阻塞性睡眠呼吸暂停低通气综合征患者上气道阻塞的动态MRI分析

目的研究阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者清醒和睡眠时上气道阻塞的情况及其变化。方法21例OSAHS患者经20h无睡眠后,分别在清醒与睡眠状态下,获得上气道正中矢状面的动态MRI影像。配对t检验比较清醒和睡眠时上气道阻塞区长度的差异。结果12例OSAHS患者清醒时有腭咽区阻塞,21例患者睡眠时均有腭咽区阻塞,清醒时和睡眠时腭咽区阻塞的符合百分比为57·14%。12例患者清醒时上气道阻塞区长度的最大值(2·99±0·51)cm、最小值(0·72±0·23)cm,两者差值(2·27±0·67)cm,分别比睡眠时的最大值(6·61±1·23)cm、最小值(0·95±0·22)cm、两者差值(5·66±1·27)cm小,差异均有统计学意义(P<0·01)。结论OSAHS患者睡眠时上气道的阻塞是变化的、多区域的。OSAHS患者清醒时上气道的阻塞仅在一定程度上提示睡眠时的阻塞情况。

Obstructive site of the upper airway in patients with obstructive sleep apnea hypopnea syndrome:analysis of dynamic MRI

OBJECTIVE: To investigate the obstructive site and the dynamic change of the upper airway in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) during sleep and wakefulness. METHODS: After being deprived of sleeping for 20 hours, sequential midline sagittal images of the upper airway were obtained in 21 patients during sleep and wakefulness with dynamic MRI. The obstructive state was studied according to hypopnea (< 10 s) and apnea (> or = 10 s). The length of obstruction site was measured and the dynamic characteristics of obstruction was observed. Statistical analysis was performed with paired t-test. RESULTS: The obstruction at the level of the palatopharynx in patients with hypopnea during wakefulness was similar to that in patients with apnea during sleep. The maximal length [(6.61 +/- 1.23) cm], the minimal length [(0.95 +/- 0.22) cm] and maximal length difference [(5.66 +/- 1.27) cm] related to apnea during sleep were longer than those correlated with hypopnea [(2.99 +/- 0.51) cm, (0.72 +/- 0.23) cm, (2.27 +/- 0.67) cm, respectively] in wakefulness. (P < 0.01). CONCLUSIONS: The obstruction of upper airway during sleep is dynamic and multilevel in patients with OSAHS. To a certain degree, hypopnea during wakefulness can give a clue to the obstructive state during sleep.