A Pulmonary Function Test (PFT) is a non-invasive diagnostic tool that provides objective measurements of lung function. The test measures parameters including the total volume of air the lungs can hold, the speed of airflow, and the efficiency of gas exchange. These measurements help physicians determine if a respiratory issue exists and what kind of problem it might be. Administering and interpreting a PFT is a collaborative effort involving several distinct roles within the healthcare system.
The Professionals Who Perform the Test
The physical administration of a Pulmonary Function Test is primarily carried out by specialized technical staff, most commonly Registered Respiratory Therapists (RRTs) or Certified Pulmonary Function Technicians. These professionals are responsible for the technical accuracy of the procedure, which is paramount for generating reliable results. Their duties begin with the calibration of equipment, such as spirometers and body plethysmographs, to ensure accurate measurements of airflow and lung volumes.
A crucial aspect of their role involves coaching the patient through required maneuvers, including forceful inhalation and exhalation efforts. The quality of the raw data collected (e.g., the Forced Expiratory Volume in one second (FEV1) or the Forced Vital Capacity (FVC)) is highly dependent on the patient’s maximal effort and the technician’s instruction. The technician must confirm that the patient’s effort meets established quality criteria, such as a sharp start and consistent exhalation time. This group is responsible for the collection and quality assurance of the technical data, but they do not perform the final diagnosis or treatment planning.
The Physicians Who Order and Interpret
Interpreting the raw PFT data falls to medical doctors who utilize the results for clinical decision-making. Pulmonologists are the specialists who most frequently order and rely on PFT results, particularly for patients with complex or severe respiratory conditions. They analyze the data to categorize the patient’s lung function pattern, focusing on the ratio of FEV1 to FVC, which is a primary indicator of an obstructive pattern, such as chronic obstructive pulmonary disease.
If the FEV1/FVC ratio is low, it suggests an issue with airflow out of the lungs. A reduced FVC with a preserved ratio suggests a restrictive pattern, indicating reduced lung volume. Pulmonologists also analyze disease severity based on the percentage of the predicted value for the patient’s age, height, and sex. Primary Care Physicians (PCPs) often initiate the process by ordering basic spirometry as a screening tool for symptoms like chronic cough or shortness of breath. PCPs refer patients whose results indicate a complicated restrictive pattern or require further specialized testing, such as diffusion capacity, to a pulmonologist for definitive diagnosis and management.
Utilization Across Medical Specialties
PFTs are ordered by a diverse range of specialists beyond respiratory medicine for specific clinical purposes. Cardiologists may request PFTs when a patient presents with shortness of breath (dyspnea) to differentiate between cardiac and pulmonary causes. A PFT helps rule out underlying lung disease, confirming if reduced exercise tolerance is due to heart failure or a coexisting respiratory limitation. This differentiation is important because treatment approaches differ significantly.
Anesthesiologists and surgeons use PFTs as a pre-operative screening tool, especially before thoracic or upper abdominal surgeries. The results assess a patient’s respiratory reserve and predict the risk of post-operative pulmonary complications, such as pneumonia or respiratory failure. Patients with significantly impaired lung function may require closer monitoring or alternative surgical approaches.
Occupational health physicians use PFTs for baseline screening and regular monitoring of workers exposed to lung irritants (e.g., silica dust or chemical fumes). Serial PFTs detect subtle, early declines in lung function, allowing for interventions like changes in protective equipment or removal from exposure before irreversible damage occurs.