Fortunately, the value of spirometry is being appreciated at long last. Most clinicians now know that both the obstructive and restrictive ventilatory disorders are best identified and monitored through spirometry. A new health care initiative, the National Lung Health Education Program, has recently recommended spirometric testing in all smokers over the age of 45, and in anyone with cough, dyspnea, mucus hypersecretion, or wheeze. The American College of Asthma, Allergy, and Immunology is promoting widespread screening among children, in order to detect asthma early. The recently published third National Health and Nutrition Examination Survey1 has indicated a large population of patients with undiagnosed chronic obstructive pulmonary disease. In response to this, spirometry is being promoted more vigorously than ever for primary care physicians’ offices, clinics, and the workplace.
Spirometry should be viewed as a simple expression of a complex process. Spirometric measurements are a function of effort, muscular coordination, elastic recoil, small airway function, large airway function, and interrelationships between these factors. Spirometry does not identify either small airway or large airway disease, nor does it make a specific diagnosis. Like other physiological measurements such as blood pressure, cardiac output, pulmonary pressure, and echocardiography, any physiological abnormality that is detected needs to be interpreted by a clinician in the context of all of the clinical information available.
It has been a long wait since John Hutchinson, a surgeon, invented the spirometer and then introduced it into the insurance industry of London as a predictor of all cause mortality. It is hoped that this special edition on spirometry will be enlightening and will inform readers about new technological advances that are intended to make spirometry more simple, inexpensive, and user-friendly. N
Thomas L. Petty, MD, is chairman of the National Lung Health Education Program and professor of medicine, University of Colorado Health Sciences Center, Denver.
1. Mannino DM. Obstructive lung disease and low lung function in adults in the United States. Arch Intern Med. 2000;160:1683-1689.