Pulmonary Laboratory Testing

Exercise-Induced Hypoxemia Test (Level 1)

Does the patient’s oxygen saturation decrease with exercise? If so, how much oxygen therapy is required to prevent significant desaturation?

This test is designed for pulmonary or cardiac disease patients with exertional dyspnea to determine if they need oxygen therapy during exercise. Measurements include a single-lead electrocardiogram (12-lead ECG available on request), blood pressure, arterial oxygen saturation by oximetry, as well as the monitoring of clinical signs and symptoms during exercise on a treadmill or stationary bicycle. If significant oxygen desaturation occurs, the patient is re-tested with supplemental oxygen therapy to establish the proper liter flow.

Pulmonary Exercise Tolerance (Level 2)

What is the patient’s ability and safety to perform exercise?

This exercise test measures the patient’s cardiopulmonary responses to a progressive increase in workload up to the maximum level tolerated by the patient. It is useful in assessing the patient’s exercise capability and/or fitness level. Measurements include those of the Level 1 exercise test plus ventilation, oxygen uptake, carbon dioxide production, respiratory exchange ratio, oxygen pulse, and anaerobic threshold. An Exercise Prescription for exercise reconditioning can also be generated from this test.

Exertional Dyspnea Evaluation (Level 3)

Why does the patient become dyspneic with exercise?

This exercise test evaluates patients who have dyspnea on exertion, but whose tests of cardiopulmonary function at rest are non-diagnostic. The differential diagnosis includes pulmonary vascular occlusive diseases, interstitial lung diseases, metabolic disorders, or subclinical pulmonary or cardiac diseases not identified at rest. This test can also help separate cardiac and pulmonary causes of dyspnea in patients who have disorders of both organ systems. Measurements include those of the previous tests plus arterial blood gas analysis during rest and exercise.

Exercise-Induced Bronchospasm Test

Does the patient who develops cough, chest tightness or wheezing during, or after exercise have subclinical asthma (hyperreactive airways)?

Screening spirometry (FEV1) is performed before and after moderate exercise to evaluate for exercise-induced airway obstruction. The patient is asked to exercise on a treadmill near his predicted maximum heart rate for up to six minutes. A single-lease electrocardiogram is monitored. If bronchospasm occurs, an aerosol bronchodilator can be administered to evaluate its effectiveness.

Special Pulmonary Physiology Test

Bronchial Challenge Test

This test is designed to evaluate patients with unexplained cough or episodes of chest tightness who are suspected of having occult or subclinical asthma, but whose spirometry is non-diagnostic. The patient’s airflow (FEV1) is measured before and after inhalation of increasing concentrations of methacholine used to stimulate the airways in order to identify any airway hyperreactivity.

Selecting a Test

Lung Function Testing

Includes a wide variety of measurements to evaluate the status of a patient’s lung health and/or investigate the cause of respiratory symptoms. This generally includes measuring lung volumes and flow rates at rest, as well as assessing gas exchange and acid-base status with arterial blood gas analysis. Some patients also require physiologic testing during exercise or other special circumstances to further understand their symptoms and lung function. The tests are provided to answer these diagnostic questions.

Please call if you have questions about any of the tests or wish to schedule an appointment.

Appointments for outpatients can be made by calling 949/764-5500. Order forms are available for your office use upon request. Inpatient tests can be scheduled through the Unit Secretary.

Pulmonary Function Tests

Pulmonary Screen (Spirometry)

This test is designed to assess the airways for obstruction, e.g., patients with asthma, COPD, or other airways diseases. It includes the Forced Vital Capacity (FVC), Timed Expiratory Lung Volume (FEVl), Peak Flow, and measurements of small airways function (FEF25075%). A flow-volume curve is also routinely transcribed and interpreted to evaluate for possible large airway obstruction.

Pre/Post Bronchodilator Screen

A Pulmonary Screen is performed before and after administering an aerosol bronchodilator to assess airway responsiveness to that medication.

Full Pulmonary Function Test

This test provides an overall assessment of the patient’s resting lung function. A Pre/Post Bronchodilator Screen is performed along with measurements of Total Lung Capacity And Diffusing Capacity (DLCO). In addition to evaluating airway function, this test identifies any loss of lung volume that might occur in restrictive lung diseases. The DLCO measures any functional abnormality of the pulmonary capillary bed, e.g., emphysema, pulmonary vascular occlusive diseases, interstitial lung diseases. Total Lung Capacity and Diffusing Capacity can each be ordered separately.

Blood Sampling

Diagnostic Blood Sampling is used to evaluate the body’s ability to pickup oxygen. The method of obtaining the Blood Sample will be based upon individual patient needs.


This is a non-invasive way to quickly estimate oxygen saturation. The color of blood is measured as it passes under a light probe placed on the patient’s fingertip. The measurements are similar to those obtained from blood samples and are particularly useful for continuous bedside monitoring, such as during changes in O2 therapy or other procedures which may affect the patient’s oxygenation, e.g., mechanical ventilation, chest physiotherapy, endoscopy.

Physiologic Shunt Study

This test measures the physiologic right-to-left shunt (venous admixture) in patients with unexplained hypoxemia, e.g., patent foramen ovale, congenital right-to-left shunt. Arterial blood gases are obtained while the patient breathes room air and again during exposure to 100% oxygen.