Nitrogen Washout Procedure

Calibration

• Connect Umbilical
  • Connect to the gas calibration port.
  • Select "gas calibration."
  • Wait for the "gas calibration successful" message to appear at the bottom of the screen.

Pre-Test Preparations

• Connect Umbilical
  • Connect to the pre-even flow sensor.
• Patient Setup
  • Instruct the patient to place lips tightly around the mouthpiece.
  • Apply a nose clip to the patient.

Test Execution

• Beginning the Test

  • Select "start" for the patient to begin breathing normally.
  • Observe four countdown breaths in the quality control gauge.
  • Perform four tidal breaths visible on the screen.

• Breathing Instructions

  • Instruct the patient to exhale fully at the bottom of the fifth tidal breath and then inhale maximally.
  • Patient should return to normal breathing.
  • Select the space bar at the end of the tidal breath.
  • Shutter will switch the patient to breathing 100% oxygen.

Monitoring During Test

• Quality Control Gauge
  • Displays respiratory rate, accumulated FRC, percent of nitrogen, and switching error.
  • Ensure switch-in occurs within ±250 mls.

End of Test

• Automatic Stop
  • The test stops automatically when the final N2 percent is ≤ 1.5%.
  • Confirmation will be shown on the QC gauge.

Results

• Scorecard
  • Displays which ATS criteria were met.