DLCO Test Procedure

Overview

The DLCO (Diffusing Capacity of the Lungs for Carbon Monoxide) test is used to measure how well gases are exchanged between the lungs and the blood.

Steps for Conducting the DLCO Test

1. Setup and Calibration

   • Select the DLCO icon on the equipment.
   • Enter the patient's hemoglobin and/or carboxyhemoglobin levels:
     • Choose 'Manual Entry' and then 'Blood'.
   • Insert the umbilical into the calibration port.
   • Select 'Gas Calibration' at the top left corner of the screen.
   • Wait for the calibration to complete.

2. Patient Preparation and Testing

   • Attach the umbilical clip to the flow sensor.
   • Connect the flow sensor to the patient circuit.
   • Select 'Start' to begin the test.
   • Instruct the patient to:
     • Put the mouthpiece in their mouth tightly and breathe normally for four breaths.
     • After the fourth breath, inhale slightly.
     • Exhale totally and completely to residual volume.
     • Inhale smoothly and quickly (not forcibly) to the very top of their lungs.
     • Hold their breath for 10 seconds.
     • Exhale completely after 10 seconds.

3. Monitoring

   • The top of the gauge turns green when the patient inhales 90% of their vital capacity.
   • The bottom of the gauge turns green when the patient inhales within the correct flow range.
   • The center of the gauge shows the patient's mouth pressure. Ensure it is within user-adjustable upper and lower limits.

4. Quality Control

   • The quality graph displays:
     • Percent of vital capacity.
     • Breath hold time.
     • Inspiratory/expiratory time.

5. Repeat Test (if necessary)

   • Insert the umbilical into the calibration port and select 'Gas Calibration' to recalibrate.
   • Place the umbilical into the prevent and repeat the test.
   • After the second test, if repeatability criteria are met, the repeatability dialog box will appear.
   • The scorecard will display which ATS and ERS standards were met.