Conduct of Anaesthesia Flashcards
Stages of anaesthesia
Preparation Induction Maintenance Emergence Recovery
Roles of an anaesthetist
Pre-op assessment care Critical care / intensive care Pain management Anaesthesia Post op care
What does the preparation stage of anaesthesia involve?
Planning Right patient, right operation Right or left side Pre medication Right equipment, right personnel Drugs drawn up IV access Monitoring
What does the induction stage of anaesthesia involve?
Quietness
Gas or IV agent
Careful monitoring of conscious level
Airway maintenance
Drugs used for IV induction
PROPOFOL
Thiopentone
Others
Features of IV drug induction
Rapid - one arm brain circulation - approx. 20 secs Obvious planes Easy to overdose Generally rapid loss of airway reflexes Apnoea is common
Drugs used in gas induction
Sevoflurane (halothane)
Features of gas induction
Common in younger children
Slow
Considerably more obvious “planes” of anaesthesia
How to monitor conscious level
Loss of verbal contact Movement Resp pattern Processed ECG stages and planes of anaesthesia
When is airway maintenance always required?
In general anaesthesia
What is the “triple airway manoeuvre”?
Head tilt
Chin lift
Jaw thrust
Simple apparatus used in airway maintenance
Face mask
Oropharyngeal ("Guedel") airway
- unconscious patient
Nasopharyngeal airway
Laryngeal mask airwayFeatures of a laryngeal mask airway
Cuffed tube with mask that sits over glottis
maintains, but does not protect the airway
What is used for resuscitation?
I-gel
2nd generation LMA
What does I-gel used in resuscitation NOT protect you from?
Aspiration
Airway complications
Obstruction
Aspiration
What causes obstruction of the airway in anaesthesia?
Ineffective triple airway manoeuvre
Airway device malposition or kinking
Laryngospasm = laryngeal spasm
Features of laryngospasm
Forced reflex adduction of vocal cords
May result in complete airway obstruction
Caused by airway (or other) stimulation in light planes of anaesthesia
Often unrelieved by simple manoeuvres
When is the airway maintained?
When it is open and not obstructed
Why intubate?
Protect the airway from gastric contents
Need for muscle relaxation -> artificial ventilation
Shared airway with risk of blood contamination
Need for tight control of blood gases
Restricted access to airway
What route is most commonly used for endotracheal intubation?
Oral route
What must be abolished in endotracheal intubation?
Laryngeal reflexes
Risks faced by the unconscious patient before the surgery even begins
AIRWAY temperature loss of protective reflexes e.g. corneal, joint position Venous thromboembolism risk Consent and identification Pressure areas
What is the best monitor?
The anaesthetic
How is monitoring done?
Basic "minimum" monitoring - SpO2, ECG, NIBP, FiO2, ETCO2 Respiratory parameters Agent monitoring Temperature, urine output, NMJ Invasive venous / arterial monitoring Processes ECG VENTILATOR DISCONNECT anaesthetic best monitor
Anaesthetic complications
Airway Breathing Circulation Related to techniques or position Awareness
Risk factors of anaesthesia awareness
Paralysed and ventilated Previous episode of awareness Chronic CNS depressant use Cardiac surgery Major trauma GA C/section
What happens during emergence/awakening?
Muscle relaxation reversed Anaesthetic agents off Resumption of spontaneous resection Return of airway reflexes/control Extubation Can be very quick or very very slow
Issues surrounding recovery
Problems with A, B and C
Pain control
Post op nausea and vomiting
