PFT DLCO Pulmonary function tests are performed to assess lung function. Spirometry is the most common and widely used lung function test, followed by diffusing capacity of the lungs for carbon monoxide (DLCO). It is also known as the transfer factor.
- DLCO is a measurement to assess the lungs’ ability to transfer gas from inspired air to the bloodstream.
- Carbon monoxide (CO) has a high affinity for hemoglobin, and it follows the same pathway as that of oxygen to finally bind with hemoglobin. Inhaled CO is used for this test due to its high affinity for hemoglobin (200 to 250 times that of oxygen). Among other potential gases for evaluating diffusing capacity, oxygen is not preferred since its uptake is limited by cardiac uptake and total body consumption.
DLCO is indicated in the evaluation of parenchymal and non-parenchymal lung diseases in conjunction with spirometry. The severity of obstructive and restrictive lung diseases, pulmonary vascular disease, and preoperative risk can be assessed using DLCO.