General anaesthetics first half 1.0 Flashcards
Objective of anaesthesia?
Inducing a lack of feeling (lack of sensation and pain)
Who was the father of surgical anaesthesia?
Hua Tuo
Who was the first surgeon who used NO2 as a GA?
Crawford Long
Triad of general anaesthetics?
Unconsciousness, analgesia, muscle relaxation
How many stages of anaesthesia are there?
4
What is stage 1 of anaesthesia?
Analgesia
Conditions of stage 1 of anaesthesia?
conscious, drowsy, antinociception, amnesia
What is stage 2 of anaesthesia?
Excitement
Conditions of stage 2 of anaesthesia?
loss of consciousness, delirium, irregular cardiorespiration, apnea, spasticity, gagging, vomiting
What is stage 3 of anaesthesia?
Anaesthesia
Conditions of stage 3 of anaesthesia?
regular respiration, loss of reflex and muscle tone
What is stage 4 of anaesthesia?
medullary paralysis
Conditions of stage 4 of anaesthesia?
Depression of cardiorespiration, death
Why is stage 1 of GA used for childbirth?
Want some lack of sensation but still need to be awake
How do you go from one stage of GA to a higher stage?
Increase the dose or potency of the GA
Which compound is used to induce stage 1 GA?
N2O
Which stage of GA causes erratic breathing?
2
What is a warning sign to an anaesthetist that a patient is too deeply anaesthetised?
Action of intercostal muscles decreasing
What are the four stages of stage 3 of GA?
Planes 1,2,3, and 4
When is the pupilary light reflex visible?
S3, planes 2-end of 3
When during GA does the corneal reflex stop?
S3P2
Precise aim of GA?
S3, P1 OR 2
When in GA is the respiratory response to skin inscision lost?
Midway through S3P2
When during GA are the muscles tense and struggling?
S2
Super ideal GA?
Stable, potent, non toxic, controllable, rapid on off, adjustable, minimal cardio and respiratory depressant
Why does the ideal GA need to be rapid on?
Through S2 quickly
Why does the ideal GA need to be rapid off?
Able to titrate dose depending on their reaction, to keep them in S3
Why is xenon not used as a GA?
V expensive
2 main types of administering GAs?
Inhalation and intravenous
