e231journal.publications.chestnet.org [ Correspondence ] Bicarbonate or Base Excess in Early

reported an original study on obese subjects suggesting that a raised bicarbonate concentration ([HCO 3 2]), without awake hypercapnia, could allow the early detection of obesity hypoventilation syndrome (OHS). Since bicarbonate was announced as a potential discrim-inant biomarker, methodologic issues about its determi-nation should be considered. Th roughout the article, the authors focused on base excess (BE), which was used for the characterization of the three groups (ie, normal daytime Pa co 2 6 kPa associated with BE , 2 mmol/L [non-OHS] or BE 2 mmol/L [early OHS], and elevated daytime Pa co 2. 6 kPa [OHS]). Overall, the authors highlighted BE in early OHS rather than arterial standard [HCO 3 2]. Nevertheless, results show a strong overlap of arteria