Anesthesia Depth Increases Delirium Incidence

Study Overview
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Brief Summary
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This study aimed to determine whether targeting bispectral index (BIS) readings of 55 (light anaesthesia) was associated with a lower incidence of delirium, dementia (POD), POCD and mortality but higher rates of awareness and complications than a standard of care anaesthesia blinded to depth monitoring.

Detailed Description
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Design: Randomised-controlled, double blind study, monocentric Setting: Level 2 medical center, major surgery (non cardiac) Ethics: Ethical approval for this study (Ethikkommission II der Ruprecht-Karls-Universität Heidelberg 2013-627N-MA) was provided by the Ethical Committee II University Medicine Mannheim, University of Heidelberg, Germany (Chairperson Prof W. Striebel) on Mai 12th 2008. Patients: n=130, aged > 70y Intervention: Light anesthesia (BIS 55 +/-5) vs. Standard of Care (BIS- blinded) Main outcome measures: Incidence of awareness, delirium, postoperative cognitive deficit (POCD), dementia (POD), memory (MAT with a computerized score for verbal working&short term, figural working&short term memories and well as attention level) Second aims: mortality, complications

Official Title
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Monitoring of Anesthesia Depth Reduces the Incidence of Postoperative Delirium and Preserves Memory Abilities Better in the High Risk Elderly

Conditions
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Delirium, Anesthesia Awareness

Intervention / Treatment
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* Device: BIS guidance of anesthesia
* Other: Standard of Care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: scheduled for major surgery above 60 min duration informed consent Exclusion Criteria: emergency surgery with large blood loss and/or preoperative cardiovascular instability, scheduled regional or neuraxial anesthesia, language barriers with the unability to understand a German audio tape, unability or unwillingness to consent,hearing disabilities

Ages Eligible for Study
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Minimum Age: 70 Years
Maximum Age: 110 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomised-controlled, double blind study, monocentric
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Bis Guided light anesthesia<br>Patients are monitored by bispectral index and held under light anesthesia (BIS level 45 to 60) | Device: BIS guidance of anesthesia<br>* Anesthesia is to be directed to a specific (light) level by the dosage of administered hypnotics and analgesics<br>|
| Placebo Comparator: Standard of Care<br>Patients receive standard of care anesthesia, BIS monitor was covered with a blind | Other: Standard of Care<br>* Anesthesia is administered as usual<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| postoperative delirium by NUDESC | in the hospital with NUDESC Score | 6 to 24 months | 
| postoperative dementia and cognitive deficit By MMSE and MAT Test | in the hospital by MMSE and MAT (automated computerized test), after discharge by a standardized questionnaire | 6 to 24 months | 
| awareness, memory function | implicit and explicit memory for intraoperative wakefulness and memory functions in general as changing conditions due to anesthesia | 1 to 3 days postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mortality and morbidity | death rate (in hospital and longterm mortality (death/month)) and complication rate (in hospital and longterm morbidity (complications/month)) | 6 to 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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bispectral index monitoring, anesthesia depth