title: [Measurement of CO diffusion capacity (II): Standardization and quality criteria].
abstract: The diffusion capacity is the technique that measures the ability of the respiratory system for gas exchange, thus allowing a diagnosis of the malfunction of the alveolar-capillary unit. The most important parameter to assess is the CO diffusion capacity (DLCO). New methods are currently being used to measure the diffusion using nitric oxide (NO). There are other methods for measuring diffusion, although in this article the single breath technique is mainly referred to, as it is the most widely used and best standardized. Its complexity, its reference equations, differences in equipment, inter-patient variability and conditions in which the DLCO is performed, lead to a wide inter-laboratory variability, although its standardization makes this a more reliable and reproductive method. The practical aspects of the technique are analyzed, by specifying the recommendations to carry out a suitable procedure, the calibration routine, calculations and adjustments. Clinical applications are also discussed. An increase in the transfer of CO occurs in diseases in which there is an increased volume of blood in the pulmonary capillaries, such as in the polycythemia and pulmonary hemorrhage. There is a decrease in DLCO in patients with alveolar volume reduction or diffusion defects, either by altered alveolar-capillary membrane (interstitial diseases) or decreased volume of blood in the pulmonary capillaries (pulmonary embolism or primary pulmonary hypertension). Other causes of decreased or increased DLCO are also highlighted.
authors.affiliation: Sección de Neumología, Hospital Maternoinfantil Gregorio Marañón, Madrid, España.
authors.forename: A
authors.initials: A
authors.lastname: Salcedo Posadas
authors.affiliation: Sección de Neumología, Hospital Infantil Universitario Niño Jesús, Madrid, España.
authors.forename: J R
authors.initials: JR
authors.lastname: Villa Asensi
authors.affiliation: Sección de Neumología Pediátrica y Fibrosis Quística, Hospital Universitario Vall d́Hebron, Barcelona, España. Electronic address: idemir@vhebron.net.
authors.forename: I
authors.initials: I
authors.lastname: de Mir Messa
authors.affiliation: Sección de Neumología Pediátrica, Hospital Universitario Donostia, San Sebastián, España; Departamento de Pediatría, Facultad de Medicina y Odontología, UPV/EHU, San Sebastián, España.
authors.forename: O
authors.initials: O
authors.lastname: Sardón Prado
authors.affiliation: Sección de Neumología Pediátrica, Consorci Hospitalari Parc Taulí, Sabadell, Barcelona, España.
authors.forename: H
authors.initials: H
authors.lastname: Larramona
mesh_terms: D002248:Carbon Monoxide / Q000502:physiology*; D002648:Child; D006801:Humans; D011653:Pulmonary Diffusing Capacity; D011786:Quality Control; D012129:Respiratory Function Tests / Q000379:methods / Q000592:standards*
chemical_list: D002248:Carbon Monoxide
keywords: Aplicaciones clínicas; Capacidad de difusión; Lung diffusion capacity; Practical aspects; Single breath technique; Técnica de la respiración única