Anesthesia machine and breathing circuits (E1) Flashcards
What are the 4 subsystems of the breathing machine?
High pressure system
Low pressure system
Breathing system
Scavenging system
T/F E cylinders are bigger than H cylinders?
FALSE; E cylinders hold 660L of O2, while H cylinders hole 6900 L
What are some safety features of gas cylinders?
Color coding
Pin-index safety system
Bull-nose or threaded outlets
Diameter index safety system
What does the pressure regulator do?
Reduces the pressure of the gas being administered to 50-55 psi
What is the oxygen flush valve? When would it be used?
Valve located between pressure regulator and flowmeter.
Use when the pressure in the circuit increases and could lead to bronchotrauma, or when the concentration of inhalant in circle system will decrease and lead to light plane of anesthesia
What are the components of the high pressure system? What is the pressure of the gas at the end of it?
Gas source, pressure regulator, pressure gauge, and oxygen flush valve
50-55 psi
What is the flow meter?
Controls the rate of gas delivery to vaporizer and to the patient’s breathing circuit; first part of low pressure system
T/F Each gas needs its own flowmeter
TRUE
Where should the O2 flowmeter be?
Always the last one in the circuit
What is the vaporizer?
Adds a specific amount of volatile liquid anesthetic to the oxygen/gas mixture
What are the two types of vaporizers and which one is more commonly used?
Vaporizer in circuit
Vaporizer out of circuit (Winner)
What is the common gas outlet?
Leads from the anesthesia machine to the breathing circuit
What are the components of the low pressure system?
Flowmeter, Vaporizer, and common gas outlet
What are the two different breathing systems?
Rebreathing system (Most common) Non-rebreathing system
What are the qualifications for using standard vs pediatric circuits in rebreathing?
Standard: >15 kg
Pediatric: 7-15 kg
For non-rebreathing systems what are the flow rates for induction, recovery, or changes in depth? What about maintenance?
50-100 ml/kg/min
20-40 mL/kg/min
How do you calculate tidal volume?
10-15 mL/kg x Patient’s weight in Kg
How do you determine the appropriate size of the reservoir bag?
5-6 X Patients tidal volume
What is the non-rebreathing system ideal for?
Patients less than 7 kg
What are the recommended flow rates for partial rebreathing and no rebreathing?
Partial: 150-200 mL/kg/min
No: 400-600 mL/Kg/min
What are the different types of breathing circuits in a non-rebreathing system?
Bain Circuit
Modified Jackson Rees
T/F A non-rebreathing system constains CO2 absorbent
FALSE
What is the purpose of a waste scavenging system?
Direct waste gas from the breathing system out of the immediate workspace and into the atmosphere
How do you calculate a time constraint?
Volume of the circuit / Oxygen flow rate
How many time circuits does it take to have a 99.9% change in the system?
5
What % change occurs after 1 time constraint?
63.2%
What are the two types of scavenging systems?
Active: uses a vacuum or fan-blower system
Passive: Open to atmospheric pressure
