Pulmonary function tests (PFTs)
These tests assess different aspects of lung function. Usually divided into three sets of tests, the full battery takes 45 minutes or so. The most common set of tests called spirometry is used to evaluate airway function. It involves taking a big breath in and then breathing out until the lungs are empty, followed by a maximal inspiration. Asthma, COPD and other “obstructive” lung diseases are diagnosed and follow with spirometry. The test may be repeated after the administration of albuterol. This called a bronchodilator challenge. Lung volumes can be measured with 2 techniques. The gold standard involves a “plethysmograph” or a small chamber in which the patients sits and takes small breaths in and out. Lung volumes are measured when parenchymal lung disease or muscle/neurologic problems are being evaluated. The other technique involves breathing in trace particles of helium and measuring their dilution—helium dilution technique. The third type of lung function involves evaluating the way in which gas is exchanged in the lung—diffusion capacity. Ideally, a drop of blood is also collected to measure the hemoglobin as this affects the results. The pattern of abnormalities detected helps a pulmonologist determine the type of lung problem present. These tests are also helpful in following the response of lung disease the treatment.
Registered Respiratory Therapists
Chest Xray (CXR)
A basic Xray test to evaluate for major abnormalities within the lungs.
Computed Tomography (CT scan)
There are many types of chest CT scans including non-contrast, contrast, high resolution, prone, inspiratory, expiratory and many more. CT scans allow better resolution of lung tissue. When used with contrast, blood vessels and masses are well visualized. Pleural and chest wall disorders are also well evaluated with CT scans.
A small flexible fiberoptic camera is carefully directed from either the nose or mouth into the airway. Once in the airway (trachea/bronchi), an inspection is performed. Additionally, lavage (the instillation and removal of saline) is performed. Needle biopsy of masses and lymph nodes as well as lung biopsy can be performed without pain. Common indications for this procedure include coughing up blood, infections, masses, lymph nodes and other lung problems. General anesthesia is not needed. Light to moderate sedation is used. Risks of the procedure include bleeding, cough, lung injure if biopsies are taken. Fever can occur after the procedure.
Unlike flexible bronchoscopy, this procedure requires general anesthesia. It is performed in an operating room. In contrast to flexible bronchoscopy, a much broader array of procedures may be performed including laser therapy, stent placement and removal, tumor removal and biopsy. Bleeding sites may also be addressed. Risks of the procedure include problems related to anesthesia, injury to the airway and vocal cords and fever after the procedure.
Right heart catheterization
This test is usually performed to evaluate the filling pressures in the different heart chambers. Suspected pulmonary hypertension is a common indication. The procedure is performed in the “cath lab”—a special procure room in the hospital. Typically, the femoral vein or right internal jugular vein (neck vein) is used. A small tube is placed in the blood vessel then long thinner tube is advanced under xray guidance into the different heart chambers. Pressures are measured, blood samples taken and pictures may be obtained. Local anesthesia is used initially, but thereafter the procedure is painless. Risks of the procedure include bleeding, introducing infection, irregular heart beats, and very rarely injure to the pulmonary artery.
This is often performed as part of a right heart catheterization. Contrast is injected directly into the pulmonary arteries using specialized catheters. Blood clots and abnormal blood vessels are identified. Patients notice a sudden flush or wave of warmth that lasts a few seconds. Risks include allergic reactions to the contrast in addition to bleeding and irregular heart beats.
This simple non-invasive test uses ultrasound to evaluate heart function. Both left and right heart structures are evaluated. Valvular dysfunction is easily identified. The test takes about 45 minutes. This test may be combined with a Bubble Study where agitated saline is injected into a peripheral IV. Abnormal passage of bubbles from the right side of the heart to the left indicates either an abnormal communication inside the heart or abnormal pulmonary blood vessels.
Six minute walk test
This basic test is used to measure exercise capacity. Patients walk for six minutes while oxygen saturation, blood pressure and pulse are measured. Periodic reassessment allows your doctor to measure response to treatment interventions.
Sleep study (polysomnography)
Considered the gold standard test for diagnosis sleep apnea and other sleep related problems. Patients generally spend one or two nights in a dedicated sleep laboratory. Multiple aspects of sleep physiology are evaluated. If appropriate, treatment is started during the sleep study and is gradually adjusted to achieve the maximum benefit. Every few years this test may need to be repeated.
Patients wear an oxygen saturation probe on their finger overnight while a computer continuously records the results. Your doctor can then adjust your oxygen prescription if needed.
This test involves spirometry performed repeatedly after the inhalation of increasing concentrations of methacholine (a chemical that in susceptible patients causes mild changes in breathing test results). Patients with symptoms suggestive of asthma but normal baseline breathing test results often undergo this assessment.
24 hour pH monitoring
A long thin probe is carefully placed through the nose into the esophagus. A monitor then measures and records the pH throughout a 24 hour period. This test is used in the evaluation of GERD (gastroesophageal reflux disease).
This simple procedure involves carefully placing a small catheter into the pleural space (between the lung and chest wall). Fluid is drained and may be sent for analysis. The catheter is removed at the end of the procedure. Risks of this procedure include bleeding, infection and lung injury. This procedure can be performed comfortably and safely in the office if xray is available.
Chest tube placement
Chest tubes are placed to drain pleural fluid, blood or air from around the lung. These tubes may be temporary or long term. The PleuRx catheter system is used for longterm drainage, and is usually placed in the operating room, in an endoscopy suite or inside the hospital. The procedure is somewhat painful and conscious sedation is used in addition to local anesthesia. Risks include infection, bleeding and lung injury.
One option for recurrent pleural effusions (accumulation of fluid in the pleural space) is pleurodesis. In this procedure, talc, or another compound, is instilled into the pleural space via a chest tube. The procedure is often performed in the operating room. A chest tube is left in place for a few days to keep fluid well drained. Pain is common and treated with oral and intravenous medications. This procedure may also be performed for pneumothorax (collapsed lung).
PICC line placement
Peripherally inserted central catheters are long thin catheters placed in the arm that may stay in place for weeks or months. They are used to administer intravenous medications at home and in the hospital. Blood may be drawn from the catheter as well. Risks include infection and blood clot formation around the catheter.
This procedure is generally performed in the intensive care unit on patients unable to be separated from the mechanical ventilator. The breathing tube or endotracheal tube is then removed and a small tube is placed directly through the neck into the airway. Anesthesia is used. The procedure is performed by two pulmonologists. One places a bronchoscope (camera) through the endotracheal tube and the second doctor makes a tiny incision and then inserts a needle into the airway. Correct positioning is confirmed by bronchoscopy. The entire procedure takes about 10 minutes. Risks include bleeding, injury to the trachea and fever. The tracheostomy tube may be removed and the small incision heals quickly. Patients are able to speak and eat with a tracheostomy tube in place.
MRI (magnetic resonance imaging)
Unlike CT scanning, this test does not use radiation. Instead, strong magnets are used. The test involves lying inside a tube and a loud pounding noise is heard. MRI is particularly useful imaging the brain, soft tissues, heart and bone. Lung MRI is rarely performed.
Cardiopulmonary exercise testing (CPET) is a type of stress or exercise test used to help evaluate shortness of breath or fatigue. The test involves placing an arterial catheter for blood pressure, blood gas and laboratory monitoring. EKG leads are placed on your chest. Next, you are asked to pedal on a stationary bicycle while breathing through a specialized mouthpiece. Inspired and expired gas is measured. Every two minutes the workload is increased. Spirometry can be done during exercise as well.