Bispectral Index In Different Ranges During Awakening Period For The Evaluation Of Awakening Quality In Elderly Hip Surgery

Objective:To investigate the bispectral index（BIS）at different ranges during the awakening period for elderly patients undergoing unilateral proximal femoral nail antiretroduction（PFNA）and unilateral artificial femoral head replacement（AFHR）under general anesthesia combined with lumbar plexus nerve block to assess the dosage of propofol and quality of postoperative awakening.Methods:Sixty elderly patients who underwent unilateral PFNA and unilateral AFHR in our hospital from September 2019 to October 2020 were selected,aged65-75 years,including 32 males and 28 females,with body mass index（BMI）value of 18.5～23.9 and Severe anemia and American Society of anesthesiologists（ASA）II-III were not observed before surgery.They were randomly divided into control group（Group C）,BIS1 group（Group B1）and BIS2 group（Group B2）with 20 cases in each group.After entering the room,the patients in the three groups were given routine ECG monitoring,Sp O₂ connection and invasive arterial monitoring,while the patients in group B1 and B2 were given BIS monitoring.All the patients were operated under general anesthesia combined with lumbar plexus block.During the operation,map and HR were used to judge the depth of anesthesia in group C,and BIS was used to judge the depth of anesthesia in group B1 and B2（the depth of anesthesia was controlled at 40～60）.After the beginning of suture,propofol was used to maintain the depth of anesthesia in three groups:the fluctuation range of map and HR in group C was 20%of the basic value;the BIS value in group B1 was maintained at 61～70;the BIS value in group B2 was maintained at 71～80;the patients in three groups were given sufficient antagonists at the end of operation.The dosage of propofol from the beginning of suture to the end of operation was observed and recorded,The number of vasoactive drugs used during PACU,tracheal extubation time,P_ETCO₂ after tracheal extubation,glucose（Glu concentration）at the beginning of suture（T1）and 5 minutes after tracheal extubation（T2）,steward’s wake-up score at the time of leaving the operating room,modified Aldrete’s score at 30 minutes of PACU,VAS score at the time of leaving PACU,whether there was any delay in wake-up,whether it occurred in postoperative hypotension and postoperative cognitive dysfunction.Results:（1）The dosage of propofol in group B1 and B2 was significantly lower than that in group C（P<0.05）,and that in group B2 was lower than that in group B1（P< 0.05）;the frequency of vasoactive drug use in group B1 and B2 was significantly lower than that in group P（P<0.05）,but there was no significant difference between group B1 and B2（P>0.05）.（2）Tracheal extubation time:Group B1 and B2 were significantly shorter than group C（P<0.05）,There was no statistical significance between group B1 and group B2（P>0.05）.After tracheal extubation,the P_ETCO₂ of the three groups were in the range of 35～45mm Hg,and there was no statistical significance.（3）Blood glucose fluctuation range between T1-T2（△Glu）:Group B1 was smaller than group B2 and group C（P<0.05）,group B2 and group C had no statistical significance（P>0.05）.（4）Steward recovery score when leaving the operating room:Group B1 and group B2 were higher than group C（P<0.05）,and the score of group B2 was higher than group B1（P<0.05）;the modified Aldrete score at 30 minutes of PACU:the scores of group B1 and group B2 were higher than group C（P<0.05）, but there was no statistical significance between group B1 and group B2（P> 0.05）.（5）The VAS score of three groups was not statistically significant when they were out of PACU（P>0.05）.（6）There were 8 cases（40%）in group C with delayed awakening,and there was no delayed awakening in group B1 and group B2.（7）Hypotension occurred in PACU:11 cases（55%）in group C,6 cases（30%）in group B1 and 5 cases（25%）in group B2.There was no postoperative cognitive impairment in group C,B1 and B2.Conclusions:BIS was maintained at 61-70 hours,elderly patients who underwent hip fracture surgery under general anesthesia combined with lumbar plexus block were able to get a better awakening effect and ensure the safety and comfort of the awakening period.