Light Versus Deep Bispectral Index (BIS) Guided Sedation for Colonoscopy

Study Overview
=================
Brief Summary
-----------------
In this trial, patients undergoing elective colonoscopy under sedation will be randomised to BIS-guided sedation targeting either light (bispectral index [BIS] 70-80) or deep (BIS<60) sedation. Sedation will be achieved with a standardised regimen of target-controlled infusion of propofol and fentanyl bolus. The primary end point will be the incidence of procedure recall in each group - this will be assessed at the conclusion of the procedure. The procedural conditions, cardio-respiratory complications and recovery including cognitive function will be assessed during and immediately after the procedure. The incidence of dreaming and patient satisfaction with anaesthesia care will be recorded immediately after the procedure. The study will be complete when the patient leaves the hospital on the day of the procedure.

Detailed Description
-----------------
Controversy exists about the need for deep sedation or light sedation during elective colonoscopy. Deep sedation ensures amnesia for the procedure and may ensure better operating conditions, but may result in cardiorespiratory side effects and prolonged recovery. Differences exist between countries regarding the prevailing depth of sedation with deeper sedation in general being administered in Australia than the United States. This study aims to explore that controversy.

Official Title
-----------------
A Randomised Controlled Trial of Light Versus Deep Sedation for Elective Outpatient Colonoscopy: Recall, Procedural Conditions and Recovery

Conditions
-----------------
Anaesthesia

Intervention / Treatment
-----------------
* Other: Sedation depth


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Plan for elective outpatient colonoscopy under sedation Able and willing to provide written informed consent for study entry and completion of all study related procedures American Society of Anesthesiologists' (ASA) physical status grade 1-3 Exclusion Criteria: Colonoscopy and gastroscopy booked as joint procedures Colonoscopy on emergency patients and/or inpatients Inadequate English comprehension (verbal and written to understand the Participant Information and Consent Form) Intellectual or psychiatric disability that prevents consent to and comprehension of study procedures Significant cognitive impairment that prevents independent conduct of activities of daily living or results in 3rd party procedural consent being obtained ASA physical status grade 4-5

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: light sedation<br>In this study the depth of sedation will be guided by the Bispectral Index monitor (BIS monitor). A BIS value of 70-80 will be targeted in the light sedation arm. | Other: Sedation depth<br>* The intervention is the depth of sedation targeted in this study. Patients enrolled in this study will be sedated with the same medications (fentanyl bolus and propofol target controlled infusion), and at the same starting doses, in each study arm. However, the depth of sedation targeted will differ between the arms, and this depth will be guided by the BIS monitor. It is expected that those patients randomised to deep sedation will require a higher dose of sedative medication to achieve their target BIS value (<60) than those in the light sedation group (BIS 70-80).<br>* Other names: Aspect medical;|
| Active Comparator: deep sedation<br>In this study the deep sedation arm will have a BIS value of less than 60 targeted. | Other: Sedation depth<br>* The intervention is the depth of sedation targeted in this study. Patients enrolled in this study will be sedated with the same medications (fentanyl bolus and propofol target controlled infusion), and at the same starting doses, in each study arm. However, the depth of sedation targeted will differ between the arms, and this depth will be guided by the BIS monitor. It is expected that those patients randomised to deep sedation will require a higher dose of sedative medication to achieve their target BIS value (<60) than those in the light sedation group (BIS 70-80).<br>* Other names: Aspect medical;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recall of procedure | Upon rousing patients will be asked if they remember anything between the commencement of sedation and when they awoke from sedation | 1 day. Day of procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complications | The treating anaesthetist will record if any of the following complications occur during the sedation for colonoscopy. Hypoxia Airway obstruction Hypotension Bradycardia Agitation | 1 day. Day of procedure only. | 
| Speed and quality of recovery | Time from starting sedation until opening eyes in the post anaesthesia care unit, and time until readiness for hospital discharge will be recorded. Cognitive function at hospital discharge, compared to pre-procedure function, will be assessed by the CogState(TM) test battery. | 1 day. Day of procedure only. Measured before discharge from hospital | 
| Satisfaction | Proceduralist and anaesthetist satisfaction with the sedation will be recorded at the end of the procedure. Patient satisfaction with their anaesthesia care will be assessed at the time they are ready for hospital discharge. | 1 day. Day of procedure only. Measured before discharge from hospital | 
| Dreaming | Upon rousing in the post anaesthesia care unit patients will be asked the modified Brice questionnaire (What is the last thing you remember before you went to sleep?, What is the first thing you remember when you woke up?, Did you remember anything in between?, and Did you have any dreams?). Dreaming will be assessed by the response to quesion 4. | 1 day. Day of procedure. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Elective outpatient colonoscopy, AMBULATORY CARE, AWARENESS AND RECALL, Propofol, Patient Safety and Satisfaction, Colonoscopy, Procedural sedation