Effects of different sedation depths of propofol on postoperative delirium in patients undergoing car-diac valve replacement under cardiopulmonary bypass: the relationship with regional cerebral oxy-gen saturation / 中华麻醉学杂志

ABSTRACT

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∕m2, 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<005). 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.