From the Research
Doubling cardiac output of the heart could increase the total flow of CO from the alveolar air to the pulmonary circulation during a DLCO test. This is because an increase in cardiac output would lead to an increase in pulmonary capillary blood volume, providing more hemoglobin to bind CO and thus enhancing CO transfer 1. The diffusion of CO across the alveolar-capillary membrane depends on the concentration gradient between alveolar air and blood, as well as the availability of hemoglobin to bind CO.
Some key factors that could influence CO transfer include:
- Increasing lung volume, which expands the surface area available for diffusion
- Elevating pulmonary capillary blood volume, providing more hemoglobin to bind CO
- Raising alveolar oxygen levels, which affects membrane diffusion properties
- Increasing the concentration of carbon monoxide in the inspired gas mixture, which increases the alveolar concentration and creates a steeper gradient that drives more CO molecules into the bloodstream
The test works because CO has a high affinity for hemoglobin, causing it to rapidly bind to hemoglobin in pulmonary capillary blood, maintaining the concentration gradient and allowing continuous diffusion 2. However, the most recent and highest quality study suggests that doubling cardiac output could have a significant impact on CO transfer, making it a crucial factor to consider during a DLCO test 1.