Diagnostics

The Pediatric Pulmonary Diagnostic Laboratory at Shands Hospital at the University of Florida is a state of the art facility that provides a wide spectrum of diagnostic testing for children of different age groups in order to diagnose different lung and airway diseases and to measure response to therapy.

The lab can perform all of the following:

Sweat Test

The “sweat test” is the procedure used for diagnosing Cystic Fibrosis (CF). The test can be performed on individuals of all ages. However, sometimes infants do not make enough sweat for the laboratory to analyze. If this is the case, the test would have to be repeated. This test is best performed at an accredited CF center.

Barium Studies

A barium swallow study or an upper GI is a test which requires you/your child to swallow a white liquid that shows up on x-ray. The technician will ask you to swallow the liquid and take a series of pictures that follow the liquid as it travels to the stomach. We are looking for problems with swallowing in the esophagus (the tube that leads from the mouth to the stomach), the windpipe (the upper airway), and the stomach.

Bronchoscopy

A bronchoscopy is a routine test that allows your doctor to see inside of your breathing tubes and to get tissue/secretion samples. These samples can be sent to the lab for various tests.

pH Probe Study

A pH probe study is a test that is done to find out if acid from the stomach is coming up into the esophagus (the tube that leads from the mouth to the stomach). This backwards movement of food and acid is called gastroesophageal reflux.

Sleep Study

A sleep study, or a polysomnogram is a noninvasive, pain-free procedure that requires spending a night in a sleep facility.


Additional Studies

Spirometry

Spirometry measures airflow and air volume as patients breathe in and out (exhales and inhales). During the test, the patient is asked to perform a series of breathing maneuvers which include taking a deep breath and exhaling very rapidly for at least 6 seconds. Parameters obtained during the test are then used for the diagnosis of obstructive lung disease and suspected restrictive lung disease in children 5 years and older. Spirometry is also used for follow up of disease progression and to demonstrate response to therapy.

Plethysmography

Plethysmography is a test used to determine different lung volumes, including volumes of air that are not exhaled by the patient. During this test, the patient is placed inside an airtight glass chamber, “the body box”, while breathing through a tube that passes through the wall to the chamber. Differences in chamber pressures and mouth pressures are measured to calculate gas volumes inside the patient’s lungs.

This method of testing is used to evaluate for possible air trapping in the lungs due to severe airway obstruction and to diagnose restrictive lung diseases.

Lung Diffusion Testing

Lung diffusion testing is used to measure the transfer of gas from the lung’s air sacs to the blood. During the procedure, patients are asked to inhale a harmless amount of carbon monoxide. The difference between the amount of the inhaled carbon monoxide and the exhaled carbon monoxide is used to calculate lung diffusion capacity. Low diffusion capacity is indicative of the presence of interstitial lung diseases (diseases that primarily affect the thin space that separates the lung air sacs from the lung blood vessels).

Infant Pulmonary Function

Testing of pulmonary function in infants includes spirometry, lung volumes, and airway resistance measurements which can be performed in infants by specialized instruments and by specially trained individuals. Since infants are unable to perform most breathing maneuvers required for pulmonary function testing, such maneuvers are performed by air pumps that passively inflate the infant’s lung at safe pressures applied at the patient’s mouth and nose and then rapidly deflate the lungs using an inflatable jacket that applies rapid compression at the infant’s chest.

The procedure is performed while the infant is sedated. The test helps diagnose infants with obstructive or restrictive lung diseases. More importantly, it helps evaluate the degree of airway obstruction caused by chronic lung diseases such as Cystic Fibrosis and chronic lung disease of prematurity. It also helps measure the degree of response to therapy.

Exercise Challenge

Patients with suspected exercise-induced asthma may need an exercise challenge to confirm the diagnosis. The test involves performing spirometry before and after exercising for at least six minutes on a bicycle or a treadmill. A certain drop in lung function after exercise is suggestive of exercise-induced bronchospasm which supports the diagnosis of exercise-induced asthma.

Exercise Challenge with Laryngoscopy

Besides performing spirometry before and after exercise challenge, laryngoscopy may need to be performed in certain patients suspected to have exercise-induced upper airway obstruction due to vocal cord dysfunction (VCD) or laryngomalacia (floppy upper airway).

Laryngoscopy is typically performed right after exercising. A small flexible scope is passed through one of the nasal passages to visualize the vocal cords. A numbing medicine could be placed in the nose before exercising or right before introducing the scope.

Cardiopulmonary Exercise Test

This test is a highly complex form of exercise testing in which patients exercise at increasing intensity until maximal capacity is reached or symptoms are reproduced. During the exercise, patients are extensively monitored by EKG, oxygen saturation, and blood pressure. Cardiac and pulmonary responses to increasing exercise intensity are then determined by analyzing the airflow and volume in and out of the patients’ lungs, and by analyzing the amount of oxygen being consumed and the amount of carbon dioxide being produced with each breath. The extensive information obtained from the patient during the test is then used to determine the patient’s overall capacity for exercise, the cause of any exercise limitation, and the patient’s level of exercise conditioning.

Impulse Oscillometry

Impulse Oscillometery (IOS) technique is a method of measuring airway resistance and lung compliance in children between 3 and 5 years of age because it requires only minimal patient cooperation. It utilizes sound waves applied at the patient’s mouth for only a few seconds while patient is breathing normally. Upper and lower airway resistance and lung compliance are then deducted from the differences between sound waves going to and sound waves returning from the patient.

Exhaled Nitric Oxide Testing

Nitric oxide is normally present in the exhaled breath but at very minute concentration. However, the concentration of exhaled nitric oxide can significantly increase when allergic inflammation of the airways is present, as is the case when the patient has asthma. Therefore, measuring the concentration of nitric oxide in the exhaled breath provides a noninvasive method to evaluate airway inflammation in asthma patients.