Breathing Systems and Scavenging Flashcards
Two types of patient breathing systems are
re-breathing and non-rebreathing
Hoses for re-breathing (2)
circle and universal F
Hoses for non-rebreathing
Mapleson A-F (bain/modified mapleson D and Mapleson F most common)
What is anatomic dead space?
airway structures that do not participate in gas exchange (oral cavity, larynx, trachea, bronchi)
what is mechanical dead space?
portion of anesthesia circuit where bidirectional flow is occurring (rebreathing of exhaled gases)
T/F: breathing tubes in a circle system constitute mechanical dead space
False - the flow is unidirectional so there is no rebreathing
Which is not an advantage of a re-breathing system?
A) saves money
B) decreases environmental pollution
C) lower resistance due to valves
D) patient breathes warm, humidified gases
C - the resistance is increased due to valves, and this is a disadvantage
Which system has more potential for leaks?
re-breathing because more components
The ______ is a shared connection between rebreathing and non-rebreathing systems
fresh gas inlet
T/F: the pop-off or adjustable pressure limiting valve should always be closed.
FALSE should always be open
When should you close the APL/pop off valve?
1) leak checking machine before use
2) administering IPPV (manual or mechanical positive pressure ventilation)
Most commonly used in a CO2 absorber
soda lime
T/F: purple soda lime means it is exhausted/
False - it just means it is actively producing heat and water from the reaction between CO2 and soda lime
3 patient signs of CO2 absorbent exhaustion.
1) increased RR
2) increased HR and BP
3) red MM (CO2 induced vasodilation)
3 functions of reservoir bag.
1) inspiratory reserve for patient
2) administer IPPV
3) allow anesthetist to monitor ventilation
You need to choose a reservoir bag for a 40kg dog. What size bag do you use?
~15ml/kg x 6 so 15ml x 40 kg x 6 = 3600ml always round up Use a 4L bag
Typical O2 flow rates for small animals < 50kg?
Induction and recovery - 50-100ml/kg/min
Maintenance - 20-50ml/kg/min
Typical O2 flow rates for large animals?
induction and recovery - 20-50ml/kg/min
Maintenance - 10-20ml/kg/min
2 things not present in non-rebreathing system
soda lime canister and unidirectional valves
Which breathing system would you use for a small patient <3kg?
non-rebreathing
Which breathing system requires a higher gas flow rate?
non-rebreathing
approximate oxygen flow rate in a non-rebreathing system?
~300ml/kg/min
Most common ETT in vet med?
Murphy
Which ETT would you use in avian patients?
Cole
What aspect of ETT has the largest effect on gas flow?
radius
A _____ (instrument) makes intubation safer and easier.
Laryngoscope
An example of an active waste gas scavenging system?
piped vacuum
F air canister is what kind of scavenging system?
passive
F air canister must be discarded when it has gained ____.
50g
What gas does an Fair canister not absorb?
N2O
