Provider News

How to Order a PFT at Seattle Children's

August 5, 2020

Seattle Children’s Pulmonary Diagnostics Lab conducts pulmonary function tests (PFTs) for children ages 5 through 21. The lab welcomes referrals from community providers. Patients do not need to be seen by the Pulmonary team first; they can be referred directly to the lab.

Please fax a New Appointment Request Form (PDF) (doc) to 206-987-3121 or use eReferral. Clearly state you are ordering a pulmonary function test (PFT) and which test(s) you are ordering.

We offer a variety of PFT tests:

  • Spirometry: Measures forced expiratory volumes and flows to determine if vital capacity is normal and whether airway obstruction is present. Appropriate for patients >5 years old.
  • Spirometry Pre- and Post-Bronchodilator: Measures forced expiratory volumes and flows to determine if vital capacity is normal and whether airway obstruction is present and whether obstruction is improved following albuterol. Appropriate for patients >5 years old. Best test for asthma.
  • Fraction of Exhaled Nitric Oxide Measurement (FENO): Measures exhaled nitric oxide. Elevated/high FENO indicates significant eosinophilic/allergic inflammation, where eosinophilic inflammation is NOT well controlled. This test may indicate that a patient needs medication adjustment or improved compliance, and also in new patients can help identify a specific phenotype of asthma (TH2 high/eosinophilic) that is particularly responsive to certain medications (e.g., inhaled steroids, monoclonal antibody blockade of IL-5 or IL-13). Appropriate for patients >5 years old.
  • Plethysmography (total lung volumes): Measures complete fractional lung volumes, including residual volume (trapped gas following a complete exhalation). Appropriate for patients >8 years old. Best test for scoliosis, pectus, and rheumatological or immune patient; former cancer patients; or bone marrow transplant patients.
  • Diffusing Capacity: Measures oxygen transport from the lungs to blood. Appropriate for patients >8 years old. Best for rheumatological disease, former cancer or bone marrow transplant patients, congenital heart disease, sickle cell disease and dyspnea.
  • Hypoxic Challenge (high-altitude test): “Airplane test” measures a patient’s ability to maintain normal oxygen saturations when breathing a reduced O2 concentration (to mimic breathing at a low partial pressure of oxygen, such as on an airplane or at altitude). Best for ex-preemies or any child on O2. Children must be developmentally/behaviorally able to tolerate having a mask with a good seal on their face for 15 minutes continuously (e.g., usually not successful for children under age 2 to 3 years old).

A “full PFT” order is generally understood as spirometry, plethysmography and diffusing capacity.

We currently do not offer exercise bronchoprovocation challenge testing to screen for exercise-triggered asthma. We intended to begin offering this test in 2020, but because it is an aerosol-generating procedure and our lab is focused on extra precautions for COVID-19, we hope to offer it when our capacity increases after the pandemic abates.

What your patients can expect at their PFT

  • Appointments run 30 to 60 minutes, depending on which tests are ordered. A full PFT plus any additional testing will last roughly 90 minutes.
  • For hypoxic challenge testing, we encourage parents to bring a tablet device or smart phone to help their child tolerate the required mask during the 15-minute procedure.
  • Patients may experience mild discomfort. If at any time patients feel pain or dizziness, continued testing will be re-evaluated.
  • We coach the child in order to obtain the best results possible and at times partner with their parent to help achieve this.
  • If a test result is not obtained, we encourage parents not to feel as if the visit was fruitless. PFTs require coordinated, sustained breathing patterns that are patient dependent. Even older children may not be able to complete all testing. The important part is to know the child has gained experience in testing procedures and to keep the experience as positive as possible should future testing be needed.
  • We ask that parents refrain from taking photos or video during their child’s appointment.

Hours and locations

The Pulmonary Diagnostic Lab is open from 8 a.m. to 5:15 p.m. every weekday except Wednesdays. It is the only place we conduct “full PFTs” and hypoxic challenges.

Some of our regional clinics offer less-complex PFTs:

  • Bellevue Clinic: Spirometry and FENO only. Monday and Wednesday.
  • North Clinic in Everett: Spirometry and FENO only. Monday only.
  • South Clinic in Federal Way: Spirometry and FENO only. Tuesday and Wednesday.

A number of our specialty clinics at the hospital – including Cystic Fibrosis, Chest Clinic and Neuromuscular – also offer spirometry and FENO.


Providers with questions are welcome to call the lab at 206-987-2174 (press option 1 if scheduling an appointment for a patient) or call our Provider-to-Provider Line at (206) 987-7777 and ask to speak with a pulmonary specialist.

More information

The new Pulmonary Diagnostics Lab page has complete details on how to order a test, what tests are available and what patients and families can expect at their appointment.