阻塞性睡眠呼吸暂停综合征患者脑血管储备功能变化的研究

目的 探讨阻塞性睡眠呼吸暂停综合征(OSAS)患者的脑血管储备(CVR)功能的变化.方法 将98例多导睡眠图检查确诊OSAS患者,根据呼吸暂停低通气指数分为轻度、中度和重度3组,并与20例正常组对照,采用经颅多普勒超声屏气试验和过度换气试验评价CVR功能.结果 OSAS患者屏气前和后大脑中动脉血流速度均大于正常者(P<0.01),屏气后的增加率明显低于正常者(P<0.01),不同程度的OSAS患者相比,屏气前和后大脑中动脉血流速度随程度加重而增加(P<0.05,P<0.01),屏气后的增加率随程度的加重而减少(P<0.05,P<0.01),OSAS患者换气前和后大脑中动脉血流速度均大于正常者(P<0.05,P<0.01),换气后的下降率明显低于正常者(P<0.01),但轻度OSAS组与正常组相比变化无统计学意义(P>0.05),不同程度的OSAS患者相比,换气前和后大脑中动脉血流速度随程度加重而增加(P<0.01),换气后的下降率则中度组下降最少,重度组次之,轻度组下降率最大.结论 OSAS可损害CVR,且随程度加重,CVR损害愈重.

Study of changes of cerebral vascular reserve function in patients with obstructive sleep apnea syndrome

Objective To investigate changes of cerebral vascular reserve （CVR） ihnction in patients with obstructive sleep apnea syndrome （OSAS）. Methods 98 cases of OSAS diagnosed by polysonmography were divided into mild, moderate and severe groups according to the apnea -hyponea index （AH[） , and controlled with 20 ncnrnal persons. CVR function was assessed by breath-holding experiments and hyperventilation experiments detected by TCD. Results Blood flow velocity of MCA was greater than normal persons in patients with OSAS either before or ＇after breath-hold experiments （ P 〈 0. 01 ） , and the rate of increase in blood flow velocity of MCA was signific.antly lower ＇after breath-hold experiments than that in normal controls （P 〈 0. 01 ）. Blood flow velocity of MCA increased while degrees of OSAHS increased in patients with OSAS either before or ＇after breath -hold experiments （ P 〈 O. 05, P 〈 O. 01 ）, and the rate of increase in blood flow velocity of MCA was lower while severity of OSAS increased after breath-hold experiments （P 〈 0. 05,P 〈 0. 01 ）. Blood flow velocity of MCA was greater in OSAS patients than that in normal controls either before or after hyperventilation experiments （P 〈 O. 05, P 〈 0. 01 ）, and the rate of decrease in blood flow velocity of MCA was lower in OSAS patients than that in normal group （ P 〈 O. O1 ）, but there was no significant difference of the change in the mild OSAS group and the normal group （P 〉 0. 05 ）. Blood flow velocity of MCA increased while severity of OSAS increased either before or ＇after hyperventilation experiments （ P 〈 O. 05, P 〈 0. O1 ）. The rate of＇ decrease in blood flow velocity of MCA was least in the moderate OSAS group （ P 〈 0. O1 ） , followed by severe OSAS group （ P 〈 0. 01 ）, and the maximum rate was fotmd in mild OSAS group after hyperventilation experiments （ P 〈 0. 05 ）. Conclusions CVR is damaged by OSAS, and the rate of the damage grows with the severity of OSAS.