慢性阻塞性肺疾病无长期氧疗指征患者夜间低氧血症的日间相关因素分析

目的探讨无长期氧疗指征的慢性阻塞性肺疾病（COPD）患者发生夜间低氧血症的日间预测指标。方法在日间静息状态下测定COPD稳定期门诊患者的血氧饱和度,筛选出48例无长期氧疗指征且日间静息SaO2≥90%的患者行肺功能检查,并采用便携式初筛诊断仪进行夜间睡眠监测。结果无氧疗指征的COPD患者中,日间静息SaO2与夜间平均血氧饱和度（MSaO2）呈明显正相关（r=0.79,P〈0.0001）,与夜间血氧饱和度低于90%时间（TB90）呈明显负相关（r=-0.75,P〈0.0001）;肺功能指标与夜间SaO2无明显相关性。与日间SaO2≥98%的COPD患者相比,日间SaO2在90%～95%间的患者夜间MSaO2更低,TB90更长（P〈0.05）。结论日间静息SaO2可作为无长期氧疗指征的COPD患者预测夜间低氧血症发生的一个有效指标。临床上90%≤日间SaO2≤95%且经睡眠监测确诊有夜间低氧血症的患者可作为长期氧疗的相对适应证,以减少COPD并发症的发生,改善患者预后。

Daytime Risk Factors of Nocturnal Hyoxemia in COPD Patients Unqualified for Long-term Oxygen Therapy

Objective To explore the daytime variables which are predictive to nocturnal hyoxemia among COPD patients unqualified for long-term oxygen therapy(LTOT).Methods Forty-eight stable COPD patients with SaO2≥90% were enrolled in this study and regarded as patients unqualified for LTOT.All patients underwent lung function examination during daytime.Their nocturnal oxygen saturation was monitored with overnight pulse oximetry(OPO).Results Daytime oxygen saturation was positively correlated with nocturnal mean SaO2(r=0.79,P<0.0001),and 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.The 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 with nocturnal hyoxemia.