@article {V{\'a}zquez-Garc{\'\i}a1217, author = {Juan Carlos V{\'a}zquez-Garc{\'\i}a and Rogelio P{\'e}rez-Padilla and Alejandro Casas and Patricia Sch{\"o}nffeldt-Guerrero and Jonatan Pereira and Claudia Vargas-Dom{\'\i}nguez and M{\'o}nica Vel{\'a}zquez-Uncal and David Mart{\'\i}nez-Brise{\~n}o and Luis Torre-Bouscoulet and Laura Gochicoa-Rangel}, title = {Reference Values for the Diffusing Capacity Determined by the Single-Breath Technique at Different Altitudes: The Latin American Single-Breath Diffusing Capacity Reference Project}, volume = {61}, number = {9}, pages = {1217--1223}, year = {2016}, doi = {10.4187/respcare.04590}, publisher = {Respiratory Care}, abstract = {BACKGROUND: The lung diffusion capacity (DLCO) determined by the single-breath technique greatly helps in the differential diagnosis and classification of severity of common lung diseases. However, widespread use of single-breath DLCO tests in Latin America has been limited, in part, by the lack of appropriate reference values. Our objective was to derive robust reference equations for single-breath DLCO from healthy Hispanic adults, using the most recent guidelines and taking into account altitude above sea level and hemoglobin.METHODS: We recruited healthy adults from Caracas (690 m), Santiago (650 m), Mexico City (2,240 m), and Bogota (2,640 m). DLCO testing was completed using an instrument that exceeds American Thoracic Society/European Respiratory Society 2005 guidelines for spirometry and single-breath DLCO and provided centralized training and a quality assurance program.RESULTS: We included 480 healthy Hispanic adults (58.3\% women) with a mean age of 46 y (range 22{\textendash}83 y). Their mean {\textpm} SD single-breath DLCO was 30.4 {\textpm} 9.2 mL/min/mm Hg. Results as a percentage of predicted by Crapo{\textquoteright}s reference values (the closest to obtained values) were 83 {\textpm} 10\% (Caracas), 91 {\textpm} 10\% (Santiago), 104 {\textpm} 17\% (Mexico City), and 118 {\textpm} 19\% (Bogota), and current suggested adjustments by hemoglobin or altitude did not correct differences, especially in Santiago and Caracas.CONCLUSIONS: We recommend these new single-breath DLCO reference equations to predict single-breath DLCO in Latin America performed with current instruments and procedures and including as a predictor altitude above sea level.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/61/9/1217}, eprint = {https://rc.rcjournal.com/content/61/9/1217.full.pdf}, journal = {Respiratory Care} }