Gas delivery Flashcards
Most efficient Mapleson during controlled ventilation
Mapleson D
During spontaneous respiration, FGF = 2-3 x MV
During controlled ventilation, FGF = 1-2 x MV
Mapleson D
Mapleson D is also called
Bain System
What is the order of effectiveness in controlled ventilation in the the Mapleson system
D > B > C > A (Dog bites can ache)
What is the order of effectiveness in spontaneous ventilation in the Mapleson system
A>D>C>B(All dogs can Bite)
What system consists of inner tubing that delivers FGF directly to the patient who then exhales down the outer corrugated tubing to the reservoir bag and APL valve
The Bain System
Which Mapleson system eliminates rebreathing, where higher fresh-gas flows are needed during SV than during controlled ventilation
Mapleson D
A patient has a fever of 103.5,what should be done with the FGF and whats the rational
Increase the fresh gas flow due to the increase in co2 production
Adjustments to the ventilatory pattern that allow the fresh-gas flow to constitute a larger proportion of the inspired gas includes all of the following except: A.Slow inspiratory time B.Low inspiratory flow C.Long Expiratory Pause D.Slow Rate E.Fast Total cycle time
E
What are the disadvantages of the Bain Circuit
Kinks,Leaks,Disconnection of the the Inner tubing
What is the advantage of the Bain Circuit
- Exhaled gas warms the fresh gas flow in the inner tubing thereby preserving humidity and warmth
- Ease of Scavenging through the overflow valve.
- Useful for head and neck surgery.
- Conserves humidity due to partial rebreathing
- Low Resistance to breathing by the tubing or circuit
The rapid flow of gas through the expiratory limb, resulting in a slight negative pressure and collapse of the breathing bag.
Venturi Effect and used to test for leaks in The Bain Circuit.
With a leak from the inspiratory limb into the expiratory limb, the pressure in the latter rises, tending to inflate the reservoir bag if there was a leak
Mapleson E is a is used in ?
Ayre’s T piece.
which system has NO RESERVOIR BAG (the expiratory limb is the reservoir) AND NO POP-OFF VALVE!!!
Mapleson E
What is rate of FGF during SV in the Mapleson E system
MVx2-3
Name the characteristics of the Mapleson E system
No reservoir
No pop-off-valve
limited resistance in the tubing
SInce there is no reservoir bag in the Map E system.
What acts as a reservoir
The open end corrugated tubing acts as the reservoir and should be have a lenght that exceeds the Tidal Volume of the patient.
What is the sole determinant of rebreathing occuring in the Map E system
The FGF is ultimately the sole determinant of whether rebreathing occurs and directly influences the O2 concentration of inspired gas – if the FGF is not equal to the inspiratory flow rate then air will be entrained creating a dilutional effect.
In the Map E system the FGF should Be equal to the inspiratory flow rate.True or false
True.
With what kind of patients is the Map E used with
Pediatric patients weigh less that 20kg
A modification of the Mapleson E Ayre’s T piece with an adjustable pop-off valve at the end of reservoir bag is called?
MAP F or Jackson Reese.
Which Mapleson system Allows the application of continuous positive airway pressure or hand ventilation
Map F
what Mapleson system Provides a visual indicator of respiration with the reservoir bag
Map F
FGF equal to 2-3x mve is recommended to prevent rebreathing of exhaled gases in the Map F system,true or false
True
Disadvantages of the Mapleson F system include the floowing except:
(1) the need for high fresh gas inflow to prevent rebreathing, (2) the possibility of high airway pressure and barotrauma should the overflow valve become occluded, and (3) the lack of humidification. Lack of humidification can be offset by allowing the fresh gas to pass through an in-line heated humidifier
4. Air liquefication.
4.
What are the Basic Functions of a breathing circuit
1) Interface between the anesthesia machine and the patient
2) Deliver O2 and other gases
3)Eliminates carbon dioxide
CO2 absorbents eliminate CO2 in circle systems
Other breathing circuits require fresh gas flow (FGF) for elimination of CO2
3 Essential components of a breathing circuit
- low resistance conduit for gas flow
- reservoir for gas that meets inspiratory flow demand
- expiratory port or valve to vent excess gas
humidifiers,pressure gauges,spirometers,peeps,waste gas scavengers
Requirements of a breathing circuit.
1) Deliver the gases from the machine or device to the alveoli in the same concentration as set and in the shortest possible time.
2) Effectively eliminate carbon dioxide
3) minimal apparatus dead space
4) low resistance to gas flow
5) allow rapid adjustment in gas concentration and flow rate
Name the Factors that will eliminate resistance in a breathing circuit.
- Short tubing,
- large diameter tubing,
- avoid sharp bends,
- caution with valves,
- minimize connections
Beneficial effects of Rebreathing
- Cost reduction
2. Adds humidification/heat to gases
Higher FGF is associated with less re-breathing in any system. T/F
T
Increase Dead space increases the chances of rebreathing T/F
T
What size of filter should placed in the anesthesia circuit to protect the machine from bacterial contamination
0.3micrometre filter
What is the meaning of HME
Heat and moisture exchanger
where will the HME be placed in the circuit
In the Y piece
What is the function of the HME
Inspiratory and expiratory barrier
Where would a standard filter be placed
In the Expiratory limb of the circuit.
When rebreathing is absent or minimal the concentration of Inspired oxygen is equal to that from the common gas outlet.True or false
T
What are the classifications of anesthetic delivery system and their specifications.
Open system:No reservoir/No rebreathing
semi open:Reservoir/no rebreathing
semi close:Reservoir/partial rebreathing
close:Reservoir and complete rebreathing
Examples of Insufflation ..open system
Blow by
open drop
simple face mask
nasal cannula
components of open system
No gas reservoir
No valve
No rebreathing
What rate of MVE should FGF be to prevent rebreathing
1-1.5 MVE
Advantages of Insufflation
Avoid direct pt contact
No rebreathing
No valves
Disadvantages of Insufflation
No ability to assist or control ventilation
May have CO2/ O2 accumulation under drapes
No control of anesthetic depth /FiO2
Environmental pollution
Name Mapleson system components
connection point to a facemask or ETT
reservoir tubing
fresh gas inflow tubing
expiratory pop-off valve or port