Intra-operative

Question 1

What is considered just before the operation (pre-operatively)?

Answer 1

• Confirm age, procedure, aware of mode of anaesthesia
• PMH
• DH
  
  • Anticoagulants [when was last dose]
  • Oral Contraceptive / Hormone Replacement
• allergies
• Previous Surgeries / GAs
  
  • any previous complications with GA’s?
  • [Common: post-operative nausea & vomiting]
• exercise tolerance
• recent infections / changes to health?
• SH
• female: LMP
• metalwork in body
  
  • cannot use diathermy pads over metal
• dentition
  
  • ​loose teeth –> intubation risk
• airway assessment

Question 2

What is diathermy?

Answer 2

technique involving the production of heat in a part of the body via high-frequency electric currents

• stimulate circulation
• relieve pain
• destroy unhealthy tissue
• clottng bleeding vessels

Question 3

What is the purpose of pre-operative airway assessment?

Answer 3

• determines difficulty of intubation
• planning ahead for blips

Question 4

Which factors are considered during pre-operative airway assessments, and what is the final grading system used?

Answer 4

​

Mallampati grade

[I – Easy to IV – difficult intubation]

• Beard /Edentulous
  
  • [more difficult to bag-mask ventilate; use guedel airway]
• Good mouth opening
  
  • [<3cm increases difficulty of intubation]
• Receding mandible & prominent upper incisors
  
  • [increases difficulty of intubation]
• Craniofacial abnormalities
• High BMI & Short/Fat Neck
  
  • [increases difficulty of intubation]
• Thyro-mental distance
  
  • [tip of jaw to thyroid notch; <7cm increases difficulty of intubation]
• Full range of neck movement
  
  • [limited increases difficulty of intubation]

Question 5

What is the normal:

a) tidal volume (TV)
b) Respiratory rate (RR)
c) Minute volume (MV)

Answer 5

a) 7ml/kg.
b) 12-18 breaths per minute
c) = TV x RR

Question 6

Why is positive end expiratory pressure (PEEP) required during ventilation?

Answer 6

To prevent airway & alveolar collapse

Question 7

What is the fundamental difference between sponataneous breathing and artificial ventilation?

Answer 7

Spontaneous = negative intrathoracic pressure via subcostal & diaghram muscles - air pulled into lungs

Artificial ventilation = positive pressure - air is pushed into lungs

Question 8

What are the two types of positive pressure ventilation?

Answer 8

1. Volume controlled ventilation
   * desired TV per breath is set, pressure can be varied to achieve
2. Pressure controlled ventilation
   * pressure is set, TV varies w compliancy of lungs

Question 9

What do

a) pressure
b) volume
c) flow

look like for the 2 types of positive pressure ventilation (volume, pressure controlled)

Answer 9

Question 10

disregarding breathing parameters, what are the differences between volume controlled and pressure controlled ventilation?

Answer 10

Question 11

What are the 3 phasesof anaesthesia

Answer 11

1. Induction
2. Maintenance
3. Recovery

Question 12

What are the 3 hallmark drugs of anaesthesia

Answer 12

1. ____ e.g. propofol
2. analgesia
3. muscle relaxants

Question 13

Which parameters does a pul.se oximeter measure?

Answer 13

• Oxygen saturation of capillary blood
• Heart rate
• Heart rhythm