Spirometry testing plays an important role in the diagnosis and management of lung disease.
It may be performed for a variety of purposes that are summarized in Table 1. Most commonly, spirometry is used to help establish clinical diagnosis, quantify severity of lung function impairment, assess response to medications (e.g. corticosteroids, bronchodilators) and patients prognosis.
Diagnosis
To evaluate symptoms, signs, or abnormal laboratory test results
To measure the physiologic effect of disease or disorder
To screen individuals at risk of having pulmonary disease
To assess preoperative risk
To assess prognosis
Monitoring
To assess response to therapeutic intervention
To monitor disease progression
To monitor patients for exacerbations of disease and recovery from exacerbations
To monitor people for adverse effects of exposure to injurious agents
To watch for adverse reactions to drugs with known pulmonary toxicity
Disability/impairment evaluations
To assess patients as part of a rehabilitation program
To assess risks as part of an insurance evaluation
To assess individuals for legal reasons
Other
Research and clinical trials
Epidemiological surveys
Derivation of reference equations
Preemployment and lung health monitoring for at-risk occupations
To assess health status before beginning at-risk physical activities
Table 1. Indications for Spirometry
Source: Graham BL et al. Standardization of Spirometry 2019 Update. An Official American Thoracic Society and European Respiratory Society Technical Statement. Am J Respir Crit Care Med. 2019 Oct 15;200(8):e70-e88. doi: 10.1164/rccm.201908-1590ST. PMID: 31613151; PMCID: PMC6794117.
When diagnosing certain diseases such as obstructive lung diseases including asthma and COPD, a bronchodilator may need to be given so that spirometry can be performed pre and post the bronchodilator to assess for any effect (bronchodilator responsiveness testing). When this test is indicated to establish the diagnosis, there are specific withhold times for treatments that the patient may already be taking so that a true result may be obtained. The module on The table below from the 2019 spirometry update shows the suggested withhold times for this test. If the aim of the test is to determine whether the patient's spirometric lung function can be further improved in addition to their regular treatment, then the patient may continue with his or her regular medication before the test. Adherence should be checked before undertaking testing.
| Bronchodilator Medication | Withholding Time |
| SABA (e.g., albuterol or salbutamol) | 4-6 h |
| SAMA (e.g., ipratropium bromide) | 12 h |
| LABA (e.g., formoterol or salmeterol) | 24 h |
| Ultra-LABA (e.g., indacaterol, vilanterol, or olodaterol) | 36 h |
| LAMA (e.g., tiotropium, umeclidinium, aclidinium, or glycopyrronium) | 36-48 h |
Table 2. Bronhodilator withholding times
Source: Graham BL et al. Standardization of Spirometry 2019 Update. An Official American Thoracic Society and European Respiratory Society Technical Statement. Am J Respir Crit Care Med. 2019 Oct 15;200(8):e70-e88. doi: 10.1164/rccm.201908-1590ST. PMID: 31613151; PMCID: PMC6794117.
Patients should be asked if they have conformed to the pretest requirements and any deviations from this should be noted. The table below from the ERS 2019 update should be used.
Table 3. Activities that should be avoided before spirometry
Source: Graham BL et al. Standardization of Spirometry 2019 Update. An Official American Thoracic Society and European Respiratory Society Technical Statement. Am J Respir Crit Care Med. 2019 Oct 15;200(8):e70-e88. doi: 10.1164/rccm.201908-1590ST. PMID: 31613151; PMCID: PMC6794117.
Spirometry is generally considered to be a low-risk procedure. Most patients perceive spirometry as a necessary test that they tolerate well. However, it can cause discomfort and potential harm in some patients. The potential harm is related to an increase in intrathoracic, intra-abdominal and intracranial pressure during the forced maneuver. This can affect abdominal and thoracic organs, increase myocardial demand, cause changes in venous return and systemic blood pressure and expansion of the chest wall and lungs. The new 2019 ATS/ERS spirometry contraindications update is presented in Table 4. Traditionally, thoracic and abdominal aneurysm were also considered a relative contraindication for spirometry. Limited data showed no adverse events in aortic aneurysms 5-13cm in size, and thoracic aortic aneurysms 5-8cm in size.
Due to increases in myocardial demand or changes in blood pressure
Acute myocardial infarction within 1 wk
Systemic hypotension or severe hypertension
Significant atrial/ventricular arrhythmia
Noncompensated heart failure
Uncontrolled pulmonary hypertension
Acute cor pulmonale
Clinically unstable pulmonary embolism
History of syncope related to forced expiration/cough
Due to increases in intracranial/intraocular pressure
Cerebral aneurysm
Brain surgery within 4 wk
Recent concussion with continuing symptoms
Eye surgery within 1 wk
Due to increases in sinus and middle ear pressures
Sinus surgery or middle ear surgery or infection within 1 wk
Due to increases in intrathoracic and intraabdominal pressure
Presence of pneumothorax
Thoracic surgery within 4 wk
Abdominal surgery within 4 wk
Late-term pregnancy
Infection control issues
Active or suspected transmissible respiratory or systemic infection, including tuberculosis
Physical conditions predisposing to transmission of infections, such as hemoptysis, significant secretions, or oral lesions or oral bleeding
Spirometry should be discontinued if the patient experiences pain during the maneuver. Relative contraindications do not preclude spirometry but should be considered when ordering spirometry. The decision to conduct spirometry is determined by the ordering healthcare professional on the basis of their evaluation of the risks and benefits of spirometry for the particular patient. Potential contraindications should be included in the request form for spirometry.
Table 4. Spirometry contraindications
Source: Graham BL et al. Standardization of Spirometry 2019 Update. An Official American Thoracic Society and European Respiratory Society Technical Statement. Am J Respir Crit Care Med. 2019 Oct 15;200(8):e70-e88. doi: 10.1164/rccm.201908-1590ST. PMID: 31613151; PMCID: PMC6794117.
Spirometry contraindications are considered to be relative, and the decision to conduct spirometry in patients with relative contraindications is determined by the ordering physician on the basis of risk-benefit evaluation for the particular patient. The location where spirometry is performed is likely to affect this decision as if you are in a specialist centre with access to emergency care, it may be more appropriate to test the patient than if you are performing spirometry in the community. In the latter case, referral to a specialist centre may be required if waiting for the suggested amount of time is not an option. The usual waiting time after major (brain, thoracic and abdominal) surgery is 4 weeks. Acute or suspected transmissible respiratory infection is also considered a relative contraindication for spirometry. Guidance for performing spirometry during COVID-19 can be found in a separate document: McGowan A, Laveneziana P, Bayat S, et al. International consensus on lung function testing during the COVID-19 pandemic and beyond. ERJ Open Res 2022; 8: 00602-2021 [DOI: 10.1183/23120541.00602-2021].
As spirometry requires cooperation between the patient and the operator, sometimes, it is not possible to perform spirometry in patients who are confused/demented or very unwell. Spirometry should be discontinued if the patient experiences pain during the maneuver, or FEV1 drops ≥ 20% from the baseline.