Instructions for an expiratory maneuver
- The patient may be seated
or standing (makes no difference to test results (ref. 1).
See to it that the patient is comfortable, have the patient
loosen or remove all restricting clothing.
- apply the noseclip with a tissue, hand
a tissue out to the patient for use when removing the mouthpiece.
Ask the patient to gently press against the noseclip to test
- hand the measuring device to the patient
- ask the patient to place the mouthpiece
in the mouth, chin slightly elevated, the neck stretched, and
- allow the patient to get accustomed
to breathing into the apparatus;
- when the patient reaches the end of
a normal expiration, quickly tell him or her to
a slow deep breath …. as deep as you can ….. deep
- do not make the patient pause at the level of the total lung capacity but say
blow as hard and as fast as you can’,
and while the patient blows out encourage to blow longer by
blow … keep it coming … a little longer ….
get it all out’.
Particularly in patients with obstructive lung disease an effort
should be made to extend the expiratory effort to 6 s or more.
The trunk and head should remain upright throughout the maneuver.
- take the mouthpiece out of the patient’s
mouth with a piece of tissue, but leave the noseclip attached
- allow the patient to rest for a short
time (15-30 s) and explain in what respect the maneuver needs
to be improved, or reassure if it was properly performed
- after a sufficiently long break repeat
the maneuver; if the test maneuvers are repeated too rapidly
the patient will not be able to perform maximally and may develop
symptom of hyperventilation
- check each FVC maneuver for satisfactory
performance, instruct the patient how to improve on it, and
assess whether 3 satisfactory maneuvers meeting criteria for
the reproducibility of FVC and FEV1 have been obtained. Do not press for more than 8 maneuvers;
in a naïve subject you might regard the first 2 as practice
- let the patient remove the mouthpiece
from the mouth using the tissue to collect any saliva, remove
Ref. 1 - Standing or sitting position
does not make a difference
- Pierson DJ, Nick NP, Petty TL. A comparison
of spirometric values with subjects in standing and sitting positions.
Chest 1976; 70: 17-20.
- Townsend MC. Spirometric forced expiratory
volumes measured in standing versus the sitting posture. Am Rev
Respir Dis 1984; 30-123-124. (According to this author in middle-aged
subjects the VC is about 70 mL smaller in the sitting than in
the standing posture).
- Lalloo UG, Becklake MR, Goldsmith CM. Effect
of standing versus sitting position on spirometric indices in
healthy subjects. Respiration 1991; 58: 122-125.