***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: This study was design ed to investigate the impact of the Entropy Module ® and Bispectral Index ® ( BIS ) monitoring on drug consumption and recovery times compared with st and ard anaesthetic practice in patients undergoing orthopaedic surgery using a combination of regional and general anaesthesia as performed by an experienced anaesthesiologist . We hypothesised that electroencephalogram monitoring would lead to a lower drug consumption as well as shorter recovery times . With institutional review board approval and written informed consent , 90 adult patients undergoing surgery to the upper or lower extremity received regional anaesthesia for post- and intraoperative pain control and were r and omised to receive general anaesthesia by propofol/remifentanil infusion controlled either solely by clinical parameters or by targeting Entropy or BIS values of 50 . Recovery times and drug consumption were recorded . Data from 79 patients were analysed . Compared with st and ard practice , patients with Entropy or BIS monitoring showed a similar propofol consumption ( st and ard practice 101±22 μg/kg/minute , Entropy 106±24 μg/kg/minute , BIS 104±20 μg/kg/minute ) and showed similar Aldrete scores ( 10/10 ) one minute after extubation : 9.1∓0.3 , 9.2±0.6 and 9.3±0.5 , respectively . Time points of extubation were 7.3±2.9 minutes , 9.2∓3.9 minutes and 6.8±2.9 minutes , respectively , demonstrating a significant difference between Entropy and BIS ( P=0.023 ) . Compared with st and ard practice , targeting an Entropy or BIS value of 50 did not result in a reduction of propofol consumption during general anaesthesia combined with regional anaesthesia as performed by an experienced anaesthesiologist in orthopaedic patients The use of cerebral monitoring may improve the ability of anesthesiologists to titrate anesthetic drugs . However , there is controversy regarding the impact of the alleged anesthetic-sparing effects of cerebral monitoring on the recovery process and patient outcome . We design ed this prospect i ve double-blinded , sham-controlled study to evaluate the impact of intraoperative monitoring with the electroencephalogram bispectral index ( BIS ™ ) or auditory evoked potential ( AEP ) device on the usage of desflurane and the time to discharge from the recovery room , as well as on patient satisfaction with their anesthetic experience and recovery . Ninety healthy patients undergoing laparoscopic general surgery procedures using a st and ardized anesthetic technique  were r and omly assigned to one of three monitoring groups : st and ard clinical practice ( control ) , BIS-guided , or AEP-guided . Both the BIS and AEP monitors were connected to all patients before induction of general anesthesia . In the control group , the anesthesiologists were not permitted to observe the BIS or AEP index values during the intraoperative period . In the BIS-guided group , the volatile anesthetic was titrated to maintain a BIS value in the range of 45–55 . In the AEP-guided group , the targeted AEP index range was 15–20 . The BIS and AEP indices , as well as end-tidal desflurane concentration , were recorded at 3–5 min intervals . Recovery times to awakening , tracheal extubation , fast-track score ≥12 , and postanesthesia care unit ( PACU ) discharge criteria were recorded at 1–10 min intervals . In addition , patient satisfaction with anesthesia and quality of recovery were evaluated on 100- and 18-point scales , respectively , at 24 h after surgery . The AEP- and BIS-guided groups were administered significantly smaller average end-tidal desflurane concentrations than the control group ( 3.8 ± 0.9 and 3.9 ± 0.6 versus 4.7 ± 1.7 , respectively ) ( P < 0.01 ) . Although the emergence times to eye opening , tracheal extubation , and obeying comm and s were consistently shorter in the AEP and BIS groups ( 6 ± 4 and 6 ± 5 versus 8 ± 8 min ; 6 ± 5 and 6 ± 4 versus 11 ± 10 min ; and 8 ± 4 and 7 ± 4 versus 12 ± 9 min , respectively ) , only the extubation times were significantly different from the control group ( P < 0.05 ) . More importantly , the length of the PACU stay was significantly shorter in both the AEP- and BIS-guided groups ( 79 ± 43 and 80 ± 47 versus 108 ± 58 min , respectively ) ( P < 0.05 ) . The patients ’ quality of recovery was also significantly higher in the two monitored groups ( 15 ± 2 versus 13 ± 3 in the control group , P < 0.05 ) . We concluded that cerebral monitoring with either the BIS or AEP devices reduced the maintenance anesthetic ( desflurane ) requirement , result ing in a shorter length of stay in the PACU and improved quality of recovery after laparoscopic surgery . However , there were no significant outcome differences between the two cerebral monitored groups Background Fast track recovery is a care process goal after cardiac surgery . Intraoperative anesthetic depth may impact recovery , but the impact of brain monitoring on time to extubation and intensive care unit ( ICU ) length of stay after cardiac surgery has not been extensively studied . Our goal was to determine if BIS-guided anesthesia improves time to extubation compared to MAC-guided anesthesia in a cardiac surgery population . Methods In this secondary outcome analysis of a r and omized controlled study , we analyzed 294 patients undergoing elective coronary bypass grafting , valve replacements , and bypass plus valve replacements at a single tertiary referral center between February 1 , 2009 and April 30 , 2010 . We analyzed cardiac surgery patients that had been r and omized to BIS-guided anesthesia alerts ( n = 131 ) or MAC-guided anesthesia alerts ( n = 163 ) . The primary outcome measure was time to extubation in the BIS-guided and anesthetic concentration-guided groups . Secondary outcomes were length of stay in the ICU and total postoperative hospital length of stay . Results Valid extubation time data were available for 247 of 294 patients . The median [ IQR ] time to extubation was 307 [ 215 to 771 ] minutes in the BIS group and 323 [ 196 to 730 ] minutes in the anesthetic concentration group ( p = 0.61 ) . The median [ IQR ] ICU length of stay was 54 [ 29 to 97 ] hours versus 70 [ 44 to 99 ] hours ( p = 0.11 ) . In terms of postoperative hospital length of stay , there was no difference between the groups with median [ IQR ] times of 6 [ 5 - 8 ] days ( p = 0.69 ) in each group . Conclusions The use of intraoperative BIS monitoring during cardiac surgery did not change time to extubation , ICU length of stay or hospital length of stay . Data regarding BIS monitoring and recovery in an exclusively cardiac surgery population are consistent with recent effectiveness studies in the general surgical population .Trial registration Clinical Trials.gov number NCT00689091 BACKGROUND Awareness is an uncommon complication of anaesthesia , affecting 0.1 - 0.2 % of all surgical patients . Bispectral index ( BIS ) monitoring measures the depth of anaesthesia and facilitates anaesthetic titration . In this trial we determined whether BIS-guided anaesthesia reduced the incidence of awareness during surgery in adults . METHODS We did a prospect i ve , r and omised , double-blind , multicentre trial . Adult patients at high risk of awareness were r and omly allocated to BIS-guided anaesthesia or routine care . Patients were assessed by a blinded observer for awareness at 2 - 6 h , 24 - 36 h , and 30 days after surgery . An independent committee , blinded to group identity , assessed every report of awareness . The primary outcome measure was confirmed awareness under anaesthesia at any time . FINDINGS Of 2463 eligible and consenting patients , 1225 were assigned to the BIS group and 1238 to the routine care group . There were two reports of awareness in the BIS-guided group and 11 reports in the routine care group ( p=0.022 ) . BIS-guided anaesthesia reduced the risk of awareness by 82 % ( 95 % CI 17 - 98 % ) . INTERPRETATION BIS-guided anaesthesia reduces the risk of awareness in at-risk adult surgical patients undergoing relaxant general anaesthesia .  