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What is Alveolar-capillary CO diffusion capacity?

21:59 - 4 May , 2021

Medical procedure



Lung diffusion is the process by which gas exchange is carried out through the alveolar-capillary area, whose functions are to provide oxygen to the blood and eliminate carbon dioxide produced by aerobic and anaerobic metabolism; while alveolar-capillary diffusion is responsible for transferring respiratory gases through the membrane of the same name. 

The alveolar-capillary diffusion capacity test allows gas exchange in the respiratory system to be analyzed and measured to detect any alveolar-capillary problem, its most significant indicator being the measurement of carbon monoxide (CO) diffusion capacity.

There are various techniques to perform such test, but the most widely accepted is the so-called single breath test.

In it, it is possible to identify an increase in CO levels, which is a sign that there are pathologies that cause an increase in blood volume in the pulmonary capillaries, such as polycythemia or that there is bleeding in the lungs. 

Likewise, if a decrease in CO appears, it is possible that there is an interstitial disease that has damaged the alveolar-capillary membrane or that a pulmonary embolism has occurred, or we are facing the development of pulmonary hypertension. 

In the Pulmonary Physiology and Inhalation Therapy Department we guarantee you the best care in respiratory ailments provided by highly trained medical personnel.

Thanks to an adequate clinical assessment and state-of-the-art equipment in pulmonary function tests, metabolic monitor, and video bronchoscopy, we offer you a timely and accurate diagnosis of your lung function. In addition, we have the most advanced mechanical ventilator system (52 mechanical ventilators).


  • Biopsies.
  • Calorimetry at rest.
  • Alveolar-capillary CO diffusion capacity.
  • Pre-bronchodilator spirometry.
  • Post-bronchodilator spirometry.
  • Video-bronchoscopy tests.
  • Cardiopulmonary tests in exercise.
  • Removal of foreign bodies.
  • Bronchial sampling.
  • Complete lung volumes.

Related centers and departments:


  • Acosta-Bustillos AT, Criales-Vera SA. Hemangiomatosis capilar pulmonar, a propósito de un caso. Anales de Radiología México. 2015;14(3):336-340.
  • Vázquez&#;García JC, Gochicoa&#;Rangel L, Del Río&#;Hidalgo RF, et al. Prueba de difusión pulmonar de monóxido de carbono con técnica de una sola respiración (DL,COsb). Recomendaciones y procedimiento. Neumol Cir Torax. 2019;78(Suppl: 2):142-153. doi:10.35366/NTS192G. 
  • Osorio BJA, Rivera D, Baide JA, et al. Estudio de la capacidad de difusión en pacientes con historia de TEP de más de un año. Med Crit. 1998;12(3):84-94.
  • García-Araque HF, Gutiérrez-Vidal SE. Aspectos básicos del manejo de la vía aérea: anatomía y fisiología. Rev Mex Anest. 2015;38(2):98-107.

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