Relationship between cerebral oxygen saturation and postoperative cognitive dysfunction in elderly patients under inhalational combined intravenous anesthesia
- VernacularTitle:静吸复合麻醉下老年患者脑氧饱和度与术后认知功能变化之间的关系
- Author:
Baosen JIA
;
Dongyu WU
;
Hong ZHANG
- Publication Type:Journal Article
- Keywords:
aged;
cognition disorders;
oxygen consumption;
anesthesia,general
- From:
Medical Journal of Chinese People's Liberation Army
2005;30(9):792-795
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the relationship between intraoperative cerebral oxygen saturation (rSO2) and postoperative cognitive dysfunction with near-infrared cerebral oximeter (INVOS 5100) in patients operated under inhalational combined intravenous anesthesia, and to determine the critical rSO2 value below which postoperative cognitive dysfunction may occur. Methods Sixty ASAⅠ-Ⅱ patients of both sexes were selected, aged 62-80yr, weighed 58-77kg, scheduled for elective abdominal surgery or surgery on the low limb. All the patients were divided into three groups according to their educational background: in group Ⅰ were the illiterate and uneducated patients (n=20);group Ⅱ the primarily educated patients (<6yr education) (n=20), and group Ⅱ the well educated patients (>6yr education) (n=20). Each group was further divided into isoflurane and sevoflurane subgroups (n=10 in each subgroup). All patients received no pre-medication. Anesthesia was induced with intravenous atropine 0.3mg, propofol 1.0-1.5mg kg-1, fentanyl 2-3μg*kg-1 and vecuronium 0.1-0.2mg*kg-1, and maintained with isoflurane or sevoflurane inhalation(0.9-1.1 MAC) supplemented with intermittent i.v. boluses of fentanyl, and recorded after entering room (baseline) (T0), after O2 inhalation (T1), after induction of anesthesia (T2), after skin incision (T3), during operation (T4), the end of surgery (T5), and awaking (T6). Mini-Mental State Examination (MMSE) was performed before anesthesia and 1, 4, 8, 12 and 24h after surgery. BP, HR, ECG, SpO2, PETCO2 and end-tidal concentration of inhalational anesthetics were continuously monitored during anesthesia. Results In all three groups rSO2 was significantly lower during operation (T4) and at the end of surgery (T5) than baseline (T0) (P<0.05). In all patients the MMSE scores at 1h after operation were significantly lower than the baseline value (P<0.05). The MMES scores in all patients significantly declined within 1-4h after surgery, and the cognitive function recovered at 4h after surgery in 85% patients. The critical values of rSO2 below which postoperative cognition dysfunction may occur were: 45 (group Ⅰ), 47 (group Ⅱ) and 49 (group Ⅲ) for isoflurane anesthesia subgroups;47 (group Ⅰ), 48 (group Ⅱ) and 50 (group Ⅲ) for sevoflurane subgroups. Conclusion The perioperative rSO2 should be maintained up to above 50% to reduce the incidence of postoperative cognitive dysfunction under inhalational combined intravenous anesthesia.
