Anaesthetics - Conduct of Anaesthesia Flashcards
What Do Anaesthetists Do?
Pre-operative Assessment
Perioperative Medicine (caring for patients around time of operation)
Pain Medicine
Critical Care/Intensive Care Medicine
Anaesthesia
What is a General Anaesthetic?
Period of controlled unconsciousness
what are the different stages and phases?
(The actual anaesthetic has 4 main stages in bold)
Pre-operative assessment and planning (Begins well before arriving in the operating theatre)
Preparation (making sure everything is set up for patients arrival and everything is as safe and slick as possible)
Induction - when the patient goes to sleep
Maintenance - keeping the patient asleep
Emergence - process of waking up
Recovery - period after anaesthetic where the patient hasnt fully recovered from the anaesthetic yet
Post-operative Care
what needs to be done pre-operativley with the patient?
Not jus information gathering, also to give information and gain consent for any additional procedures like nerve blocks
Need to work hard to get people to trust us
what preparation is needed?
Right people (One of these people is an anaesthetist and the other is anaesthetic assistant who is usually a highly trained nurse or a operating department practitioner)
Right skills (Need a specialised anaesthetist for any specialised type of surgeries)
Right place
Right time (Important to know not to do elective procedures out of hours)
what do you need to do with this machine before hand? and what need to be done with the team?
Machine Checks and Brief
Series of monitors, ventilator and other things to keep patient comfortable and asleep
Lots of safety features
Team brief – whole team talks through a case and make sure of any issues that may come up
when you check in a patient, what information needs to be checked?
Correct patient
Correct procedure
Correct (and marked) site
Consent
Monitoring - Association of Anaesthetists minimum standard:
5 minimum standards of monitoring - Every anaesthetic must have these 5 things working before, what are they?
ECG (As arrhythmias are possible under anaesthesia) - 3 lead ECG, one each shoulder then on left side of the chest - green
Oxygen saturation - Finger for adult or toe on a child - blue line
Non-invasive blood pressure (As patients often drop BP under anaesthetic) - cuff on patients arm - bottom pink
End Tidal C02 (Amount of CO2 in the gas that the patient is breathing out and allows us to check things like the patency of the patients airway) - Small plastic tube attached to breathing circuit we use to give patient O2 - grey
Airway Pressure Monitoring (picture on front of card) - Graph at bottom is airway pressure – gives good info on how we are ventilating patient and patency of their airway
Monitoring Standard - Every anaesthetic must have these in place before it is commenced - what are they?
ECG
NIBP
Saturations
ETC02
Airway Pressure
Ture or false?
Blood pressure normally goes up under anaesthesia
False (often vasodilate patients)
Ture or false?
End tidal CO2 measures how much CO2 the patient breathes in
False (its how much the patient breathes out)
Ture or false?
There are 5 pieces of monitoring that must be present before a GA is given
True
what is pictured here that is often needed to give the anaesthetics?
Intravenous Access
Need good reliable IV access
Need a canula before the are anaesthetised
Pre-oxygenation:
100% oxygen for a couple minutes before they are anaesthetised
Why do we give supplemental oxygen?
Increase time to desaturation
Reduced Functional Residual Capacity under anaesthesia (total volume of lungs reduced as your muscles relax and reduced FRC means there is less oxygen for blood to take so less time before the patient begins to desaturate)
what s the first phase of anaesthesia?
induction
First phase of anaesthetic
Can be IV or inhalation
Inhalation often for small children who cant tolerate cannula being put in
IV is fast and inhalation slow
what drugs are used for induction?
Analgesic - Fentanyl, Alfentanil
Hypnotic - Propofol (most common, white sutff in picture), Thiopentone, Ketamine
Muscle Relaxant
Multi stage approach if IV
Get first 2 and sometimes a muscle relaxant to
Planes of Anaesthesia - is it an on/off switch?
no
whata re the Planes of Anaesthesia?
(Hard to see in IV as so quick but will see in inhalation)
1: Analgesia and amnesia
2: Delirium to unconsciousness
3: Surgical anaesthesia
4: Apnoea to death (want to avoid)
All patients under anaesthesia need some degree of airway management, why is this?
Loss of airway reflexes
Relaxation of tissues
Airway Management:
what type of airway management is shown?
tripple airway maneuver
Airway Management:
what type of airway management is shown?
Anaesthetic mask
Same mask as pre-oxygenation
many sizes
Airway Management:
what type of airway management is shown?
Oropharyngeal airway
“Guedel”
May sometimes use a oropharyngeal airway
Get a tongue that may of slipped backwards
Give a clear path of mouth to upper airway
Airway Management:
what type of airway management is shown?
Laryngeal Mask Airway (LMA)
Same as a mask over the face but sits on the larynx
Provides tight seal to direct gas flow towards patients airway
Airway Management:
what type of airway management is shown?
