Application Of Non-Invasive Monitoring Of Regional Cerebral Oxygen Saturation In Patients With OSA

Objective:This study aims to monitor regional cerebral oxygen saturation（r SO₂）in patients with obstructive sleep apnea（OSA）,to analyze the correlation between r SO₂and brain function injury,and explore the application significance of r SO2monitoring in patients with OSA.Methods:Forty subjects were selected,who were referred for nocturnal snoring and suspected with obstructive sleep apnea.All subjects’gender,age,body mass index,neck circumference and education level were collected as general data.Epworth sleepiness scale（ESS）,Montreal cognitive assessment（Mo CA）and Mini-mental state examination（MMSE）were underwent and analyzed.And all subjects underwent full night polysomnography coupled with regional cerebral oxygen saturation monitoring for seven hours.According to the apnea hypopnea index,the subjects were divided into four groups.The Apnea Hypopnea Index（AHI）,Lowest oxygen saturation（LSa O₂）,Oxygen desaturation index（ODI）,Pulse oxygen saturation（Sp O₂）and r SO₂under awake state and sleep state were recorded.SPSS25.0 was used for data analysis.Results:（1）The BMI and ESS scores in the severe OSA group were significantly higher than those in the simple snoring group（p<0.05）,and the neck circumference of the severe OSA group was significantly higher than that of the other three groups（p<0.05）.（2）For indexes of PSG,AHI and LSa O₂in moderate OSA group were significantly higher than those in simple snoring group（p<0.05）,AHI and LSa O₂in severe OSA group were significantly higher than those in the other three groups;ODI in simple snoring group was significantly lower than those in the other three groups（p<0.05）,and ODI in mild OSA group was significantly lower than those in the other three groups（p<0.05）.（3）The total score of MOCA in moderate OSA group was significantly lower than that in simple snoring group（p<0.05）,the total MOCA score and abstract score of the severe OSA group were significantly lower than those of the other three groups（p<0.05）.The scores of language and delayed recall in simple snoring group were significantly higher than those in severe OSA patients（p<0.05）.（4）The total score of MMSE,the scores of attention and numeracy,and the scores of recall in the severe OSA group were significantly lower than those in the other three groups（p<0.05）.The total score of MMSE in the moderate OSA group was significantly lower than that in the simple snoring and the mild OSA group（p<0.05）.（5）During wakefulness,mean pulse oxygen saturation was（96.05±1.09%）and mean cerebral oxygen saturation was（66.53±2.14%）,the two indicators decreased to（93.49±2.06%）and（62.81±2.94%）respectively during sleep（p<0.001）.Sp O₂and r SO₂showed a similar decreasing trend from wakefulness to sleep（snoring group p<0.05,mild,moderate and severe OSA group p<0.001）.（6）AHI in OSA patients was negatively correlated with r SO₂in sleep period（r=-0.367,p<0.01）,but not significantly correlated with r SO₂in awake period（p>0.05）.LSa O₂in OSA patients was positively correlated with r SO₂in awake period（r=0.369,p<0.05）and r SO₂in sleeping period（r=0.566,p<0.05）.（7）The total score of Mo CA and MMSE in OSA patients was negatively correlated with AHI;the total score of Mo CA was positively correlated with LSa O₂,awake Sp O₂,sleep Sp O₂,awake r SO₂and sleep r SO₂;and the MMSE score was positively correlated with LSa O₂,awake Sp O₂,sleep Sp O₂and sleep r SO₂.（8）The main predictor of the total score of Mo CA was Sleep r SO₂（β=-0.498,p=0.002）,the main predictors of the total score of MMSE was Sleep r SO2（β=-0.523,p=0.042）and sleep Sp O₂（β=0.334,p=0.049）.Conclusion:Apnea and hypopnea occur repeatedly in OSA patients during sleep,resulting in lower cerebral oxygen saturation in sleep period than in awake period,and cognitive function is affected.Monitoring of regional cerebral oxygen saturation in OSA patients provides a non-invasive and effective monitoring method for evaluating the balance of oxygen supply and demand in OSA patients.