Pulmonary Function Testing

Flashcards based on key concepts from the lecture notes on Pulmonary Function Testing (PFT).

What are the primary purposes of Pulmonary Function Testing (PFT)?

1) Evaluate pulmonary causes of dyspnea, 2) Differentiate between obstructive and restrictive pulmonary disorders, 3) Evaluate the effectiveness of therapies, 4) Follow the course of a particular disease, 5) Assess severity of pathophysiological impairment and determine pre-operative status.

What are the components of Pulmonary Function Testing?

PFT is subdivided into: 1) lung volumes and capacities, 2) forced respiratory flow rates of volume measurements, 3) pulmonary diffusion capacity measurement, 4) tests of respiratory muscle strength, 5) cardiopulmonary exercise testing.

What does the Closed Circuit Helium Dilution test measure in PFT?

It measures the residual volume in the lungs and helps determine total lung capacity.

What is the procedure for the open circuit nitrogen washout test in PFT?

The patient inhales and exhales 100% oxygen through a one-way valve for about 7 minutes, while measuring nitrogen concentration to determine FRC.

How is FRC calculated in the open circuit nitrogen washout test?

FRC = (Final ^2N2 concentration X expired volume - N2 tissue volume).

What happens to the nitrogen concentration during the nitrogen washout test?

The nitrogen concentration drops as nitrogen is washed out from the blood and tissues.

What is measured in body plethysmography?

Body plethysmography measures changes in lung volume by using pressure changes in a closed system to determine lung function.

What is the significance of measuring the forced expiratory volume in PFT?

It helps determine the degree of obstruction in the airways and evaluate respiratory function.