目的 探讨不同吸入氧浓度对有脑卒中病史患者围术期脑血管功能的影响。 方法 选择上海交通大学医学院附属仁济医院2020年6月至2024年3月期间拟行择期手术且有缺血性脑卒中病史的患者150例，采用随机数字表法分为F30组［术中吸入氧浓度（FiO?）为30%］和F80组（FiO?为80%），每组75例。围术期持续经颅多普勒（TCD）监测双侧大脑中动脉（MCA）血流，包括平均血流速度（Vm）、阻力指数（RI）和搏动指数（PI），并应用FORE-SIGHT Oximeter监测脑氧饱和度（rScO?）。分别于术前、诱导后1 h、拔管前采集动脉血气，监测pH值、动脉二氧化碳分压（PaCO?）、氧合指数（OI）、碱剩余（BE）、血细胞比容（Hct）和乳酸（Lac）。于术后24 h采集外周血，检测血栓素A?（TXA?）和前列环素（PGI?）含量。术后1个月通过电话随访，采用ABCD2评分和Essen卒中风险评分（ESRS）评估患者脑缺血事件再发生风险。 结果 围术期动脉血气各项指标在两组间差异无统计学意义（P > 0.05）。与F30组相比，F80组患者术末患侧MCA的Vm下降幅度更小［（8.18 ± 3.34）% vs. （13.57 ± 5.32）%，P < 0.05），而双侧RI和PI变化率组间差异无统计学意义（P > 0.05）。诱导后1 h和拔管前，F80组患侧脑氧饱和度较术前的升高幅度显著大于F30组（P < 0.05），对侧脑氧饱和度两组差异无统计学意义（P > 0.05）。拔管前及术后1 d，F80组外周血TXA?含量显著低于F30组，PGI?含量则高于F30组（P < 0.05）。两组术后1个月内根据ABCD²和ESRS评估的脑缺血高风险患者比例差异无统计学意义（P > 0.05）。 结论 对于有脑卒中病史的患者，全身麻醉手术中采用80%吸入氧浓度相比30%可更好地维持围术期脑血流动力学稳定和脑氧供，提高脑血管内皮功能，但对术后短期脑血管事件发生率无显著影响。

Objective To investigate the effects of different inspired oxygen concentrations on perioperative cerebrovascular function in patients with a history of ischemic stroke. Methods A total of 150 patients scheduled for elective surgery with a history of ischemic stroke were enrolled from Renji Hospital， Shanghai Jiao Tong University School of Medicine， between June 2020 and March 2024. Using a random number table， patients were allocated into two groups： F30 group （intraoperative fraction of inspired oxygen， FiO? = 30%） and F80 group （FiO? = 80%）， with 75 patients in each group. Bilateral middle cerebral artery （MCA） blood flow was continuously monitored using transcranial Doppler （TCD）， including mean flow velocity （Vm）， resistance index （RI）， and pulsatility index （PI）. Cerebral oxygen saturation （rScO?） was measured using a FORE-SIGHT oximeter. Arterial blood gas analysis was performed preoperatively， 1 hour after induction， and before extubation to assess pH， partial pressure of arterial carbon dioxide （PaCO?）， oxygenation index （OI）， base excess （BE）， hematocrit （Hct）， and lactate （Lac）. Peripheral blood samples were collected 24 hours postoperatively to measure thromboxane A? （TXA?） and prostacyclin （PGI?） levels. At 1 month postoperatively， telephone follow-up was conducted to evaluate the risk of recurrent cerebral ischemic events using the ABCD2 score and Essen Stroke Risk Score （ESRS）. Results No significant differences were observed in baseline characteristics between the two groups. Perioperative arterial blood gas parameters did not differ significantly between groups （P > 0.05）. Compared with the F30 group， the F80 group exhibited a smaller reduction in mean flow velocity （Vm） of the affected MCA at the end of surgery （8.18% ± 3.34% vs. 13.57% ± 5.32%， P < 0.05）， while no significant intergroup differences were found in RI or PI. At 1 hour after induction and before extubation， rScO? of the affected hemisphere was significantly increased in the F80 group as compared with the F30 group （P < 0.05）， whereas no significant difference was observed in the contralateral hemisphere. Before extubation and on postoperative day 1， TXA? levels were significantly lower and PGI? levels higher in F80 group compared with F30 group （P < 0.05）. The proportion of patients at high risk of cerebral ischemia by ABCD2 and ESRS at 1 month postoperatively did not differ between groups （P > 0.05）. Conclusion In patients with a history of stroke， intraoperative administration of 80% FiO? under general anesthesia better maintains perioperative cerebral hemodynamic stability and cerebral oxygen saturation， improves cerebrovascular endothelial function， but does not significantly affect the short-term incidence of postoperative cerebrovascular events compared with 30% FiO?.