Anaesthetics - conduct of anaesthesia Flashcards
- Describe the basic phases of general anaesthesia (eg, induction, maintenance and recovery).
- Discuss the priorities involved in and the skills required for the care of the unconscious patient.
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What are the basic phases of general anaesthesia (7)
Pre-operative Assessment Preparation Induction Maintenance Emergence Recovery Post-operative Care and Pain Management
What are the 4 factors to consider in the induction phase of anaesthesia
Quietness
Gas or IV Agent
Careful monitoring of conscious level
Airway maintenance
For quietness, where is GA usually induced
Mostly in theatre now, may still do it in separate anaesthetic room
GA is administered either by … or … agent
Gas or IV
Examples of IV GA agents
Propofol - COMMONEST
Thiopentone
How long do IV GA agents usually take to have an effect
Rapid - one ‘arm-brain’ circulation time (~20s)
What resp condition is common when you’re under IV GA
Apnoea
Example of gas GA agent
Sevoflurane
How long do gas GA agents usually take to have an effect compared to IV agents
Slower
Gas GA agents are more used in what group of people
Children
Gas agents have more obvious ‘planes’ of anaesthesia than IV agents - what does this mean
Means that there’s more identifiable stages the patient is progressing through
What are the planes of anaesthesia
Analgesia/sedation
Excitation
Anaesthesia - light –> deep
Overdose
What happens to reflexes as anaesthesia progresses from light –> deep
Heightened during light stage then supressed
During the induction phase, conscious level also has to be monitored - what ways can this be done?
Loss of verbal contact
Any movement
Respiratory pattern
EEG
What “plane” of anaesthesia they’re in
Airway has to be maintained during the induction of GA - what are the ways this can be done?
Triple airway manœuvre - head tilt + chin lift + jaw thrust
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Simple apparatus -face mask -oropharyngeal airway - common -nasopharyngeal airway - less common OR Advanced apparatus -laryngeal mask airway -(endotracheal) intubation
Oropharyngeal airways can only be tolerated when
unconscious
A laryngeal mask airway (supraglottic airway) is a more advanced airway management option where a cuffed tube with a ‘mask’ sits over the glottis (vocal cords)
Although it maintains the airway (i.e. lets air in), it doesn’t do what?
protect the airway (i.e. making sure gastric contents aren’t aspirated into resp tract)
What is the ‘i-gel’ + when is it the airway of choice?
A newer generation of the laryngeal mask airway (LMA)
In emergency situations like MI
A complication of the airway is OBSTRUCTION - what can cause this (3)
Ineffective triply airway manoeuvre
Malpositioning of airway device
Laryngospasm
A complication of the airway is ASPIRATION - what can cause this (2)
GA - protective airway reflexes lost, e.g. gag, swallow, cough
Foreign body in lower airway, e.g. gastric contents, blood
Difference between maintaining and protecting the airway + what are the only 2 ways of protecting an airway
Maintaining means keeping it open and unobstructed but protecting refers to the prevention of things being aspirated into the airway
If conscious or anaesthetised with a cuffed tube below the vocal cords
What does endotracheal intubation involve
Placing cuffed tube in the trachea
Reasons for intubation (5)
Protect airway from gastric contents
If muscle relaxants are used
Shared airway, i.e. if the surgery is performed in the same space as the airway
When blood gases need to be tightly controlled
When there’s restricted access to airway, e.g. maxillofacial surgery
