Differences in functional exercise capacity and pulmonary function tests between acute respiratory distress syndrome (ARDS) of pulmonary and extrapulmonary origin

Methods A total of 46 patients without comorbidity and more than 2-year survival after an ADRS episode were identified between 2000 and 2006. 27 patients finally participated in this study (13 ADRSp and 14 ADRSexp). Demographic data, smoke status, ventilator data, length of ICU and hospital stays and measures of severity of illness such as the Acute Physiology, Age, and Chronic Health Evaluation; Acute Lung Injury Score and Sepsis-Related Organ Failure Assessment were evaluated. Pulmonary function tests were performed using standard procedures. Spirometry, static volumes by pletismography and diffusing capacity form carbon monoxide by single-breath were measured. Normal values were calculated following the European Coal and Steel Union guidelines. Functional capacity was measure with a standardized six-minute walk test (6MWT) using standard protocol. Normal values for 6MWT were according with the Enright y Sherill reference equations.