Machine Check

Question 1

What are the 9 components of a Machine Check

Answer 1

1. Emergency Equipment
2. High Pressure System
3. Low Pressure System
4. Oxygen Sensor
5. Scavenger System
6. Ventilator
7. Breathing Circuit
8. Monitors
9. Final

Question 2

How do you check emergency equipment?

Answer 2

• ambu bag available w mask
• backup E-cylinder at least 1000psi
• suction on and ready
• emergency airway/LMA
• jet ventilation

Question 3

How do you check the high pressure system

Answer 3

1) turn off the pipeline source (H tank or DISS)
2) remove the O2 sensor and cap the inlet
3) open the E-cylinder and verify psi >1000psi
4) close E-cylinder
5) depress O2 flush
6) watch bourdon gauge for e-cylinder drop to zero
7) turn on anesthesia machine
8) listen for O2 low pressure alarm
9) reconnect pipeline or H-tank
10) ensure bourdon gauge for pipeline reads 50psi

Question 4

How do you check a low pressure system?

Answer 4

1) test flowmeters by turning on and check for smooth operation of floats
2) attempt to create a hypoxemic mixture

3) ensure flow control valves closed and vaporizers off
4) ensure vaporizer mounted, (fill vaporizers if need), and interlocked

5) verify master switch and flow control knobs are off
6) attach suction bulb to CGO
7) collapse and squeeze bulb
8) ensure stays collapsed for 10 seconds
9) open one vaporizer at a time and repeat with each vaporizer
10) remove suction bulb
11) reconnect fresh gas hose

Question 5

How to check the oxygen sensor?

Answer 5

• calibrate O2 monitor by ensuring it reads 21% in room air
• verify low O2 alarm (set to 30%)
• re-install sensor and flush with O2
• verify monitor now reads 90%

Question 6

How do you check the scavenging system?

Answer 6

• ensure proper connections between scavenging system and APL valve, spill valve, and waste gas vacuum
• adjust waste gas vacuum
• fully open APL valve
• occlude Y-piece
• add minimum O2 flow
• allow scavenger reservoir bag to completely collapse
• verify absorber pressure gauge reads zero
• occlude y-piece and depress O2 flush
• ensure the reservoir bag distends
• verify absorber pressure gauge reads <10cm H2O

Question 7

How do you check the Breathing circuit

Answer 7

• replace circuit
• place second breathing bag on Y-piece
• set appropriate vent parameters
• switch to mechanical vent mode
• before fill bellows listen for low pressure alarm
• fill the bellows and breathing bag with the oxygen flush
• set O2 flows to minimum and other gas flows to zero
• verify that during inspiration the bellows deliver the appropriate Vt
• verify that during expiration the bellows fill completely
• set FGF to about 5L/min
• verify the bellows and lungs fill and empty appropriately without sustained pressure at end expiration
• check for proper action of the unidirectional valves
• pinch circuit and listen for high PIP alarm
• turn the vent off and switch to bag APL mode
• ventilate manually and ensure inflation/deflation of artificial lungs
• remove second breathing bag from y-piece
• check that the breathing circuit is complete, up damaged, and unobstructed
• verify CO2 absorbent is adequate, full, not purple
• perform leak check: set all gas flows to zero/minimum, close APL valve, occlude y piece, pressurize breathing circuit to 30cmH2O with o2 flush, ensure pressure remains fixed for at least 10 seconds; listen for sustained pressure alarm; open APL valve and ensure pressure drops

Question 8

How do you check the Ventilator?

Answer 8

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