Machine Check

Question 1

Steps of the preliminary check

Answer 1

1. Check the bulk gas supply/medical gas alarm panel is functioning.
2. Check my resuscitation device is present and check for leaks, connect to oxygen and check the oxygen reservoir bag fills, attach a 2L bag and perform a 2-bag check.
3. Patient monitor on.
4. Check scavenging and that the ball float is in the green zone.
5. Machine is plugged into a UPS (uninterrupted power supply) and that the battery is charging.
6. Machine can move freely.
7. Service dates on machine and monitor.
8. Systems switch on.
9. Gas sample line is clean and free of defects.
10. Gas sample line reads 21% oxygen +/- 3% in room air.
11. Patency of the d-fend water trap.
12. Depress the condenser drain button to drain condensate.
13. Check Aladdin cassettes are full and filling ports are closed and that the Sevoflurane cassette is positioned and locked in the active bay.
14. Ensure the correct agent is identified on the ASD (anaesthesia systems display).

Question 2

Alternative oxygen, oxygen flush, Agent delivery checks.

Answer 2

1. Turn on alternative flow and set oxygen flow meter to 6L/min, confirm gas analyser reads 100% +/-3% on ASD and patient monitor.
2. Select end case, end case now.
3. Select checkout.
4. Attach 2L reservoir bag to the ACGO.
5. Using the oxygen flush fill the reservoir bag and observe that it fills within 4 seconds, indicating a 35-75 L/min delivery of oxygen.
6. Remove the reservoir bag.
7. Switch ACGO to circle.
8. Check negative pressure device for leak prior to test.
9. Select ‘Low P leak’ follow on-screen instructions 1-4.
10. Select pass/fail whichever appropriate.
11. Select back.
12. Insert desflurane and ensure that the correct agent is identified on the display and it matches the cassette.
13. Select agent delivery and follow not screen instructions 1-6.
14. Press back when complete.
15. Insert isoflurane cassette if present and repeat agent delivery.

Question 3

Circuit and absorber checks

Answer 3

Absorber checks

1. Check the colour of the soda lime.
2. Take the absorber out of circuit.

Circuit checks

1. Connect circuit and attach breathing filter to distal end. Connect reservoir bag to filter.
2. Extend circuit tubing out and ensure it is clean and correctly connected to the machine.
3. Select start case, start case now, then end case, end case now - to observe circuit pressure gauge on ASD.
4. Close APL valve. Pressurise the circuit using the oxygen flush until the airway pressure reads just above 30cmH2O. Allow pressure to settle and confirm pressure holds for at least 5 seconds.
5. Replace absorber canister in circuit, ensuring it is seated correctly.
6. Re-pressurise as in 4 and confirm pressure holds for at least 5 seconds.
7. Open APL valve. Observe passive spilling of the reservoir bags but ensure bags do not empty completely ensuring scavenging is patent but not overactive.
8. Close APL valve. Squeeze both bags alternately ensuring free movement of the uni-directional valves and ensure that no resistance is detected in the circuit.
9. Open APL valve and squeeze both bags simultaneously ensuring even and easy gas spill.

Question 4

Ventilator Tests

Answer 4

1. Set the Bag/Vent switch to Vent.
2. Fill the bellows using the oxygen flush.
3. Observe bellows do not drop for 10 seconds.
4. Select start case, start case now and ok.
5. At an oxygen flow of 6L/min observe on ASD that the Paw does not rise over 5cmH2O confirming that the pressure relief valve is working correctly.
6. Scroll to set oxygen flow at basal rate.
7. Ventilator settings;
   Mode: volume control ventilation
   Tidal volume: 500ml
   Rate: 12/min
   I:E ratio: 1:2
   P limit: 40
   PEEP: off
8. Set the bag/vent switch to bag and back to Vent to start the ventilator cycling.
9. Ensure; the bellows cycle during mechanical ventilation and end tidal volume (Vte) reaches set tidal volume (Vt) +/-10% within 6-8 breaths. (to see Vte select spectrometry button).

