The Impact Of BIS-guided Anesthesia On The Postoperative Delirium In Elderly Patients With Chronic Anemia

Objective Anemia in the elderly has become an important public health problem, the incidence increased year by year. Anemia can lead to patients with decreased memory, attention and calculation, which indicates anemia and cognitive impairment have some relevance.The elderly have a high incidence of postoperative cognitive dysfunction and delirium, although the specific pathogenesis is unknown, the relevant reports suggest it is associated with a variety of factors, anesthesia is an important factor. BIS(bispectral index) values can accurately reflect the depth of anesthesia, previous studies carried out the impact of BIS-guided anesthesia for postoperative cognitive in elderly patients, but whether BIS monitoring has the same impact for elderly patients with chronic anemia is not clear. This study focuse on the influence of BIS monitoring on the incidence of postoperative delirium in elderly patients with chronic anemia.Methods 180 patients undergoing elective abdominal surgery patients receiving general anesthesia, were randomly divided into BIS group and control group. And this is a prospective study.Patients selected by age(65-85 years), preoperative hemoglobin(Hb) Men <120g / L, women <110g / L, ASAII-III level, preoperative mini-mental state examination, MMSE) ≥20. Half an hour before surgery intramuscular injection of 0.1g luminal powder.In both group, anesthesia was induced with midazolam 0.05 mg / kg, propofol(1-2) mg / kg, sufentanil 0.5μg / kg, cis atracurium 0.2 mg / kg, and anesthesia was maintained with propofol TCI(2.0-2.5) μg / ml, sufentanil 0.3μg / kg(before skin incision additional), remifentanil(0.05-0.3) μg / kg.min, cis atracurium(0.1-0.2) mg / kg / h. BIS Group maintained BIS values(40-60), and adjust propofol infusion rate under BIS value;the control group using conventional anesthesia and adjusted propofol infusion rate according to the physician’s clinical experience. Day before surgery all patients were assessed by MMSE in the ward, and 1-7 days after operation of delirium assessment. Observed in patients with the incidence of postoperative delirium and the heart rate(HR), mean arterial pressure(MAP) changes at each time,along with the propofol dosage during anesthesia, operation time, extubation time, awake time and so on.Data analysis was performed using SPSS(Version 13.0). The threshold for significance was set at P < 0.05Results 1. The general condition(age, sex, weight, education level),complications, hemoglobin(Hb), type of surgery, hospitalization costs, hemodynamic at each time point were no statistics significance differences in the two groups of patients.2. There were no differences in surgery time, anesthesia time, recovery time of spontaneous breathing, the PACU time of the two groups.The postoperative hospital stay and awake extubation time of BIS monitoring group was shorter than that in the control group, the awake extubation time(26 ± 7) min and hospital stay(11.5 ± 2.3) days of BIS monitoring group, significantly earlier than the control group(41 ± 12) min,(12.6 ± 4.4) days, the difference was statistically significant(P <0.05).3. The amount of intraoperative blood transfusion and infusion, hemoglobin(Hb) changes and hematocrit( Hct) showed no significant difference.4. The statistics of intraoperative anesthetic dosage and vasoactive drugs dosage show propofol and remifentanil dosage were different,and the difference was statistically significant,.BIS-guided anesthesia decreased the dosage of propofol and remifentanil compared with the control group(P < 0.05). Other indicators showed no statistical difference.5. The overall incidence of postoperative delirium of 17.8% in BIS monitoring group lower than 31.1% in the control group, the incidence of delirium in the first day of 13.3% was significantly lower than the 28.9% in the control group, the incidence of 5.6% the next day is also lower than 14.4% in the control group,. The difference was statistically significant(P <0.05). BIS-guided anesthesia decrease duration of delirium(P<0.05)., Differences in infection,cardiovascular complications, respiratory complications, were not statistically significant.Conclusion 1. BIS-guided anesthesia reduce the amount of anesthetic compared with the control group, the awake extubation time and length of hospital stay were significantly shorter than the control group, suggesting that BIS-guided anesthesia promote rapid recovery, worthing of clinical use.2.BIS monitored anesthesia reduces the incidence of postoperative delirium,improve the prognosis of patients in elderly patients with chronic anemia.