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

Melbourne Health200 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

SUPPORTIVE_CARE

Masking

TRIPLE

Enrollment

200

Conditions

Anaesthesia

Interventions

Sedation depthOTHER

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).

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Recall of procedure

Upon rousing patients will be asked if they remember anything between the commencement of sedation and when they awoke from sedation

Time frame: 1 day. Day of procedure

Secondary Outcomes

Complications

The treating anaesthetist will record if any of the following complications occur during the sedation for colonoscopy. 1. Hypoxia 2. Airway obstruction 3. Hypotension 4. Bradycardia 5. Agitation

Time frame: 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.

Time frame: 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.

Time frame: 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.

Time frame: 1 day. Day of procedure.