High pressure alarm

1. Squeeze reservoir bag to simulate high airway pressure. Confirm that ‘ppeak high’ (high airway pressure) appears on the ASD and that an audible alarm sounds.
2. Re-fill the bellows using the oxygen flush and cycle ventilator for 2-3 breaths to ensure bellows not unseated.

Low pressure alarm
1. As ventilator cycles, remove reservoir bag from the circuit. Confirm ‘unable to drive bellows’ appears on the ASD and that an audible Alarm sounds. Ensure AD then displays ‘ppeak low. leak?’ and that the audible alarm commences.

• Return bag/vent switch to bag.
• Select end case, end case now.
• Select checkout to display completed checks.
• Attach appropriate face mask.
• Confirm APL valve open.

Question 5

High pressure system check

Answer 5

1. Disconnect all wall gas supplies.
2. Open all gas cylinder valves until pressure is registered in the gas supplies kpa window on the ASD then close all valves.
3. Observe that the pressure does not drop confirming that no leak is present. Drain the machine. Turn oxygen cylinder on. Start case with 6L/min flow. Set 25% oxygen 75% nitrous oxide. Turn oxygen cylinder off. Drain the machine with the oxygen flush.
4. Switch to the ACGO and attach the filter with the gas sampling line to the ACGO.
5. Open oxygen cylinder.
6. Select start case, start case now and observe oxygen flow is 6L/min.
7. Check pressure registers above 5000 kpa and analyse contents. Gas analysis should confirm 100% oxygen +/- 3%.
8. Close oxygen cylinder and drain oxygen from the machine using the oxygen flush.
9. Check in alarm setup that the low oxygen alarm is set at 18% or higher.

If an air cylinder is present;

1. Check cylinder contents is above 5000 kpa.
2. Select yes to use air only in the oxygen supply fail menu.
3. The gas % window on the ASD should confirm 21% oxygen +/-3%.
4. Close air cylinder and drain machine of air.

If a nitrous oxide cylinder is present;

1. Open nitrous oxide cylinder and ensure nitrous oxide is available by confirming pressure of nitrous oxide.
2. Check no nitrous oxide detected in gas % window on ASD.
3. Analyse contents as follows;
   a. Turn on the oxygen cylinder.
   b. Select gas setup on ASD.
   c. Select yes to end air only (if applicable) and reselect gas setup.
   d. Select nitrous oxide and oxygen at 50% then close.
   e. At flows of 2L/min analyse gas contents observing 50% oxygen : 50% nitrous oxide on ASD +/- 3%.
   f. Turn off nitrous oxide cylinder and drain. Turn up flows to drain.
   g. Select oxygen and turn up to 100%.
   h. Turn off oxygen cylinder and drain.

(if only one cylinder key - leave on oxygen cylinder).

Question 6

Low pressure system checks

Answer 6

1. Plug oxygen into wall supply and tug test.
2. Confirm oxygen supply reads approximately 410kpa.
3. Confirm 100% oxygen +/-3%
4. Check auxiliary flow meter and test to maximum flows.
5. Disconnect oxygen and drain the machine using the oxygen flush.
6. Plug medical air probe into the wall supply and tug test.
7. Confirm medical air supply reads approximately 410kpa.
8. Select yes to use air only.
9. Confirm 21% oxygen +/-3% on the ASD.
10. Disconnect wall supply probe and drain the machine of air.
11. Plug nitrous oxide into wall supply and tug test.
12. Confirm nitrous oxide supply reads approximately 410kpa.
13. Check no nitrous oxide detected in the gas % window on the ASD.
14. Reconnect oxygen probe at wall supply and select gas setup and yes to end air only.
15. Reselect gas setup and select nitrous oxide and close.
16. Set oxygen to 50% (at 2L/min gas flow). Confirm 50% oxygen to 50% nitrous oxide mix on the ASD and patient monitor (+/- 3%).

