What is a PFT Test?

7.0 Further Pulmonary Function Tests

The following tests are commonly performed in the pulmonary function laboratory. ComPAS Freedom™ has an extensive manual entry and database capability. 

7.1 Arterial Blood Gases

Most blood tests performed use blood drawn from veins in the arms. An arterial blood gas is a blood test, which requires taking a sample of blood from the artery, usually in the wrist. Blood from the artery comes straight from the heart, after it has been oxygenated (blood which travel through the heart and lungs gets rid of carbon dioxide which is a waste product it picks up from the body, and picks up oxygen that will be delivered to the body).

The blood sample from the artery is then analyzed for the amount of oxygen in it, the amount of carbon dioxide (there is always some, and in some diseases this can be increased). The pH of the blood, hemoglobin, and carbon monoxide level (which will be elevated in people smoking) and several other tests are also run on the blood sample.

The information gained by this test will help determine if a person might require oxygen or help explain other possible processes occurring.

7.2 Pulse Oximetry

Pulse oximetry is a tool to again look at the oxygen levels in people. Oxygen saturation tells us how much of the hemoglobin is loaded with oxygen in the blood stream. Most people will be between 92% and 99% saturated. This test is not nearly as accurate as doing an arterial blood gas, but will often be more than enough for evaluation of a patient's oxygen level.

7.3 Respiratory Muscle Strength (MIP MEP)

There are diseases that can affect the muscles throughout the body. The muscles of breathing are the same as those in the leg or the arm. There are groups of muscles used to inhale (breath in) and exhale (breath out). When these muscles become weak, it can lead to problems with difficulty breathing. This test is designed to evaluate those muscles of breathing. The test is often called MIP/MEP - maximum inspiratory and expiratory pressure.