How to perform the procedure including reading and storing the results

Overview

To perform spirometry correctly it is important that the procedure is conducted to internationally agreed quality assurance standards. To achieve this, communication with the patient is key and this is covered within the "Communication with the patient" section. Here we will concentrate on how the test is quality assured, how the test is performed, in terms of the acceptability criteria to ensure a good quality test, but also the repeatability criteria that ensure the test is maximal and the best the patient is able to achieve at that point in time. We will also look at the important parameters to be mindful of during the procedure and how the results should be reported appropriately.

Aims

To demonstrate how to quality assure the spirometry equipment
To demonstrate the performance of quality assured spirometry to international standards
To understand the important parameters that should be available during the manoeuvre
To understand the appropriate storage of spirometry results

Checklist (spirometer)

Calibrate the device accordingly.
Use clean mouthpiece connected to a bacterial filter.

Checklist (patient)

Check patient is safe to undertake the assessment.
Make the patient feel at ease.
Check patient identity.
Measure the height and weight of the patient without shoes.
Ensure proper sitting position for the patient and adjust the height of the mouthpiece so that the neck is in a neutral position.
Keep the instruction simple and concise.
Explain that a minimum of three manoeuvres are needed for the test. Repeating the procedure doesn't mean that the test wasn't done correctly.
Perform slow vital capacity before any forced manoeuvres.
Measure the relaxed vital capacity (also known as slow vital capacity)

Instruct the patient to breathe normally. Wait for at least three stable breaths before starting the procedure.
Option 1: measure the EVC = instruct the patient to inhale up to TLC then without holding the breath exhale to RV.
Option 2: measure the IVC = instruct the patient to exhale to RV then inhale deeply up to TLC

Assessment of the slow vital capacity

Ensure patient breathing at FRC prior to manoeuvre.
Ensure initial inspiration is maximal, i.e. gradual plateau of volume time curve.
Ensure expiration is relaxed, but not slow, and there is a gradual plateau in the volume time curve to residual volume.

Measure the forced vital capacity (also referred to as forced expiratory vital capacity)

Instruct the patient to breathe normally. Wait for stable breathing before starting the procedure.
Instruct the patient to inhale rapidly up to TLC and immediately exhale as forcefully and as sudden as possible without hesitation.
Actively coach and encourage the patient to continue until an expiratory plateau is reached (<25ml change for >1sec.
Immediately instruct the patient to rapidly inhale as deep as possible.
Explain that a minimum of three manoeuvres are needed for the test. Repeating the procedure doesn't mean that the test wasn't done correctly.

Assessment of the forced vital capacity

Ensure initial inspiration is maximal, i.e. gradual plateau of volume time curve.
Ensure expiration is forced and meets acceptability criteria, and there is a plateau in the volume time curve to residual volume that again meets acceptability criteria.
If performing a maximal flow-volume loop then second inhalation must also be maximal flow to Total Lung Capacity ensuring minimal difference between FEVC and FIVC.

Coach the patient throughout the test. Check Module Communication with the patient/coaching for more details.
Choose the best results based on acceptability, usability and reproducibility criteria (see Table 1).

	Required for Acceptability		Required for Usability
Acceptability and Usability Criterion	FEV₁	FVC	FEV₁	FVC
Must have BEV ≤5% of FVC or 0.100 L, whichever is greater	Yes	Yes	Yes	Yes
Must have no evidence of a faulty zero-flow setting	Yes	Yes	Yes	Yes
Must have no cough in the first second of expiration*	Yes	No	Yes	No
Must have no glottic closure in the first second of expiration*	Yes	Yes	Yes	Yes
Must have no glottic closure after 1 s of expiration	No	Yes	No	No
Must achieve one of these three EOFE indicators: 1. Expiratory plateau (≤0.025 L in the last 1 s of expiration) 2. Expiratory time ≥15 s 3. FVC is within the repeatability tolerance of or is greater than the largest prior observed FVC^†	No	Yes	No	No
Must have no evidence of obstructed mouthpiece or spirometer	Yes	Yes	No	No
Must have no evidence of a leak	Yes	Yes	No	No
If the maximal inspiration after EOFE is greater than FVC, then FIVC − FVC must be ≤0.100 L or 5% of FVC, whichever is greater^‡	Yes	Yes	No	No
Repeatability criteria (applied to acceptable FVC and FEV₁ values) Age >6 yr: The difference between the two largest FVC values must be ≤0.150 L, and the difference between the two largest FEV₁ values must be ≤0.150 L Age ≤6 yr: The difference between the two largest FVC values must be ≤0.100 L or 10% of the highest value, whichever is greater, and the difference between the two largest FEV₁ values must be ≤0.100 L or 10% of the highest value, whichever is greater

Definition of abbreviations: BEV = back-extrapolated volume; EOFE = end of forced expiration; FEV_0.75 = forced expiratory volume in the first 0.75 seconds; FIVC = forced inspiratory VC.

* For children aged 6 years or younger, must have at least 0.75 seconds of expiration without glottic closure or cough for acceptable or usable measurement of FEV_0.75.

^† Occurs when the patient cannot expire long enough to achieve a plateau (e.g., children with high elastic recoil or patients with restrictive lung disease) or when the patient inspires or comes off the mouthpiece before a plateau. For within-maneuver acceptability, the FVC must be greater than or within the repeatability tolerance of the largest FVC observed before this maneuver within the current prebronchodilator or the current post-bronchodilator testing set.

^‡ Although the performance of a maximal forced inspiration is strongly recommended, its absence does not preclude a maneuver from being judged acceptable, unless extrathoracic obstruction is specifically being investigated.

Table 1: Summary of Acceptability, Usability, and Repeatability Criteria for FEV₁ and FVC

From: Standardization of Spirometry 2019 Update An Official American Thoracic Society and European Respiratory Society Technical Statement. Brian L. Graham et al. Am J Respir Crit Care Med 2019. 200:e70-e88

Video 1: Calibration

Video 2: Measure height and weight - CUT OUT RELEVANT PART

Video 3: How to perform the slow vital capacity

Video 4: How to perform the forced vital capacity

CDN Connection Issue

How to perform the procedure including reading and storing the results

How to perform the procedure including reading and storing the results

Overview

Aims

Checklist (spirometer)

Checklist (patient)

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