TY - JOUR T1 - Pulmonary gas exchange in severe obesity: The effects of bariatric surgery JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P2114 AU - Eva Rivas AU - Ebymar Arismendi AU - Alvar Agusti AU - Marcelo Sanchez AU - Salvadora Delgado AU - Concepcion Gistau AU - Peter D. Wagner AU - Roberto Rodriguez-Roisin Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P2114.abstract N2 - Severe obesity (SO) is a growing health problem associated with chronic systemic inflammation. Bariatric surgery (BS) is the most efficacious weight loss therapy. Its potential effects on ventilation-perfusion (VA/Q) distributions have not been explored before.We investigated VA/Q distributions and thoracic CT in SO subjects before and one year after BS.We enrolled 21 SO (49±[SE]2 yrs, 19 females, body mass index [BMI] 45±2 kg/m2, 19 never smokers) and 9 normal weight, sex- and age-matched (BMI 25±1 kg/m2, never smokers) control subjects, in whom we assessed respiratory and inert gases, systemic and pulmonary hemodynamics and thoracic CT, breathing ambient air and 100% O2, and serum biomarkers.Before BS, SO subjects had: (1) abnormal AaPO2 (27±2, mmHg) and mild arterial hypoxemia (76±2, mmHg) caused by mild shunt (4.0±1.0, %QT) and broadly unimodal distributions of VA/Q ratios (Log SDQ [normal <0.60], 0.85±0.06); (2) a two-fold increase in shunt during 100% O2 breathing (9.6±1.1, %QT; p<0.001), without reversion of hypoxic pulmonary vasoconstriction (Log SDQ, 0.88±0.07); and, (3) mild atelectasis that increased while breathing 100% O2 (from 2.1±0.2 to 2.6±0.3%; p<0.05). There was a post-operative successful excess weight loss (79±6%) associated with significant systemic inflammation, shunt and VA/Q distributions, and atelectasis improvements. Pre-BS BMI (p<0.005) and leptin levels (p<0.02) were independently associated to post-BS AaPO2 improvement (overall adjusted r2, 0.56).SO is associated with shunt and VA/Q disturbances, lung atelectasis and systemic inflammation. BS improves these abnormalities supporting a cause-effect relationship.Supported by FIS (080311),CIBERES and Almirall. ER -