A Pulmonary Function Test (PFT) is a non-invasive diagnostic tool that provides objective measurements of how effectively a patient’s lungs are working. The test measures lung capacity, the speed of airflow, and the efficiency of gas exchange. PFTs involve the patient breathing into specialized equipment, such as a spirometer, following specific instructions from a trained professional. The testing process involves a distinct separation between the technical administration of the test and the medical interpretation of the results, ensuring the data collected is accurate and the diagnosis is precise.
The Specialists Who Perform the Test
The professionals who administer PFTs ensure the patient performs the breathing maneuvers correctly, which directly impacts the reliability of the data collected. Their role is to coach the patient through the forceful inhalations and exhalations required for tests like spirometry and to maintain the complex testing equipment. Accuracy in these procedures depends on the skill of the technician and the cooperation of the patient.
Respiratory Therapists (RTs) frequently perform PFTs as part of their practice in cardiopulmonary care. RTs hold specialized training in respiratory physiology, allowing them to perform various diagnostic tests, including PFTs, alongside managing therapy and mechanical ventilation. They are often the first point of contact for patients, guiding them through each step.
A specialized group includes Certified Pulmonary Function Technologists (CPFT) and Registered Pulmonary Function Technologists (RPFT). These individuals dedicate their training to the technical performance of lung function testing. Certification is obtained through the National Board for Respiratory Care (NBRC) by passing an examination that evaluates their expertise in instrumentation, testing procedures, and quality control.
Settings Where PFTs Are Administered
PFTs are administered in various clinical locations, with the setting often determining the complexity of the tests available. Dedicated Hospital PFT Laboratories offer the most comprehensive range of tests, including full lung volume measurements using body plethysmography and diffusing capacity studies. These labs are equipped to handle complex cases and measure lung mechanics.
Outpatient clinics and specialized centers affiliated with pulmonology or allergy practices also routinely administer PFTs. These settings commonly provide standard spirometry, which measures how much and how quickly air can be moved in and out of the lungs, for focused diagnostic work and monitoring.
Basic spirometry, the most common component of a PFT, may sometimes be conducted within a Primary Care Physician’s office. These office-based tests are less comprehensive than those performed in a specialized laboratory. If initial spirometry suggests a restrictive lung pattern or requires detailed analysis, the patient is referred to a dedicated PFT lab.
Ordering and Interpreting the Results
The process of PFT management begins with a physician ordering the tests when symptoms like chronic cough or shortness of breath suggest a lung dysfunction. Pulmonologists, who specialize in respiratory system diseases, are the most frequent prescribers of these tests, but they are also ordered by Allergists, Cardiologists, and Primary Care Physicians. The test results are important for determining a diagnosis, assessing the severity of a known condition like asthma or COPD, and monitoring the effectiveness of treatment.
Interpretation of the raw data collected by the technologist is a distinct clinical function performed by a physician, most often a Pulmonologist. The interpreting physician compares the patient’s measured lung values, such as forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), against predicted normal values based on the patient’s age, height, gender, and ethnicity. This comparison allows them to identify patterns indicative of obstructive defects, like those seen in asthma, or restrictive defects, which may suggest conditions such as pulmonary fibrosis.
The physician integrates the PFT findings with the patient’s medical history and other diagnostic information to establish a final diagnosis and treatment plan. The technologist’s role ends with the production of accurate, reliable data, while the physician’s expertise translates that data into clinical significance. This collaboration ensures the patient receives a precise diagnosis and appropriate management for their respiratory health.