anaesthetics 2 - The conduct of general anaesthesia

Question 1

What does the anaesthetist actually do?

Answer 1

pre-op assessment and care 
critical and intensive care 
pain management 
anaesthesia 
post-op care

Question 2

Process of anaesthesia

Answer 2

pre-op assessment
preparation 
induction 
maintenance 
emergence 
recovery 
post op care and pain management

Question 3

Preparation for anaesthesia

Answer 3

planning - right patient - right operation - correct side - pre medication - right equipment - right personnel - drugs drawn up - IV access - monitoring

Question 4

Induction of anaesthesia

Answer 4

quietness with a gas or IV agent

Question 5

IV agent used in induction of anaesthesia

Answer 5

Propofol and thiopentone

Question 6

IV induction of anaesthesia

Answer 6

rapid, 1 arm brain circulation time 20s, no obvious planes, easy to overdose, rapid loss of airway reflexes, apnoea common

Question 7

Gas induction of anaesthesia

Answer 7

halothane in young children, obvious planes of anaesthesia, venous access hard - IVDA

Question 8

Planes of anaesthesia

Answer 8

analgesia/sedation
excitation
anaesthesia
overdose

Question 9

Induction - monitoring conscious level

Answer 9

loss of verbal contact 
movement 
respiratory 
processed EEG - BIS 
stages/planes of anaesthesia

Question 10

Is airway management required in GA?

Answer 10

yes always

Question 11

Simple airway manoeuvres

Answer 11

head tilt, chin life, jaw thrust - triple airway manoeuvre

Question 12

Anaesthetic face mask

Answer 12

identical to those in resus
contoured to face for gas tight seal
size from neonatal to large adult

Question 13

oropharyngeal airway

Answer 13

Guedel in US - rigid plastic

only tolerated if unconscious

Question 14

What would an oropharyngeal airway cause in an awake patient?

Answer 14

laryngospasm

Question 15

Laryngeal mask airway

Answer 15

cuffed tube with mask over glottis

maintains but not protect airway

Question 16

Resuscitation device - LMA

Answer 16

I-gel
easy insertion
not protect from aspiration

Question 17

Airway complications - obstruction

Answer 17

ineffective triple airway manoeuvre
airway device malposition
laryngospasm

Question 18

laryngospasm

Answer 18

forced reflex adduction of vocal cords
complete airway obstruction
airway stimulation in light patients
often unrelieved by simple manoeuvres

Question 19

Airway complications - aspiration

Answer 19

anaesthesia means loss of protective airway reflexes egg gag, cough
foreign material in lower airway eg gastric content

Question 20

Difference between maintained and protected airway

Answer 20

maintained - open and unobstructed

protected - only cuffed tube in trachea protects airway

Question 21

Endotracheal intubation

Answer 21

cuffed tube in trachea - oral route
laryngeal reflexes must be abolished
laryngoscope, muscle relaxant, position

Question 22

Is endotracheal intubation able in awake patients?

Answer 22

yes with LA and fibre optics

Question 23

5 reasons to intubate

Answer 23

1. protect airway from gastric contents
2. muscle relaxation, artificial ventilation
3. shared airway with risk of blood contamination
4. tight control of blood gases needed
5. restricted airway access

Question 24

Risks to unconscious patient

Answer 24

airway - temperature - pressure areas - consent and identify - VTE - loss of protective reflex eg corneal - patient position

Question 25

Continuing anaesthesia

Answer 25

care, muscle relaxation and analgesics

monitor, fluid, documentation

Question 26

Monitoring patient includes…

Answer 26

basic: SpO2, ECG, FiO2, ETCO2, Nibp
respiratory, temperature, urine output, NMJ
invasive venous/arterial 
processed EEG, agent monitoring 
ventilator disconnect

Question 27

Anaesthetic complications

Answer 27

ABC, technique/position, awareness

Question 28

risk factors for being awake during surgery

Answer 28

paralysed and ventilated, previous episode of awareness, chronic CNS depressant, cardiac and trauma surgery

Question 29

Emergence/awakening

Answer 29

muscle relaxation reversed 
anaesthetic agents off 
resume spontaneous respiration 
return airway reflexes/control 
extubation

Question 30

conduct of LA

Answer 30

same level of care
IV access, monitoring, presence of anaesthetist
spinal, epidural, plexus block, nerve block

Question 31

Recovery

Answer 31

a dedicated area with trained staff
many not regained consciousness or airway control
ABC, pain, N&V, discharge back to ward