscle tone (especially horses)
- eye rotation
- pupil changes
- jaw tone (different for each patient)
- Whisker/ pedal reflex
- Anal tone (reliable in horses)
- Mucous membrane colour
- CRT
- Toe-web/ core temperature
Name 4 things you would monitor with pulmonary monitoring?
- breathing rate, rhythm, nature and effort
- observe bag and chest excursions
- ventilometer or respirometer if available
- mm colour
what can be used to show if ventilation is within acceptable limits?
Spirometry
What is the normal minute volume?
100-300mg/ml/kg
What is the normal tidal volume?
7-10ml/kg
What two methods are superior for assessing function of respiratory system?
Blood gas analysis and capnography
What is the dead space?
This is the amount of space that is not involved in the exchange of gases.
Delivery of oxygen means what?
How much oxygen is being delivered to the tissues by how much blood pressure
How do you work out CaO2?
SaO2 x Hb x 1.34 + (0.003 x PaO2)
Name 4 things that we can measure to get an idea of the delivery of oxygen?
- CaCo2
- MAP
- Respiratory
- Cardiovascular
3 methods to measure respiration?
- oesophageal stethoscope
- capnograph
- pulse oximeter
Name 3 methods to measure cardiovascular?
- ECG
- Blood pressure
- Pulse
What is Heffner’s constant?
It is 1.34 and is the number of molecules attached to haemoglobin.
Name 2 limitations to pulse oximetry?
- low heart rates/ extremely high heart rates- not picked up
- probe design.
What is a massive advantage of pulse oximetry?
Early warning - cyanosis is a crude estimation
What happens to the blood pH if there is less oxygen?
decreases
What should PaO2 at normal room saturation?
100
What can PaO2 go up to one 100% oxygen?
500
If the patient is going blue from cyanosis, what does this mean?
The patient is very de-saturated.
How does pulse oximetry work?
Probe (transmitter and reciever or IR and red light), transilluminates a pulsatile arteriolar bed.
computer analysis absorption of light.
What happens if the oxyhaemaglobin or haemaglobin are not carrying oxygen?
There is more red light and IR absorption.
What is methaemaglobin?
Cannot bind oxygen therefore more red light absorption.
What is the reading on a pulse oximeter telling us?
The ratio of haemaglobin and % oxygen saturation.
How is the haemoglobin saturation SPO2% (from pulse oximeter) related to the PaO2 of the blood?
Oxygen content is dependent on both PaO2 and SPO2.
Oxygen content = SPO2 x Hb x 1.34 + (0.003 x Pa03)
On an oxygen-haemaglobin dissociation curve, what does a shift to the right represent?
A decreased affinity for oxygen to bind to haemaglobin.
Name three factors which decrease an oxygen’s affinity for haemoglobin?
- decreased pH
- increased DPG (moves O2 from red blood cells to tissues)
- increased temp
Name three factors which will increase oxygen’s affinity for Hb?
- increased pH
- Decreased DHP
- Decreased temp
Name 4 things that blood gas analysis can monitor?
- pH
- HCo3
- PCo2
- Po2
Which is the most accurate device for measuring oxygen content and what is a good alternative?
Blood gas analysis is the most accurate, however capnograph is a good alternative (PaCo2)
Why is pulse oximetry, especially in anaemic patients?
Because, whilst the Hb content of 15g/dL and PCV 45%, cyanosis might start to manifest at about SaO285% with no other clinical signs.
HOWEVER in an anaemic patients, Hb 9g/dL and PCV of 27%, cyanosis might not manifest until about SaO2 73% therefore this is dangerous!
Need pulse oximetry to pick up desaturation early.
Which three stages will require supportive oxygenation?
- during ALL anaesthetics (even if just IV)
- pre-induction e.g. masks
- Recovery (high risk surgery)
Name three methods to increase Fraction of Inspired Oxygen (FIO%)?
- Intranasal
- Intratracheal (post-op horse)
- Tracheostomy (emergency)
Which sites should you use to monitor pulse rates?
Peripheral pulse - early warning.
Name 5 sites where you can monitor pulse rates?
- femoral artery
- dorsal metatarsal artery
- lingual artery
- Auricular
- compare the femoral and dorsal metatarsal
With hypotension, which pulse disappears?
Dorsal metatarsal
Which is not a good artery in terms of monitoring subtle changes?
Femoral, therefore good comparison.
Name two further arteries which can be monitored in a horse and dogs?
Facial artery in horses and lingual artery in dogs.