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:

Spirometry

Spirometry equipment measures airflow and air volume as patients breaths in and out (exhales and inhales). During the test 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 diagnosis of obstructive lung disease or 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 or commonly called as “body box” is equipment that is used to determine different lung volumes including volumes of air that are not exhaled by patient. During this test patient are placed seated inside an air tight glass chamber while breathing through a tube that passes through the wall fo 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. It is also useful test of measuring airway resistance.

Lung Diffusion Testing

Lung diffusion testing is used to measure the transfer of gas from the lung’s air sacs to blood. During procedure patients are asked to inhale 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 the performed by air pumps that passively inflate the infant’s lung at safe pressures applied at te4h 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 infant is sleeping or consciously 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 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 six minutes on a bicycle or a tread mill.  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 till 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 air flow 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 patient’s mouth for only few seconds while patient is normally breathing. Upper and lower airway resistance and lung compliance are then deduced 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 patient has asthma. Therefore, measuring the concentration of nitric oxide in the exhaled breath provides a non invasive method to evaluate airway inflammation in asthma patients.

Bronchoscopy

Flexible bronchoscopy can be performed at UF/ Shands hospital in children of all age groups. The procedure requires sedation and continuous monitoring. It is conducted by a team consisting of a pediatric pulmonologist, a respiratory therapist and a nurse.

A small flexible scope is typically passed through the nose to the back of the throat and then passed into patients airways.

Besides visualizing the airways to detect possible abnormalities, flexible bronchoscopy can also be used to remove secretions and foreign bodies and to obtain cultures and small lung biopsies.

Sleep Study

A sleep study, or a polysomnogram is a noninvasive, pain-free procedure that requires spending a night in a sleep facility. Prior to the sleep study, a sleep technician will attach monitoring leads to your body. Your breathing will be monitored by placing belts on your chest and abdomen. Any unusual body movements will also be recorded by video. A cannula will also be placed under your nose to monitor air flow and levels of carbon dioxide.

For more information, view the Sleep Study Resources.