ABA ABA Anesthetic Equipment and Technology 1 — Questions and Answers
Question 1: What is the primary purpose of the circle breathing system in anesthesia delivery?
- To deliver high fresh gas flows only
- To reuse exhaled gases after CO2 absorption (Correct answer)
- To prevent hypoxia by nitrogen enrichment
- To measure end-tidal gas concentrations
Correct answer: To reuse exhaled gases after CO2 absorption
The circle system allows rebreathing of exhaled gases after passing through a CO2 absorber, reducing waste anesthetic gas and conserving heat and humidity.
Question 2: Which anesthesia machine safety device mechanically links N2O and O2 flow controls to prevent delivery of a hypoxic gas mixture?
- Vaporizer interlock system
- Oxygen ratio monitor controller (ORMC) (Correct answer)
- Fail-safe valve
- One-way check valve
Correct answer: Oxygen ratio monitor controller (ORMC)
The ORMC mechanically links nitrous oxide and oxygen flow controls to ensure a minimum oxygen concentration is always maintained.
Question 3: In the United States, what does the color coding on medical gas cylinders indicate?
- Flow rate capacity
- Gas content identification (Correct answer)
- Maximum pressure rating
- Cylinder manufacture date
Correct answer: Gas content identification
Color coding on US medical gas cylinders identifies the gas content, such as green for oxygen and blue for nitrous oxide.
Question 4: What is the function of the Adjustable Pressure Limiting (APL) valve in an anesthesia breathing circuit?
- To humidify inspired gases
- To vent excess gas and limit maximum circuit pressure (Correct answer)
- To prevent backflow of exhaled gases
- To regulate fresh gas composition
Correct answer: To vent excess gas and limit maximum circuit pressure
The APL valve vents excess gas from the breathing circuit to scavenging, preventing dangerous pressure buildup and barotrauma.
Question 5: Which CO2 absorbent material was phased out of anesthesia machines due to reactions with volatile anesthetics producing toxic byproducts?
- Sodasorb
- Amsorb Plus
- Baralyme (Correct answer)
- Medisorb
Correct answer: Baralyme
Baralyme was associated with reactions with desflurane and sevoflurane to produce compound A and carbon monoxide, leading to its discontinuation.
Question 6: What is the primary purpose of fresh gas decoupling in modern anesthesia ventilators?
- To isolate fresh gas flow from tidal volume delivery during inspiration (Correct answer)
- To regulate humidity in the breathing circuit
- To allow safe scavenging of waste anesthetic gases
- To monitor fresh gas oxygen concentration
Correct answer: To isolate fresh gas flow from tidal volume delivery during inspiration
Fresh gas decoupling prevents the fresh gas flow from adding to or subtracting from the set tidal volume during positive pressure ventilation.
ABA ABA Anesthetic Equipment and Technology 1
What is the primary purpose of the circle breathing system in anesthesia delivery?