Relationship between cerebral oxygen saturation and postoperative cognitive dysfunction in elderly patients / 中华麻醉学杂志

ABSTRACT

Objective To investigate the relationship of intraoperative cerebral oxygen saturation(rSO_2 )monitored with near-infrared cerebral oximeter (INNOS 5100) and postoperative cognitive dysfunction in patientsoperated upon under isoflurane or sevoflurane anesthesia and to determine the critical rSO_2 value below whichpostoperative cognitive dysfunction may occur.Methods Sixty ASA Ⅰ- Ⅱ patients of both sexes aged 62-80 yr,weighing58-77 kg schedules for elective abdominal surgery or surgery on the low limb were divided into threegroups according to their levels of education group Ⅰthe illierate and uneducated (n = 20); group Ⅱ primaryschool education (6yr education (n = 20). Each group was furtherdivided into isoflurane and sevoflurane subgroups (n = 10 in each subgroup). The patients were unpremedicated.Anesthesia was induced with intravenous atropine 0. 3mg, propofol 1 .0-1. 5 mg?kg~(-1), fentanyl 2-3?g?kg~(-1) andvecuronium o. 1-0.2 mg?kg~(-1) and maintained with isoflurane or sevoflurane inhalation (0.9-1. 1 MAC )supplemented with intermittent i.v. boluses of fentanyl and recorded before anesthesia (baseline), after O_2inhalation(T_1), after induction of anesthesia(T_2), after skin incision (T_3), during operation (T_4)and at the end ofsurgery (T_5). Mini-Mental State Examination (MMSE) was performed before anesthesia and 1,4, 8, 12 and 24 hafter surgery. BP, HR, ECG, SpO_2, P_(ET) CO_2 and end-tidal concentration of inhalational anesthetics werecontinuously monitored during anesthesia. Results In all three groups rSO_2 was significantly lower during operation(T_4) and at the end of surgery (T_5 ) than baseline (T_0 ) (P