Anti hypoxic device

1. Change oxygen to 25%.
2. Confirm with gas analysis on the ASD and patient monitor that no less than 25% oxygen +/-3% can be delivered.

Oxygen failure alarm test

1. Set gas flow to 4L/min.
2. Disconnect oxygen wall supply.
3. Confirm nitrous oxide supply is cut off and that the audible oxygen failure alarm is sounding.
4. Confirm ASD displays “oxygen supply pressure low”.
5. Reconnect wall supplies of all gases and tug test pipeline connections including suction and scavenging.
6. Reconfirm pressure display registers gas supply.

Question 7

Level 3 machine check

Answer 7

Circuit checks
Check any changed or new items in the breathing circuit; filters, angle pieces, catheter mounts.
1. Attach new breathing filter to distal end of circuit and connect gas sampling line a.d reservoir bag to filter.
2. Extend circuit tubing out and ensure it is clean and correctly connected to the machine.
3. Select start case, start case now, then end case, end case now if circuit pressure gauge is not visible on the ASD.
4. Close APL valve. Pressurise the circuit using the oxygen flush button until the airway pressure gauge reads just above 30cmH2O. Allow pressure to settle and confirm pressure holds for at least 5 seconds.
5. Open APL valve. Observe passive spilling of the reservoir bags but ensure bags do not empty completely confirming scavenging is patent but not overactive.
6. Close APL valve. Squeeze reservoir bags simultaneously ensuring free movement of the unidirectional valves and ensure that no resistance is detected in the circuit.
7. Open the APL valve and squeeze both reservoir bags simultaneously ensuring even and easy gas spill.
8. Select checkout and circuit leak following the instructions on the ASD.

Agent Delivery Checks
If a cassette has been changed between cases perform this check as per level 2 guidelines;
1. Select agent delivery and follow on-screen instructions.
2. Select checkout and then low p leak (only for a non-desflurane cassette) and follow on-screen instructions.
3. Select pass/fail whichever appropriate. (if a cassette fails it should be removed from the machine for service).
4. Select back.
5. Switch the ACGO to circle.

Suction tests
Replace any used suction items - yankauer suction, suction catheter, suction tubing, suction liner and recheck as follows;
1. Check suction tubing is clean and approximately 2-3m in length.
2. Check suction unit is assembled correctly.
3. Turn suction on to Max setting and listen to flow to confirm system patent from suction tip to suction gauge.
4. Occlude suction tubing and ensure a negative pressure of approximately -60kpa is achieved within 10 seconds.

Monitoring
Ensure all monitoring is cleaned between patients as per hospital protocol.
1. Check pulse oximetry present and functioning.
2. ECG leads present.
3. Blood pressure cuff present and appropriate size for patient.
4. Temperature probe and cable available.
5. Stethoscope present.
6. Nerve stimulator available.
7. Pressure cables available.

Airway Equipment
Replace all soiled/disposable airway equipment and perform the following checks as per the level 2 guidelines;
1. Check for the presence and function of 2 laryngoscope blades - sizes appropriate for my patient.
2. Check availability of the following essential items;
a. mask
b. marks forceps
C. airways oropharyngeal and nasopharyngeal
d. intubation aids bougies and stylets
e. selection of LMAs
f. selection of ETTs
g. Ties/tapes
h. Syringe

Drugs
Check suxamethonium and emergency drug levels are adequate. Ensure adequate stock of all other drugs.

Other

a. Reconfirm the presence of the resuscitation device.
b. Appropriate hand hygiene observed throughout level 2 & 3 checks.

If the circuit has been changed - checkout vent and gas and follow on-screen instructions. (This allows the aisys cs2 to recalculate the new circuit compliance. Failure to do this may result in inaccurate volumes being delivered to the patient by the ventilator.)