Frail Status of Elderly Patients After Repair and Anesthesia Guided by the bispectraL Index

Study Overview
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Brief Summary
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The first aim of this study is to compare two methods of administration of intravenous anesthetics to obtain the same level of depth (bispectral index between 40 and 60): manual or automated and to determine a mid-term (6 months) influence of the frail phenotype on self-sufficient elderly patients after general anesthesia.

Detailed Description
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To date, patients over the age of 60 yrs represent 25% of the population and are at increased risk of surgical repair. Reduction of postoperative morbidity and mortality are now two main concerns for medical research. Dependence on caregivers and cognitive impairments are two major risks in the elderly and even more in frail patients after surgery under general anesthesia. In this context continuous monitoring of the depth of anesthesia through bispectral index may reduce its occurrence with better control of too deep sedation periods (vasopressors…). Previous studies by the investigators' team suggest a better duration in the expected interval of Bispectral Index with automated control of administration of intravenous anesthetics guided by Bispectral Index. This method remains to be tested in this high-risk population. As a consequence, a randomization into two groups will be carried on elderly patients (> 70 yrs): manual administration of anesthetics guided by Bispectral Index (manual group) or automated administration (automated group). Complete preoperative assessments will determine the FRAIL status (with a decrease in the physiological reserve) and abilities of the patient according to the self-sufficient scale. At six months a follow-up will determine the geriatric status of the patient to explore the rate of impairment and to examine predictive factors in the preoperative assessment. Finally, the influence of the method of administration will be reported. Four hundred and thirty patients will be included in this multicenter study with 215 patients per group and stratification of the presence of a cancer and of the abdominal repair. The follow-up in this study allows the patient or his/her relatives to keep in touch with a physician and to prescribe some therapy early if frailty or any other cognitive impairment appears.

Official Title
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Influence of the Modality of General Anesthesia Guided by the Bispectral Index (Manual or Automated) on the Occurrence of a Loss of Capability in Elderly Patients (> 70 Yrs): a Randomized Multicenter Study

Conditions
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Anesthesia, General, Aged, 70 and Over

Intervention / Treatment
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* Other: Toolbox: Automated group
* Other: Manual group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients aged > 70 years old American Society of Anesthesiologists class I to III Scheduled for abdominal surgery under total intra-venous anesthesia Self sufficient (living at home or in a non medical institution) Written consent to the study Exclusion Criteria: Allergy to any intravenous agent (propofol or remifentanil) Cognitive impairment with a Mini Mental State Examination < 20 Severe visual or hearing deficiency, apraxia Restriction of the use of bispectral index

Ages Eligible for Study
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Minimum Age: 70 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
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Toolbox: Automated group<br>Toolbox: Automated administration of intravenous anesthetic (propofol 1%) and analgesic (remifentanil, Ultiva(r)) guided by the Bispectral index through a controller with a previously described algorithm. Objective of depth anesthesia: 40-60 | Other: Toolbox: Automated group<br>* A dedicated algorithm controls the infusion rate of drugs depending on the magnitude of variation of the bispectral index<br>* Other names: controller;|
| Active Comparator: Manual group<br>Manual administration of intravenous anesthetic (propofol 1%) and analgesic (remifentanil, Ultiva(r)) guided by the Bispectral index as usually performed in the operative theater. Objective of depth anesthesia: 40-60 | Other: Manual group<br>* The anesthesiologist controls the infusion rate of drugs depending of the magnitude of variation of the bispectral index<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of patients without occurrence of disability according to the InterRai scale | Disability is evaluated using the InterRai scale; a death is considered as an irreversible disability institutionalization is considered as a severe disability InterRai scale would discriminate other patients | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality at day 28 |  | 28 days | 
| Mortality at month 6 |  | 6 months | 
| Rate of postoperative cognitive dysfunction | Cognitive dysfunction is evaluated using the Mini Mental State examination | 6 months | 
| Incidence of pneumopathy | Defined as a septic syndrome (fever) + increased number of polynuclear cells + typical image on chest X-ray + treatment with antibiotics | 6 months | 
| Incidence of pulmonary embolism | Diagnosis on CT-scan with contrast injection | 6 months | 
| Incidence of postoperative myocardial infarction | EKG modification and raised troponin | 6 months | 
| Incidence of evolution of the frail phenotype | Frail phenotype accordingly to Fried Scale | 6 months | 
| Quality of the general anesthesia | Defined as the time with a Bispectral Index in the interval 40-60 | 1 day | 
| Performance of the automated system | Defined according to the Varvell score | 1 day | 
| Presence of Suppression Ratio | Defined as a period of isoelectric cortical signal with a threshold at 10% for 1 minute | 1 day | 
| Occurrence of arterial hypotension requiring treatment | Defined as a drop of 20% or more of the mean arterial pressure compared to the basal value measured before anesthetic induction and the requirement for a vasoactive agent | 1 day | 
| Patients'satisfaction about general anesthesia | Evaluation using a numeric scale from 0 (the worst remembrance) to 10 (an excellent moment) | 1 day | 
| Occurrence of awareness | Postoperative specific questionnaire | 3 months |