ELFH Flashcards
Which Mapleson system is most efficient for spontaneously ventilating patients
Mapleson A
What is the name of the co-axial version of Mapleson A circuit
Lack system
What is the volume of an adult reservoir bag in a breathing circuit
2L
What is a Jackson-Rees system
Mapleson F
Has an open ended reservoir bag which allows PEEP and controlled leak
Give 4 roles/benefits of a reservoir bag on breathing system
1- Allow higher peak inspiratory flow to be delivered as ventilator alone is not enough for normal respiration
2- Rough visual assessment of ventilating volume
3- provide PEEP
4- Prevent wastage of FGF during expiratory pause
How many multiples of minute ventilation does a Bain system require to prevent rebreathing during spontaneous ventilation
2-3X
(Mapleson D)
Why is Magill system inefficient during controlled ventilation
APL valve at patient side of circuit so most of expired gases are vented off.
What size are soda lime granules
4-8 mesh
What are the constituents of baralyme
80% Calcium hydroxide
20% Barium Hydroxide
Does soda lime produce more or less compound A during low FGF
More
What are the constituents of Sodalime
75% Calcium Oxide (CaO)
20% Water
3% Sodium hydroxide (NaOH)
1% Potassium hydroxide (KOH)
Why can FIO2 slowly decrease over time during low flow anaesthesia
If metabolic requirements exceed O2 supply in FGF the oxygen conc. in the system will start to decrease
What is the MAC of Nitrous Oxide
105%
How does water affect sodalite efficiency
Water is generated by the overall reaction of CO2 with soda lime but it’s presence or absence does not influence performance of sodalite
Can Nitrous Oxide be safely delivered using a quantiflex mixer? How does this work?
Yes.
Quantiflex mixer allows a full range oxygen/nitrous oxide mixtures to be administered from 21-100% oxygen so avoiding accidental hypoxic mixtures.
Why can nitrous oxide not be used as an anaesthetic agent by itself?
MAC is 105% so can’t deliver enough whilst also giving oxygen
What is the pin index of nitrous oxide
3, 5
What colour is the collar of a nitrous oxide cyllinder
French Blue
What is the difference between a Magill and Lack system
APL valve is at machine end in Lack system
In Lack system there is an inner co-axial tube for expired gas and FGF is on external limb.
What proportion of MV is required for spontaneous ventilation using Magill circuit
70% of MV
Summarise Cardiff Aldasorber
Canister containing charcoal that acts as passive scavenger. Absorbs anaesthetic gasses including isoflurane but not Nitrous oxide. Low resistance. Can be reactivated by heating to remove absorbed gasses. No indicator die so hard to tell when saturated.
When filled what percentage of the volume of a canister is taken up by sodalime granules
50%
Which anaesthetic gas causes production of Compound A in soda lime
Sevoflurane
Which 3 anaesthetic gases cause production of CO in soda lime
DIE
Desflurane
Isoflurane
Enflurane
