EDAIC Anesthetic Equipment and Safety 5 — Questions and Answers
Question 1: Which type of vaporizer is classified as 'out-of-circuit' and agent-specific, using a variable bypass design?
- Tec-series (e.g., Tec 7) vaporizer (Correct answer)
- Goldman vaporizer
- Copper Kettle vaporizer
- Oxford Miniature Vaporizer (OMV)
Correct answer: Tec-series (e.g., Tec 7) vaporizer
Tec-series vaporizers are out-of-circuit, agent-specific, variable-bypass vaporizers that split fresh gas flow between a bypass channel and a vaporizing chamber.
Question 2: The diameter index safety system (DISS) is used to prevent misconnection of:
- Pipeline gas hoses to incorrect wall outlets (Correct answer)
- Cylinders to yokes
- Breathing circuit components
- Vaporizers to the back bar
Correct answer: Pipeline gas hoses to incorrect wall outlets
DISS uses unique threaded fittings of specific diameter for each gas to prevent incorrect pipeline hose connections to wall outlets or the anesthesia machine.
Question 3: A critical failure of the hypoxic guard (oxygen ratio monitor controller) would most likely result in:
- Delivery of a hypoxic gas mixture to the patient (Correct answer)
- Excess anesthetic agent being delivered
- Failure of the ventilator bellows
- Inaccurate end-tidal CO2 readings
Correct answer: Delivery of a hypoxic gas mixture to the patient
The hypoxic guard links oxygen and nitrous oxide flowmeters to prevent delivery of a nitrous oxide–oxygen mixture with less than 21–25% oxygen.
Question 4: When a breathing system leak test is performed and the circuit cannot maintain pressure at 30 cmH2O, the FIRST corrective action should be:
- Systematically inspect all connections, the reservoir bag, and the CO2 absorber canister seal (Correct answer)
- Replace the entire breathing circuit immediately
- Increase fresh gas flow to compensate for the leak
- Proceed with the case and monitor SpO2 closely
Correct answer: Systematically inspect all connections, the reservoir bag, and the CO2 absorber canister seal
A systematic check of all connections, the bag, and the canister seal identifies the most common sites of leak before replacing components or proceeding.
Question 5: Compound A, a nephrotoxic vinyl ether, is produced when which agent reacts with desiccated CO2 absorbent?
- Sevoflurane (Correct answer)
- Desflurane
- Isoflurane
- Halothane
Correct answer: Sevoflurane
Sevoflurane reacts with desiccated CO2 absorbents (especially those containing strong bases like KOH) to produce Compound A, a potentially nephrotoxic vinyl ether.
Question 6: Which safety feature of modern anesthesia ventilators is designed to limit airway pressure and prevent barotrauma?
- Adjustable pressure-limiting (APL) valve set to a defined peak pressure (Correct answer)
- Oxygen flush valve bypass
- Low-pressure alarm on the pipeline inlet
- Spirometer volume alarm
Correct answer: Adjustable pressure-limiting (APL) valve set to a defined peak pressure
The APL (pop-off) valve can be set to a maximum pressure limit so that excess pressure is vented, protecting the patient's lungs from barotrauma.
Question 7: The Bodok seal (plastic/neoprene washer) on a gas cylinder yoke serves to:
- Create an airtight seal between the cylinder valve and the yoke to prevent gas leaks (Correct answer)
- Identify the type of gas in the cylinder
- Maintain cylinder pressure within a safe range
- Act as a filter for particulate contamination
Correct answer: Create an airtight seal between the cylinder valve and the yoke to prevent gas leaks
The Bodok seal provides a gas-tight junction between the cylinder valve block and the yoke, preventing leakage of potentially dangerous gases.
EDAIC Anesthetic Equipment and Safety 5
Which type of vaporizer is classified as 'out-of-circuit' and agent-specific, using a variable bypass design?