The physiologic basis of spirometry

Department of Pediatrics, University of Kentucky College of Medicine, Lexington KY 40536, USA.
Respiratory care (Impact Factor: 1.84). 12/2009; 54(12):1717-26.
Source: PubMed


Spirometry is the most useful and commonly available tests of pulmonary function. It is a physiological test that measures individual inhalation and exhalation volumes of air as a function of time. Pulmonologists and general-practice physicians commonly use spirometry in their offices in the assessment and management of lung disease. Spirometric indices are well validated and easily interpreted by comparison with established normal values. The remarkable reproducibility of spirometry results from the presence of compliant intrathoracic airways that act as air flow regulators during forced expiration. Because of this anatomic arrangement, expiratory flow becomes dependent solely on the elasticity of the lungs and airway resistance once a certain degree of expiratory force is exerted. Insight into this aspect of respiratory physiology can help in the interpretation of spirometry.

Download full-text


Available from: Don Hayes
  • Source
    • "Spirometry is the most useful and commonly available test of pulmonary function [1] . Prediction values are available only for conventional lung function devices using the mouth piece. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Conventional oral spirometry is a commonly used test for respiratory functions. However, the nasal passages are the primary pathway for regulating ventilation and modulating ventilated air. Here, we tested the validity of using the nasal route (nasal spirometry) for the evaluation of respiratory functions. 250 healthy young adults (150 males and 100 females; 17 to 23 years of age) were subjected to two spirometry tests: oral spirometry by using a mouth piece and nasal spirometry by using a face mask. Measurement parameters included: Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume first second (FEV1), FEV1/FVC%, Forced expiratory flow (FEF25/75%). and maximum voluntary ventilation (MVV). In both males and females, only VC was significantly higher in nasal than oral spirometry, while FVC, FEV1, FEV1/FVC % FEF25/75% and MVV were significantly higher in oral than nasal spirometry. Prediction equations for different measurements of nasal spirometry were derived by multiple regression analysis using sex, height, and weight as independent variables. We conclude that nasal spirometry could be a valid procedure which may be more real in expressing normal respiratory functions.
    Full-text · Article · Jan 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The authors examined the extent to which socioeconomic position, behavior-related factors, cardiovascular risk factors, inflammatory markers, and chronic diseases explain the association between poor lung function and mortality in 4,817 participants (68.9% men) from the Whitehall II Study aged 60.8 years (standard deviation, 5.9), on average. Forced expiratory volume in 1 second (FEV(1)) was used to measure lung function in 2002-2004. A total of 139 participants died during a mean follow-up period of 6.4 years (standard deviation, 0.8). In a model adjusted for age and sex, being in the lowest tertile of FEV(1)/height(2) was associated with a 1.92-fold (95% confidence interval: 1.35, 2.73) increased risk of mortality compared with being in the top 2 tertiles. Once age, sex, and smoking history were taken into account, the most important explanatory factors for this association were inflammatory markers (21.3% reduction in the FEV(1)/height(2)-mortality association), coronary heart disease, stroke, and diabetes (11.7% reduction), and alcohol consumption, diet, physical activity, and body mass index (9.8% reduction). The contribution of socioeconomic position and cardiovascular risk factors was small (≤ 3.5% reduction). Taken together, these factors explained 32.5% of the association. Multiple pathways link lung function to mortality; these results show inflammatory markers to be particularly important.
    Full-text · Article · Oct 2010 · American journal of epidemiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Ethnic differences in lung function are recognized. However, most of the modern lung function equipments are pre-programmed with Caucasian reference values. Objective: Measure spirometric values among healthy Saudi male and female adults and compare with the Caucasian reference values in a standard spirometer. Methods: Thirty healthy Saudi young adults (15 males and 15 females; mean age 25 years) participated in this study. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC (%), and maximal voluntary ventilation (MVV) were recorded using a portable digital spirometer. Results: Mean values of FVC, FEV1, FEV1/FVC (%) and MVV for the Saudi subjects were significantly lower than the Caucasians predicted values. Conclusion: Interpretation of lung function tests of Saudi subjects based on the Caucasian prediction equations is generally not valid, as the parameters of lung function tests in Saudi subjects are lower than the Caucasian reference values. The present results underline an urgent need for larger studies to develop prediction equations based on normative spirometric values for Saudi population involving subjects of all ages and both genders living in different climates of the country.
    Full-text · Article · Feb 2011 · Asian biomedicine
Show more