丙泊酚不同镇静深度对体外循环下心脏瓣膜置换术患者术后谵妄的影响：与脑氧饱和度的关系

Effects of different sedation depths of propofol on postoperative delirium in patients undergoing cardiac valve replacement under cardiopulmonary bypass： the relationship with regional cerebral oxygen saturation

目的 评价丙泊酚不同镇静深度对体外循环（CPB）下心脏瓣膜置换术患者术后谵妄的影响及其与脑氧饱和度（rSO2）的关系.方法 择期CPB下行主动脉瓣膜置换术患者40例,性别不限,年龄26～64岁,体重指数17～25 kg∕m^2,ASA分级Ⅲ或Ⅳ级,采用随机数字表法分为2组（n=20）：调节丙泊酚输注速率,CPB期间A组维持50≤BIS值〈60,B组维持35≤BIS值〈45.入室后至缝皮结束采用近红外光谱仪持续采集患者双侧rSO2,记录rSO2最低值,观察低脑氧饱和度（rSO2低于55%或降低幅度超过基础值20%）的发生情况.术后入ICU 12 h内至出ICU采用CAM-ICU量表评价谵妄发生情况.结果 与A组比较,B组术后谵妄发生率、低脑氧饱和度发生率和rSO2最低值降低（P〈0.05）.结论 CPB期间维持35≤BIS值〈45可减少心脏瓣膜置换术患者术后谵妄的发生,与改善术中rSO2有关。

Objective To evaluate the effects of different sedation depths of propofol on postopera-tive delirium in patients undergoing cardiac valve replacement under cardiopulmonary bypass（CPB）and the relationship with regional cerebral oxygen saturation（rSO2）. Methods Forty American Society of An-esthesiologists physical statusⅢorⅣpatients of both sexes, aged 26-64 yr, with body mass index of 17-25 kg∕m^2, scheduled for elective aortic valve replacement with CPB, were divided into A and B groups （n=20 each）using a random number table. The infusion rate of propofol was adjusted to maintain the cor-responding anesthetic depth with 50≤BIS value〈60 during CPB in group A and with 35≤BIS value〈45 during CPB in group B. Bilateral rSO2was measured using the near infrared spectroscopy from admission to the operating room until the end of skin suturing. The minimum rSO2was recorded, and occurrence of low cerebral oxygen saturation（rSO2was less than 55% or the decrease in rSO2〉20% of the baseline）was ob-served. Postoperative delirium was evaluated using Confusion Assessment Method for the Intensive Care Unit （ICU）from 12 h after admission to ICU until discharge from ICU. Results The incidence of postoperative delirium, low cerebral oxygen saturation and minimum rSO2were significantly lower in group B than in group A（P〈0.05）. Conclusion Maintaining 35≤ BIS value〈 45 during CPB can reduce the develop-ment of postoperative delirium and is related to improving intraoperative rSO2in patients undergoing cardiac valve replacement.