Propofol and Dexmedetomidine Versus a Propofol Only Regimen for Sedation During Colonoscopy

Study Overview
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Brief Summary
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An ideal sedative for colonoscopy should have properties that include: rapid onset and offset of action, provide cardiopulmonary stability, have minimal adverse effects, and allow for smooth recovery, and early discharge. Propofol is often used solely because of its rapid onset and short duration of action---a property which is ideal for a fast recovery and early discharge in the ambulatory setting. However, the use of propofol has been associated with undesirable effects such as hypotension, hypoventilation and apnea requiring assisted ventilation. Balanced anesthesia, using a combination of medications with different mechanisms of action can reduce the total amount of each sedative agent used and minimize their side effects while achieving the desired level of sedation. Dexmedetomidine is one agent that has been used either alone or in combination with propofol for sedation during colonoscopy. While there are many advantages to using dexmedetomidine, there is concern that the use of this agent for sedation during colonoscopy may prolong post-operative recovery time and readiness for discharge home. No study has definitively assessed whether the use of dexmedetomidine in combination with propofol during ambulatory colonoscopy prolongs post-operative recovery time as determined by the Modified Post Anesthesia Discharge Scoring System (MPADSS).

Detailed Description
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In this study, investigators plan to prospectively compare in a randomized, controlled, double-blind trial, the sedation technique for colonoscopy between two groups. Group 1: sedation with dexmedetomidine and propopfol versus group 2: sedation with saline placebo and propofol. The study will have the following outcome measures for each group. Primary outcome measure: Readiness-for-discharge (RFD) at 10, 20 and 30 minutes after the colonoscopic procedure. Ready-for-discharge is defined as attainment of MPADSS score of 9-10. Secondary outcome measures: Total propofol consumption in mg/kg/duration of procedure in minutes; Side effects: lowest intraoperative percent (%) drop in mean arterial pressure (MAP) from baseline, incidence of sustained bradycardic episodes (HR<50 for at least 5 minutes) intraoperatively, incidence of apneic episodes intraoperatively requiring positive pressure ventilation. Methods: One hundred patients will be recruited and randomized into two groups. For sedation, Group 1 will receive intravenous dexmedetomidine 0.3 ug/kg bolused at the onset of the procedure followed by titrated doses of propofol. Group 2 will receive a saline placebo bolus at the onset of the procedure followed by titrated doses of propofol. A hospital research pharmacist, based on a randomization table, will allocate to the anesthesia provider giving the sedation, the bolus syringe labelled dexmedetomidine/or saline study agent. The anesthesia provider, gastroenterologist, nurses as well as the subject will be blinded as to the syringe's actual content. A Bispectral Index (BIS) Monitor will be used during sedation. All subjects will be targeted to maintain a BIS score between 60-70. Outcome measures will be evaluated for statistical significance in a non-inferiority assessment. Investigators hypothesize that there will be no difference in the time to discharge between the two treatment groups.

Official Title
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Comparing Time to Readiness for Discharge After Colonoscopy: Propofol and Dexmedetomidine vs Propofol Only Sedation

Conditions
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Colonoscopy

Intervention / Treatment
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* Drug: Dexmedetomidine
* Other: Saline placebo
* Drug: Propofol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: • patients scheduled to undergo colonoscopy at SUNY Downstate Medical Center. Exclusion Criteria: < 18 years old > 75 years old Cognitively Impaired patients (Cognitively impaired patients are excluded from the study because our primary outcome involves a very strict discharge criteria that requires the patient to respond to and perform tasks on our pre-existing discharge scale checklist. These may be impossible to assess or will be difficult to standardize for patients whom are Cognitively Impaired.) Pregnant patients Patients who use a wheelchair or ambulates with crutches (Patients using a wheelchair are excluded from the study because our primary outcome involves a very strict discharge criteria that requires the patient to respond to and perform tasks on our pre-existing discharge scale checklist. These may be impossible to assess or will be difficult to standardize for patients whom who use a wheel-chair). Limited exercise tolerance (as this could represent active coronary disease) Total body weight greater than 105 kg (due to maximal dose of drug available in randomized syringes containing study drug) Propofol, soy, glycerol or dexmedetomidine allergy Significant renal impairment Significant hepatic impairment Inability to read or write in English

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexmedetomidine and propofol<br>Intravenous dexmedetomidine 0.3 ug/kg followed by propofol. Titrated doses of propofol will be given at the discretion of the anesthesiologist based on a target BIS range between 60-70. | Drug: Dexmedetomidine<br>* Dexmedetomidine 0.3 ug/kg intravenous bolus<br>* Other names: Precedex;Drug: Propofol<br>* Propofol titrated intravenous boluses<br>* Other names: Diprivan;|
| Placebo Comparator: Saline placebo and propofol<br>Intravenous saline placebo followed by propofol. Titrated doses of propofol will be given at the discretion of the anesthesiologist based on a target BIS range between 60-70. | Other: Saline placebo<br>* Intravenous saline/placebo<br>Drug: Propofol<br>* Propofol titrated intravenous boluses<br>* Other names: Diprivan;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Subjects Ready for Discharge in Each Group at 30 Minutes Post Procedure | Each subject was assessed for readiness for discharge at 10, 20 and 30 minutes after the procedure, using the Modified Post-Anesthesia Discharge Scoring System (MPADSS). A subject getting an MPADS score of 9-10 is deemed ready for discharge. The percentage of subjects ready for discharge in each group at 10, 20 and 30 minutes will be measured as primary outcome. | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average Total Propofol Consumption Per Group | Total propofol consumption per subject was measured as μg/kg/min of procedure in minutes. The average propofol consumption in each group will be measured as secondary outcome. | between 7 and 57 minutes (median 19 min) | 
| Number of Participants With Sustained Bradycardic Episodes | Incidence of sustained bradycardic episodes (HR<50 for at least 5 minutes) intraoperatively in each group | 30 minutes | 
| Lowest Intraoperative % Change in MAP From Baseline | Lowest intraoperative percent (%) change in mean arterial pressure (MAP) from baseline (average in each group) | 30 minutes | 
| Number of Participants With Apneic Episodes Intraoperatively Requiring Positive Pressure Ventilation | Incidence of apneic episodes intraoperatively requiring positive pressure ventilation in each group | 30 minutes |