***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 
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    ***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 This study was performed to investigate the quality of different intravenous sedation techniques , and the correlation between the Bispectral Index ( BIS ) values and the Observer 's Assessment of Alertness/Sedation ( OAA/S ) scores .  Eighty patients undergoing sinonasal surgery were r and omly assigned to one of four groups . Group MF received midazolam and fentanyl , group PF received propofol and fentanyl , group MR received midazolam and remifentanil , and group PR received propofol and remifentanil .  Heart rate and mean arterial pressuure values were not different among the groups . SpO 2 decreased only after intravenous medication in groups MF and MR ( P<0.017 ) . Emesis was less common with propofol . A positive relationship existed between the BIS values and OAA/S scores during the operation in all groups and the strongest correlation was observed in group PR ( r=0.565 and P<0.001 ) . In conclusion , these four intravenous sedation techniques did not change mean arterial pressure , heart rate or SpO 2 clinical ly and produced a similar level of light sedation . The BIS was useful for monitoring of sedation during sinonasal surgery under local anaesthesia with intravenous sedation 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 BACKGROUND We compared the propofol requirements and recovery times when either the bispectral index ( BIS ) monitor or the cerebral state monitor ( CSM ) is used to guide propofol anaesthesia . METHODS Forty patients undergoing laparoscopic cholecystectomy were studied . All patients were monitored with both monitors and were r and omly allocated into two groups according to the monitor used to titrate propofol administration . Propofol was administered to maintain BIS or CSM within 40 and 60 .  Propofol consumption and clinical markers of recovery were assessed after surgery . RESULTS In the CSM group , the values of cerebral state index ( CSI ) and BIS were 47 ( 5 ) and 38 ( 6 ) , respectively ( P=0.00054 ) . In the BIS group , the values of CSI and BIS were 47 ( 5 ) and 45 ( 2 ) , respectively ( P=0.15 ) . In the BIS group , the total amount of propofol used was lower [ 109 ( 20 ) microg kg(-1 ) min(-1 ) ] than in the CSM group [ 130 ( 27 ) microg kg(-1 ) min(-1 ) ] ( P=0.018 ) . The time to eye opening was lower in the BIS [ 7.2 ( 3.5 ) min ] than in the CSM group [ 10.7 ( 6.6 ) ] ( P=0.038 ) . There were no differences in fentanyl consumption , or in other clinical markers of recovery . CONCLUSIONS Compared with BIS , propofol anaesthesia guided with CSI result ed in 20 % higher propofol doses . This , however , does not lead to clinical ly relevant differences in recovery times 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 : Intraoperative awareness with explicit recall occurs in approximately 0.15 % of all surgical cases . Efficacy trials based on the Bispectral Index ® ( BIS ) monitor ( Covidien , Boulder , CO ) and anesthetic concentrations have focused on high-risk patients , but there are no effectiveness data applicable to an unselected surgical population . Methods : We conducted a r and omized controlled trial of unselected surgical patients at three hospitals of a tertiary academic medical center . Surgical cases were r and omized to alerting algorithms based on either BIS values or anesthetic concentrations . The primary outcome was the incidence of definite intraoperative awareness ; prespecified secondary outcomes included postanesthetic recovery variables . Results : The study was terminated because of futility . At interim analysis the incidence of definite awareness was 0.12 % ( 11/9,376 ) ( 95 % CI : 0.07–0.21 % ) in the anesthetic concentration group and 0.08 % ( 8/9,460 ) ( 95 % CI : 0.04–0.16 % ) in the BIS group ( P = 0.48 ) . There was no significant difference between the two groups in terms of meeting criteria for recovery room discharge or incidence of nausea and vomiting . By post hoc secondary analysis , the BIS protocol was associated with a 4.7-fold reduction in definite or possible awareness events compared with a cohort receiving no intervention ( P = 0.001 ; 95 % CI : 1.7–13.1 ) . Conclusion : This negative trial could not detect a difference in the incidence of definite awareness or recovery variables between monitoring protocol s based on either BIS values or anesthetic concentration . By post hoc analysis , a protocol based on BIS monitoring reduced the incidence of definite or possible intraoperative awareness compared with routine care Background : Bispectral Index (BIS)–titrated administration allows a reduction of propofol infusion rates in patients undergoing surgery . Result ing differences in anesthetic depth might affect the stress response to surgery involving neural circuitry not reflected in the electroencephalogram . Methods : Forty patients scheduled to undergo elective coronary artery bypass grafting receiving a background infusion of remifentanil ( 0.3 & mgr;g · kg−1 · min−1 ) were anesthetized with intravenous propofol delivered by target-controlled infusion according to the Marsh pharmacokinetic model under BIS monitoring . In a r and omized , prospect i ve design , 20 patients received propofol at a target concentration of 3 & mgr;g/ml , whereas in 20 patients propofol was titrated to maintain a BIS value of 40–50  . Plasma concentrations of propofol  ( by means of gas chromatography – mass spectrometry ) , epinephrine , norepinephrine ( by means of high-pressure liquid chromatography ) , cortisol ( by means of radioimmunoassay ) , and interleukins 6 and 10 ( by means of enzyme-linked immunosorbent assay ) were measured repeatedly throughout surgery . Results : BIS monitoring allowed a 30 % reduction of propofol infusion rates and a similar decrease in plasma propofol concentrations in the BIS group without affecting the stress response to surgery for the group mean . None of the patients reported awareness during a st and ardized interview . Interestingly , propofol – remifentanil anesthesia blunted the release of epinephrine and cortisol to bypass surgery completely even when the propofol infusion rate was reduced according to BIS values . Conclusions : Total intravenous anesthesia using propofol – remifentanil effectively attenuates the neurohumoral stress response to coronary bypass surgery involving cardiopulmonary bypass . Titration of propofol using BIS allows for significant reduction of propofol consumption , with only minor effects on stress response under these conditions BACKGROUND Awareness is a serious complication of general anesthes 
    Output:
    
RESULTS The use of monitoring with the bispectral index has shown benefits reducing time to extubation , orientation in time and place , and discharge from both the operating room and post anesthetic care unit .
Clinical ly , anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking , mainly by reducing the administration of general anesthetics as well as the risk of adverse events