One-year Mortality After Surgery and Low Bispectral Index

Study Overview
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Brief Summary
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A correlation between deep anesthesia (defined as time with Bispectral Index (BIS) lower than 45) and death within 1 yr after surgery has previously been reported. In order to confirm or refute these findings, the investigators have designed a study which compares two methods of administration for total intravenous anesthesia (propofol and remifentanil): manual administration: the anesthesiologists are instructed to maintain the BIS value between 40 and 60. closed loop administration: an algorithm is used to maintain the BIS value between 40 and 60. Based on previous studies, the amount of time that BIS is maintained above 40 is greater when anesthetics agents are administered using closed loop compared with manual administration.

Official Title
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One-year Mortality According to the Method of Total Intravenous Anesthesia. A Prospective, Randomized and Multicenter Study

Conditions
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General Anesthesia

Intervention / Treatment
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* Device: manual administration of iv anesthetics (propofol and remifentanil) using the Toolbox platform
* Device: closed-loop administration of iv anesthetics (propofol and remifentanil) using the Toolbox platform


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiology patient classification status I, II and III patients aged between 50 and 85 years old born in France surgical procedures lasting more than one hour Exclusion Criteria: American Society of Anesthesiology patient classification status IV patients born out of France pace-maker surgical procedure on the skull or avoiding an adequate positioning of the bispectral index electrode dementia, history of central nervous system disease (tumor, vascular event, Parkinson disease, ...) psychiatric illness (severe depression or psychosis), patients receiving a psychotropic treatment anesthesia performed during the year before inclusion in this study except for diagnostic procedures allergy to propofol, soja, peanuts, or to sufentanil, remifentanil, or morphine, to a myorelaxant or to an excipient, hypersensibility to sufentanil, to remifentanil, or to other derivate of fentanyl

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: manual administration of iv anesthetics<br> | Device: manual administration of iv anesthetics (propofol and remifentanil) using the Toolbox platform<br>* the anesthesiologists are instructed to maintain the BIS values between 40 and 60 throughout anesthesia using target controlled infusion method<br>|
| Experimental: closed-loop administration of iv anesthetics<br> | Device: closed-loop administration of iv anesthetics (propofol and remifentanil) using the Toolbox platform<br>* an algorithm is used to maintain automatically the BIS values between 40 and 60<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality rate during the first year following anesthesia |  | one year after anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| conduct of anesthesia (duration of anesthesia with bispectral index < 45, bispectral index < 40, bispectral index > 60, bispectral index > 65, and burst suppression ratio) |  | end of anesthesia | 
| intraoperative awareness |  | one month postoperatively | 
| patients' satisfaction in the postanesthesia care unit (nausea, vomiting, shivering) |  | end of the stay in the postanesthesia care unit | 
| postoperative complication during the hospital stay (ancillary study) |  | one month after anesthesia | 
| major medical events during the first year following anesthesia |  | one year after anesthesia | 
| relation between patients' characteristics and mortality rate during the first year following anesthesia |  | one year after anesthesia | 
| intraoperative parameters, notably hemodynamic parameters, and their relation between them and mortality rate during the first year following anesthesia |  | one year after anesthesia | 
| in-hospital and one month mortality |  | one year after anesthesia |