Bispectral Index Monitoring for Sedation in Elective Colonoscopies of Adult Patients: a Randomized Controlled Trial

Study Overview
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Brief Summary
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The primary aim of the study is to determine the rate sedation-induced adverse events, comparing BIS-guided sedation with clinical observation. Secondary outcomes were to examine patient characteristics who developed adverse events, propofol and remifentanil dosage and patient satisfaction analyzing different time points undergoing elective colonoscopy.

Detailed Description
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Randomized double-blind clinical trial in patients undergoing scheduled colonoscopies in endoscopy rooms of the Galdakao-Usánsolo Hospital (Bizkaia, Spain) and Mendaro Hospital (Gipuzkoa, Spain). The investigators will compare the rate of cardiorrespiratory adverse events as well as the anesthetic drugs dosage, need for rescue medication and patient satisfaction among the experimental group in which sedation is guided by BIS and the control group in which the anesthesiologist is blind to the result of the BIS. The investigators hypothesized that BIS monitoring would be associated with better outcomes than clinical observation. The BIS is the parameter of anesthetic depth monitoring most used today. Its use was approved by the Food and Drug Administration (FDA) in 1996 as an aid to control the effects of certain anesthetic agents. It is validated in the operating room (Recommendation grade A), but not outside it due to lack of conclusive studies. 180 patients are needed to obtain statistically significant differences between both groups. Qualitative variables are expressed in the form of frequencies and percentages and continuous variables in the form of means and standard deviations. Comparisons of percentages will be made by the Chi square test (or Exact Fisher's test, when the expected frequencies are less than 5) and the difference of means in the continuous variables by the t test as well as by the Wilcoxon nonparametric test if the distribution of the variable requires it. The degree of agreement between the BIS and Ramsay scale will be made through the weighted Kappa test. Statistical significance will be assumed when p <0.05. All statistical analyzes will be carried out using SAS V9.4. (SAS institute, Inc., Carey, NC).

Official Title
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Bispectral Index Monitoring for Sedation in Elective Colonoscopies of Adult Patients: a Randomized Controlled Trial

Conditions
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Colonoscopy

Intervention / Treatment
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* Device: BIS monitor
* Device: Ramsay scale


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Indication of complete colonoscopy on a scheduled basis. Classification of physical status ASA I, II and III, with the exception of patients with moderate to severe kidney and / or liver disease. Intermittent or persistent mild asthma. It implies the absence of daily symptoms and FEV1> 80% (GINA 2004). Body Mass Index (BMI) less than 35 kg / m2, and greater than 18 kg/m2. Intact neurological capacity. Acceptance to participate in the study after the contribution of written informed consent. Exclusion Criteria: ASA IV. BMI greater than 35 kg / m2, and less than 18 kg/m2. Refusal to participate in the study. Allergy to any of the medications used in sedation, or its components. Known mental or neurological disease. Renal and / or moderate to severe Hepatic insufficiency. Chronic Obstructive Pulmonary Disease (COPD) or Obstructive Sleep Apnea. Chronic opiate users.

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: We compared the results of two groups of patients. Experimental group, in which sedation is adjusted using as main parameters the information obtained by the bispectral index monitor. Control Group, with sedation based on subjective monitoring using the Ramsay scale as a reference.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: BIS<br>Group of patients (90) in whom sedation is adjusted using as main parameters the information obtained by the BIS sedation monitor (BIS VISTA, Aspect Medical Systems, USA). | Device: BIS monitor<br>* The investigators will place on the forehead of all patients the sensor BIS quatroTM, that connects with this monitor, and they will guide sedation and will record the values obtained.<br>* Other names: BIS VISTA; Aspect Medical Systems, USA;|
| Active Comparator: Ramsay<br>Group of patients (90) in whom sedation is based on subjective monitoring of the level of sedation, using the Ramsay scale as a reference. | Device: Ramsay scale<br>* In this group, sedation is guided by the Ramsay monitoring scale. The investigators will talk with the patients and will determine the corresponding level of sedation.<br>* Other names: Conventional monitoring;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sedation-induced adverse events | Compare the rate of cardiorrespiratory adverse events between the two groups | 1 year. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characteristics of patients who developed adverse events | Describe the patient characteristics | 1 year. | 
| The pharmacological dosage | The investigators will note if there is significant differences in the dose of phamacological drugs, and rescue propofol | 1 year. | 
| Level of satisfaction with the colonoscopy. | The investigators will distribute a satisfaction questionnaire to all patients after the colonoscopy to find out their opinion about the quality of sedation. | 1 year. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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bispectral index monitor, sedation, adverse effects