The Analysis Of Related Predictive Factors Of Chronic Obstructive Pulmonary Disease Patients With Nocturnal Hypoxemia

Objective:To study the predictive factors of nocturnal hypoxemia in patients with chronic obstructive pulmonary disease (COPD), beneficial to early diagnosis, early treatment, delay complications.Method:Pulmonary functions, daytime arterial blood gases and nocturnal oxygen level were measured in45patients with COPD admitted to third affiliated hospital to Anhui Medical University (excepted sleep apnea hypopena syndrome) and compared with those of normal control group (30people)Result:The decreased extents of nocturnal mean oxyhemoglobin saturation (MSaO2) and nocturnal lowest oxygen saturation (LSaO2) were high in patients with COPD compared with that in normal subjects(P<0.05). From the distribution of oxyhemoglobin,the percentage of the time that oxyhemoglobin saturation (SaO2)<90%during sleep (T90) in patients were found higher than those in normal subjects(P <0.01). The correlative analysis indicated that daytime SaO2and absolute value of FEV1were related to the nocturnal MSaO2(r=0.704,0.435). So predictive formula of nocturnal oxyhemoglobin level was derived as follow:MSaO2(%)=0.536×SaO2(%)+2.35×FEV2(L)+38.805. Daytime SaO2and absolute value of FEV1were also found concerned with nocturnal oxygen distribution.Conclusion:It was observered that hypoxemia became worse in patients with COPD than in normal subjects during sleep. The level and the distribution of nocturnal oxygen may be predicted by daytime SaO2and absolute value of FEV1.