DLCO
DIFFUSION CAPACITY OF LUNGS FOR CARBON MONOXIDE
- It is a common PFT that measures how effective is gas diffusion in the alveoli.
- Patient inhales small amounts of CO ⇒ reaches the alveoli ⇒ then diffuses across the alveolar wall into the pulmonary capillaries.
- The speed with which CO diffuses, tells us how good is the gas exchange.
Alveolar-Capillary membrane
Gas transfer ( DLCO) is reduced in:
- a) COPD ( surface area of exchange is reduced)
- b) Fluid in alveoli ( not blood)
- c) Pulmonary fibrosis & Interstitial lung disease
- d) Anemia
Gas transfer is increased in :
- a) Asthma ( may be normal)
- b) Polycythemia
- c) Pulmonary hemorrhage