经颅多普勒超声结合屏气试验评价健康吸烟者脑血管反应性

目的 应用经颅多普勒超声联合屏气试验研究健康吸烟者脑血管反应性。方法 选取男性健康吸烟者46例，男性健康不吸烟者42例，采用经颅多普勒超声检测并记录双侧大脑中动脉（middle cerebral artery，MCA）多普勒频谱，检测参数包括收缩期峰值流速（peak systolicvelocity，PSV），搏动指数（pulsatility index，PI），阻力指数（resistance index，RI），嘱受检者做屏气试验，记录屏气末双侧MCA多普勒频谱，测量参数同上，并计算屏气前后各参数变化率，通过参数变化率的大小分析脑血管反应性。结果 屏气后两组MCA峰值流速均表现为随屏气时间延长而增快，两组的PI及RI均降低，屏气前后各参数差异有统计学意义（P <0.05）。吸烟组屏气试验后PSV变化率为（23±7）％，不吸烟组为（37±9）％，两组间差异有统计学意义（P <0.05）；吸烟组屏气试验后PI值变化率为（19±5）％，不吸烟组为（25±8）％，两组间差异有统计学意义（P <0.05）；吸烟组屏气试验后RI值变化率为（21±6）％，不吸烟组为（35±7）％，两组间差异有统计学意义（P <0.05）。结论 健康吸烟者屏气后MCA的PSV、PI及RI的变化率均较健康不吸烟者减低，吸烟可使脑血管反应性降低。

Transcranial Doppler Combined with Breathing-holding Test for Evaluation Cerebrovascular reactivity in Healthy smoking Men

Objective To use transcranial doppler （TCD） combined with breathing-holding test for evaluating middle cerebral artery reactivity in healthy smoking men. Methods Forty-six healthy smoking men （group A） and 42 healthy non-smoking men （group B） were enrolled. Before and after breathing, the peak systolic velocity （PSV） of middle cerebral artery was monitored by TCD, meanwhile the pulsatility index （PI） and resistance index （RI） were detected, the difference before and after the breathing-holding test and the change rate between two groups were calculated. Results After breathing-holding test, the PSV of the two groups were both increased, the PI and RI were both decreased, there was significant difference between before and after breathing- holding test, P〈0.05; The change rate of PSV in group A was （23±7）%, group B was （37±9）%, and the change rate between the two groups was statistically significant （P〈0.05）. The change rate of PI in group A was （19±5）%, group B was （25±8）%, and the change rate between the two groups was statistically significant （P〈0.05）. The change rate of RI in group A was （21±6）%, group B was （35±7）%, and the change rate between the two groups was statistically significant （P〈0.05）. Conclusion The cerebrovascular reactivity of healthy smoking men was lower than healthy nonsmoking men, smoking can result in diminution of cerebrovascular reactivity. TCD combined with breathing-holding test can assess the cerebrovascular reactivity.