Berry R B, Asyali M A, McNellis M I, Khoo M C
Department of Medicine, Veterans Affairs Medical Center, Long Beach 90822; University of California, Irvine, California, USA.
J Appl Physiol (1985). 1998 Oct;85(4):1434-41. doi: 10.1152/jappl.1998.85.4.1434.
We studied the within-night variability of the maximum esophageal pressure deflection before apnea termination (DPmax) in nine patients with severe obstructive sleep apnea as an index of the arousal threshold and the mean electroencephalogram (EEG) delta power for each 30 s as an index of the timing of sleep cycles. Periodicity in the time variation of delta power and DPmax was analyzed by determining their power spectral density and their relationship determined by cross correlation. DPmax and delta power varied cyclically and in phase with a major periodicity (major peak in power spectral density) of 117.6 +/- 8.8 (SE) min. The correlation between the values of DPmax and delta power was significant (P < 0.001) in each subject (mean r = 0.47 +/- 0.03), and the coherence between DPmax and delta power at their dominant frequency was high. Within cycles of non-rapid-eye-movement sleep, DPmax and delta power increased, reaching peak values on average at or after midcycle. These findings suggest that the arousal threshold to airway occlusion in patients with obstructive sleep apnea varies cyclically during the night synchronous to the underlying cycles of sleep.
我们研究了9名重度阻塞性睡眠呼吸暂停患者在呼吸暂停终止前最大食管压力偏移（DPmax）的夜间变异性，将其作为觉醒阈值指标，并研究了每30秒的平均脑电图（EEG）δ波功率，将其作为睡眠周期时间的指标。通过确定δ波功率和DPmax的功率谱密度来分析其时间变化的周期性，并通过互相关确定它们之间的关系。DPmax和δ波功率呈周期性变化且相位一致，主要周期（功率谱密度中的主要峰值）为117.6±8.8（SE）分钟。每个受试者中DPmax值与δ波功率之间的相关性显著（P<0.001）（平均r=0.47±0.03），且DPmax与δ波功率在其主导频率处的相干性较高。在非快速眼动睡眠周期内，DPmax和δ波功率增加，平均在周期中期或之后达到峰值。这些发现表明，阻塞性睡眠呼吸暂停患者对气道阻塞的觉醒阈值在夜间与潜在的睡眠周期同步周期性变化。
