conduct of GA Flashcards
what is a GA
CONTROLLED period of unconsciousness during which you will feel nothing and remember nothing
stages of getting an anaesthetic
pre-op assessment and planning
preparation
anaesthetic: induction, maintenance, emergence, recovery
post-op care
pre-op assessment and planning - when does it happen
can begin months in advance
takes into account how major the surgery is and the complexity of the patients needs
what happens in the pre-op assessment
information gathering and giving
informed consent
trust and communication
what happens in the preparation period
right people available - anaesthetist and assistant (ODP, nurse), theatre team and surgeon
right environment
right equipment - machine checks and team brief
what happens when the patient is checked in
part of WHO theatre checklist
correct patient for correct procedure
correct site and position marked
adequate consent and in time
what is required when monitoring a patient
5 minimum standards of monitoring
must be ready and working before beginning GA
ECG monitoring
oxygen saturations
non-invasive BP (NIBP)
end tidal CO2 - info about airway CO2 levels in blood and patency of airway
airway pressure monitoring - info about how we are ventilating patient and airway patency
what is another thing as well as the 5 monitors that the patient requires before anaesthetic
IV access
usually in back of hand for ease of access
what is pre-oxygenation
give patients additional oxygen to breathe through a tight fitting face mask before anaesthetic
usually 100% oxygen
why are patients given supplemental oxygen before GA
common for pts under GA to become apnoeic and stop breathing - pause between patient stopping breathing and the anaesthetist getting more oxygen into the pts lungs
reduced FRC - less oxygen available for the blood to take out, less time before patient starts to desaturate
when is a gaseous induction given
normally reserved for small children who won’t tolerate a cannula being placed
slower induction than IV
3 parts to induction
analgesic - short acting opiate (fentanyl, alfentanil)
hypnotic - propofol, sometimes thiopentone, ketamine, benzodiazepines
muscle relaxant - avoid unless necessary
planes of anaesthesia
distinct stages between consciousness and unconsciousness that can be seen as the patient goes off to sleep
- analgesia and amnesia (patient feels floaty and relaxed)
- delirium to unconsciousness (can be associated with some excitatory behaviour - small children move about and can get upset)
- surgical anaesthesia - patient doesnt move in response to surgical stimulus
- apnoea to death - AVOID
airway management
some degree required for all patients under anaesthetic - minimally invasive to invasive
why is airway management required in patients under anaesthetic
relaxed muscles of upper airway and soft tissue collapse
some degree of airway obstruction in all patients
loss of airway reflexes - no coughing or swallowing, nothing to protect from own secretions
what is the simplest airway management
triple airway manoeuvre
head tilt, jaw thrust, open mouth
accompanied with anaesthetic mask
what can be used for aiway management after triple airway manoeuvre and anaesthetic mask
oropharyngeal airway aka Guedel
splints open the upper airway
draws up the tongue which can slip backwardxs
what can be used for aiway management after oropharyngeal airways
laryngeal mask airway - LMA
sits over the larynx with a tight seal to direct gas flow towards the patients airway
doesn’t protect the airway
what is used if the patient needs more definitive airway management or protection
endotracheal tube
what is an endotracheal tube
sits within the trachea
cuffed tube with a balloon at the end which sits in the trachea and stops anything coming past the cuff - protects the airway
how are endotracheal tubes inserted
with a laryngoscope
reasons to intubate
protection from aspiration e.g. emergency intervention and unfasted
need for muscle relaxation - facilitate ventilatoin
shared airway - surgeon and anaesthetist are both working in the same area
need for tight CO2 control
minimal access to patient
what are the 3 ways for how a patient breathes during an operation
spontaneous ventilation - patient breathes completely on their own
supported ventilation - mix of the 2
controlled ventilation - patient is paralysed and we completely take over
monitoring circulation under anaesthesia
haemodynamic instability is common
measure BP at least every 5 mins
vasoactive drugs may be necessary to maintain BP
