Alone, Dlco is not enough to confirm the presence of or differentiate between the 2 lung conditions. 2 Both PAH and ILD can reduce Dlco, the former by reducing capillary blood volume and the latter by causing fibrosis of the delicate interface necessary for gas diffusion between alveolar air and capillary blood. The specificity and sensitivity of Dlco for specific lung diseases has not been studied extensively until recently, particularly for pulmonary arterial hypertension (PAH) and systemic sclerosis with or without interstitial lung disease (ILD). When Dlco is below the predicted reference range (75% to 140% of predicted) it becomes a clue to the presence of a physiologic problem that ultimately may impair exercise, and even affect long-term survival from common lung diseases and disorders. 1 But has anyone stopped to ask why Dlco measurement is ordered, how it is determined, and what it means when it is reduced or not?ĭlco is a calculated, derived value that indirectly assesses the ability of the lungs to “transfer” oxygen to blood through the use of a test gas (namely, CO) that has a greater affinity for blood hemoglobin. Every clinician knows that Dlco measures the quantity of carbon monoxide (CO) transferred per minute from alveolar gas to red blood cells (specifically hemoglobin) in pulmonary capillaries, and that this value, expressed as mL/min/mm Hg, represents mL of CO transferred per minute for each mm Hg of pressure difference across the total available functioning lung gas exchange surface. 2016 56(5):440-445.Ĭarbon monoxide diffusing capacity (Dlco) probably is the least understood pulmonary function test (PFT) in clinical practice worldwide, even among experienced pulmonologists. Using and interpreting carbon monoxide diffusing capacity (Dlco) correctly. UC Davis Medical Center, Sacramento, California.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |