pFT

Pft commonly refers to pulmonary function testing (PFT), a group of noninvasive assessments that evaluate the function of the lungs and airways. The tests typically include spirometry, which measures airflow and volumes such as forced vital capacity (FVC) and the ratio of forced expiratory volume in one second (FEV1) to FVC; measurement of lung volumes by methods such as body plethysmography; and diffusion capacity testing, usually DLCO, which assesses gas transfer across the alveolar-capillary membrane.

Indications include evaluation of suspected respiratory symptoms such as dyspnea, chronic cough, and wheeze; monitoring of chronic lung diseases (asthma, chronic obstructive pulmonary disease, and interstitial lung disease); assessment of disease severity; and preoperative evaluation or monitoring response to therapy.

Procedure: Tests are performed with the patient seated and breathing through a mouthpiece coordinated with a flow sensor. Spirometry requires maximal inhalation followed by a rapid, forceful exhalation. Body plethysmography measures thoracic gas volumes by changes in pressure in a sealed chamber. DLCO involves inhaling a trace gas and measuring its uptake.

Interpretation: Results are compared to reference values adjusted for age, sex, height, and ethnicity. Obstructive patterns show reduced FEV1/FVC; restrictive patterns show reduced lung volumes; DLCO can be reduced in interstitial disease or emphysema; overall results guide diagnosis and management.

Preparation and limitations: Patient effort affects accuracy; results require quality control and interpretation by trained professionals. Pft does not diagnose disease alone and should be integrated with history, imaging, and other tests.