In the evaluation and follow-up of patients with respiratory pathology, pulmonary function tests (PFTS) are a crucial tool.
In the evaluation and follow-up of patients with respiratory pathology, pulmonary function tests (PFTS) are a crucial tool. They offer crucial details about the size and integrity of the pulmonary capillary bed, the size and shape of the large and small airways, and the pulmonary parenchyma.
Different patterns of abnormalities are seen in different respiratory diseases, helping to establish a diagnosis even though they do not provide a diagnosis per se. We outline the justifications for PFTS, detail aberrant findings, and link them to underlying pathophysiology.
Types of PFT Pulmonary Function Test
Spirometry
Asthma, chronic obstructive pulmonary disorder (COPD), and pulmonary fibrosis can all be diagnosed and monitored using the pulmonary test known as spirometry, which measures the volume and rate of breathing.
A specialised device called a spirometer, which can measure the volume and flow rate of air moving via a tube into the machine, is used in the spirometry test. To enable the equipment to take the proper measurements, the patient is told to inhale deeply and blow into the tube as forcefully as possible. Bronihial provocation, which is the injection of drugs that can either restrict or open the airways and allow the response to be evaluated, may be started in some instances.
Lung volume measurement
The plethysmography test measures the amount of air in the lungs before and after a patient has taken a big breath. A weak chest wall with pulmonary fibrosis can be diagnosed with exceptional success with this kind of pulmonary test.
The patient is instructed to breathe into a tube that is attached to a computer so that the computer can measure their lung volume during plethysmography. Patients may occasionally be instructed to inhale nitrogen or helium gas and exhale it. The lung volume can be determined by the air volume.
Lung diffusion capacity
A test known as lung diffusion capacity is performed to gauge how well the lungs are doing at transferring oxygen into the blood. Lung tissue function and the rate at which blood is pumped to the lungs can both be determined by the results of a lung diffusion capacity test.
This test entails the patient inhaling a gas through a tube, holding their breath for a moment, and then exhaling the gas through the tube.
Oxygen level tests
Examining the amount of oxygen in the bloodstream is done using oxygen level testing.
The measurement of blood oxygen levels via pulse oximetry is done without the use of a needle and requires applying a sensor to the finger or ear. In contrast, arterial blood gas tests require the collection of a blood sample from an artery in the wrist, which is subsequently examined in a laboratory to determine the precise level of oxygen in the blood.
Other tests
There are numerous other tests that can offer illustrative data regarding a person's pulmonary function. These consist of:
Test of the ability to cover the greatest distance in six minutes while walking: the six-minute walk test.
Cardiopulmonary exercise test: During periods of controlled exercise and rest, this test keeps track of the patient's heart and lungs.
Test to replicate high altitude: This test measures how well the patient can function in a simulated environment with less oxygen.
When viewed collectively, these tests are less focused on pulmonary function. The outcomes of these tests may also be impacted by other bodily processes, such as how well the cardiovascular system is working.
