Carlson Barbara Waag, Neelon Virginia J, Carlson John R, Hartman Marilyn, Dogra Sunil
School of Nursing and Biobehavioral Laboratory, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Biol Res Nurs. 2009 Apr;10(4):307-17. doi: 10.1177/1099800408330396.
The aim of this descriptive exploratory study was to describe patterns of cerebral oxygen reserves during sleep and their association with cerebrovascular risk factors in elders.
Participants--115 elders, age 70+ years--were monitored overnight using standard polysomnography. Measures included arterial oxyhemoglobin (SaO2) and regional measures of percentage of cerebral oxyhemoglobin saturation (rcSO2) via cerebral oximetry. Participants were classified based on the magnitude of change in rcSO2 from resting baseline to the end of the first nonrapid-eye-movement (NREM) period. One-way ANOVA and Chi-square were used to test group differences in SaO2 and the prevalence of cerebrovascular risk factors.
20 participants (Group 1) experienced an increase in rcSO2 during sleep along with sleeping rcSO2 levels >or= 55%; 95 participants experienced a decline in rcSO2; 72 participants (Group 2) had sleeping rcSO2 levels >or= 55%; and 23 participants had sleeping rcSO2 levels <55% (Group 3). Although all three groups had equivalent declines in SaO2 levels during sleep, Group 3 had more cardiovascular comorbidity than Groups 1 and 2.
Although SaO2 levels decline in most people during sleep, compensatory vascular responses to these drops in SaO2 are important for preventing rcSO2 from falling during sleep. Those entering sleep with lower baseline rcSO2 levels and those with greater declines in cerebral oxygenation during sleep may have greater cardiovascular burden and be at greater risk for stroke and other forms of disabling cerebrovascular disease.
这项描述性探索性研究的目的是描述老年人睡眠期间脑氧储备模式及其与脑血管危险因素的关联。
115名70岁及以上的老年人参与研究，通过标准多导睡眠监测仪进行夜间监测。测量指标包括动脉血氧血红蛋白（SaO2）以及通过脑血氧饱和度测定法测量的脑血氧血红蛋白饱和度百分比（rcSO2）的区域测量值。根据从静息基线到第一个非快速眼动（NREM）期结束时rcSO2的变化幅度对参与者进行分类。使用单因素方差分析和卡方检验来检验SaO2的组间差异以及脑血管危险因素的患病率。
20名参与者（第1组）睡眠期间rcSO2增加，且睡眠rcSO2水平≥55%；95名参与者rcSO2下降；72名参与者（第2组）睡眠rcSO2水平≥55%；23名参与者睡眠rcSO2水平<55%（第3组）。尽管三组在睡眠期间SaO2水平的下降幅度相当，但第3组的心血管合并症比第1组和第2组更多。
尽管大多数人睡眠期间SaO2水平会下降，但对这些SaO2下降的代偿性血管反应对于防止睡眠期间rcSO2下降很重要。那些以较低的基线rcSO2水平进入睡眠的人以及那些睡眠期间脑氧合下降幅度更大的人可能有更大的心血管负担，患中风和其他形式致残性脑血管疾病的风险也更高。