With a cost of routine BIS monitoring at US16 dollars per use in Australia and a number needed to treat of 138 , the cost of preventing one case of awareness in high-risk patients is about 2200 dollars Purpose This study was design ed to investigate the effect of bispectral index ( BIS ) monitoring on the recovery profiles , level of postoperative cognitive dysfunction , and anesthetic drug requirements of elderly patients undergoing elective orthopedic surgery with general anesthesia . Methods Sixty-eight patients over the age of 60 were r and omized into one of two groups . In the st and ard practice ( SP ) group , the anesthesiologists were blinded to the BIS value , and isoflurane was titrated according to st and ard clinical practice . In the BIS group , isoflurane was titrated to maintain a BIS value between 50–60 . Results The total isoflurane usage was 30 % lower in the BIS group compared to the SP group ( 5.6 ± 3 vs 7.7 ± 3 mL , P < 0.05 ) . The time to orientation was faster in the BIS group compared to the SP group ( 9.5 ± 3vs 13.1 ± 4 min , P < 0.001 ) . There were no differences in the postoperative psychometric tests between the two groups . Conclusions There was no difference in the level of postoperative cognitive dysfunction between the two groups . However , titration of isoflurane using the BIS index decreased utilization of isoflurane and contributed to faster emergence of elderly patients undergoing elective knee or hip replacement surgery . RésuméObjectifRechercher l’effet du monitorage par l’index  bispectral ( BIS ) sur les profils de récupération , le niveau de déficit cognitif postopératoire et les besoins d’anesthésiques chez des patients âgés qui subissent une intervention orthopédique non urgente avec anesthésie générale . MéthodeSoixante-huit patients de plus de 60 ans ont été répartis au hasard en deux groupes . Pour ceux du groupe de pratique courante ( PC ) , la valeur du BIS n’était pas connue des anesthésiologistes et l’isoflurane a été titré selon les normes de la pratique clinique . Pour les patients du groupe BIS , l’isoflurane a été titré de façon à maintenir un BIS entre 50 et 60.RésultatsL’utilisation totale d’isoflurane a été plus basse de 30 % dans le groupe BIS , comparé au groupe PC ( 5,6 ± 3 vs 7,7 ± 3 mL , P < 0,05 ) . Le retour à la conscience a été plus rapide dans le groupe BIS , comparé au groupe PC ( 9,5 ± 3 vs 13,1 ±4 min , P < 0,001 ) . Les tests psychométriques postopératoires n’ont présenté aucune différence intergroupe . Conclusion Le niveau de déficit cognitif postopératoire n’était pas différent d’un groupe à l’autre . Cependant , le titrage de l’isoflurane à l’aide de l’index BIS a permis de réduire l’utilisation d’isoflurane et a favorisé une récupération plus rapide chez des patients âgés qui subissent la mise en place d’une prothèse totale de hanche BACKGROUND Recent studies have suggested that electroencephalogram bispectral index ( BIS ) monitoring can improve recovery after anaesthesia and save money by shortening patients postoperative stay . The aim of the study is to evaluate the management of drugs and to measure immediate recovery after anaesthesia with or without BIS monitoring . METHODS We studied 90 patients undergoing abdominal surgery r and omly allocated to one of two groups of 45 each with or without BIS monitoring . St and ard monitoring ( EKG , arterial oxygen saturation and non-invasive blood pressure ) was applied . All groups were monitored with BIS , using electrodes ( Zipprep , Aspect Medical Systems ) applied to the forehead . In the group 2 the BIS value was blinded to the anaesthesiologist . The BIS value was displayed using Spacelabs Medical BIS Ultraview Monitor . After obtaining baseline values for the BIS index ( group 1 ) and haemodynamic data ( all groups ) anaesthesia was induced with a bolus dose of remifentanil and TPS , and vecuronium . The anaesthesia was maintained with Remifentanil and Sevoflurane . At st and ard times BIS , haemodynamic and respiratory parameters were recorded . Recovery times were measured by a study 
    Output:
    
BIS-guided anaesthesia can reduce the risk of intraoperative awareness in surgical patients at high risk for awareness in comparison to using clinical signs as a guide for anaesthetic depth .
BIS-guided anaesthesia and ETAG-guided anaesthesia may be equivalent in protection against intraoperative awareness but the evidence for this is inconclusive .
In addition , anaesthesia guided by BIS kept within the recommended range improves anaesthetic delivery and postoperative recovery from relatively deep anaesthesia