Endotracheal Tube (ETT)
More definitive airways management
Sits within the trachea
Cuffed tube, balloon at end protects patient airway form anything coming past the cuff
Inserted using laryngoscope
what are the reasons to intubate?
Protection from aspiration (patients who are unfasted)
Need for muscle relaxation
Shared airway (surgery of mouth or face)
Need for tight C02 control
Minimal access to patient
3 options for how the patient breaths during surgery, what are they?
Spontaneous ventilation (patient breathes themselves)
Controlled ventilation (we take over it completely)
Supported ventilation (mixture of the 2)
how are anaethatists involved in the patients circulation?
Control of haemodynamics (changes are common) - BP at least every 5 minutes
Vasoactive drugs (tighten up blood vessels to maintain blood pressure may be needed)
what are the risks of induction?
Anaphylaxis (to the agents we use)
Regurgitation and aspiration (that’s why we ask patient to be fasted for when they come for operations)
Airway obstruction and hypoxia
Laryngospasm (vocal cords constricting stopping gas getting into lungs)
Cardiovascular instability
Rarely, cardiac arrest
What Other Risks Are There?
what is the risk of Awareness?
1:8200-1:135900
One of the biggest concerns a patient will come with
Not common but there are things to increase patients risk
1 in 8200 is for those getting muscle relaxants and 1 in 135900 for those getting no muscle relaxant
Movement under anaesthesia is not a sign of awareness but things like tachycardia, high BP or sweaty (all these are called sign of lightness in anaesthetic)
use Depth of Anaesthesia Monitoring:
- Measure amount of anaesthetic agent being breathed in and out
- Can also use limited ECG/EMG??
- Depth of anaesthesia monitor is being applied to the patient head and this is a limited EMG called BIS
What Other Risks Are There?
what is the risk of Eye Injury?
1:1000
Patients don’t naturally close eyes during anaesthetic so can dry out and also cant protect eyes
Close eyes or place lubricating matter in the eyes
What Other Risks Are There?
what is the risk of Hypothermia?
1:25-1:2
Major concern
Vasodilation drops core temperature
More covered up the patient then less the risk
Use forced warm air blankets to keep patient warm
What Other Risks Are There?
what is the risk of a Pressure Injury?
1:5
Patients don’t move under analgesia
Pads at different areas
Be aware of where cables are
What Other Risks Are There?
what is the risk of VTE?
1:100-1:4
Risk varies Widley on what operation the patient is getting and on the patient factors
VTE Prophylaxis:
- Keeping patients active as long as before surgery
- TED stockings
- White things on patients calf’s are flowtrons which inflate and deflate to pump blood out of the patients legs
What Other Risks Are There?
what is the risk of Nerve Injury?
1:1000
Peripheral nerves can become damaged
Any nerve over a bony prominence are at particular risk, common ones are the ulnar and common perineal nerve
Also possible to injury brachial plexus through poor positioning and poor padding
Careful positioning and pressure point padding can help
What Other Risks Are There?
overall what are all the risks under anaesthesia?
Awareness (1:8200, 1:135900)
Eye Trauma (1:1000)
Hypothermia (~1:25-1:2)
Pressure injury (1:5)
Nerve injury (1:1000)
Thromboembolism (1:100-1:4)
how is maintenance done during surgery?
Vapour (“gas”)
Intravenous anaesthesia (TIVA)
What is the Anaesthetist Doing (during surgery)?
Vigilance
Constant adjustment (how much anaesthetic they are getting and hemodynamics and other factors)
Anticipation (blood loss/fluid shifts/major events)
Key moments in surgery
Analgesia (individualized plan for patient)
Anti-emesis (common after anaesthetic and surgery)
Documentation
Communication
Advocacy
what are the properties of Analgesia?
Long-acting
Multi-modal
Intravenous vs local vs regional
what are the features of Anti-emesis (drug that is effective against vomiting and nausea)?
Multi-modal (often use multiple agents)
Pharmacological vs non-pharmacological
Risk assessed
what documentation is required?
- Prescription record
- Observation chart
- Ventilation chart
- Fluid balance
(Anaesthetic chart seen in picture)
what are the risk of Emergence?
T(his is the next stage, Process of waking up)
All same risks of “going to sleep”
what is done in Emergence?
Theatre “sign out”
Reversal of neuromuscular blockade
Anaesthetic agent stopped
Return of spontaneous breathing
Return of airway reflexes (start to see them swallowing or coughing)
Suctioning and removal of airway device
Transfer to recovery room
May be delirious on emergence
what is involved in the recovery of a patient?
Specific area
Dedicated, highly trained staff
Manage ABC until “awake”
Initial post-operative analgesia
Management of nausea
Handover to ward
Summary:
Phases of anaesthesia (_______________________________)
Care of the unconscious patient (__________)
Induction, maintenance, emergence, recovery
Risks, skills
