Procedures for recording forced vital capacity
| Check the spirometer calibration |
| Explain the test |
| Prepare the subject |
| Ask about smoking, recent illness, medication use, etc. |
| Measure weight and height without shoes |
| Wash hands |
| Instruct and demonstrate the test to the subject, to include |
| Correct posture with head slightly elevated |
| Inhale rapidly and completely |
| Position of the mouthpiece (open circuit) |
| Exhale with maximal force |
| Perform manoeuvre (closed circuit method) |
| Have subject assume the correct posture |
| Attach nose clip, place mouthpiece in mouth and close lips around the mouthpiece |
| Inhale completely and rapidly with a pause of <1 s at TLC |
| Exhale maximally until no more air can be expelled while maintaining an upright posture |
| Repeat instructions as necessary, coaching vigorously |
| Repeat for a minimum of three manoeuvres; no more than eight are usually required |
| Check test repeatability and perform more manoeuvres as necessary |
| Perform manoeuvre (open circuit method) |
| Have subject assume the correct posture |
| Attach nose clip |
| Inhale completely and rapidly with a pause of <1 s at TLC |
| Place mouthpiece in mouth and close lips around the mouthpiece |
| Exhale maximally until no more air can be expelled while maintaining an upright posture |
| Repeat instructions as necessary, coaching vigorously |
| Repeat for a minimum of three manoeuvres; no more than eight are usually required |
| Check test repeatability and perform more manoeuvres as necessary |
TLC: total lung capacity.