Pulmonary Tests and Procedures in Children:
Pulmonary tests are an important aspect of diagnosing lung disorders in children. Dr. Peter Schochet and Dr. Hauw Lie are board certified pediatric pulmonologists that care for children with asthma and other lung disorders. They perform physical exams and provide or order pediatric pulmonary tests that include comprehensive diagnostic testing as well as numerous diagnostic and therapeutic procedures:
Pulmonary Tests and Procedures
- Flexible Fiber Optic Bronchoscopy
- Polysomnography (Sleep Study) Interpretation
- Simple Exercise Testing
- Pulse Oximetry
- Radiological Imaging Studies
- Computerized axial tomography (CAT or CT) scan
- Magnetic Resonance Imaging (MRI)
- Oxygen and Carbon Dioxide Monitoring
- Pulmonary Function Testing
- Fraction of Exhaled Nitric Oxide Testing
- Spirometry (Lung Function Test) and Bronchodilator Response
- Sweat Test
Pulmonary function testing (PFT) is a series of breathing tests that measure lung function. PTF is used to determine how efficiently the lungs take in and exhale air and transfer oxygen to the blood. PFT is usually performed to:
- Diagnose respiratory conditions
- Assess lung and airway growth
- Monitor chronic respiratory conditions
- Evaluate medication effectiveness
Pulmonary function testing may include:
- Exercise testing
- Lung volume measurements
A spirometry test is the most common pulmonary function test that is used to measure lung function. During a spirometry test, the patient breathes into a mouthpiece, usually while sitting in a special booth called a body plethysmograph. The mouthpiece is connected to a spirometer that records the amount and rate of air being inhaled and exhaled. Spirometry testing is used to diagnose certain lung conditions, including:
- Chronic obstructive pulmonary disease (COPD)
- Pulmonary fibrosis
Spirometry testing can also be used to assess medication effectiveness or change in a pulmonary condition.
During the spirometry test, your child will be asked to forcefully exhale into the mouthpiece while wearing a nose clip to ensure all of the air is measured. The spirometry test typically requires at least 3 long blasts of air and takes just a few minutes. Your child may be asked to use a bronchodilator medication (Albuterol) after the test and repeat the spirometry test 15 minutes later to assess lung response to the bronchodilator.
Spirometry testing will measure:
- Forced vital capacity (FVC): The amount of air forcefully exhaled after a deep breath.
- Forced expiratory volume in 1 second (FEV1): The amount of air forcefully exhaled in 1 second.
Measuring the fraction of exhaled nitric oxide (FeNO) is a useful method of evaluating therapy in individual patients. It has proved useful as a noninvasive marker of airway inflammation, in order to guide adjustment of the dose of inhaled corticosteroids.
Pediatric polysomnography (PSG) is a sleep study test used in diagnosing sleep disorders in children. During polysomnography, information is collected regarding:
- Brain waves
- Blood oxygen levels
- Eye and leg movements
- Respiratory effort or events
- Heart rhythm
Polysomnography is typically performed at night in a sleep center laboratory setting under the supervision of experienced pediatric technologists. The patient is closely monitored overnight, and the information obtained from the polysomnogram is then analyzed by scoring several variants of sleep including:
- Sleep onset latency: Time elapsed from lights out to onset of sleep.
- Sleep stages: REM (Rapid Eye Movement) sleep, slow wave sleep, and 2 stages of light sleep.
- Sleep efficiency: Minutes of sleep divided by minutes in bed.
- Breathing irregularities
- Leg movements
- Body position
- Oxygen saturation
- Cardiac rhythm abnormalities
Once the polysomnogram is scored, your doctor will interpret the data. PSG is beneficial in diagnosing sleep apnea, hypoventilation syndromes, and other sleep-related disorders.
Pulmonary function can often be evaluated through the body’s response to exercise. Depending on the pulmonary condition being tested, your child may be recommended for:
- 6- minute walk test (simple pulmonary stress test): Measures how far the patient can walk in 6 minutes. At the conclusion of the test, the child rates shortness of breath from 0-10 on a special scale. A finger probe is used to evaluate oxygen levels and heart rate. Slowing down or resting is permitted if necessary.
- Cardio pulmonary exercise test (CPET): 12-15 minute test that measures breathing variations, as well as blood and oxygen flow to the muscles, during exercise. Patient walks on a treadmill or pedals a stationary bicycle while breathing into a mouthpiece. Other monitoring devices are used to measure vital functions as resistance is increased. Monitoring continues while the child rests afterwards.
- Exercise-induced asthma challenge: Measures functionality of the lungs before and after exercise. Testing is similar to CPET, but for a shorter time period and with no resistance. Used to identify exercise-induced asthma, to set exercise limits, or to evaluate the effectiveness of current medications.
- Pulse Oximetry: Pulse oximetry is a non-invasive test used for monitoring oxygen saturation in the blood. A sensor device is placed on the patient’s body, usually the fingertip, which transmits wavelengths of light that pass through a pulsating capillary bed to a photodetector. The photodetector measures absorbency of the wavelengths to determine blood oxygen levels. Often used overnight to determine if oxygen levels drop during sleep.
Several radiological imaging studies may be used in determining pulmonary conditions or disorders. Thoracic (chest) imaging can be instrumental in diagnosing, as well as evaluating treatment effectiveness in conditions such as:
- Pulmonary embolism
- Cystic fibrosis
Radiological imaging studies include:
X-ray: Provides images of the internal organs. A chest x-ray can be used to evaluate the lungs and help diagnose and monitor certain lung conditions, such as pneumonia or emphysema.
Computerized Axial tomography (CAT or CT) scan: Combination of special x-ray equipment and computer technology to produce more detailed imaging. The horizontal (axial) images provide a cross-sectional view of the organs. Often used to identify pulmonary embolism.
Magnetic Resonating Imaging (MRI): Provides 3- dimensional pictures of the organs using a magnetic field and radio wave energy. Can detect problems not seen on CT scans or x-rays without the use of radiation.
Ultrasound: High frequency sound is used to produce images of what’s happening inside of the body in real time. Used to confirm conditions such as pneumonia, pulmonary edema, and pneumothorax.
Oxygen and carbon dioxide monitoring involves attaching electrode-containing sensors to the skin to measure oxygen and carbon dioxide levels in the blood. The electrodes warm the skin, which causes capillary dilation resulting in an increase in blood flow and oxygen delivery to the skin surface. The sensors are connected to a monitor where the oxygen and carbon dioxide levels are displayed.
Oxygen and carbon dioxide levels may also be measured by performing an arterial blood gas (ABG) test. An ABG test uses the blood taken from an artery to measure:
- Partial pressure of oxygen
- Partial pressure of carbon dioxide
- Oxygen content and saturation values
- ABG testing can identify how efficiently the lungs remove carbon dioxide from the blood and move oxygen into the blood.
Sweat testing is the most reliable method for diagnosing cystic fibrosis (CF). Sweat testing involves measuring the amount of chloride and sodium (salt) present in the patient’s sweat. During the sweat test, small electrodes and gauze are placed on the forearm or leg while a special machine stimulates sweating at the area under the electrodes. The gauze absorbs the sweat, which is then analyzed for chloride content. Stimulation is administered in 5-minute increments.
Sweat testing is not painful and usually takes approximately 30 minutes. Results of the sweat test are generally available the same day.
Our offices are located in the Texas Health Presbyterian Hospital Plano, Medical Office Building 1 (MOB 1). If your child is in need of a specialist in pediatric pulmonology, please call us or submit an online appointment request.