Closed-loop Anesthesia, Using Bispectral Index as the Control Variable, During Liver Transplantation

Study Overview
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Brief Summary
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To compare closed-loop anesthesia to manual administration of propofol and remifentanil during liver transplantation

Detailed Description
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The Bispectral Index (BIS) is an electroencephalogram-derived measure of anesthetic depth. We hypothesized that BIS can also indicate the adequacy of analgesia. Therefore we built a combined closed-loop anesthesia system using BIS as control variable and two proportional-differential control algorithms, a propofol and a remifentanil target-controlled infusion system. The effectiveness of such a closed-loop anesthesia system has been demonstrated in a prospective, randomized study. Elimination of anesthetic agents, propofol in particular, is strongly reduced during liver transplantation. Closed-loop anesthesia could provide adequacy for requirements in respect to the various phases of transplantation. Two groups of patients are compared: one in which propofol and remifentanil are administered by the anesthesiologist, using target-controlled infusion systems, and one in which propofol and remifentanil are administered automatically by the combined closed-loop anesthesia system. In both groups the goal is to maintain BIS between 40 and 60, the range recommended by the manufacturer during anesthesia. We expect the combined closed-loop anesthesia system group to do better: i.e. diminished consumption of propofol (primary outcome measure).

Official Title
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Comparison of Manual Propofol and Remifentanil Administration and Dual Closed-loop, Using Bispectral Index as the Control Variable, During Liver Transplantation

Conditions
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Liver Transplantation

Intervention / Treatment
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* Device: Closed loop administration
* Device: Manual administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: liver transplantation Exclusion Criteria: pregnant women allergy to propofol or remifentanil, neurological or muscular disorder, liver encephalopathy, patients taking psychotropic agents

Ages Eligible for Study
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Minimum Age: 18 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>Manual administration | Device: Manual administration<br>* intraoperative manual administration of propofol and remifentanil<br>* Other names: target controlled anesthesia;|
| Experimental: 2<br>Closed-loop administration | Device: Closed loop administration<br>* intraoperative closed loop administration of propofol and remifentanil<br>* Other names: closed-loop;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| consumption of propofol during anesthesia maintenance |  | during anesthesia maintenance | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| - consumption of remifentanil - target modifications - hemodynamic events - volume loading and transfusion - extubation time, explicit memorization - time passed at BIS between 40 and 60 - MDAPE, wobble - global score - dysfunction of each system. |  | during anesthesia maintenance | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Liver Transplantation, Anesthesia, general, Closed-loop