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
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
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
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.
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,
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.