TY - JOUR T1 - Daytime risk factors of nocturnal hyoxemia in COPD patients unqualified for long-term oxygen therapy JF - European Respiratory Journal JO - Eur Respir J VL - 40 IS - Suppl 56 SP - P2910 AU - Yijia Wang AU - Lianqin Tao AU - Guochao Shi AU - Huanying Wan AU - Xiaoting Cai AU - Haixing Zhu Y1 - 2012/09/01 UR - http://erj.ersjournals.com/content/40/Suppl_56/P2910.abstract N2 - Objective To identity daytime variables that are predicative to nocturnal hyoxemia among COPD patients unqualified for long-term oxygen therapy (LTOT). Methods Forty-eight stable COPD patients with daytime SaO2≥90% were enrolled to this study and regarded as patients unqualified for LTOT. Patients were divided into 4 groups depending on daytime SaO2 (SaO2≥98%, group 1; SaO2=97%, group 2; SaO2=96%, group 3; 90%≤SaO2≤95%, group 4). All patients underwent lung function examination during daytime. Their nocturnal oxygen saturations were monitored with overnight pulse oximetry (OPO). Results Daytime oxygen saturation was positively correlated with nocturnal mean SaO2 (r=0.79, P<0.0001), while negatively correlated with time spend with saturation below 90% (TB90) (r= -0.75, P<0.0001). No significant relationship was found between lung function parameters and nocturnal SaO2. Patients with daytime oxygen saturation between 90% and 95% were more likely to have lower nocturnal oxygen saturation and longer TB90 (P<0.05). Conclusions Daytime oxygen saturation may effectively predict the occurrence of nocturnal hyoxemia in stable COPD patients unqualified for LTOT. To reduce COPD complications and improve prognosis, we suggest a relative indication of LTOT for patients with daytime oxygen saturation between 90% and 95% and diagnosed with nocturnal hyoxemia.View this table:Spearman rank correlation coefficient between daytime SaO2View this table:K-W test and SNK test among different SaO2 levels of COPD patients ER -