Effect of general anesthesia guided by electroencephalography monitoring on postoperative delirium in elderly patients with non-acute fragile brain function / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of general anesthesia guided by electroencephalography (EEG) monitoring on postoperative delirium (POD) in elderly patients with non-acute fragile brain function.Methods:Sixty patients of both sexes with non-acute fragile brain function, aged 65-85 yr, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, with body mass index of 18-30 kg/m 2, undergoing hip replacement, were divided into 2 groups ( n=30 each) by a random number table method: conventional general anesthesia group (group C) and general anesthesia guided by EEG monitoring group (group E). Anesthesia was maintained by intravenous infusion of propofol 50-150 μg·kg -1·min -1 and remifentanil 0.05-0.30 μg·kg -1·min -1 and intermittent intravenous boluses of rocuronium.In group E, the dose of anesthetic was reduced when the EEG burst-suppression ratio≥10% for more than 1 min or anesthesia index (AI) <40.If the situation mentioned above still existed after 1 min, the dose of anesthetic was continued to be reduced or norepinephrine was injected intravenously.In group C, the amount of intraoperative anesthesia was adjusted according to the changes in hemodynamics.Norepinephrine 4-10 μg or dopamine 1 mg was given intravenously in the light of the patients′ heart rates when intraoperative hypotension occurred.At 10 min after anesthesia induction, immediately after skin incision, immediately at the end of surgery and at 1 h after surgery, blood samples were obtained from the artery and jugular venous bulb for blood gas analysis and for calculation of jugular bulb blood oxygen content (CjvO 2), artery-jugular bulb blood oxygen content difference (Ca-jvO 2), cerebral oxygen uptake rate (CERO 2) and jugular-arterial blood lactate concentration difference (Djv-aLac). The emergence time, amounts of intraoperative anesthetics, use of noradrenaline, cumulative time of EEG burst inhibition and duration of AI<40 were recorded.The development of POD was assessed within 5 days after surgery by the confusion assessment method for the intensive care unit and the duration was recorded. Results:Compared with group C, recovery time, cumulative time of EEG burst inhibition and duration of AI<40 were significantly shortened, the intraoperative consumption of propofol and remifentanil was decreased, the requirement for intraoperative noradrenaline was increased, CjvO 2 was increased, Ca-jvO 2 and CERO 2 were decreased immediately at the end of surgery and at 1 h after surgery, the incidence of POD within 5 days after surgery was decreased, and POD duration was shortened in group E ( P<0.05). Conclusion:General anesthesia guided by EEG monitoring can reduce the development of POD in elderly patients with non-acute fragile brain function.