BREATHING SYSTEM

*9. Calibrate the O₂ Monitor

1. Ensure the monitor reads 21% in room air.
2. Verify that the low O₂ alarm is enabled and functioning.
3. Reinstall the sensor in the circuit, and flush the breathing system with O₂ .
4. Verify that monitor now reads greater than 90%.

10. Check Initial Status of Breathing System

1. Set the selector switch to Bag mode.
2. Check that the breathing circuit is complete, undamaged, and unobstructed.
3. Verify that the carbon dioxide absorbent is adequate.
4. Install the breathing circuit accessory equipment (e.g., humidifier, PEEP valve) to be used during the case.

11. Perform a Leak Check of the Breathing System

1. Set all gas flows to zero (or minimum).
2. Close the APL (pop-off) valve, and occlude the Y-piece.
3. Pressurize the breathing system to about 30 cm H₂ O with an O₂ flush.
4. Ensure that pressure remains fixed for at least 10 seconds.
5. Open the APL (pop-off) valve, and ensure that the pressure decreases.